CN106555855B

CN106555855B - Differential mechanism, power transmission system and vehicle

Info

Publication number: CN106555855B
Application number: CN201510624687.0A
Authority: CN
Inventors: 杨冬生; 廉玉波; 张金涛; 罗红斌
Original assignee: BYD Co Ltd
Current assignee: BYD Co Ltd
Priority date: 2015-09-25
Filing date: 2015-09-25
Publication date: 2020-05-22
Anticipated expiration: 2035-09-25
Also published as: CN106555855A

Abstract

The invention discloses a differential, a power train and a vehicle. The differential mechanism consists of a first planet carrier, a first planet wheel, a first gear ring, a second planet carrier, a second planet wheel, a second gear ring and an input part, wherein the first planet wheel is arranged on the first planet carrier, the first planet wheel is meshed with the first gear ring, the second planet wheel is arranged on the second planet carrier, the second planet wheel is meshed with the second gear ring and is also meshed with the first planet wheel, and the first gear ring and the second gear ring form two power output ends of the differential mechanism; the input part, first planet carrier and second planet carrier coaxial arrangement and input part and first planet carrier and second planet carrier linkage. The differential mechanism utilizes the planetary differential principle, has higher space utilization rate and smaller axial size in the structure and connection form, and has more advantages in production and assembly.

Description

Differential mechanism, power transmission system and vehicle

Technical Field

The invention relates to a differential, a power transmission system with the differential and a vehicle with the power transmission system.

Background

In one of the differential technologies known to the inventor, the differential includes a driven gear of a main reducer (main reducer driven gear), a planetary gear, a central wheel, etc., the planetary gear is mounted on an auxiliary plate of the driven gear through a square shaft and a shaft sleeve and is meshed with the central wheel, the rotating and moving functions of the planetary gear are realized by a rotating pair and a plane moving pair, and the central wheel is connected with a left half shaft and a right half shaft through an angular positioning pin and a cylindrical pair or a spline, so as to achieve the purpose of outputting torque. The differential eliminates the original components such as left and right shells, planetary gear shafts and the like of the differential, and directly installs the planetary gear on the auxiliary plate of the driven gear of the main reducer by using a square shaft and a shaft sleeve, thereby effectively reducing the number of parts of the differential, simplifying the structure and lightening the weight.

However, the differential mechanism utilizes a symmetrical bevel gear structure to realize inter-wheel differential, is only a partial innovation of the traditional symmetrical bevel gear differential mechanism, and cannot really solve the defects of overlarge axial size, large mass of a shell and a bevel gear and relative reliability deviation of the differential mechanism.

Disclosure of Invention

The present invention is directed to solving, at least to some extent, one of the above-mentioned problems in the prior art.

Therefore, the invention provides a differential mechanism which realizes a differential function by utilizing a planetary differential principle and has a compact and simple structure.

The invention also provides a power transmission system with the differential mechanism.

The invention also provides a vehicle with the power transmission system.

The differential mechanism comprises a first planet carrier, a first planet wheel, a first gear ring, a second planet carrier, a second planet wheel, a second gear ring and an input part, wherein the first planet wheel is connected with the first planet carrier, the first planet wheel is meshed with the first gear ring, the second planet wheel is connected with the second planet carrier, the second planet wheel is meshed with the second gear ring, the second planet wheel is further meshed with the first planet wheel, the first gear ring and the second gear ring form two power output ends of the differential mechanism, the input part, the first planet carrier and the second planet carrier are coaxially arranged, and the input part is respectively linked with the first planet carrier and the second planet carrier.

The differential mechanism according to the embodiment of the invention utilizes the planetary differential principle, has higher space utilization rate in structure and connection form, has smaller axial size, and has more advantages in production and assembly.

In addition, the differential mechanism according to the embodiment of the invention can also have the following additional technical characteristics:

according to some embodiments of the invention, the first planet wheel partially overlaps the second planet wheel in the axial direction.

According to some embodiments of the invention, the first planet comprises: a first tooth and a second tooth, the second planet comprising: the first tooth part is meshed with the first gear ring, the second tooth part and the third tooth part are correspondingly overlapped and meshed in the axial direction, and the fourth tooth part is meshed with the second gear ring.

According to some embodiments of the invention, the first planet wheels are a plurality of and circumferentially spaced apart, the second planet wheels are a plurality of and circumferentially spaced apart, and the plurality of first planet wheels and the plurality of second planet wheels are respectively and correspondingly meshed.

According to some embodiments of the invention, the first planet gear and the second planet gear are both cylindrical gears.

According to some embodiments of the invention, the first ring gear and the second ring gear are symmetrically arranged.

According to some embodiments of the invention, each of the first ring gear and the second ring gear comprises:

the gear box comprises a main body flat plate part and an annular side wall part arranged on the outer periphery of the main body flat plate part, wherein a plurality of teeth are arranged on the inner wall surface of the annular side wall part, a cavity is defined between the main body flat plate part and the annular side wall part, and the cavity of the first gear ring and the cavity of the second gear ring face each other to form an installation space.

According to some embodiments of the invention, the first planet carrier and the first planet wheel and the second planet carrier and the second planet wheel are received in the mounting space.

According to some embodiments of the invention, the input is configured as an input gear.

According to some embodiments of the invention, the input gear is configured as a ring and is fitted over the outer surfaces of the first and second ring gears.

