CN108204432B - Multi-mode infinite stepless speed change transmission device - Google Patents

Abstract

The present invention relates to a multi-mode infinitely variable transmission comprising a double planetary gear set having a first, second and third gear member and a single planetary gear set having a fourth, fifth and sixth gear member. In one mode, the first set of clutches is engaged, allowing engine power to be transferred to the first drive member and infinitely variable power to be transferred between the second infinitely variable power machine and the second drive member. The third transmission member combines the engine power and the infinitely variable power into a first combined power that is transmitted from the third transmission member to the fourth transmission member. The fifth transmission member transmits the return power to the engine shaft, and the sixth transmission member combines the first combined power and the return power into a second combined power, which is output to the output shaft to rotate the output shaft at a series of rotational speeds.

Description

Multi-mode infinite stepless speed change transmission device

Cross Reference to Related Applications

This application is a continuation-in-part application of U.S. patent application serial No. 14/536,097 filed on 7/11/2014, which is a continuation-in-part application of U.S. patent application serial No. 14/536,097 filed on 31/12/31/2013 and granted as U.S. patent No.9,206,885 on 8/12/2015, the entire disclosures of which are incorporated herein by reference.

Technical Field

The present disclosure relates to infinitely variable transmissions, and more particularly to infinitely variable transmissions having a plurality of different power modes.

Background

In various settings, it is useful to utilize both a conventional engine (e.g., an internal combustion engine) and an infinitely variable power source (e.g., an electric or hydrostatic motor, an infinitely variable chain drive, etc.) to provide available power. For example, a portion of the engine power may be split to drive a first infinitely variable machine (e.g., a first electric machine acting as a generator), which in turn may drive a second infinitely variable machine (e.g., a second electric machine acting as a motor using electrical power from the first electric machine). In some configurations, power from both types of sources (i.e., the engine and infinitely variable power source) may be combined for final power transfer (e.g., to the axle) via an infinitely variable transmission ("IVT") or a continuously variable transmission ("CVT"). This may be referred to as "split mode" or "split path mode" operation because power transfer may be split between the mechanical path from the engine and the infinitely variable transmission path. The split mode operation may be implemented in various known ways. For example, a planetary gear set may be utilized to sum rotational power from the engine and from the electric machine, with the summed power being transferred downstream within an associated power system. This may allow power to be transferred (e.g., to the wheels) at an infinitely variable effective transmission ratio. However, various problems may arise, including limitations associated with the maximum practical speed of the infinitely variable power source.

Other types of transmissions, as well as the operation of IVT or CVT transmissions, may introduce various other problems. For example, in certain configurations, transmission shifts (e.g., transitions between different gear ratios) may cause jerking, hysteresis, or other transient effects on available power (e.g., at the wheels of the vehicle or at an attached tool or implement) of the vehicle or other detrimental effects on system performance and user experience.

Disclosure of Invention

In one aspect, the present disclosure provides a work vehicle including an engine having an engine shaft, a first Infinitely Variable Power (IVP) machine, a second Infinitely Variable Power (IVP) machine, an output shaft, and an Infinitely Variable Transmission (IVT) having a plurality of transmission modes. The IVT is configured to transmit power between the engine, the first IVP machine, the second IVP machine, and the output shaft along different paths in different ones of the plurality of transmission modes. The IVT includes a plurality of clutches, each clutch configured to be engaged and alternately disengaged. Further, the IVT includes a double planetary gear set including a first gear member, a second gear member, and a third gear member. Additionally, the IVT includes a single planetary gear set that includes a fourth, fifth and sixth transmission member. In a first transmission mode of the IVT, a first subset of the plurality of clutches is engaged, allowing engine power to be transmitted from the engine to the first transmission component, and allowing IVP to be transmitted between the second IVP machine and the second transmission component. In the first transmission mode, the third transmission component combines the engine power and the IVP power into a first combined power that is transmitted from the third transmission component to the fourth transmission component. In the first transmission mode, the fifth transmission member transmits a return power to the engine shaft, and the sixth transmission member combines the first combined power and the return power into a second combined power, which is output to the output shaft to rotate the output shaft at a range of rotational speeds.

In another aspect, a work vehicle is disclosed that includes an engine having an engine shaft and an Infinitely Variable Power (IVP) source having a first electric machine and a second electric machine. The work vehicle further includes an output shaft and an Infinitely Variable Transmission (IVT) having a plurality of transmission modes. The IVT is configured to transmit power between the engine, the first electric machine, the second electric machine, and the output shaft along different paths in different ones of the plurality of transmission modes. The IVT includes a plurality of clutches, each clutch configured to be engaged and alternately disengaged. The IVT also includes a first planetary gear set including a first transmission member, a second transmission member, and a third transmission member. Additionally, the IVT includes a second planetary gear set including a fourth gear member, a fifth gear member, and a sixth gear member. In a first transmission mode of the IVT, a first subset of the plurality of clutches is engaged, allowing engine power to be transmitted from the engine to the first transmission component, and allowing IVP to be transmitted between the second electric machine and the second transmission component. In the first transmission mode, the third transmission component combines the engine power and the IVP power into a first combined power that is transmitted from the third transmission component to the fourth transmission component. Additionally, in the first transmission mode, the fifth transmission member transmits return power to the engine shaft. In addition, in the first transmission mode, the sixth transmission member combines the first combined power and the return power into a second combined power. The second combined power of the first transmission mode provides a range of rotational speeds for the output shaft. The first electric machine has a generator mode and a motor mode. The first electric machine, when in the generator mode, is configured to generate electrical energy from mechanical energy input to the first electric machine. Additionally, the second electric machine has a generator mode and a motor mode. The second electric machine, when in the generator mode, is configured to generate electrical energy from mechanical energy input to the second electric machine. In the first transmission mode of the IVT, the first and second electric machines are configured to be simultaneously in a generator mode to collectively generate power.

The details of one or more implementations are set forth in the accompanying drawings and the description below. Other features and advantages will become apparent from the description, the drawings, and the claims.

Drawings

FIG. 1 is a side view of an example work vehicle that may include an infinitely variable transmission;

FIG. 2 is a schematic illustration of a powertrain of the vehicle of FIG. 1;

FIG. 3 is a schematic illustration of an infinitely variable transmission that may be included in the powertrain of FIG. 2;

FIG. 4 is a graphical representation of infinitely variable power source speeds and wheel speeds for various operating modes of the infinitely variable transmission of FIG. 3;

FIG. 5 is a schematic illustration of another infinitely variable transmission that may be included in the powertrain of FIG. 2;

FIG. 6 is a graphical representation of infinitely variable power source speeds and wheel speeds for various operating modes of the infinitely variable transmission of FIG. 5;

FIG. 7 is a schematic illustration of another infinitely variable transmission that may be included in the powertrain of FIG. 2;

FIG. 8 is a graphical representation of infinitely variable power source speeds and wheel speeds for various operating modes of the infinitely variable transmission of FIG. 7;

FIG. 9 is a schematic illustration of a powertrain similar to the powertrain of FIG. 3 having a power storage and transmission system;

FIG. 10 is a schematic illustration of a power system similar to that of FIG. 7, with another power storage and transmission system;

FIG. 11 is a diagrammatical view of a transient power event management process that may be employed with the power systems of FIGS. 9 and 10;

FIG. 12 is a schematic illustration of the power system associated with the power system of FIG. 3, wherein the power system is shown in a first configuration;

FIG. 13 is a graph illustrating wheel speeds of a vehicle and rotational speeds of electric machines of the powertrain of FIG. 12 at a given engine speed according to an example embodiment of the present disclosure;

FIG. 14 is a schematic illustration of the powertrain of FIG. 12 shown in a second configuration;

FIG. 15 is a schematic illustration of the powertrain associated with the powertrain of FIG. 12, wherein the powertrain is shown in a first configuration; and

FIG. 16 is a schematic illustration of the powertrain of FIG. 15 shown in a second configuration.

Like reference symbols in the various drawings indicate like elements.

Detailed Description

One or more example embodiments of the disclosed power system arrangement for energy storage and transfer are described below, as shown in the figures illustrated in the above figures. Various modifications to the example embodiments may be apparent to those skilled in the art.

In various known configurations, one or more planetary gear sets may be utilized to combine the power output of an IVP and an engine (e.g., an internal combustion engine). For example, in a planetary gear set, a first member of the gear set (e.g., a ring gear) may receive power from the engine, a second member of the gear set (e.g., a sun gear) may receive power from the IVP, and a third member of the gear set (e.g., a planet carrier) may sum the power from the engine and the IVP at the output of the gear set. (for ease of identification, in particular, in the context of a planetary gear set, a "member" may be used herein to indicate an element for transmitting power such as a sun gear, a ring gear, or a planet carrier.) it should be appreciated that this configuration may allow for substantially infinite and continuous gear ratios for the planetary gear set. For example, for a fixed engine speed, a particular gear ratio may be set by varying the speed of the IVP relative to the engine speed.

In some cases, it may be useful to facilitate a zero-power mode of the vehicle (or other machine) in which the output speed of the wheels (or other machine output) reaches a speed of zero without stopping the engine or disengaging the torque at the wheels. In this way, vehicle power may be utilized to hold the vehicle stationary, for example. This state can be achieved with a planetary gear set configured as described above. For example, if the engine rotates the sun gear at a first positive speed and directs the IVP (e.g., an electric motor powered by a generator) to rotate the ring gear at an equivalent negative speed, the associated planet gear carrier (which may be connected, for example, to the differential drive shaft) may not rotate at all. Additionally, if the IVP provides output rotation at a slightly different (and opposite) speed than the engine, the vehicle may enter a "creep" mode in which the vehicle is moving very slowly, but the wheel torque is high. For heavy work vehicles used in the agricultural, construction, and forestry industries (such as the tractor shown in fig. 1), the zero-power and creep modes are particularly useful. As the wheel speed increases, the vehicle may then eventually enter a normal driving mode. In conventional configurations, each of these modes may be a split path mode in which power transfer is split between a purely mechanical path from the engine and a hybrid path through the IVP.

One problem associated with infinitely variable power systems may relate to the relative efficiency of power transfer in the various modes. For example, it should be appreciated that the mechanical transfer of power from the engine to the gear set (i.e., mechanical path transfer) may be an efficient power transfer mode, while the transfer of power through the IVP may be less efficient (e.g., because mechanical power must be converted by a first machine to electrical or hydraulic power, transferred to a second machine, and then converted back to mechanical power). Thus, the significant motivation for utilizing the mechanical path is heavier (e.g., by increasing the speed of the engine) than the IVP path. However, this greater utilization of the mechanical path may also drive the required IVP speed in zero power and creep modes, as these modes may require near or actual speed matching between the IVP and engine speeds. This can lead to increased wear on the associated gears and other parts (e.g., the planet gear members that receive power from the IVP and associated bearings), even to the point of part failure. Additionally, to achieve the proper speed, the size and power of the associated IVP may need to be significantly increased from the preferred size and power. The multi-mode infinitely variable transmission ("MIVT") disclosed herein can address these issues, as well as other advantages. For example, by selectively using clutches and/or brakes, MIVT may allow for heavier utilization of the mechanical path while avoiding the need for excessive IVP speeds in zero power and creep modes.

As will become apparent from the discussion herein, MIVT may be advantageously used in various settings and various machines. For example, referring now to fig. 1, the MIVT may be included in the powertrain 22 of the vehicle 20. In fig. 1, the vehicle 20 is depicted as a tractor. However, it should be understood that other configurations are possible, including configurations of the vehicle 20 that are one of a different type of tractor, a skidder trailer, or various other work vehicle types. It should be further understood that the disclosed IVT may also be used in non-work vehicle and non-vehicle applications (e.g., fixed position power systems).

