MXPA97003768A - Mechanism of transmission changes with b ramp actuator - Google Patents

Abstract

The present invention relates to a transmission shifting system for a transmission having a main shaft and at least one counter shaft disposed substantially within a housing having parallel axes of rotation, at least two pairs of gears, each pair comprising a counter-gear engaged non-rotatably to said counter-shaft in permanent engagement with a corresponding main arrow gear rotationally supported on said main arrow, said main arrow gear sustained in said main arrow being able to be connected to said main arrow by a axially movable jaw clutch, the shifting system comprising: a ball-ramp mechanism comprising a drive ring connected non-rotatably to said main arrow and a control ring disposed adjacent said drive ring, both surrounding said main arrow and having opposite faces provi These have circumferentially extending grooves, arranged as at least three opposing pairs of grooves, including portions of varying depth, and bearing members disposed in each opposite pair of grooves, said grooves in said drive ring and said control ring being arranged so that the relative angular movement of said driving ring and said control ring in any direction, from a starting position thereof, causes axial movement of said control ring away from said driving ring to axially displace said clutch jaw, thereby pivotally coupling said main arrow gear to said main arrow, a coil assembly mounted in said housing and electrically energized to create an electromagnetic field for frictionally coupling said control ring to said main arrow gear, thereby causing relative rotation between said ring or control and said drive ring, a clutch plate adapted to frictionally link said coil assembly to electrical energization of said coil assembly, said clutch plate being non-rotatably linked to said control ring, where said clutch The jaw makes axial contact with said control ring and has axially bevelled clutch teeth formed therein, adapted to link a corresponding plurality of axially bevelled linking cavities formed in said main arrow engagement.

Description

MECHANISM OF TRANSMISSION CHANGES WITH BALL RAMP ACTUATOR BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift mechanism for a gear shift transmission, and more specifically to a shift mechanism for a gear shift transmission, where a bevelled jaw clutch is moved by a ball ramp actuator towards contact with linking cavities formed in a main arrow gear. 2. Description of the Prior Art Transmission gear transmissions using gearbox housing assemblies are well known in the prior art, where one or more axially movable shifters (also known as shift rails) and piston rod shafts changes, each carrying an associated shift fork, are selectively moved axially to link or disengage a selected transmission gear by axial movement of a clutch member, or of a gear having clutch teeth or jaw clutch, such as can be seen by reference to U.S. Patent Nos. 3,105,395; 3,283,613; 3,611,483; 4,152,949; 4,194,410; 4,445,393; 4,754,665; 4,876,924; and 5,053,961, the disclosures of which are incorporated herein by reference. Electronically controlled shift bar housing assemblies, driven by pressurized hydraulic fluid, pressurized air, or electric motors and controls for these, are also known in the prior art, as can be seen by reference to the patents of United States Nos. 4,428,248; 4,445,393; 4,722,237; and 4,873,881, all assigned to the same assignee as this invention and incorporated herein by reference. Although the electronically controlled and electronically controlled shift bar housing assemblies of the prior art are generally satisfactory and are currently used in production applications for remotely controlled and / or automatically controlled gear shift transmissions, the prior art assemblies are not totally satisfactory because they are complicated, as well as expensive to produce, install and service them. The pneumatic systems of the prior art are slow and difficult to control, due to the compressibility of the air used to drive the rails of changes. The use of hydraulic fluid as an operating medium has proven to be difficult due to leakage in the system, which results in degraded performance and requires excessive maintenance.