According to some embodiments of the invention, a gap is provided between the first ring gear and the second ring gear, the input gear surrounding and covering the gap.

According to some embodiments of the invention, the input gear is a final drive driven gear.

According to some embodiments of the invention, the first planet carrier has a first connecting carrier, the second planet carrier has a second connecting carrier, the first connecting carrier is for connecting the first planet carrier with the input, the second connecting carrier is for connecting the second planet carrier with the input, wherein each of the first connecting carrier and the second connecting carrier comprises:

the extension arm parts are arranged on the outer peripheral surface of the central body part, are radially distributed by taking the central body part as the center, and are used for being connected with the input part.

According to some embodiments of the invention, each set of the first planet wheel and the second planet wheel that mesh correspondingly is located between two adjacent extension arm portions.

According to some embodiments of the invention each of said first planet wheels has a first planet wheel axle, both ends of said first planet wheel axle being connected to said first planet carrier and said second planet carrier, respectively, and each of said second planet wheels has a second planet wheel axle, both ends of said second planet wheel axle being connected to said first planet carrier and said second planet carrier, respectively.

According to some embodiments of the invention, the first planet gear has a revolution radius that is the same as a revolution radius of the second planet gear.

According to some embodiments of the invention, the first planet carrier and the second planet carrier are each configured as a circular plate-like structure, and the first planet carrier and the second planet carrier are of a split-type structure.

According to some embodiments of the invention, the first planet wheel has a first axis of revolution that is coincident with the second axis of revolution of the first planet wheel.

The power transmission system comprises the differential mechanism.

A vehicle according to an embodiment of the invention includes the power transmission system described above.

Drawings

FIG. 1 is an exploded view of a differential according to an embodiment of the present invention;

FIG. 2 is an exploded view from another perspective of a differential according to an embodiment of the present invention;

FIG. 3 is a perspective view of a differential according to an embodiment of the present invention;

FIG. 4 is a schematic plan view of a differential according to an embodiment of the present invention;

fig. 5 is a perspective view of the differential according to the embodiment of the invention, in which the second carrier and the second ring gear, etc. are not shown;

FIG. 6 is a schematic of the engagement of a first planet and a second planet;

fig. 7 is a schematic view of the meshing principle of the first planet wheel and the second planet wheel;

FIG. 8 is a perspective view of the first gear ring or the second gear ring according to yet another embodiment of the present invention;

FIG. 9 is a perspective view of the first ring gear or the second ring gear according to yet another embodiment of the present invention;

FIG. 10 is a schematic representation of a powertrain according to an embodiment of the present invention;

FIG. 11 is a schematic illustration of a vehicle according to an embodiment of the present invention.

Detailed Description

Reference will now be made in detail to embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to the same or similar elements or elements having the same or similar function throughout. The embodiments described below with reference to the drawings are illustrative and intended to be illustrative of the invention and are not to be construed as limiting the invention.

In the description of the present invention, it is to be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used only for convenience of description and simplicity of description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be considered as limiting the present invention.

Furthermore, the terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In the present invention, unless otherwise expressly stated or limited, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can, for example, be fixedly connected, detachably connected, or integrally formed; can be mechanically connected, electrically connected or can communicate with each other; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

In the present invention, unless otherwise expressly stated or limited, "above" or "below" a first feature means that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact with each other via another feature therebetween. Also, the first feature being "on," "above" and "over" the second feature includes the first feature being directly on and obliquely above the second feature, or merely indicating that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature includes the first feature being directly under and obliquely below the second feature, or simply meaning that the first feature is at a lesser elevation than the second feature.

The differential 100 according to the embodiment of the present invention will be described in detail with reference to fig. 1 to 7, wherein the differential 100 can be used for an inter-wheel differential speed or an inter-axle differential speed, for example, the inter-wheel differential speed, and the differential 100 can enable left and right driving wheels to roll at different angular velocities when the vehicle is running in a curve or on an uneven road surface, so as to ensure that the driving wheels on both sides make a pure rolling motion with the ground.

As shown in fig. 1, a differential 100 according to an embodiment of the present invention is composed of an input portion 3, a first carrier 11, first planet gears 12, and a first ring gear 13, and a second carrier 21, second planet gears 22, and a second ring gear 23.

In conjunction with the embodiments of fig. 1 and 2, each of the first carrier 11 and the second carrier 21 may be configured as a circular plate-like structure, which may reduce the axial dimension of the differential 100 to some extent. In some embodiments, the first planet carrier 11 and the second planet carrier 21 may be a split structure, and since a single small component is relatively easy to form, the separate machining of the first planet carrier 11 and the second planet carrier 21 may simplify the manufacturing process and improve the machining precision.