Additionally, as noted above, one advantage of the disclosed MIVT is that it may allow the vehicle to be operated in various power modes (e.g., zero power mode, creep mode, and split path drive mode), such that various combinations of engine and IVP power may be utilized. For example, by using various clutches and/or brakes associated with one or more planetary gear sets, the MIVT may allow engine power to be disconnected from the IVT output even while the engine continues to operate. For example, if the IVP drives a first member of the planetary gear set and the engine drives a second member of the planetary gear set, in certain embodiments and modes, the clutch may disconnect the operating engine from the second member and the brake may stop rotation of the third member of the gear set, thereby allowing power to be transferred only from the IVP through gear reduction of the planetary gear set. In this manner, for example, the vehicle 20 may be driven (or held) using only electrical power (or hydraulic power, etc.) in some modes, while the vehicle 20 may be driven (or held) using combined electrical power and engine power in other modes. Thus, the MIVT can avoid some of the previous limitations on the fraction of power that can be diverted from the engine through the electrical (or hydraulic, etc.) path, among other benefits.

Referring now to FIG. 2, various components of an example power system 22 are depicted. For example, the engine 24 may provide mechanical power to the MIVT26 (e.g., via a rotating shaft). The engine 24 may also provide mechanical power to the IVP28, and the IVP28 may include one or more IVP machines (e.g., an electric motor and generator or a hydrostatic machine having a hydrostatic motor and associated pump). The MIVT26 a may additionally receive mechanical power from the IVP 28.

The MIVT26 a may include various clutches 30 and brakes 32 that may be controlled by various actuators 34. The actuators 34, in turn, may be controlled by a transmission control unit ("TCU") 36 (or another controller), which may receive various inputs from various sensors or devices (not shown) via a CAN bus (not shown) of the vehicle 20. The MIVT26 a may include one or more output shafts 38a, the output shafts 38a being used to transfer mechanical power from the MIVT26 a to various other components (e.g., a differential drive shaft). In some embodiments, additional gear sets (e.g., range gear sets) may be interposed between the MIVT26 and other parts of the vehicle 20 (e.g., the differential drive shafts). In some embodiments, the IVP28 may also directly power other parts of the vehicle 20 (e.g., via the direct IVP drive shaft 38 b).

Referring now to fig. 3, the various internal components of an example MIVT26 are illustrated. It should be noted that the schematic representation of the transmission shown in fig. 3 (as well as the transmissions shown in fig. 5 and 7) illustrates an example implementation in simplified form for the sake of clarity, and thus may not depict all components associated with the represented transmission. The engine 24 may include an internal combustion engine 24a, and the internal combustion engine 24a may provide mechanical power directly to the shaft S1. In contrast, for example, power transfer between a ring gear of a planetary gear set and a sun gear of the planetary gear set via a planet carrier of the planetary gear set (and associated planet gears) may not be considered "direct". example IVP28a may include a generator 40 and an electric motor 42. the generator 40 may receive mechanical power via a gear 46 and a gear 44 attached to the shaft S1, and may generate electric power that is transferred to the electric motor 42. the electric motor 42 may convert the received electric power to mechanical power, thereby rotating the shaft S2.

While various example configurations may be described herein using specific terms such as "generator" and "motor," it should be understood that these (and similar) terms may be used to generally refer to an electric machine that is capable of operating as a generator or as a motor. For example, the generator 40 may sometimes operate as an electric motor, and the electric motor 42 may sometimes operate as a generator. Likewise, it should be understood that the actual operating modes of other infinitely variable power sources may similarly differ from those explicitly described herein.

In some embodiments, the MIVT26 a may include a planetary gear set 48 and a double planetary gear set 50. In some embodiments, planetary gear set 48 and double planetary gear set 50 may be configured to sum mechanical power from engine 24a and IVP28 a. By using one or more associated clutches and/or brakes, the MIVT26 a may provide an output that utilizes only power from the IVP28a in certain modes.

The planetary gear set 48 may include, for example, a planet gear carrier 52 holding planet gears 54, the planet gears 54 being meshingly engageable with a sun gear 56 and a ring gear 58. The drive clutch 60 may be configured to engage the planet carrier 52 and the sun gear 56 (e.g., based on signals from the TCU36) in order to control power transfer between these gears. For example, in a fully engaged state, the drive clutch 60 may lock the planet carrier 52 to the sun gear 56. As depicted in fig. 3, the engine 24a may directly drive the planet carrier 52 via shaft S1. Thus, engagement of the clutch 60 effectively locks the sun gear 56 to the shaft S1 and to the output of the engine 24 a. The reverse brake 62 may be anchored to a stationary housing of the MIVT26 a (or another feature) and may be configured to engage to stop the ring gear 58 from rotating.

In some embodiments, the output member of the planetary gear set 48 may transfer power directly to the input member of the double planetary gear set 50. For example, sun gear 56 may be integrally connected with ring gear 64, thereby directly connecting the output of planetary gear set 48 (i.e., sun gear 56) to the input of double planetary gear set 50 (i.e., ring gear 64).

The double planetary gear set 50 may also receive power input from the IVP28 a. For example, the motor 42 may drive rotation of the shaft S2 along with the attached gear 66. Gear 66 may mesh with a gear 68 mounted to shaft S1, and gear 68 may directly transfer power to (e.g., may be integrally formed with) the sun gear 70 of the double planetary gear set 50. The sun gear 70 may mesh with planet gears 72 (one shown) that may be directly connected to planet gears 74 (one shown), with both sets of planet gears 72 and 74 being carried by a planet carrier 76. Each of the planet gears 74 may mesh with one of various planet gears 88, and these planet gears 88 may in turn mesh with the ring gear 78. The planet gear carrier 76 may be connected to the ring gear 78 (e.g., via the planet gears 74 and 88), and the creep brake 80 may be anchored to the stationary housing of the MIVT26 a (or another feature) and configured to engage the ring gear 78 to stop the component from rotating.

The planet carrier 76 may provide a mechanical power output from the double planetary gear set 50 to transfer mechanical power to various components of the vehicle 20. For example, the planet carrier 76 may be integrally connected with the output gear 82, and the output gear 82 may mesh with the gear along the idle shaft S3. In some embodiments, an additional gearbox 84 (e.g., a range gearbox) may be interposed between the MIVT26 a and other parts of the vehicle 20 (e.g., a differential drive shaft ("DDS")) or may be included as part of the MIVT26 a. In this manner, for example, various shifts may be achieved within the baseline infinitely variable transmission ratio provided by the MIVT26 a.

In some operating modes, the MIVT26 a (as configured in fig. 3) may provide a zero power and creep mode in which only power from the IVP28a is provided to the wheels of the vehicle 20. For example, drive clutch 60 may be disengaged and brake 80 may be engaged with ring gear 78 (or ring gear 64 (not shown) in some configurations). Thus, this may disconnect the engine 24a from the double planetary gear set 50 while providing a fixed gear (e.g., ring gear 78) about which a member of the double planetary gear set 50 may rotate. Mechanical power from the IVP28a may be provided to the sun gear 70, and the sun gear 70 may drive the planet carrier 76 about the ring gear 78. This, in turn, may cause rotation of the output gear 82 driven by the IVP28a, rather than the engine 24a, which may allow the wheels of the vehicle 20 to be driven (e.g., via the gearbox 84) using only power from the IVP28 a.

To shift the vehicle out of this IVP-only mode, the reverse of the above-described process may be performed. For example, drive clutch 60 may be engaged, thereby connecting engine 24a to sun gear 56 and ring gear 64. At the same time (or nearly the same time), the creep brake 80 may be disengaged, thereby allowing the double planetary gear set 50 to provide an output at gear 82 that represents the summation of power from the IVP28a and the engine 24A. It should be appreciated that by such selective use of two of a set of friction elements (e.g., clutches and brakes), transitions between various operating modes of the vehicle 20 may generally be facilitated.

In some embodiments, it may be beneficial to implement transitions between modes in a particular manner (e.g., between the full IVP creep mode and the combined drive mode). For example, when drive clutch 60 is engaged, sun gear 70 (via IVP28 a) may be rotated at a speed such that ring gear 78 is substantially stopped, even without the use of brake 80. To provide a more seamless shift between modes, it may be beneficial to shift between the drive mode and the creep mode at this time. In this manner, for example, brake 80 may be engaged and clutch 60 may be disengaged with minimal disruption to vehicle operation. Similar seamless shift points may also be obtained for shifting from creep mode to drive mode, and may represent target points for those shift operations (and others). However, it should be understood that in some embodiments, ramp (or other) modulation of the clutch 60 (or other component) may be utilized.

In some applications, whether in creep mode, drive mode, or otherwise, it may be desirable to operate the vehicle 20 in reverse. In MIVT26 a as depicted in fig. 3, for example, the reverse brake 62 may be engaged for this purpose.

Referring now to fig. 4, a graph of the relationship between wheel speed (in kilometers per hour) and speed (in revolutions per minute) of the motor 42 for the configuration of MIVT26 a in fig. 3 is shown. Various curves of operation of the vehicle 20 with various gear gears (not shown) engaged within the gearbox 84 are illustrated. It should be understood that the numbers shown in fig. 4 should be considered as examples only.

For example, line 90 may represent operation of the vehicle in the creep mode (e.g., under the influence of electricity only). It can be seen that at zero motor speed, there may be zero vehicle speed, with non-zero motor speed being proportional to vehicle speed. In creep mode (e.g., brake 80 is engaged, drive clutch 60 is disengaged, and an a-range gear (not shown) in gearbox 84 is engaged), vehicle 20 may accelerate to a transition point. For example, as described above, the vehicle 20 may accelerate to a point where, based on engine speed and the associated gear ratio, the ring gear 78 may be relatively stationary even though the brake 80 is not engaged. At this point (or another), the brake 80 may be disengaged and the clutch 60 engaged, thereby relatively seamlessly shifting the vehicle 20 into split mode driving. The motor 42 may then begin to decelerate along line 92, even as the speed of the motor 42 changes direction (i.e., from positive to negative rotation), the vehicle speed (now being driven in split path mode by both the motor 42 and the engine 24 a) increases.

Continuing, the vehicle 20 may shift from an A-range gear in the gearbox 84 to a higher B-range gear (not shown). To continue accelerating the vehicle 20, the direction of rotation of the motor 42 may now be appropriately switched, thereby jumping from the negative rotation sum line 92 to the positive rotation sum line 94. The motor 42 may then be decelerated again, then shifted further in the gearbox 84 to a higher C-range gear (not shown), and the motor 42 jumps correspondingly from line 94 to line 96. By modulating the rotation of the motor 42 in this manner, gear shifting between the various gear gears of the gear box 84 can be achieved at the start of gear shifting (e.g., at the end of a-range driving) at the same reduction ratio as the end of gear shifting (e.g., at the start of B-range driving). (it should be understood that the reduction ratio may be the product of the gear ratios of the planetary gear sets 48, 50 and the meshing gears of the gearbox 84 (e.g., the A-range gears))

Various benefits may be obtained from the configuration of fig. 3 (and other configurations contemplated by the present disclosure). For example, in the configuration of fig. 3 (and other configurations), the gearbox 84 may be located downstream of the planetary gear sets 48 and 50. This may allow the full range of torques and speeds produced at the output of the MIVT26 a (i.e., available from various combinations of power of the engine 24a and the motor 42) to be used with each gear or gear of the gearbox 84. For example, an electric-only mode (or any of a variety of split path modes) may be utilized with each gear or gear of the gearbox 84. This may provide significant flexibility during vehicle operation.