As shown in fig. 1 to 2 in conjunction with fig. 6, the first planetary gears 12 are arranged on the first carrier 11, for example, each first planetary gear 12 has a first planetary gear shaft 14, both ends of the first planetary gear shaft 14 are rotatably supported on the first carrier 11 and the second carrier 21, respectively, for example, both ends of the first planetary gear shaft 14 can be rotatably supported in corresponding shaft holes of the first carrier 11 and the second carrier 21 by bearings, and the first planetary gears 12 can be fixed on the corresponding first planetary gear shafts 14. Of course, both ends of the first planet carrier shaft 14 and the first planet carrier 11 and the second planet carrier 21 may also be fixedly connected, for example, both ends of the first planet carrier shaft 14 are respectively welded and fixed with the corresponding shaft holes of the first planet carrier 11 and the second planet carrier 21, at this time, the first planet gears 12 are rotatably sleeved on the corresponding first planet carrier shaft 14, for example, the first planet gears 12 can be rotatably sleeved on the first planet carrier shaft 14 through bearings. Thus, the first planet carrier 11 and the second planet carrier 21 can be connected through the first planet carrier shaft 14, so that the first planet carrier 11 and the second planet carrier 21 keep moving at the same speed and in the same direction (namely, the first planet carrier 11 and the second planet carrier 21 are linked), and in the connection mode, the first planet carrier 11 and the second planet carrier 21 can well support/fix the first planet carrier shaft 14, and the first planet carrier shaft 14 is prevented from being disconnected from a single planet carrier, so that the differential 100 fails. Referring to fig. 1 and 2, the first planetary gears 12 are engaged with the first ring gear 13, and may be embodied in an inner-meshing manner, that is, the first planetary gears 12 are located inside the first ring gear 13 and are meshed with teeth on the first ring gear 13. The first planetary gears 12 are preferably plural and equally spaced in the circumferential direction inside the first ring gear 13, for example, as a preferred embodiment, the number of the first planetary gears 12 may be three, and any two adjacent first planetary gears 12 are spaced apart by an angle of 120 °.

As shown in fig. 1-2 and in conjunction with fig. 6, the second planetary gears 22 are arranged on the second planetary gear carrier 21, for example, each second planetary gear 22 has a second planetary gear shaft 24, for example, both ends of the second planetary gear shaft 24 can be rotatably supported by bearings in the shaft holes of the first planetary gear carrier 11 and the second planetary gear carrier 21 corresponding to each other, and the second planetary gears 22 can be fixed on the corresponding second planetary gear shafts 24. Of course, both ends of the second planetary gear shaft 24 and the first and second

planetary gear carriers

11 and 21 may also be fixedly connected, for example, both ends of the second planetary gear shaft 24 are respectively welded and fixed with the corresponding shaft holes of the first and second

planetary gear carriers

11 and 21, at this time, the second planetary gear 22 is rotatably sleeved on the corresponding second planetary gear shaft 24, for example, the second planetary gear 22 may be rotatably sleeved on the second planetary gear shaft 24 through a bearing. Therefore, the purpose of connecting the first planet carrier 11 and the second planet carrier 21 can be achieved through the second planet carrier shaft 24, so that the first planet carrier 11 and the second planet carrier 21 keep moving at the same speed and in the same direction, and by adopting the connection mode, the first planet carrier 11 and the second planet carrier 21 can well support/fix the second planet carrier shaft 24, and the second planet carrier shaft 24 is prevented from being disconnected with a single planet carrier to cause the failure of the differential 100.

Furthermore, in other embodiments of the present invention, in order to keep the first planet carrier 11 and the second planet carrier 21 capable of moving at the same speed and in the same direction, not only the above-mentioned manner of connecting the first planet carrier 11 and the second planet carrier 21 through the first planet shaft 14 and/or the second planet shaft 24 can be adopted, but also the first planet carrier 11 and the second planet carrier 21 can be directly fixedly connected through the intermediate connection structure 6, or the planet shafts and the intermediate connection structure 6 can be adopted to connect the first planet carrier 11 and the second planet carrier 21, and the specific configuration of the intermediate connection structure 6 will be described in detail below.

Referring to fig. 1 and 2, the second planetary gear 22 is meshed with the second ring gear 23, and may be in an inner meshing manner, that is, the second planetary gear 22 is located inside the second ring gear 23 and is meshed with teeth on the second ring gear 23. The second planetary gears 22 are preferably plural and equally spaced in the circumferential direction inside the second ring gear 23, for example, as a preferred embodiment, the number of the second planetary gears 22 may be three, and any two adjacent second planetary gears 22 are spaced by an angle of 120 °.

It should be noted that fig. 4 is a schematic plan view of a differential 100 according to an embodiment of the present invention, in which the meshing relationship between the first planetary gear 12 and the second planetary gear 22 and the meshing relationship between the first planetary gear 12 and the first ring gear 13 and between the second planetary gear 22 and the second ring gear 23 are schematically shown, and since fig. 4 is a plan view and the three meshing relationships are shown at the same time, the relative positional relationship among the components is only schematic and does not show or imply the actual spatial arrangement positions of the components.

In the embodiment where the first planetary gear 12 and the second planetary gear 22 are both plural, it is preferable that the plural first planetary gears 12 and the plural second planetary gears 22 are respectively engaged correspondingly. For example, as shown in fig. 1, 2 and 5, if the first planet wheel 12 and the second planet wheel 22 are three, the first planet wheel 12 can be meshed with the corresponding first second planet wheel 22, the second first planet wheel 12 can be meshed with the corresponding second planet wheel 22, and the third first planet wheel 12 can be meshed with the corresponding third second planet wheel 22, so that there are multiple sets of first planet wheels 12 and second planet wheels 22 meshed with each other, and when the differential 100 transmits power, the power is transmitted between the multiple sets of first planet wheels 12 and second planet wheels 22 meshed with each other more stably and reliably.

In this regard, referring to the embodiment of fig. 4, the revolution axis O of the first planet wheel 12 coincides with the revolution axis O of the second planet wheel 22, and the revolution radii of the first planet wheel 12 and the second planet wheel 22 (i.e., the distances of the central axes of the planet wheels from the revolution axis O) are the same.