Additionally, in the configuration of fig. 3 (and other configurations), split mode driving may be achieved using a relatively simple planetary path, which may reduce wear, improve life, and reduce cost of the MIVT26 a, among other benefits. This may be particularly useful, for example, for applications where a majority of the operating time is expected to be spent in a split path mode (e.g., for various agricultural operations with the vehicle 20). In the split path mode, for example, power from the engine 24a may be provided to the ring gear 64 through the clutch 60, and power from the motor 42 is provided to the sun gear 70. Together, these components (i.e., the ring gear 64 and the sun gear 70) may cause the planet carrier 76 (via the planet gears 72) to rotate, which in turn may cause the gear 82 to rotate, and power is correspondingly transmitted into the gearbox 84. In contrast, in electric-only mode, power from motor 42 may be provided to sun gear 70, and then in turn to planet gears 72, planet gears 74 (which may be directly connected to gear 72 or integrally formed with gear 72), and planet gears 88. When ring gear 78 is locked by brake 80, power may flow from planet gears 72, 74, and 88 to planet carrier 76, and so on. In this manner, it should be appreciated that less gear mesh is utilized in the split path power mode as compared to the electric-only mode, which may indicate a relative increase in power transfer efficiency and may also result in a relative reduction in partial wear.

Referring now also to fig. 5, another example MIVT26 b is illustrated. As depicted in fig. 5, the MIVT26 b may include a planetary gear set 98 and a double planetary gear set 100. The internal combustion engine 24b may directly drive the hydrostatic drive (e.g., the pump 102 and the electric motor 104) and the shaft S4, and the hydrostatic drive (e.g., with the electric motor 104) may drive the shaft S5. The planetary gear set 98 may include a sun gear 106, a planet gear carrier 108, and a ring gear 110. The drive clutch 112 may be configured to engage the shaft S4 to connect the output of the engine 24b to the sun gear 106. The creep clutch 114 may be configured to engage both the planet carrier 108 and the ring gear 110, thereby potentially locking the planet carrier 108 and the ring gear 110 together. The reverse brake 116 may be configured to engage the ring gear 110. Thus, in some configurations, the reverse brake 116 may be utilized to reverse the output of the planetary gear set 98 relative to the output of the engine 24 b.

The planetary gear set 98 may include an output directly connected to (e.g., directly connected to or integral with) an input of a double planetary gear set 100. For example, as depicted in fig. 5, the planet carrier 108 may be the output member for the planetary gear set 98, and may directly connect (i.e., via gears 118 and 120) the planet carrier 122 of the double planetary gear set 100. Additionally, in some configurations, the input to the gear set 100 may rotate directly with another component of the gear set 100. For example, the planet gear carrier 122 may be formed as a unitary component with the ring gear 124 such that the two components rotate in unison.

The motor 104 may provide additional input to the double planetary gear set 100. For example, the motor 104 may provide input power to both sun gears 126 and 128 via shaft S5. The double planetary gear set 100 may also include, for example, a ring gear 130 and a planet carrier 134.

In this configuration, similar to the discussion above regarding the embodiment of fig. 3, the various clutches and brakes associated with the MIVT26 b may be utilized to switch between the various operating modes of the vehicle 20. For example, when the drive clutch 112 is disengaged, power cannot be transferred from the running engine 24b to the planetary gear set 98 or the double planetary gear set 100. Additionally, when the creep clutch 114 is engaged and the reverse brake 116 is engaged, the gear 118 may be locked. Thus, engagement of the creep clutch 114 and the reverse brake 116 may prevent both the ring gear 124 and the planet gear carrier 122 from rotating (although the planet gears 132 may still rotate about the carrier 122). In this manner, the double planetary gear set 100 may transmit power from the motor 104 to the output gear 140 (e.g., in a forward or reverse creep mode) even though the engine 24b may be running.

In certain embodiments, additional power transfer components may be provided to facilitate various types of vehicle operations and operating modes. For example, a low clutch 136 and a high clutch 138 may be included within the double planetary gear set 100, wherein the high clutch 138 is configured to engage the ring gear 130 and the output gear 140, and the low clutch 136 is configured to engage both the planet carrier 134 and the output gear 140. Thus, in the creep mode or other modes, the clutches 136 and 138 may be selectively activated to adjust the effective overall gear ratios of the two planetary gear sets 98 and 100.

In certain embodiments, the gearbox 142 may be interposed between the dual planetary gear set 100 and other components of the vehicle 20 (e.g., DDS), and may include various gears (e.g., range gears). Additionally, in certain embodiments, the configuration shown in fig. 5 may allow for shifting between fixed gear ratios within the gearbox 142 (and in the context of infinitely variable transmission ratios provided by the hydrostatic machines 102, 104) without having to change the direction of rotation for the motor 104. For example, the vehicle 20 may begin operating at zero speed, with the engine 24b disconnected from the transmission (via clutch 112) and clutch 114 and brake 116 engaged. Thus, the motor 104 may provide unique power to the output gear 140 (and the gearbox 142). The motor 104 may be turned on in either the positive direction (for positive direction creep mode operation) or the negative direction (for negative direction creep mode operation). Assuming, for example, an initial positive direction of driving, the rotation of the motor 104 (and thus the shaft S5) may accelerate in the positive direction, causing the sun gears 126, 128 to also accelerate. Initially, for example, the low clutch 136 may be engaged whereby power may be transferred from the sun gear 128 to the output gear 140 via the planet carrier 134. Within the gearbox 142, a first low gear may be engaged, thereby completing a power transmission path from the motor 104 to other components of the vehicle 20 (e.g., a differential drive shaft).

At a particular speed of motor 104, ring gear 110 tends to be relatively stationary even when brake 116 is not engaged, depending upon the particular associated gear ratio. Additionally, as described above, this may provide an available point for transitioning between operating modes (e.g., creep mode and split path mode) or various gears (e.g., range gears within the gearbox 142). Thus, continuing the above example, once the motor 104 has accelerated through the creep mode to such a speed match point (or at various other times), the reverse brake 116 may be disengaged and the drive clutch 112 may be engaged. This provides a mechanical transmission path for power from the engine 24b to the double planetary gear set 100. At the same time (or nearly the same time), the low clutch 136 may also be disengaged and the high clutch 138 may be engaged. However, due to the configuration shown in fig. 5, it may not be necessary to reverse the direction of rotation of the motor 104 at this time in order to continue the forward acceleration of the vehicle 20 (as is possible, for example, for the configuration shown in fig. 3). In some embodiments, the rotational speed of the motor 104 may simply be reduced from the rotational speed at the transition when the vehicle accelerates accordingly after the clutch 112 is engaged (i.e., enters split path mode).

Referring now to fig. 6, for example, a graph of the relationship between wheel speed (in kilometers per hour) and speed of the motor 104 (in revolutions per minute) for the configuration of MIVT26 b in fig. 5 is shown. Various curves of operation of the vehicle 20 with various gears engaged within the gearbox 142 are illustrated. It should be understood that the numbers shown in fig. 6 should be considered as examples only.

For example, line 150 may represent operation of vehicle 20 in creep mode (e.g., under hydrostatic power only). It can be seen that at zero motor speed, there will be zero vehicle speed, with non-zero motor speed being directly proportional to vehicle speed. In the creep mode (e.g., the reverse brake 116 and creep clutch 114 are engaged, the drive clutch 112 is disengaged and an a-range gear (not shown) in the gearbox 142 is engaged), the vehicle may accelerate to a transition point. In some embodiments, this may be a point where ring gear 110 may be relatively stationary even though brake 116 is not engaged, based on engine speed and associated gear ratio. At this transition point (or another), the brake 116 may be disengaged and the clutch 112 engaged, thereby shifting the vehicle into split mode driving. The motor 104 may then begin to decelerate along line 152, even as the speed of the motor 104 changes direction (i.e., from positive to negative rotation), the vehicle speed (now driven by both the motor 104 and the engine 24 b) increases.

Continuing, the vehicle may shift from the previous A-range gear in the gearbox 142 to a higher B-range gear (not shown). For continued acceleration of the vehicle 20, the directional acceleration of the rotation of the motor 104 may again be suitably switched (but not, immediately, the direction of rotation of the motor 104) and the appropriate gear (with or without switching between the clutches 136 and 138) engaged. The motor 104 may then accelerate along line 154, and the vehicle 20 accelerates accordingly.

Referring now to fig. 7, another example MIVT26 c is illustrated. As depicted in fig. 7, internal combustion engine 24c may provide mechanical power to generator 172, and generator 172 may provide electrical power to electric motor 174 via power cable 176. The motor 174 may drive rotation of the sun gear 182 of the double planetary gear set 178 (e.g., via direct connection). The gear set 178 may also be configured to receive mechanical power from the engine 24c via shaft S7, with the drive clutch 196 configured to engage both the shaft S7 and the other sun gear 180. The planet carrier 184, including the planet gears 192, may be directly connected to the ring gear 190 (e.g., integral with the ring gear 190), and the ring gear 190 itself may be configured to receive power from the sun gear 182 via the planet carrier 186. The ring gear 188 may be meshed with the planet gears 192. Additionally, the planet carrier 186 may form an output member of the gear set 178 and may, for example, be directly connected to an input member of the gearbox 202 (e.g., integrally formed with the input member of the gearbox 202).

As in other embodiments discussed herein, multiple clutches and brakes (e.g., as illustrated in fig. 7) within the MIVT26 c may allow for available transitions between various operating modes, including a creep mode powered only by the motor 174 and a split path mode powered by both the motor 174 and the engine 24 c. For example, the clutch 196 may be engaged with the shaft S7 and the sun gear 180 to transfer power from the engine 24c to the double planetary gear set 178. Likewise, the clutch 198 may engage both the ring gear 188 and the planet carrier 184 in order to lock these components together. Finally, the reverse brake 200 may engage the ring gear 188 to stop rotation of that gear.

As such, it should be appreciated that clutch 198, brake 200, and clutch 196 may be selectively engaged (and disengaged) to provide various operating modes. For example, with clutch 196 disengaged and both clutch 198 and reverse mode brake 200 engaged, vehicle 20 may be driven under power from motor 174 only. Likewise, other operating modes are possible for various other configurations (e.g., various combinations of two of the clutches 198, brake 200, and clutch 196 being engaged).

Referring now also to fig. 8, for example, a graph of the relationship between wheel speed (in kilometers per hour) and speed (in revolutions per minute) of the motor 174 for the configuration of MIVT26 c in fig. 7 is shown. Various curves of operation of the vehicle 20 with various gears engaged within the gearbox 202 are illustrated. It should be understood that the numbers shown in fig. 8 should be considered as examples only.

For example, line 212 may represent operation of the vehicle 20 in the creep mode (e.g., under the influence of electric power only). It can be seen that at zero motor speed, there may be zero vehicle speed, with non-zero motor speed being directly related to vehicle speed. In creep mode (e.g., reverse brake 200 and clutch 198 engaged, drive clutch 196 disengaged, and an a-range gear (not shown) in gearbox 202 engaged), the vehicle may accelerate to a transition point. For example, the vehicle 20 may accelerate to a point where, based on engine speed and associated gear ratio, the ring gear 188 may be relatively stationary even though the brake 200 is not engaged. At this point (or another), clutch 198 may be disengaged and clutch 196 engaged, thereby shifting the vehicle into split mode driving. At (or near) this point, the motor 174 may then reverse its direction of rotation, thereby transitioning from line 212 to line 214. Thus, the vehicle 20 may continue to accelerate (now driven by both the motor 174 and the engine 24 c), even as the speed of the motor 174 changes direction (i.e., from negative to positive rotation), the vehicle speed increases. Similar shifting may also be accomplished by switching the motor 174 from line 214 to line 216, etc., for example, from an A-range gear (not shown) to a B-range gear (not shown).

In certain embodiments, including configurations involving various transmissions discussed above, it may be useful to provide an energy storage and transfer ("ESD") capability to a powertrain arrangement to power a vehicle system in addition to (or instead of) a conventional engine. For example, it may be useful to provide one or more electric, hydraulic, or other energy storage devices as part of (or in communication with) the powertrain 22 relative to the vehicle 20. Energy from the engine 24 may be received for storage at these devices (e.g., energy in mechanical form provided from the engine 24 is subsequently converted to non-mechanical form for storage). The stored energy may then be released for transfer to various vehicle components (e.g., a transmission or other powertrain component) in various beneficial ways.

In certain embodiments of the disclosed powertrain arrangement, an ESD system may be used to reduce adverse effects of transient power events of the vehicle 20. Transient power events may include the following events: the power available from the engine 24 (at least in the current operating state of the engine 24) may be insufficient for one or more ongoing (or requested) operations. For example, when an operator requests a power operation, a transient power event may occur, but the available (i.e., remaining) power from the engine 24 is insufficient (at least under current operating conditions) to complete the operation without adverse effects (e.g., without reducing the power supply to other vehicle systems). For example, while the engine 24 is actively providing power to various vehicle systems (e.g., a set of drive wheels), an operator may request operation requiring additional power over that currently available to the engine 24. In certain embodiments, the ESD system may be utilized to supplement (or replace) the available engine power for this operation while avoiding various problems (e.g., power lag, inefficient engine operation, pitching of the vehicle 20, etc.).

For example, transient power events may also occur when the engine is not providing power to the associated powertrain. In some embodiments, the ESD system may be utilized to power various vehicle systems when the engine is off or not running.

In certain embodiments, components of the IVP (e.g., an electrical generator or a hydraulic pump) may be configured to receive mechanical power from the engine 24 and convert the power to a different form (e.g., electrical power or hydraulic pressure/flow). A portion of the converted power may be routed to an energy storage device (e.g., a battery or an accumulator) for storage. The stored energy may then be released from the energy storage device to components of the IVP (e.g., an electric motor or a hydraulic motor) for conversion back to mechanical power, as needed (i.e., during a particular transient power event). The mechanical power may then be routed through the vehicle 20 as needed. For example, the MIVT may be configured to receive power from the IVP to supplement mechanical power received directly from the engine 24.

In certain implementations, smooth shifting may be provided utilizing the ESD system in the disclosed power system arrangement. During certain shifting events of the transmission of the vehicle 20 (e.g., during a transition from a first gear or gear of the multi-speed transmission to a second gear or gear of the multi-speed transmission), there may be a greater demand for power at the input of the transmission available from the engine 24 (i.e., a transient power event may occur). For example, one or more clutches of the transmission may slip as the transmission begins to assume a load (e.g., an increasing load) after a shift event. Even when power is transmitted through the transmission to the transmission output, this slip can result in power dissipation within the transmission itself (e.g., due to energy loss as the clutch slips). In this manner, the power required at the transmission input may be significantly greater than the power available at the transmission output.

Due to this loss of power (or other factors), various adverse events may occur with respect to the engine 24, transmission, or other vehicle systems. For example, due to excessive power demand at the transmission input, the engine 24 may temporarily "droop" or suffer other reduced performance, which may be perceived by the user as hesitation of the vehicle 20 (or the engine 24). Similarly, the transmission may perform a sub-optimal shift, which may be perceived by the user as a jerk, bump, or even stalling of the vehicle 20.

The smooth slip provided by the ESD system may help address these (and other) issues. For example, during steady (or other) operation of the vehicle 20, a portion of the power from the engine 24 may be routed to the ESD system (e.g., via the IVP) for storage (e.g., as stored electrical, hydraulic, power, or other energy). During the shift event, the ESD system may then transfer a portion of the stored energy to the associated transmission (e.g., via the IVP), as appropriate, to supplement the power directly provided by the engine 24. In this manner, power transfer from the ESD system may allow for relatively smooth shift operations even if the shift event causes a power demand at the transmission that exceeds the (current) power output of the engine 24. This may be useful, for example, to avoid the need to increase engine speed during a gear shift. Additionally, using an ESD system for smooth shifting may reduce the need for complex transmission designs (and controls) that may otherwise be necessary to provide smooth shifting during various shifting events.

The ESD system may provide various other benefits in addition to (or instead of) a smooth shift. In some embodiments, the ESD system may be utilized for load balancing, where the energy stored in the available ESD, rather than increased power transfer from the engine 24, is used to meet the increased power demand during operation other than a shift event. In certain implementations, this may allow engine 24 to operate at a relatively constant load and a relatively constant speed during a wide range of operation of vehicle 20, which in turn may result in a given configuration of engine 24 being more efficiently utilized. As such, the ESD system may be utilized to power operation of the vehicle 20 (or a subsystem thereof) without any uninterrupted power transfer from the engine 24. For example, in a "pure" electric (or hydraulic) mode, where the engine 24 is unable to provide any power for operation of the vehicle 20, the ESD system may use previously stored energy to power operation of various vehicle systems.

In some embodiments, the ESD system may be included in the IVP of the vehicle 20, or may otherwise interface with the IVP of the vehicle 20. For example, the IVP of the vehicle 20 may include a first IVP machine configured as a generator or a hydraulic pump, which may be configured to receive mechanical power from the engine 24 and convert the power into an electric or hydraulic (or other) form, respectively. A battery or accumulator (or other energy storage device) may be in communication with the first IVP machine such that a portion (i.e., part or all) of the converted power may be routed to the battery or accumulator for storage. The second IVP machine (e.g., an electric or hydraulic motor) of the IVP may be configured to receive electrical power from a battery or storage battery (or directly from the first IVP machine) and convert the received electrical power into mechanical form for downstream components of the vehicle powertrain 22.

The ESD system may be controlled in various ways. In certain embodiments, the routing of power to and from the ESD system may be regulated using a controller configured as a computing device of various designs (e.g., processor and memory architectures, programmable electronic circuits, etc.). In certain embodiments, for example, operation of the ESD system (as part of the disclosed power system arrangement) may be regulated by the TCU36, or may be regulated by a different controller (not shown). The ESD system may be controlled based upon a variety of inputs, including inputs from speed sensors (not shown) of the engine or other vehicle components, inputs from sensors (not shown) associated with gear shifting operations, vehicle power consumption or demand, or inputs from a variety of other devices (not shown).

With additional reference to FIG. 9, an example powertrain arrangement is depicted that includes an ESD system. The powertrain of fig. 9 is configured to transfer mechanical power from the internal combustion engine 24d to various vehicle components and systems. As depicted, mechanical power from the engine 24d is routed along shaft S8 to the planetary gear set 48d and the double planetary gear set 50d and the generator 230. (it should be understood that in other configurations, a different IVP machine may be utilized instead of or in addition to the generator 230.) the generator 230 is in electrical communication with a battery 234 (or other electrical energy storage device) and an electric motor 232. The generator 230 and the motor 232 together may be considered an IVP28 d in communication with an ESD system 228 including a battery 234 (or batteries 234, as appropriate), and various other components (not shown) including various power electronics, controllers, and the like.

The planetary gear set 48d and the double planetary gear set 50d and the IVP28 d are configured to operate in a similar manner as the planetary gear set 48, the double planetary gear set 50 and the IVP28a of fig. 3 (as discussed in detail above) to provide an MIVT26 d having a similar function as the MIVT26 a. However, MIVT26 d may exhibit various differences. For example, in fig. 9 it can be seen that shaft S16 is configured to receive power from shaft S8 via a transmission gear for generator 230 to power rotation of auxiliary drive pulley 250. Likewise, shaft S10, powered by gear 44d of shaft S8 (which also powers generator 230), may power transmission control, scavenging, and other pumps.

During ongoing operation, power from the engine 24d may be variously routed through the MIVT26 d to the gearbox 84d (e.g., configured as a controllable gearbox) to provide infinitely variable multi-mode power transfer to various vehicle systems. As depicted, for example, the output gear 82d of the double planetary gear set 50d is configured to mesh with the input gears 236 and 238 of the gearbox 84 d. Through selective operation of the clutch 252, the output gear 82d can correspondingly power rotation of one of the transfer shafts S11 and S13, respectively. The gearbox 84d may be shifted between the various gear gears 240, 242, 244, 246, and 248 using selective control of various other clutches 254, the gear gears 240, 242, 244, 246, and 248 may correspond to gears a-E, respectively, for the gearbox 84 d. In this manner, power may be routed from the engine 24 and the motor 232 to the differential drive shaft S12 a. Additionally, as depicted, the brake 256 and the clutch 258 may be controlled to transfer power from the gearbox 84d to the driveshaft S12b for mechanical front wheel drive. (it should be understood that the depicted configuration of the various gears of the gearbox 84d are shown as examples only-the ESD system may also be utilized with respect to other configurations of the gearbox 84 d).

Other devices and functions may also be provided. For example, it can be seen that gear 44d of shaft S8 is configured to rotate idler gear 68d on shaft S12a and provide power to generator 230. In turn, gear 68d may power the rotation of PTO shaft S14, and in some configurations, may power front PTO shaft S15.

Once converted to electronic form, a portion of the power received at the generator 230 is routed to the ESD 228 for storage in the battery 234, as regulated by a suitable controller (not shown). In certain implementations, power may be continuously routed from the generator 230 to the battery 234 as long as the engine 24d is running and the battery 234 is not fully charged. In some implementations, power may be more selectively routed from the generator 230 to the battery 234. For example, under certain control strategies, electrical power may be routed from the generator 230 to the battery 234 only when it has been detected (e.g., via various engine or other sensors (not shown)) that the generator 230 is generating excess power for the current power demand of vehicle operation.

Energy for powering the operation of the motor 232 may be released from the battery 234 as needed. As described above, with respect to the motor 42 of fig. 3, power from the motor 232 may then be routed through the double planetary gear set 50d to supplement (or replace) power from the engine 24 d. This is useful, for example, to ensure that the various systems and devices of the vehicle 20 are provided with appropriate power, even while the engine 24d is maintained at an optimal and relatively constant operating speed.

In some implementations, power from the battery 234 may be used to perform smooth shifting operations via the motor 232. For example, during (or before or after) a shift from the a-range gear 240 to the B-range gear 242, the associated controller may identify that additional power may be required at the gearbox 84d in order to ensure a smooth shift, and in some embodiments, in order to avoid the need to increase engine speed or power. Thus, for an A-B shift event (and other shift events), energy may be released from the battery 234 to the motor 232 so that the motor 232 may provide additional power to the gearbox 84d (i.e., via the dual planetary gear set 50 d).

Smooth shifting, such as in the above examples, may be achieved based on various factors. In certain implementations, for example, a signal from the TCU36 (or other device) may indicate that a shift between gears of the gearbox 84d is about to occur (or is occurring or has recently occurred). In the event that such a shift event is identified as (or expected to) result in a transient power event, power may be routed from the ESD 228 accordingly. In certain implementations, an engine sensor, shaft speed sensor, or other sensor (not shown) may detect an indication of insufficient power at the gearbox 84d (e.g., due to clutch slip within the gearbox 84d during a gear shift operation). Routing of power from the ESD 228 to the gearbox 84d may then be accomplished accordingly.