In particular, as shown in fig. 1-2, 4-7, the first planet gears 12 are in meshing engagement with the second planet gears 22. In other words, for the first planet wheel 12, it meshes not only with the first ring gear 13, but also with the second planet wheel 22, and for the second planet wheel 22, it meshes not only with the second ring gear 23, but also with the first planet wheel 12.

As shown in fig. 1-4, the first ring gear 13 and the second ring gear 23 may form two power output ends of the differential 100, and the first planet carrier 11 and the second planet carrier 21 correspond to power input ends of the differential 100, for example, in one embodiment of the present invention, the first planet carrier 11 and the second planet carrier 21 are linked with the input part 3, in other words, the motion states of the input part 3, the first planet carrier 11 and the second planet carrier 21 are the same (i.e., the same speed and the same direction). As a preferred embodiment, the input 3, the first carrier 11 and the second carrier 21 are arranged coaxially. Thus, the power output from the external power source can be input from the input portion 3, and can be output from the first ring gear 13 and the second ring gear 23, respectively, after the differential action of the differential 100. At this time, as an alternative embodiment, the input portion 3 may be connected to a power source such as an engine, a motor, etc., and the first and second ring gears 13 and 23 may be connected to the corresponding half shafts, which are in turn connected to the corresponding wheels, through a gear transmission structure, but is not limited thereto.

The operation of the differential 100 will be briefly described by taking the differential 100 as an example of the inter-wheel differential, in which the first gear 13 may be connected to a left half shaft via a gear transmission structure, the left half shaft may be connected to a left wheel, the second gear 23 may be connected to a right half shaft via a gear transmission structure, the right half shaft may be connected to a right wheel, the power output from a power source such as an engine and/or a motor may be output to the input portion 3 via the speed reduction effect of a main speed reducer, and the input portion 3 drives the first planet carrier 11 and the second planet carrier 21 to rotate synchronously. If the vehicle runs on a flat road surface and does not turn, the left wheel and the right wheel theoretically rotate at the same speed, the differential mechanism 100 does not play a role in differential speed at the moment, the first planet carrier 11 and the second planet carrier 21 rotate at the same speed and in the same direction, the first gear ring 13 and the second gear ring 23 rotate at the same speed and in the same direction, and the first planet wheel 12 and the second planet wheel 22 only revolve and do not rotate. If the vehicle runs on an uneven road or turns, the left wheel and the right wheel theoretically have different rotating speeds, the rotating speeds of the first gear ring 13 and the second gear ring 23 are also different, namely, a rotating speed difference exists, at the moment, the first planet wheel 12 and the second planet wheel 22 rotate while revolving, the rotation of the first planet wheel 12 and the second planet wheel 22 can accelerate one of the first gear ring 13 and the second gear ring 23 and decelerate the other one of the first gear ring and the second gear ring 23, and the rotating speed difference between the accelerated gear ring and the decelerated gear ring is the rotating speed difference between the left wheel and the right wheel, so that the differential action is realized.

In summary, the differential 100 according to the embodiment of the present invention utilizes the planetary differential principle, and has higher space utilization rate, smaller axial dimension, and more advantages in terms of production and assembly in terms of structure and connection form. Such structural style not only can avoid the axial and radial size defects of the bevel gear, but also can better utilize the hollow space inside the driving and driven gear, thereby realizing better space utilization rate, greatly facilitating the whole vehicle arrangement of the differential mechanism 100 assembly and the limitation of the weight, and simultaneously having higher reliability and better transmission efficiency, being beneficial to improving the reliability of a power transmission chain and the power output fluency during the bending, and having higher practicability compared with the symmetrical bevel gear differential mechanism.

The meshing relationship of the first planetary gear 12 and the second planetary gear 22 will be described in detail below with reference to specific embodiments.

Referring to fig. 1-2 in conjunction with fig. 6-7, the first planet gear 12 and the second planet gear 22 partially overlap in the axial direction (left-right direction in fig. 6-7), that is, the first planet gear 12 and the second planet gear 22 only partially overlap, and the other parts are offset, so that the overlapping parts of the first planet gear 12 and the second planet gear 22 can mesh with each other, and the offset parts can mesh with the respective ring gears.

Specifically, as shown in fig. 6 and 7, the first planet gear 12 may include a first tooth portion 151 and a second tooth portion 152 (with a dashed line K2 in fig. 7 as a boundary line), the second planet gear 22 may include a third tooth portion 153 and a fourth tooth portion 154 (with a dashed line K1 in fig. 7 as a boundary line), the second tooth portion 152 and the third tooth portion 153 form an overlapping portion, that is, the second tooth portion 152 and the third tooth portion 153 are axially overlapped and meshed with each other, the first tooth portion 151 and the fourth tooth portion 154 are axially offset and meshed with the respective corresponding ring gears, that is, the first tooth portion 151 is meshed with the first ring gear 13, and the fourth tooth portion 154 is meshed with the second ring gear 23.

Therefore, the axial size of the differential 100 is more compact, and the volume of the differential 100 is smaller, which is beneficial to the installation and arrangement of the differential 100.

According to some embodiments of the invention, the number of teeth of the first ring gear 13 is equal to the number of teeth of the second ring gear 23, and the number of teeth of the first planet gear 12 is equal to the number of teeth of the second planet gear 22.