In some implementations, power from the battery 234 may be utilized for other operations. For example, in situations where operation of the engine 24d may not be feasible or practical (e.g., during operation of the vehicle 20 in an enclosed space), energy from the battery 234 may be utilized to enable electric-only operation of the vehicle 20. In certain implementations, electric-only operation may be automatically achieved (e.g., based on receiving a drive or other command while the vehicle is keyed on but the engine 24d is off). In some implementations, electric-only operation may be achieved based on other factors (e.g., based on an operator toggling a particular switch, button, or lever).

As another example, in the event that use of a particular vehicle tool places an increased power demand on the vehicle 20, energy from the battery 234 may be utilized to ensure that appropriate power is available at the tool without significantly adversely affecting operation of other vehicle systems (e.g., vehicle drive wheels) or without significantly increasing engine speed. For example, the vehicle' S driveline may be subject to increased power demands while a mechanical tool (e.g., a bagging device, a seed planting device, a soil conditioning device, a cutting blade, etc.) is being driven by the PTO shaft S14 or while a power-operated hydraulic tool (e.g., a loading bucket, a dump truck chassis, an excavator arm, a soil conditioning device, etc.) from the front PTO shaft S15 or another shaft (i.e., converted by a suitable hydraulic pump (not shown)) is being used. Thus, in certain embodiments, energy from the battery 234 (converted to mechanical energy by the motor 232) may be utilized to supplement (or replace) power from the engine 24d relative to the associated implement (or other vehicle system) during operation of such an implement.

In certain implementations, power from the battery 234 may be automatically utilized whenever any vehicle implement (or any vehicle implement of a particular configuration) is operated. In some implementations, power from the battery 234 may be more selectively utilized. For example, an engine sensor, shaft speed sensor, or other sensor (not shown) may detect an indication of insufficient power due to tool operation and may draw power from the battery 234 as appropriate.

In addition, referring to fig. 10, another example MIVT26e is configured similarly to the MIVT26 c of fig. 7. The internal combustion engine 24e provides mechanical power to the double planetary gear set 178e and the generator 172e (or other IVP machine) included in the IVP28e via shaft S17. The generator 172e converts mechanical power from the engine 24e into electrical power that is routed to the motor 174 e. The motor 174e then converts the electrical power to mechanical power that is also routed to the double planetary gear set 178 e. In this manner, the MIVT26e may be used to combine power from the engine 24e and the IVP28e via the double planetary gear set 178e to provide continuously variable power to the transmission 202 e.

In the depicted embodiment, the generator 230 is in electrical communication with a battery 260 (or other electrical energy storage device) and a motor 232. In this manner, mechanical energy from the engine 24e may be stored as electrical energy in the battery 260 and released by the motor 174e as appropriate to power the double planetary gear set 178 e. As described in detail with respect to the configuration of fig. 9, energy from the battery 260 may be utilized to provide smooth shifting, to operate the vehicle 20 in an electric-only mode, to provide power for operation of tools of the vehicle 20 (or to provide power to other vehicle systems during operation of such tools), and so forth.

It should be understood that the various storage devices of the ESD system (e.g., batteries 234 and 260) may receive and store energy from sources other than the associated engines (e.g., engines 24d and 24 e). For example, in certain implementations, a regeneration system (e.g., a system for capturing energy from braking operations) may be configured to route power to the ESD system for later use (e.g., for smooth shifts, electric-only operations, etc.) or may form part of the ESD system. Likewise, it should be understood that the ESD system may be utilized with powertrain systems and transmissions (including MIVT) other than those specifically depicted. In certain embodiments, for example, an ESD system (not shown) may be implemented with respect to the powertrain depicted in fig. 5 or with respect to various other powertrain configurations (not shown) via a hydraulic accumulator 264 (see fig. 5, hydraulic connections not shown).

The various operations described above (and others) may be implemented as part of a transient power event management ("TPEM") approach. Additionally, referring to fig. 11, for example, the TPEM method 300 may be implemented for the vehicle 20 by various controllers (e.g., TCU36) or other devices.

TPEM method 300 may include identifying 302 a transient power event. For example, using an engine speed sensor, various axle speed sensors, other sensors or devices, the controller may identify 302 that the current (or upcoming) operating state of the associated vehicle has resulted in (or is likely to result in) a power deficit. For example, a shift operation 304 (e.g., a recent, ongoing, or imminent shift operation 304) may be identified 302 during which the transmission may require more power from the engine (e.g., due to clutch slip) than is available from the engine (at least in the current operating state). For example, due to clutch slip during a shift event, more power from the engine may be required at the input of the transmission than is available from the engine at the current engine speed. Similarly, an operation 306 of the tool (e.g., an operation 306 in which the tool is in progress or is imminent) may be identified 302 during which the power demand of the tool (e.g., in combination with other power demands for other vehicle systems) may exceed the power derived from the engine. In certain implementations, identifying 302 a transient power event may include identifying 302 operation of the vehicle (or a subsystem thereof) while the engine is off (or otherwise de-energized). For example, while the engine is in the off state 308, driving operations or operation of vehicle implements (e.g., ongoing or imminent driving or implement operations) may be identified 302.

The method 300 may also include causing 320 an energy storage device (e.g., which may form part of a larger ESD system) to provide stored energy to a component of an IVP (e.g., an IVP machine). For example, the method 300 may be utilized to cause 320 energy 320 from a battery to be provided to an electric motor, to cause 320 energy from a hydraulic accumulator to be provided to a hydraulic motor, and so forth. (in some implementations, it should be understood that this may be prior to the method 300, resulting in 322 energy being stored in the IVP

The method 300 may then include providing 330 power to the transmission from a component of the IVP (e.g., from an IVP machine). For example, the method 300 may include providing 330 power from an electric or hydraulic motor to various configurations of MIVT, transmissions with fixed gear ratios, including other transmissions in an associated powertrain.

In certain implementations, the method 300 may also include providing 340 power from the engine to the transmission. For example, where the engine is not in the off state 308, the MIVT (or other device) may be utilized to sum the power received from the engine and the IVP, respectively, such that power from both the engine and the IVP may be provided 330, 340 to the associated transmission.

Referring now to fig. 12-16, the present disclosure will be discussed in accordance with further example embodiments. It should be noted that the schematic representations of the transmissions shown in fig. 12, 14, 15, and 16 illustrate example implementations in simplified form for the sake of clarity, and thus may not depict all of the components associated with the illustrated power system.

As will be discussed, the powertrain system of the present disclosure provides a multi-mode Infinitely Variable Transmission (IVT). The IVT provides split-path power transfer to combine power from the engine and at least one Infinitely Variable Power (IVP) machine. For example, the powertrain may include an engine, a first electric machine, and a second electric machine.

As mentioned above, it may be useful to facilitate a zero power mode of the vehicle (or other machine) in which the output speed of the wheels (or other machine output) reaches a speed of zero without stopping the engine or releasing torque at the wheels. In this way, vehicle power may be utilized to hold the vehicle stationary, for example. This state may be achieved with a planetary gear set, for example. For example, if the engine rotates the sun gear at a first positive speed and directs an IVP machine (e.g., an electric motor powered by a generator) to rotate the ring gear at an equivalent negative speed, the associated planet gear carrier (which may be connected, for example, with a differential drive shaft) may not rotate at all. Additionally, if the IVP provides output rotation at a slightly different (and opposite) speed than the engine, the vehicle may enter a "creep" mode, where the vehicle moves very slowly, but the wheel torque is high. For heavy work vehicles used in the agricultural, construction, and forestry industries (such as the tractor shown in fig. 1), the zero-power and creep modes are particularly useful. As the wheel speed increases, the vehicle may then eventually enter a normal driving mode (i.e., a "field mode").

As will be discussed, in at least one mode of the IVT of the present disclosure, split-path power transfer may be provided in which a zero-power state may be achieved. The split path power transfer may continue as the speed of the vehicle increases from a zero power state to the creep mode. Further, in at least one mode, the first and second IVP machines may collectively generate power to meet the power demand. The IVP machines may generate power collectively when the vehicle is in a zero-power state and as the vehicle speed increases therefrom to creep mode. Accordingly, the vehicle may be used to perform a wide variety of tasks while meeting the high power demands of various electrical components.

Additionally, the IVT may be configured in various ways, wherein the above-described split path of zero power with common power generation capability may be an optional feature for a particular IVT. Thus, the IVT may be modular and configurable. In other words, the IVT may have a first configuration (e.g., fig. 12) in which the IVT provides a split path, zero power, common power generation capability, and a second configuration (e.g., fig. 14) in which the IVT does not provide that capability. Thus, the transmission is configured according to the type of work the vehicle is to perform, according to space constraints within the vehicle, or in other ways.

Now, the exemplary embodiment illustrated in fig. 12 will be discussed in detail. As shown in FIG. 12, the powertrain 22 may include an engine 502, such as an internal combustion engine. The engine 502 may provide mechanical power directly to the engine shaft 509.

The power system 22 may additionally include an Infinitely Variable Power (IVP) source 501, and the IVP source 501 may include at least one IVP machine. As shown in the illustrated embodiment, the IVP source 501 may include a first IVP machine 504 and a second IVP machine 506. In some embodiments, the first IVP machine 504 may comprise a first electric machine 503 and the second IVP machine 506 may comprise a second electric machine 505.

The powertrain 22 may also include a multi-Mode Infinitely Variable Transmission (MIVT), indicated generally at 515. The MIVT515 may transfer mechanical power between the engine 502, the first electric machine 503, and the second electric machine 505, as will be discussed in detail below. The MIVT515 may also transmit power to the output shaft 507. Depending on the current transmission mode of the MIVT515, power may be transferred through the MIVT515 along different paths. A vehicle (e.g., the tractor of fig. 1 or another work vehicle) may include wheels that may be rotatably driven (e.g., via one or more differentials) by output shaft 507.

As will be discussed, the first electric machine 503 may be switched between a generator mode and a motor mode. In the generator mode, the first electric machine 503 may receive mechanical energy from the MIVT515 and convert it into electrical energy that may be supplied to the second electric machine 505 and/or the implement 521. Conversely, in the motoring mode, the first electric machine 503 may convert electrical energy to mechanical energy that is supplied to the MIVT 515.

Likewise, the second electric machine 505 can be switched between a motor mode and a generator mode. In the motoring mode, the second electric machine 505 may convert electrical energy to mechanical energy that is supplied to the MIVT 515. Conversely, in the generator mode, the second electric machine 505 may receive mechanical energy from the MIVT515 and convert it to electrical energy that may be supplied to the first electric machine 503 and/or the implement 521.

The implement 521 may be a sowing tool, a shovel, a bucket, or other device. In some embodiments, the implement 521 may be powered by electrical energy supplied at least in part by the IVP 501. Additionally, the implement 521 may be mounted onboard the vehicle, or may be remote from the vehicle and tethered to the vehicle at least by a power cable.

The MIVT515 may include the first planetary gear set 508. The first planetary gear set 508 may be a double planetary gear set that includes a plurality of gear members. For example, a double planetary gear set may include a first sun gear 510, a first ring gear 512, a plurality of first planet gears 514 having an associated carrier 525, a second sun gear 516, a second ring gear 518, and a plurality of second planet gears 520 having an associated carrier 527. In some embodiments, first sun gear 510, first ring gear 512, and first planet gears 514 may together comprise a so-called "LO gear set" of first planetary gear set 508, and second sun gear 516, second ring gear 518, and second planet gears 520 may together comprise a so-called "HI gear set" of first planetary gear set 508. Additionally, in some embodiments, the second ring gear 518 may be directly engaged to rotate with the carrier 525 of the first planetary gears 514.

The MIVT515 may additionally include a second planetary gear set 522. The second planetary gear set 522 may be a single planetary gear set that includes a plurality of transmission members. For example, a single planetary gearset may include a sun gear 524, a ring gear 526, and a plurality of planet gears 528 having an associated carrier 529.

As will be discussed, in at least one mode of the MIVT515, the power and torque output of the first planetary gear set 508 may be input to the second planetary gear set 522, and the second planetary gear set 522 may in turn provide power and/or torque to the output shaft 507 of the vehicle. In some embodiments, power system 22 may provide zero power and/or creep modes in this manner.

The MIVT515 may include a plurality of transmission components (e.g., gears, shafts, etc.) that transmit mechanical power through the MIVT 515. These components may be configured to transmit power between the engine 502, the first electric machine 503, the second electric machine 505, and ultimately to the output shaft 507. One or more of these transfer components may define a "transfer leg". In some embodiments, a first transfer branch may transfer power between the engine 502 and the first planetary gear set 508. Likewise, in some embodiments, a first transfer branch may transfer power between the first planetary gear set 522 and the second planetary gear set 522. Furthermore, in some embodiments, a third transmission branch may transmit power between the second planetary gear set 522 and the output shaft 507, etc., as will be explained in detail below.

One or more of the transfer legs of the MIVT515 may include a series of interconnected and/or meshed gears. These gears may be spur gears, bevel gears, or other types of gears. Additionally, two gears within a particular transfer branch may be meshed together (e.g., with parallel but spaced apart axes of rotation). Further, two gears within a particular transfer leg may mesh with each other for rotation and be interconnected by a shaft (e.g., one or more shafts coaxial with the two gears of interest).

In some embodiments, two shafts within a particular transmission branch may engage each other for rotation, and alternatively, disengage from each other. For example, a clutch may be included in the transfer branch and interposed between the two shafts. In the clutch coupled position, the two shafts may be engaged with each other for rotation. In the non-clutch coupled position, the two shafts are disengageable for independent rotation.

As shown in fig. 12, the MIVT515 may include a plurality of clutches 569. In some embodiments, the plurality of clutches 569 of the MIVT515 includes a first clutch 570, a second clutch 572, a third clutch 574, a fourth clutch 576, a fifth clutch 578, a sixth clutch 580, and a seventh clutch 582. Each of these clutches 569 is independently operable and actuatable between a clutch coupled position (i.e., engaged position, energized position, etc.) and, alternatively, a non-clutch coupled position (i.e., disengaged position, de-energized position, etc.). In some embodiments, clutches 569 are operatively connected to respective ones of the transfer branches.

Different transfer branches of the MIVT515 may transfer power at a given time according to the mode of the MIVT 515. For each transmission mode, a predetermined subset of the plurality of clutches 570, 572, 574, 576, 578, 580, 582 may be engaged while the other clutches are disengaged. Different subsets of the clutches 570, 572, 574, 576, 578, 580, 582 can be engaged in different modes. This allows power to be routed through the MIVT515 in various ways to supply the mechanical and electrical demands of the vehicle.

The different transmission modes of the MIVT515 will now be discussed. Fig. 13 illustrates these different transmission modes according to an example embodiment of the present disclosure. Specifically, fig. 13 illustrates a relationship between the wheel speed of the vehicle (X-axis) and the rotation speed of the second electric machine 505 (Y-axis). In some embodiments, the MIVT515 may provide a first mode (represented by line 584 in fig. 13), a second mode (represented by line 586), a third mode (represented by line 588), a fourth mode (represented by line 590), a fifth mode (represented by line 592), and a sixth mode (represented by line 594). These modes may represent a forward mode of the vehicle in which the vehicle moves forward from a stationary position. The MIVT515 may also include additional modes, such as at least one reverse mode, in which the vehicle moves in an opposite reverse direction from a stationary position.

In the first mode of the MIVT515, the first, fourth, and fifth clutches 570, 576, 578 may be in clutch engaged positions, while the other clutches 572, 574, 580, 582 may be in non-clutch engaged positions. As such, power (i.e., engine power) may be transferred from the engine shaft 509 to the carrier 527 of the second planetary gears 520 of the first planetary gear set 508 along the first transfer branch. More specifically, power may be transferred from the engine shaft 509 through the first clutch 570 and through the fourth clutch 576 to gear 536 via the first transfer branch. Gear 536 meshes with a gear 540 attached to a carrier 527 of the second planetary gear 520. In some embodiments, the first transfer branch may be a unidirectional power transfer path from the engine shaft 509 to the second planetary gear 520.

Additionally, in the first mode of the MIVT515, a second transfer branch may be defined between the first electric machine 503 and the engine shaft 509 to transfer power therebetween (i.e., IVP power transfer). The second transmission branch may include a gear 546 that is meshed to rotate with the shaft of the first electric machine 503. Gear 546 may be in mesh with gear 548, which gear 548 is mounted on the opposite end of the coaxial shaft along with gear 550. Gear 550 may mesh with gear 530. The second transmission branch may be a bidirectional power transmission path between the first electric machine 503 and the engine shaft 509. In other words, the first electric machine 503 may: (a) operating in a generator mode, receiving power from gear 546 and converting it into electrical energy to supply the implement 521, the second electric machine 505, or otherwise; or (b) operate in a motoring mode, providing power to the gear 546, and ultimately returning to the first transfer branch discussed above. In some embodiments, the direction of power transfer through the transfer branch is controlled by controlling the first electric machine 503 (i.e., by controlling the speed and direction of rotation of gear 546).

In addition, in this first mode of the MIVT515, a third transfer branch may be defined between the second sun gear 516 and the second electric machine 505 to transfer power therebetween (i.e., IVP power transfer). More specifically, power can be transmitted between the second sun gear 516 and the second electric machine 505 in either direction by means of the gear 554 and the gear 552 that mesh with each other. As shown in fig. 12, the gear 554 is engaged to rotate with the second sun gear 516, and the gear 552 is engaged to rotate with the second electric machine 505. This third transmission branch may be a bidirectional power transmission path between the second sun gear 516 and the second electric machine 505, which means that the second electric machine 505 may: (a) operate in a motor mode and power the second sun gear 516; or (b) operate in a generator mode, receive mechanical power and convert it to electrical power that can be supplied to the first electric machine 503, the implement 521, or other electrical power consumers. For example, by controlling the second electric machine 505 (i.e., by controlling the speed and direction of rotation of the gear 552) in some embodiments, the direction of power transfer through the transfer branch may be controlled.

Additionally, a fourth transfer branch may be defined between the second ring gear 518 and the sun gear 524 of the second planetary gear set 522. More specifically, power (i.e., combined power) may be transferred from the second ring gear 518 through the first planetary gears 514 to the gear 556, the gear 556 meshing with the gear 557, the gear 557 meshing with the gear 558, and the gear 558 meshing with the gear 560. Gear 560 may be engaged for rotation with the sun gear 524 of the second planetary gear set 522. The fourth transfer branch may be a unidirectional power transfer path from the second ring gear 518 to the sun gear 524.

A fifth transfer branch in the first transfer mode from the ring gear 526 of the second planetary gear set 522 to the engine shaft 509 may be defined. More specifically, power may be transmitted from the ring gear 526 to the gear 531 through the fifth transmission branch, and engaged so as to rotate together with the ring gear 526. Gear 531 may mesh with gear 532, and power may be transferred from gear 532 back to engine shaft 509. Gear 532 may be considered a flywheel. In some embodiments, the fifth transfer branch may be a unidirectional power transfer path from the ring gear 526 to the engine shaft 509.

Additionally, a sixth transfer branch from the ring gear 528 of the second planetary gear set 522 to the output shaft 507 may be defined. More specifically, power may be transferred from the planetary gears 528 to the gear 542 through the clutch 578, the gear 542 meshing with the gear 544, the gear 544 being engaged for rotation with the output shaft 507. The sixth transfer branch may be a one-way transfer path from the ring gear 528 to the output shaft 507.

It should be appreciated that in this first transmission mode, both the first planetary gear set 508 and the second planetary gear set 522 provide split paths for power transfer within the MIVT 515. The first planetary gear set 508 combines the input from the engine 502 and the input/output of the second electric machine 505, so that the output of the first planetary gear set 508 (i.e., first combined power) is input to the second planetary gear set 522. In addition, the second planetary gear set 522 combines the input from the first planetary gear set 508 and the output to the engine shaft 59, so that the output of the second planetary gear set 522 (i.e., the second combined power) is output to the output shaft 507.

Furthermore, zero power may be achieved in this first transmission mode of the MIVT 515. Specifically, the combination at the second planetary gear set 522 may include a sun gear 524 that receives power input from the first planetary gear set 508 and a ring gear 526 that outputs power toward the engine shaft 509, thereby causing the carrier 529 of the planetary gears 528 to remain stationary (i.e., zero rotational speed) while maintaining torque at the output shaft 507. In addition, as shown in fig. 13, the speed of the second electric machine 505 may be increased in the first mode to increase the wheel speed of the vehicle from a zero-power state (i.e., creep mode).

Additionally, in some embodiments, the first electric machine 503 and the second electric machine 505 may simultaneously generate power collectively in the zero-power state and in the creep mode. In the example of fig. 13, for example, a zero-power condition may be represented at point 596, where the gear 552 of the second electric machine 505 is rotating in a first direction. The speed of the vehicle can be increased by decreasing the speed of gear 552. In some embodiments, the second electric machine 505 may generate power from a zero power state (point 596) to a point where the output speed of the gear 552 is equal to zero (point 598). At the same time, the first electric machine 503 may also be in generator mode.

Assuming that the speed of the gear 552 starts to rotate in the opposite direction and increases from there (from point 598 to point 600), the second electric machine 505 may enter a motoring mode such that the second electric machine 505 provides power to the gear 552.

According to an exemplary embodiment, the second transmission mode is represented by line 586 in FIG. 13. In the second mode of the MIVT515, the first, third and fifth clutches 570, 574, 578 may be in clutch engaged positions, while the other clutches 572, 576, 580, 582 may be in non-clutch engaged positions. As such, power may be transferred from the engine shaft 509 to the first ring gear 512 of the first planetary gear set 508 along a first transfer branch. More specifically, power may be transferred from the engine shaft 509, through the first clutch 570, and through the third clutch 574 to the gear 534 via the first transfer branch. Gear 534 meshes with gear 538 attached to ring gear 512. In some embodiments, the first transfer branch may be a unidirectional power transfer path from the engine shaft 509 to the ring gear.

In addition, in this second transmission mode, the second transfer branch between the first electric machine 503 and the gear 530 may be substantially the same as discussed above.

Further, a third transmission branch may be defined between the second electric machine 505 and the first sun gear 510 of the first planetary gear set 508. More specifically, power can be transmitted between the first sun gear 510 and the second electric machine 505 in either direction by means of the gear 552 and the gear 554 that mesh with each other. This third transmission branch may be a bidirectional power transmission path between the first sun gear 510 and the second electric machine 505, which means that the second electric machine 505 may: (a) operate in a motor mode and power sun gear 510; or (b) operate in a generator mode, receive mechanical power and convert it to electrical power that can be supplied to the first electric machine 503, the implement 521, or other electrical power consumers.