According to some embodiments of the present invention, the first planet gears 12 and the second planet gears 22 are cylindrical gears, and the differential 100 using cylindrical gears is more compact than a conventional symmetrical bevel gear differential, and in particular, has a higher space utilization rate in structure and connection form, a smaller axial size, and is more advantageous in production and assembly.

The structure of the first ring gear 13 and the second ring gear 23 will be described in detail below with reference to specific embodiments.

In some embodiments of the present invention, the first gear ring 13 and the second gear ring 23 are of a symmetrical structure, in other words, the first gear ring 13 and the second gear ring 23 are symmetrically arranged, which can increase the versatility of the gear rings and reduce the cost.

Specifically, as shown in fig. 1 to 2, each of the first ring gear 13 and the second ring gear 23 includes: the main body flat plate portion 161 and the annular side wall portion 162 provided at the outer peripheral edge of the main body flat plate portion 161 may be integrally molded components. A plurality of gear teeth are provided on the inner wall surface of the annular side wall portion 162, cavities a1, a2 are defined between the main body flat plate portion 161 and the annular side wall portion 162, that is, a cavity a1 is defined between the main body flat plate portion 161 and the annular side wall portion 162 of the first ring gear 13, a cavity a2 is defined between the main body flat plate portion 161 and the annular side wall portion 162 of the second ring gear 23 (see fig. 4), the cavity a1 in the first ring gear 13 and the cavity a2 in the second ring gear 23 face each other to constitute an installation space a (see fig. 4), wherein the first planet carrier 11 and the first planet wheels 12 and the second planet carrier 21 and the second planet wheels 22 are received in the installation space a, this allows the differential 100 to be relatively more compact, occupy less space, be easier to deploy, meanwhile, the first gear ring 13 and the second gear ring 23 serve as the outer shell, a planet carrier and a planet gear which are contained in the outer shell can be protected, and the service life is prolonged. In addition, the installation space a defined by the first gear ring 13 and the second gear ring 23 is relatively closed, and external impurities are not easy to enter the installation space a to influence moving parts, so that the stable operation of the differential 100 is ensured.

The specific configuration of the input section 3 is described in detail below with reference to specific embodiments.

According to some embodiments of the invention, the input 3 is configured as an input gear. Further, as shown in fig. 1 to 3, the input gear 3 is configured in a ring shape (the teeth of the input gear 3 are formed on the outer peripheral surface) and is fitted over the outer surfaces of the first ring gear 13 and the second ring gear 23, and it is understood that the inner diameter of the input gear 3 may be sized larger than the outer diameters of the first ring gear 13 and the second ring gear 23, so that the components inside the two ring gears are not exposed by fitting the input gear 3 over the outside of the first ring gear 13 and the second ring gear 23, thereby protecting the components inside the ring gears.

As shown in fig. 4, the first ring gear 13 and the second ring gear 23 are provided with a gap D in the axial direction, that is, the first ring gear 13 and the second ring gear 23 are spaced apart from each other in the axial direction and do not closely adhere to each other. Since the width of the meshing portion of the first planetary gear 12 and the second planetary gear 22 determines the size of the gap D to some extent (in addition, the thickness of the extension arm 63 may also determine the gap D, which will be described below, and it is first described that the width of the meshing portion of the two planetary gears 22 determines the gap D), that is, the width of the meshing portion of the first planetary gear 12 and the second planetary gear 22 may be equal to the minimum value of the gap D, the size of the gap D may be indirectly controlled by controlling the width of the meshing portion of the first planetary gear 12 and the second planetary gear 22, and for those skilled in the art, the width of the meshing portion of the first planetary gear 12 and the second planetary gear 22 may be set relatively narrow on the premise of ensuring stable power transmission of the first planetary gear 12 and the second planetary gear 22 and the service life of the first planetary gear 12 and the second planetary gear 22, this effectively reduces the clearance D, resulting in a smaller, more compact axial dimension of the differential 100, and easier layout.

Further, the input gear 3 surrounds and covers the gap D. Therefore, the installation space A is better in sealing performance, external sundries are more difficult to enter the installation space A to influence moving parts, stable operation of the differential mechanism 100 is further guaranteed, and meanwhile the axial space and the radial space of the differential mechanism can be saved at least to a certain extent.

In a preferred embodiment, the input gear 3 is a final drive driven gear. Therefore, the hollow space in the driving reduction driven gear can be better utilized, the better space utilization rate is realized, and the whole vehicle arrangement and the limitation on the weight of the differential mechanism 100 assembly are greatly facilitated.

Note that the gap D in fig. 4 (see fig. 1 to 2) refers to a distance between the annular side wall portion 162 of the first ring gear 13 and the annular side wall portion 162 of the second ring gear 23. For example, referring to the embodiment of fig. 1, 2, and 4, the first and second ring gears 13 and 23 each include a main body flat plate portion 161 and an annular side wall portion 162.

While in other embodiments of the present invention, as in the embodiment with reference to fig. 8 and 9, each of the first and second ring gears 13 and 23 further includes an annular flange portion 163, the annular flange portion 163 extending from an end surface of the annular side wall portion 162 in a direction away from the main plate portion 161, in the embodiment of fig. 8, an inner diameter of the annular flange portion 163 may be substantially equal to an outer diameter of the annular side wall portion 162, so that the annular flange portion 163 corresponds to protruding the annular side wall portion 162 (i.e., the outer peripheral surface of the first or second ring gear 13 or 23) outward in the radial direction. In the embodiment of fig. 9, the outer diameter of the annular flange portion 163 may be substantially equal to the outer diameter of the annular side wall portion 162, and the inner diameter of the annular flange portion 163 may be larger than the inner diameter of the annular side wall portion 162, i.e., the thickness of the annular flange portion 163 is thinner than the thickness of the annular side wall portion 162.

However, in the ring gear structure of the embodiment shown in fig. 1, 2 and 4, the gap D between the two ring gears refers to the gap between the annular side wall portions 162 of the two ring gears. In the ring gear structure in the embodiment of fig. 8 and 9, the gap D between the two ring gears refers to the gap between the annular flange portions 163 of the two ring gears.

For this clearance D, it is mentioned above that the meshing width of the two planetary gears may determine the size of the clearance D to some extent, and at the same time, the thickness of the extension arm 63 also determines the size of the clearance D to some extent. Specifically, when the meshing width of the two planetary gears is equal to the thickness of the extension arm portion 63, the size of the gap D may be substantially equal to the meshing width of the two planetary gears or the thickness of the extension arm portion 63. When the thickness of the extension arm portion 63 is larger than the meshing width of the two planetary gears, the size of the gap D may be substantially equal to the thickness of the extension arm portion 63. When the thickness of the extension arm portion 63 is smaller than the meshing width of the two planetary gears, the size of the gap D may be substantially equal to the meshing width of the two planetary gears.

The intermediate connection structure 6 will be described in detail below with reference to specific examples.

As shown in fig. 1 and 2, the intermediate connection structure 6 functions to connect the first and

second carriers

11 and 21 to the input portion 3 so that the first and

second carriers

11 and 21 and the input portion 3 can be coaxially linked. The intermediate connection structure 6 may be fixedly connected to the first carrier 11 and the second carrier 21, respectively, and the input unit 3 may be fixed to an outer surface of the intermediate connection structure 6, so that the first carrier 11 and the second carrier 21 can be coaxially interlocked with the input unit 3.

The present invention provides a possible embodiment for the specific configuration of the intermediate connection structure 6, which of course does not represent or imply that the intermediate connection structure 6 of the present invention can only adopt the configuration of this embodiment. That is, the intermediate connecting structure 6 to be described in the following embodiments is only a possible embodiment and does not limit the scope of the present invention.

Specifically, referring to fig. 1 and 2, the input portion 3 in this embodiment is an annular input gear 3, the first planet carrier 11 has a first connecting bracket 61 and the second planet carrier 21 has a second connecting bracket 62, the first connecting bracket 61 is used for connecting the first planet carrier 11 with the input portion 3 (i.e., the input gear 3), the second connecting bracket 62 is used for connecting the second planet carrier 21 with the input portion 3 (i.e., the input gear 3), wherein the first connecting bracket 61 and the second connecting bracket 62 may have the same structure and each may include: a central body portion 64 and an extension arm portion 63 (see fig. 5), wherein the central body portion of the first connecting bracket 61 and the central body portion of the second connecting bracket 62 may be integrally formed to form a common central body portion 64, but not limited thereto.

As shown in fig. 5, the plurality of extension arm portions 63 are provided on the outer peripheral surface of the central body portion 64, and the plurality of extension arm portions 63 and the central body portion 64 may be an integral structure, but are not limited thereto. The plurality of extension arm portions 63 are distributed substantially radially about the central body portion 64, and in the example of fig. 5, the extension arm portions 63 are distributed at equal intervals in three numbers. The extension arm portion 63 is for connection with the input portion 3, and specifically, an outer end of the extension arm portion 63 may extend to and be fixed to an inner peripheral surface of the input portion 3, such as an annular final drive driven gear.

Each set of the corresponding engaged first planetary gear 12 and second planetary gear 22 is located between two adjacent extension arm portions 63, as in the example of fig. 5, there are three extension arm portions 63, and the three extension arm portions 63 define three accommodating cavities (each two adjacent extension arm portions 63 define an accommodating cavity with the inner peripheral surface of the input gear 3), and a pair of engaged first planetary gear 12 and second planetary gear 22 can be disposed in each accommodating cavity, so that the overall structure of the differential 100 is more compact, and the center of gravity of the differential 100 is closer to or located at the center position, which greatly improves the unstable operation, the short service life and the like of the differential 100 caused by the eccentricity or the large eccentricity when the differential 100 operates at high speed.

In a further embodiment, as shown in fig. 3 and 4, the first ring gear 13 may be coaxially connected with a first output shaft 41, and the second ring gear 23 may be coaxially connected with a second output shaft 42. As shown in fig. 2 and 4, while the first carrier 11 is coaxially connected with the first carrier shaft 111, the second carrier 21 is coaxially connected with the second carrier shaft 211, the first output shaft 41 may be a hollow shaft and may be coaxially sleeved on the first carrier shaft 111, and the second output shaft 42 may also be a hollow shaft and may be coaxially sleeved on the second carrier shaft 211. The first planet carrier shaft 111 is fixed coaxially with the central body 64 of the first connecting carrier 61, and the second planet carrier shaft 211 is fixed coaxially with the central body 64 of the second connecting carrier 62, but is not limited thereto.