Additionally, a fourth transfer branch may be defined between the carrier 525 of the first planetary gear 514 and the sun gear 524 of the second planetary gear set 522. More specifically, power may be transferred from the first planetary gears 514 to the gears 556, gears 556 mesh with gears 557, gears 557 mesh with gears 558, and gears 558 mesh with gears 560. Gear 560 may be engaged for rotation with the sun gear 524 of the second planetary gear set 522. The fourth transfer branch may be a unidirectional power transfer path from the second ring gear 518 to the sun gear 524.

Additionally, a fifth transfer branch in this second gear mode from the ring gear 526 of the second planetary gear set 522 to the engine shaft 509 may be defined. The fifth transfer branch may be configured as discussed above with respect to the first transmission mode.

Additionally, a sixth transfer branch from the planet gear 528 of the second planetary gear set to the output shaft 507 may be defined. More specifically, power may be transferred from the planetary gears 528 to the gear 542 through the clutch 578, the gear 542 meshing with the gear 544, the gear 544 being engaged for rotation with the output shaft 507. The sixth transfer branch may be a one-way transfer path from the ring gear 528 to the output shaft 507.

Referring to fig. 13, when the MIVT515 is in the second transmission mode, the first electric machine 503 and the second electric machine 505 may collectively generate power. This co-generation occurs when the speed of the gear 552 of the second electric machine 505 is at the speed represented by point 602 and as the speed of the gear 552 decreases toward zero at point 604. Then, as the speed of the gear 552 increases in the opposite direction, the second electric machine 505 may enter a motor mode.

It should be appreciated that the second electric machine 505 may remain in generator mode from a zero power condition in the first transmission phase through the lower output speed range of the second transmission phase (e.g., from point 596 to point 604 in fig. 13). In one example sequence, the MIVT515 may be in a zero power state (at point 596) and the MIVT515 may remain in the first transmission mode as the wheel speed of the MIVT515 increases. At point 598, the second electric machine 505 may remain in generator mode by shifting the MIVT515 into the second transmission phase (i.e., to point 602). As the output speed increases, the MIVT515 may remain in the second gear mode. Thus, as shown in fig. 13, there is sufficient overlap between the first transmission mode and the second transmission mode such that the second electric machine 505 can be continuously maintained in generator mode from the first transmission mode to the second transmission mode.

The third transmission mode (i.e., the first field mode) of the MIVT515 may be represented by line 588 in fig. 13. In the third drive mode, the first, third and sixth clutches 570, 574, 580 may be in clutch engaged positions, while the other clutches 572, 576, 578, 582 may be in non-clutch engaged positions. As such, power may be transferred from the engine shaft 509 to the first ring gear 512 of the first planetary gear set 508 along a first transfer branch. More specifically, power may be transferred from the engine shaft 509, through the first clutch 570, and through the third clutch 574 to the gear 534 via the first transfer branch. Gear 534 meshes with gear 538 attached to ring gear 512. In some embodiments, the first transfer branch may be a unidirectional power transfer path from the engine shaft 509 to the ring gear.

In addition, in this third transmission mode, the third transfer branch between the first electric machine 503 and the gear 530 may be substantially the same as discussed above with respect to the first and second transmission modes.

Furthermore, the third transfer branch between the second electric machine 505 and the first sun gear 510 may be substantially the same as discussed above with respect to the second transmission mode.

Further, the first planetary gear set 508 may combine the power at the first ring gear 512 and the first sun gear 510 and the power output from the first planetary gears 514 to the output shaft 507. More specifically, in this fourth transmission branch, power may be transmitted from first planetary gear 514 through sixth clutch 580 to gear 562, which is meshed with gear 544. Gear 544 may be engaged for rotation with output shaft 507.

It should be appreciated that in this third transmission mode, power transfer through the MIVT515 bypasses the second planetary gear set 522. In other words, the power output from the first planetary gear set 508 is directly transmitted to the output shaft 507.

Further, it should be appreciated that from point 606 to point 608 of fig. 13, the second electric machine 505 may be in generator mode. Thus, assuming that the MIVT515 is in the second transmission mode, the output speed continues to increase, and the power demand is still high enough, the MIVT515 may shift from the second transmission mode to the third transmission mode (i.e., by adjusting the speed of gear 552 from point 604 to point 606 in fig. 13).

The fourth transmission mode (i.e., the second field mode) of the MIVT515 may be represented by line 590 in fig. 13. In the fourth gear mode, the first, fourth and sixth clutches 570, 576, 580 may be in clutch engaged positions, while the other clutches 572, 574, 578, 582 may be in non-clutch engaged positions. As such, power may be transferred from the engine shaft 509 to the second planetary gears 520 of the first planetary gear set 508 along a first transfer branch. More specifically, power may be transferred from the engine shaft 509, through the first clutch 570, and through the fourth clutch 576 to the gear 536 through the first transfer branch. Gear 536 meshes with gear 540 attached to carrier 527 of planetary gear 520. In some embodiments, the first transfer branch may be a unidirectional power transfer path from the engine shaft 509 to the second planetary gear 520.

In addition, in this fourth transmission mode, the second transfer branch between the first electric machine 503 and the gear 530 may be substantially the same as discussed above with respect to the first, second and third transmission modes.

Further, the third transmission branch between the second electric machine 505 and the second sun gear 516 may be substantially the same as discussed above with respect to the first transmission mode.

Further, the first planetary gear set 508 may combine the power of the second planetary gears 520 and the second sun gear 516 and the power output from the second ring gear 518 to the output shaft 507. More specifically, in this fourth transfer branch, power may be transferred from second ring gear 518, through first planetary gear 514, through sixth clutch 580, to gear 562, and ultimately to gear 544 to rotate output shaft 507.

The fifth transmission mode (i.e., the third field mode) of the MIVT515 may be represented by line 592 in fig. 13. In the fifth drive mode, the first, third and seventh clutches 570, 574, 582 may be in clutch engaged positions, while the other clutches 572, 576, 578, 580 may be in non-clutch engaged positions. As such, power may be transferred from the engine shaft 509 to the first ring gear 512 of the first planetary gear set 508 along a first transfer branch, similar to the first transfer branch defined in the first transmission mode.

In addition, in this fifth transmission mode, the second transfer branch between the first electric machine 503 and the gear 530 may be substantially the same as discussed above with respect to the first, second and third transmission modes.

Furthermore, the third transfer branch between the second electric machine 505 and the first sun gear 510 may be substantially the same as discussed above with respect to the second transmission mode and the third transmission mode.

Further, the first planetary gear set 508 may combine the power of the first ring gear 512 and the first sun gear 510 and the power output from the second planetary gears 514 to the output shaft 507. More specifically, in the fifth transmission branch, power can be transmitted from the carrier 525 of the first planetary gear 514 to the gear 556 meshed with the gear 557 to rotate the output shaft 507.

The sixth transmission mode (i.e., the fourth field mode) of the MIVT515 may be represented by line 594 of fig. 13. In the sixth transmission mode, the first, fourth and seventh clutches 570, 576, 582 may be in clutch engaged positions, while the other clutches 572, 574, 578, 580 may be in non-clutch engaged positions. As such, power may be transferred from the engine shaft 509 to the second planetary gears 520 of the second planetary gear set 508 along a first transfer branch, similar to the first transfer branch defined in the fourth transmission mode.

In addition, in this sixth transmission mode, the second transmission branch between the first electric machine 503 and the gear 530 may be substantially the same as discussed above with respect to the first, second, third, fourth and fifth transmission modes.

Furthermore, the third transfer branch between the second electric machine 505 and the second sun gear 516 may be substantially the same as discussed above with respect to the fourth transmission mode.

Further, the first planetary gear set 508 may combine the power of the second planetary gears 520 and the second sun gear 516 and the power output from the second ring gear 518 to the output shaft 507. More specifically, in this fourth transfer branch, power may be transferred from second ring gear 518, through first planetary gear 514, through sixth clutch 580, to gear 562, and ultimately to gear 544 to rotate output shaft 507.

The MIVT515 may also include one or more reverse modes. The reverse mode may be similar to the first, second, third, fourth, fifth, and sixth gear modes described above, except that in each mode, second clutch 572 is clutched rather than first clutch 570.

Thus, as an example of the first reverse mode, the second, fourth and fifth clutches 572, 576, 578 are coupled by the clutches, while the other clutches 570, 574, 580, 582 remain non-clutched. As such, power is transferred from the engine shaft 509 to the second planetary gears 520 of the first planetary gear set 508 through the second clutch 572 (i.e., the reverse clutch). Specifically, power is transferred from engine shaft 509 to gear 530, gear 530 meshing with gear 550, and gear 550 meshing with gear 568. This power is transmitted to the gear 531 meshing with the gear 532 through the second clutch 572. This power is transmitted through fourth clutch 576 to gear 536, which is meshed with gear 540, and finally to second planetary gear 520. The other transfer branches may be the same as described above with respect to the first transfer mode. Other reverse drive modes may be similarly configured (i.e., similar to the modes described in detail below, except that the second clutch 572, but not the first clutch 570, is clutched).

Referring now to FIG. 14, certain modular features of the powertrain 22 'and the MIVT 515' will be discussed in detail. The power system 22 'and the MIVT 515' of fig. 14 may have a modular construction that differs from the modular configuration of the MIVT515 implemented in fig. 12.

As shown, the MIVT 515' may be substantially similar to the MIVT515 of fig. 12, except that the second planetary gear set 522 and associated gears 542, 558, and 560 and fifth clutch 578 of fig. 12 may be omitted in the configuration of fig. 14.

In some embodiments, the MIVT 515' may have a third mode, a fourth mode, a fifth mode, and a sixth mode. These modes may correspond to the third, fourth, fifth, and sixth modes, respectively, as described above.

The first and second modes (zero power mode and creep mode) as described above would not be available for the MIVT 515' of fig. 14. This is because the planetary gear set 508 combines the engine power provided by the engine 502 and the second MIVP 501 as discussed above. The combined output power is transmitted directly from gear set 508 to output shaft 507. This is in contrast to the arrangement of fig. 12, in which the combined output power from the first planetary gear set 508 is transferred to the second planetary gear set 522, the second planetary gear set 522 splitting the input power between the output shaft 507 and the gear 532.

Thus, the modular configuration of the MIVT 515' of fig. 14 does not provide the zero-power, co-generation capability of the MIVT515 of fig. 12. However, for some vehicles and/or some consumers, such capability may not be necessary. In addition, the modular configuration of fig. 14 may be more compact than the modular configuration of fig. 12 because it includes fewer components. Thus, depending on the type of work to be performed by the vehicle, space constraints within the vehicle, and/or other considerations, a first work vehicle may be constructed to include the modular configuration of fig. 14, and a second work vehicle may be constructed to include the modular configuration of fig. 12.

Referring now to fig. 15, additional embodiments of MIVT 715 will be discussed, according to example embodiments. The MIVT 715 may be substantially similar to the implementation of the MIVT515 of fig. 12 in several respects. Therefore, common features will not be explained again. Additionally, components in fig. 15 that correspond to components of fig. 12 will be identified with corresponding reference numerals increased by 200.

The MIVT 715 differs from the embodiment of fig. 12 in that the engine shaft 709 may be substantially coaxial with a central axis of the first planetary gear set 708. In other respects, the MIVT 715 may be similar to the embodiment of fig. 12. For example, the MIVT 715 may have six forward drive modes and at least one reverse drive mode using the same clutch modes discussed above with respect to the embodiment of fig. 12.

The embodiment of fig. 15 may be configured for a work vehicle with certain space limitations and/or a particular architecture. For example, the embodiment of fig. 15 may be used with a "short-drop" work vehicle — a work vehicle having an engine 702 that is relatively low and disposed rearward toward the cab of the work vehicle. In contrast, the embodiment of fig. 12 may be used with a "short-drop" work vehicle, a work vehicle having an engine 502 that is relatively tall and disposed above the front axle.