Further, as an alternative embodiment, the radial dimensions of the first ring gear 13 and the second ring gear 23 are the same, and each of the first ring gear 13 and the second ring gear 23 may be an integrally molded component.

In addition, for the technical solutions and/or technical features described in the above embodiments, those skilled in the art can combine the technical solutions and/or technical features in the above embodiments without conflict or contradiction, and the combined technical solution may be a superposition of two or more technical solutions, a superposition of two or more technical features, or a superposition of two or more technical solutions and technical features, so that functional interaction and support of each technical solution and/or technical feature with each other can be achieved, and the combined solution has a more superior technical effect.

For example, a person skilled in the art may combine the solution of the first planet gear 12 partially overlapping the second planet gear 22 with the solution of the first planet carrier 11 and the second planet carrier 21 having the plate-like structure, which may effectively reduce the axial size of the differential 100, thereby making the differential 100 smaller in size.

For another example, a person skilled in the art may combine the scheme that the first planet wheel 12 and the second planet wheel 22 partially overlap with the scheme that the planet wheel and the planet carrier are accommodated in the installation space, so that not only the axial size of the differential 100 may be effectively reduced, but also the planet wheel and the planet carrier are hidden in the installation space and prevented from being exposed and damaged, thereby increasing the service life and reducing the maintenance cost.

For another example, a person skilled in the art may combine a scheme in which the revolution axis of the first planet wheel 12 coincides with the revolution axis of the second planet wheel 22 with a scheme in which the revolution radius of the first planet wheel 12 is the same as the revolution radius of the second planet wheel 22, so that the differential 100 has a more compact structure, a smaller occupied volume, and a more convenient arrangement.

For another example, a person skilled in the art may combine a scheme in which the input portion 3 is configured as an annular input gear and is sleeved on the outer peripheral surfaces of the first gear ring 13 and the second gear ring 23 with a scheme in which the input gear 3 is a main reducer driven gear, so that the differential 100 can better utilize the hollow space inside the main reducer driven gear, thereby achieving better space utilization, greatly facilitating the entire vehicle layout of the differential assembly and the restriction on the weight size, and by directly setting the input portion 3 as the annular main reducer driven gear, the main reducer driven gear is not required to be set separately, thereby not only reducing the parts of the entire power drive system and reducing the cost, but also making the structure of the differential 100 more compact and small.

For another example, a person skilled in the art may configure the input portion 3 as a combination of a ring-shaped input gear and a scheme that the input gear 3 surrounds and covers the gap, so that on one hand, the structure of the differential 100 is relatively compact, and the gap is covered by the input gear 3, and the installation space defined by the shells of the two planetary gear trains is relatively more closed, so as to sufficiently protect the components inside the installation space and prolong the service life of the components.

It should be understood, of course, that the above descriptions of examples are only illustrative, and those skilled in the art can freely combine technical solutions and/or combinations of technical features without conflict, and the combined solutions have more advantageous technical effects.

In addition, it is understood that the combined technical solutions also fall into the protection scope of the present invention.

Overall, the differential 100 according to the embodiment of the present invention can effectively save space and reduce weight, and particularly, such a planetary gear type differential 100 can reduce the weight by about 30% and the axial dimension by about 70% as compared with the conventional bevel gear type differential, not only can reduce the friction of the bearings, but also can realize the torque distribution of the left wheel and the right wheel, so that the load distribution of the differential mechanism 100 is more reasonable, the rigidity of the differential mechanism 100 is better, in addition, the transmission efficiency is also improved to a certain extent due to the adoption of the cylindrical gear, for example, the efficiency of the conventional bevel gear transmission with 6-grade precision and 7-grade precision is about 0.97-0.98, and the transmission efficiency of the cylindrical gears with 6-level precision and 7-level precision is about 0.98-0.99, and in addition, the cylindrical gears are adopted, so that the working noise of the differential mechanism 100 is reduced, the heat productivity is reduced, and the service life of the differential mechanism 100 is greatly prolonged. In short, the differential 100 according to the embodiment of the present invention has many advantages of light weight, small size, low cost, high transmission efficiency, low noise, low heat generation, long service life, and the like.

Meanwhile, since the differential 100 according to an embodiment of the present invention may omit a sun gear, the omission of the sun gear may have the following advantages:

from mechanical analysis, the differential is realized by eliminating the sun gear and utilizing the gear ring, because the number of teeth of the gear ring is more than that of the sun gear, and the pitch circle is larger (the pitch circle refers to a pair of circles tangent at the node when the gears are in meshing transmission), so that the load and bearing torque can be more evenly distributed, which is beneficial to prolonging the service life of the differential 100. Meanwhile, the differential mechanism 100 can be better lubricated and cooled due to the fact that the sun wheel is not arranged, namely, a cavity can be formed inside the planetary wheel due to the fact that the sun wheel is omitted, the gear ring and the planetary wheel are meshed in an inner meshing relation (the sun wheel and the planetary wheel are meshed outside), lubricating oil can be stored in the gear ring, and therefore cooling and lubricating effects can be greatly improved. In addition, since the sun gear is eliminated, the number of parts is reduced, the mass and cost of the differential 100 are reduced, and the differential 100 becomes more compact and lighter.