Referring now to FIG. 16, a second modular configuration of MIVT 715' is shown. As shown, the MIVT 715' may be substantially similar to the MIVT 715 of fig. 15, except that the second planetary gear set 722, associated gears, and fifth clutch 778 of fig. 15 may be omitted in the configuration of fig. 14. Thus, the embodiment of FIG. 16 does not provide the zero-power, co-generation capability of the MIVT 715 of FIG. 15. However, as explained above with respect to fig. 14, such a capability may not be necessary for some vehicles. Additionally, the MIVT 715' of fig. 16 may be more compact than the MIVT 715 of fig. 15. Thus, the MIVT 715' of fig. 16 may be used for a vehicle with certain spatial constraints.

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and/or "comprising," when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

The description of the present disclosure has been presented for purposes of illustration and description, but is not intended to be exhaustive or limited to the disclosure in the form disclosed. Many modifications and variations will be apparent to those of ordinary skill in the art without departing from the scope and spirit of the disclosure. The embodiments specifically referenced herein were chosen and described in order to best explain the principles of the disclosure and its practical application, and to enable others of ordinary skill in the art to understand the disclosure and identify alternatives, modifications, and variations to the described examples. Accordingly, various other implementations are within the scope of the following claims.

Claims (20)

1. A work vehicle, comprising:

an engine having an engine shaft;

a first infinitely variable power machine;

a second infinitely variable power machine;

an output shaft; and

an infinitely variable transmission having a plurality of transmission modes, the infinitely variable transmission configured to transfer power along different paths between the engine, the first infinitely variable power machine, the second infinitely variable power machine, and the output shaft in different ones of the plurality of transmission modes, the infinitely variable transmission comprising:

a plurality of clutches, each clutch configured to be engaged and alternately disengaged;

a double planetary gear set including a first transmission member, a second transmission member, and a third transmission member; and

a single planetary gear set including a fourth, fifth and sixth transmission member;

wherein in a first drive mode of the infinitely variable transmission, a first subset of the plurality of clutches is engaged allowing engine power to be transferred from the engine to the first drive component and infinitely variable power to be transferred between the second infinitely variable power machine and the second drive component;

wherein in the first transmission mode, the third transmission member combines the engine power and the infinitely variable power into a first combined power that is transmitted from the third transmission member to the fourth transmission member; and is

Wherein in the first transmission mode, the fifth transmission component transmits a return power to the engine shaft, and the sixth transmission component combines the first combined power and the return power into a second combined power, which is output to the output shaft to rotate the output shaft at a range of rotational speeds.

2. The work vehicle of claim 1, wherein the range of rotational speeds includes a non-zero rotational creep speed and a zero rotational speed that maintains torque at the output shaft; and is

Wherein in a second drive mode of the infinitely variable transmission, a second subset of the plurality of clutches is engaged allowing engine power to be transferred from the engine to one of the first, second, and third drive components and infinitely variable power to be transferred between another of the first, second, and third drive components and the second infinitely variable power machine;

wherein in the second transmission mode, the remaining of the first, second, and third transmission components combine the engine power and the infinitely variable power into a third combined power that is output to the output shaft; and is

Wherein in the second transmission mode, the third combined power bypasses the single planetary gear set and is output to the output shaft.

3. The work vehicle of claim 1, wherein said first infinitely variable power machine is a first electric machine, and wherein said second infinitely variable power machine is a second electric machine.

4. The work vehicle of claim 3, wherein said first electric machine has a generator mode and a motor mode;

wherein the first electric machine, when in the generator mode, is configured to generate electrical energy from mechanical energy input to the first electric machine;

wherein the second electric machine has a generator mode and a motor mode;

wherein the second electric machine, when in the generator mode, is configured to generate electrical energy from mechanical energy input to the second electric machine; and is

Wherein, in the first transmission mode of the infinitely variable transmission, the first and second electric machines are configured to be simultaneously in a generator mode to collectively generate electricity.

5. The work vehicle of claim 4, wherein said plurality of transmission modes of said infinitely variable transmission includes said first transmission mode and a second transmission mode;

wherein in the second transmission mode, the first electric machine is configured to be in the generator mode or the motor mode; and is

Wherein the second electric machine is configured to be in the motoring mode.

6. The work vehicle of claim 5, wherein said plurality of transmission modes of said infinitely variable transmission includes said first, second and third transmission modes; and is

Wherein in the third transmission mode, a second subset of the plurality of clutches is engaged allowing engine power to be transmitted from the engine to one of the first, second, and third transmission components and infinitely variable power to be transmitted between another of the first, second, and third transmission components and the second infinitely variable power machine;

wherein in the third transmission mode, the remaining of the first, second, and third transmission components combine the engine power and the infinitely variable power into a third combined power that is output to the output shaft; and is

Wherein in the third transmission mode, the third combined power bypasses the single planetary gear set and is output to the output shaft.

7. The work vehicle of claim 1, wherein said plurality of transmission modes of said infinitely variable transmission includes said first transmission mode and a second transmission mode;

wherein in the first transmission mode, the first transmission member is a first set of planet gears, the second transmission member is a first sun gear, and the third transmission member is a first ring gear engaged for rotation with a second set of planet gears of the double planetary gear set;

wherein in the second transmission mode, a second subset of the plurality of clutches is engaged allowing engine power to be transferred from the engine to the second ring gear of the double planetary gear set and allowing infinitely variable power to be transferred from the second electric machine to the second sun gear of the double planetary gear set; and is

Wherein in the second transmission mode, the second set of planet gears combines engine power and infinitely variable power into a first combined power that is output to the single set of planet gears.

8. The work vehicle of claim 7, wherein in the second transmission mode, the first combined power is output to a sun gear of the single planetary gear set;

wherein in the second transmission mode, the ring gear of the single planetary gear set outputs return power to the engine shaft; and is

Wherein, in the second transmission mode, a set of planet gears of the single set of planet gears combine the first combined power and the return power into a second combined power that is output to the output shaft.

9. The work vehicle of claim 1, wherein said fourth transmission member comprises a sun gear of said set of single planet gears;

wherein the fifth transmission member comprises a ring gear of the single planetary gear set;

wherein the sixth transmission member comprises a plurality of planet gears of the single set of planet gears, the plurality of planet gears being connected by a carrier; and is

Wherein in the first transmission mode, the carrier outputs the second combined power to the output shaft to maintain the torque at the output shaft when the rotation speed of the output shaft is substantially zero.

10. The work vehicle of claim 1, wherein the engine shaft is configured to rotate about an axis of rotation;

wherein the double planetary gear set has a central shaft; and is

Wherein the central axis and the rotational axis are coaxial.

11. The work vehicle of claim 1, wherein said first infinitely variable power machine is a first electric machine;

wherein the second infinitely variable power machine is a second electric machine;

the work vehicle further includes an implement electrically connected to at least one of the first electric machine and the second electric machine; and is

Wherein the implement is configured to receive power supplied by the at least one of the first electric machine and the second electric machine.

12. A work vehicle, comprising:

an engine having an engine shaft;

an infinitely variable power source having a first electric machine and a second electric machine;

an output shaft; and

an infinitely variable transmission having a plurality of transmission modes, the infinitely variable transmission configured to transmit power between the engine, the first electric machine, the second electric machine, and the output shaft along different paths in different ones of the plurality of transmission modes, the infinitely variable transmission comprising:

a plurality of clutches, each clutch configured to be engaged and alternately disengaged;

a first planetary gear set including a first transmission member, a second transmission member, and a third transmission member; and

a second planetary gear set including a fourth transmission member, a fifth transmission member, and a sixth transmission member;

wherein in a first transmission mode of the infinitely variable transmission, a first subset of the plurality of clutches is engaged allowing engine power to be transmitted from the engine to the first transmission component and infinitely variable power to be transmitted between the second electric machine and the second transmission component;

wherein in the first transmission mode, the third transmission member combines the engine power and the infinitely variable power into a first combined power that is transmitted from the third transmission member to the fourth transmission member;

wherein in the first transmission mode, the fifth transmission component transmits return power to the engine shaft;

wherein in the first transmission mode, the sixth transmission component combines the first combined power and the return power into a second combined power;

wherein the second combined power of the first transmission mode provides a range of rotational speeds for the output shaft;

wherein the first electric machine has a generator mode and a motor mode;

wherein the first electric machine, when in the generator mode, is configured to generate electrical energy from mechanical energy input to the first electric machine;

wherein the second electric machine has a generator mode and a motor mode;

wherein the second electric machine, when in the generator mode, is configured to generate electrical energy from mechanical energy input to the second electric machine; and is

Wherein, in the first transmission mode of the infinitely variable transmission, the first and second electric machines are configured to be simultaneously in a generator mode to collectively generate electricity.

13. The work vehicle of claim 12, wherein said range of rotational speeds includes a zero power speed; and is

Wherein the second combined power maintains torque at the output shaft at the zero-power speed.

14. The work vehicle of claim 12, wherein said first planetary gear set is a double planetary gear set; and is

Wherein the second planetary gear set is a single planetary gear set.

15. The work vehicle of claim 14, wherein said plurality of transmission modes of said infinitely variable transmission includes said first transmission mode and a second transmission mode;

wherein in the first transmission mode, the first transmission member is a first set of planet gears, the second transmission member is a first sun gear, and the third transmission member is a first ring gear engaged for rotation with a second set of planet gears of the first planetary gear set;

wherein in the second transmission mode, a second subset of the plurality of clutches is engaged allowing engine power to be transferred from the engine to the second ring gear of the first planetary gear set and allowing infinitely variable power to be transferred from the second electric machine to the second sun gear of the first planetary gear set; and is

Wherein in the second transmission mode, the second set of planetary gears combines engine power and infinitely variable power into a first combined power that is output to the second planetary gear set.

16. The work vehicle of claim 12, wherein said plurality of transmission modes of said infinitely variable transmission includes said first transmission mode and a second transmission mode;

wherein in the second transmission mode, the first electric machine is configured to be in the generator mode or the motor mode; and is

Wherein the second electric machine is configured to be in the motoring mode.

17. The work vehicle of claim 16, wherein said plurality of transmission modes of said infinitely variable transmission includes said first, second and third transmission modes; and is

Wherein in the third transmission mode, a second subset of the plurality of clutches is engaged allowing engine power to be transmitted from the engine to one of the first, second and third transmission members and infinitely variable power to be transmitted between the other of the first, second and third transmission members and the second electric machine;

wherein in the third transmission mode, the remaining of the first, second, and third transmission components combine the engine power and the infinitely variable power into a third combined power that is output to the output shaft; and is

Wherein in the third transmission mode, the third combined power bypasses the second planetary gear set and is output to the output shaft.

18. The work vehicle of claim 12, wherein said fourth transmission member comprises a sun gear of said second planetary gear set;

wherein the fifth gear member comprises the ring gear of the second planetary gear set;

wherein the sixth transmission member comprises a plurality of planet gears of the second planetary gear set, the plurality of planet gears being connected by a carrier; and is

Wherein in the first transmission mode, the carrier outputs the second combined power to the output shaft.

19. The work vehicle of claim 12, wherein the engine shaft is configured to rotate about an axis of rotation;

wherein the first planetary gear set has a central shaft; and is

Wherein the central axis and the rotational axis are coaxial.

20. The work vehicle of claim 12, further comprising an implement electrically connected to at least one of said first electric machine and said second electric machine.

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