A power transmission system 1000 according to an embodiment of the present invention, which power transmission system 1000 includes the differential 100 in the above-described embodiment, will be briefly described below. Referring to fig. 10, the power transmission system 1000 includes a differential 100, a transmission 200, and a power source 300, wherein power output from the power source 300 is output to the differential 100 through a speed change function of the transmission 200, and is distributed to driving wheels on both sides by the differential 100. It should be understood that the powertrain 1000 illustrated in FIG. 10 is intended as an example, and not as a limitation on the scope of the present invention. Further, it should be understood that other configurations of the powertrain system according to embodiments of the present invention, such as engines, transmissions, etc., are known in the art and will not be described in detail herein.

Referring to fig. 11, a vehicle 10000 according to an embodiment of the present invention is briefly described below, where the vehicle 10000 includes the power transmission system 1000 in the above embodiment, and the power transmission system 1000 may be used for forward driving or backward driving, but the present invention is not limited thereto. It should be understood that other configurations of the vehicle according to the embodiment of the present invention, such as a brake system, a driving system, a steering system, etc., are known in the art and well known to those skilled in the art, and thus will not be described in detail herein.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples described in this specification can be combined and combined by those skilled in the art.

Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention, and that variations, modifications, substitutions and alterations can be made to the above embodiments by those of ordinary skill in the art within the scope of the present invention.

Claims

1. A differential, consisting of a first planet carrier, a first planet wheel, a first annulus, a second planet carrier, a second planet wheel, a second annulus and an input, the first planet wheel being connected to the first planet carrier, the first planet wheel being in engagement with the first annulus, the second planet wheel being connected to the second planet carrier, the second planet wheel being in engagement with the second annulus and the second planet wheel also being in engagement with the first planet wheel, wherein the first annulus and the second annulus constitute two power outputs of the differential, the input, the first planet carrier and the second planet carrier being coaxially arranged and the input being in linkage with the first planet carrier and the second planet carrier, respectively; the first carrier has a first connecting bracket for connecting the first carrier with the input portion, the second carrier has a second connecting bracket for connecting the second carrier with the input portion, wherein each of the first and second connecting brackets includes: the extension arm part is arranged on the outer peripheral surface of the central body part, and the extension arm parts are distributed radially by taking the central body part as the center, wherein the extension arm parts are used for being connected with the input part.

2. The differential of claim 1, wherein the first planet gear partially overlaps the second planet gear in an axial direction.

3. The differential of claim 2, wherein the first planet comprises: a first tooth and a second tooth, the second planet comprising: the first tooth part is meshed with the first gear ring, the second tooth part and the third tooth part are correspondingly overlapped and meshed in the axial direction, and the fourth tooth part is meshed with the second gear ring.

4. The differential of claim 1, wherein the first plurality of planet gears are circumferentially spaced apart and the second plurality of planet gears are circumferentially spaced apart and the first plurality of planet gears and the second plurality of planet gears are each correspondingly meshed.

5. The differential of claim 1, wherein the first planet gear and the second planet gear are both cylindrical gears.

6. The differential of claim 1, wherein the first ring gear and the second ring gear are symmetrically disposed.

7. The differential of claim 6, wherein each of the first ring gear and the second ring gear comprises:

8. The differential of claim 7, wherein the first carrier and the first planet gear and the second carrier and the second planet gear are received within the mounting space.

9. The differential of claim 1, wherein the input is configured as an input gear.

10. The differential of claim 9, wherein the input gear is configured as an annulus and fits over the first and second ring gear outer surfaces.

11. The differential of claim 9, wherein a gap is provided between the first ring gear and the second ring gear, the input gear surrounding and covering the gap.

12. The differential of claim 9, wherein said input gear is a final drive driven gear.

13. The differential of claim 1, wherein each set of the first and second planet wheels in respective meshing engagement is located between two adjacent ones of the extension arms.

14. The differential of claim 1, wherein each of said first planet gears has a first planet gear shaft connected at both ends to said first carrier and said second carrier, respectively, and each of said second planet gears has a second planet gear shaft connected at both ends to said first carrier and said second carrier, respectively.

15. The differential of claim 1, wherein the first planet gears have a radius of revolution that is the same as a radius of revolution of the second planet gears;

the first and second planet carriers are spaced apart, and the first and second planet gears are arranged in direct mesh between the first and second planet carriers such that the first and second planet carriers are located on opposite outer sides of the first and second planet gears, respectively.

16. The differential of claim 1, wherein the first carrier and the second carrier are each configured as a circular plate-like structure, and the first carrier and the second carrier are of a split-type structure.

17. The differential of claim 1, wherein the revolution axis of the first planet is coincident with the revolution axis of the second planet;

each of the first ring gear and the second ring gear includes: an annular side wall portion provided on an inner wall surface thereof with a plurality of teeth for meshing with the planetary gears, and an annular flange portion extending from an end surface of the annular side wall portion of one of the ring gears toward the annular side wall portion of the other ring gear or provided on end surfaces of the annular side wall portions of the two ring gears, respectively, and extending opposite to each other, the annular flange portion having an inner diameter larger than that of the annular side wall portion.

18. The differential of claim 17, wherein the annular flange portion has an outer diameter that is substantially equal to an outer diameter of the annular side wall portion or an inner diameter that is substantially equal to an outer diameter of the annular side wall portion such that the annular flange portion projects radially outward from the annular side wall portion.

19. A drivetrain, characterized by comprising a differential according to any one of claims 1 to 18.

20. A vehicle comprising the powertrain of claim 19.