It is known to automate a traditional manual gearbox (transmission) by electronically controlling a plurality of actuators to move the gear shift mechanism of the transmission in coordination with a fully or partially automated traction line master clutch. The actuators move the transmission shift rails by holding the shift forks, which in turn control the axial movement of a jaw clutch at the end of each shift fork. The jaw clutch slides axially along a muted main shaft of the transmission to engage gear and non-rotatably couples the input of the transmission output. Similar mechanical transmissions are well known in the prior art and can be seen by reference to U.S. Patent Nos. 3,105,395; 3,283,613; 4,754,665; 4,876,924; and 5,053,961, the disclosures of which are incorporated herein by reference. It is also known to use ball-ramp actuators driven by a separate pulse motor for each pair of ball-ramp actuators in a transmission to load clutch packs in the main shaft to frictionally transfer rotational movement of the main shaft to the gears that they go in the main arrow that mesh with gears in a parallel counter-shaft. U.S. Patent No. 5, 078,249, the disclosure of which is incorporated herein by reference, discloses such a gearbox. The ball ramp units consist of two pressure rings and an adjustment ring disposed between them. Both the pressure rings and the adjusting ring use opposite pairs of variable depth grooves to capture a bearing member to axially expand and contract the pressure ring depending on the rotational direction of the adjusting ring relative to the pressure ring. The rotary movement of the adjusting ring is supplied by a motor that is reacted against the transmission case. The use of an electric motor driver to rotate the adjusting ring relative to the transmission case results in complications and expense associated with certain mechanical and electrical components. The gear required to transfer the relatively high speed rotary movement of a motor to the low displacement rotary motion of the adjusting gear creates much of the complications. Gear reduction reduces the response speed of the ball ramp actuator, thereby reducing the speed that the transmission can execute. SUMMARY OF THE INVENTION In accordance with the present invention, the disadvantages of the prior art are overcome or minimized by the use of relative rotation of the countershaft and rotating main shaft in combination with an electromagnetic coil assembly to energize a ramp clutch of ball that axially displaces a bevelled jaw clutch to engage a main transmission shaft gear to a main drive shaft. In this manner, a simple electromagnetic coil assembly can be used to control the engagement of the ball ramp actuator to move the jaw clutch of the present invention without the complication of a motor or other rotary actuator having to use an adjusting ring. driven by a gear, with its consequent slow response and mechanical complication. The beveled shape of a portion of the jaw clutch links the main arrow gear in a way that allows the ball ramp actuator to continue to force the jaw clutch toward the main arrow gear. The above is accomplished by selectively electromagnetically coupling a ball ramp control ring to a main transmission shaft gear by means of a clutch plate where an electric coil is used to introduce a magnetic field into the clutch plate which in turn it is coupled non-rotatably with the control ring. The control ring makes contact with and axially moves the jaw clutch which is non-rotatably connected to the main arrow in notches that allow axial movement of the jaw clutch in response to the ball-ramp mechanism. Thus, in the preferred embodiment, the control ring is selectively magnetically coupled to the main shaft gear which is continuously driven by the counter-shaft through a counter-gear engagement meshing with the main shaft gear. The relative rotation between the control ring and a drive ring, which is mounted on the main shaft, causes the ball-ramp actuator to expand axially, thereby moving the jaw clutch into engagement with the main shaft gear for Attach the main arrow gear to the main arrow for output to the vehicle's traction line. The control ring comprises a first side of the ball ramp mechanism, wherein the second side comprises the drive ring. The control ring is moved axially by the operation of bearing elements that link corresponding grooves of variable depth formed in both the control ring and the drive ring. With the relative rotational movement of the control ring relative to the drive ring, the ball ramp mechanism expands axially when the rolling elements pass through the variable depth grooves formed in both the control ring and the drive rings. Bevelled edges are formed in the jaw clutches, where the jaw clutches make contact with corresponding linking cavities formed in the main arrow gear. The beveled contact surfaces of the jaw clutch and the main arrow gear provide the bottom for the beveled teeth in cavities that allow continuous force of the ball ramp actuator to further link the jaw clutch with the main arrow gear. In this way, while the jaw clutch links the main arrow gear, the geometry of the bevelled jaw clutch and the linking cavities formed in the main arrow gear allow additional relative rotational movement between the control ring and the drive ring , thereby causing the ball ramp actuator to continue to expand axially to increase the level of linkage between the jaw clutch and the main arrow gear. Magnetic flux grooves formed in the clutch plate prevent displacement of the flow through the clutch plate so that the clutch plate is magnetically attracted only to the main shaft gear and not to the coil assembly. In a first alternative embodiment, a coil assembly is used to electromagnetically link the clutch plate and the control ring to the main shaft gear of the transmission, thereby providing relative rotation between the control ring and the drive ring . The drive ring is connected to the transmission housing. The coil assembly is adapted to surround the ball-ramp mechanism and induces an electromagnetic field directly to the clutch plate which is magnetically attracted to and frictionally links the main arrow gear. A cam ramp mechanism can be used in place of a ball-ramp mechanism to generate the axial force required to link the jaw clutch of the present invention with the main arrow gear. A second embodiment discloses a drive ring that is formed as a part with the jaw clutch. A control ring extends to non-rotationally connect the control ring to a clutch plate where the clutch plate is rotatably connected electromagnetically to a main shaft gear. The relative movement between the main arrow gear and the main arrow energizes the ball ramp mechanism. One provision of the present invention is to provide control of a ball ramp actuator connected to a jaw clutch in a transmission shift system using an electric coil. Another provision of the present invention is to provide a compact ball ramp drive system for controlling the axial movement of a jaw clutch in a gear shift transmission. Another provision of the present invention is to provide control of a ball-ramp actuator for loading a jaw clutch using an electric coil to induce an electromagnetic field in a clutch plate that is non-rotatably connected to the control ring of a ball ramp actuator. Another provision of the present invention is to provide a compact ball-ramp drive system for controlling the axial movement of a jaw clutch having beveled surfaces linking linkage cavities formed in the main shaft gear of a shift transmission. gears Still another provision of the present invention is to provide a compact ball-ramp drive system for controlling the axial movement of a jaw clutch having bevelled surfaces that link bonding cavities formed in the main arrow gear to allow additional actuation of the jaw clutch. ball ramp actuator until the beveled surfaces fully link the linking cavities in a gear change transmission. Although the present invention is described in relation to use in a twin counter-type transmission, any suitable type of gearbox can make use of the present invention to couple a gear to a rotating shaft. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a partial cross-sectional view of a transmission having a system of changes in accordance with the present invention.; Figure 2 is a cross-sectional view of two respective jaw ball actuators and jaw clutches of the present invention, installed with respective main arrow gears in a transmission; Figure 3 is an axial cross-sectional view of the ball-ramp mechanism of the present invention, taken along line III-III of Figure 2; Figure 4 is a cross-sectional view of the ball-ramp mechanism of the present invention, taken along the line IV-IV of Figure 3 at a minimum spacing, - Figure 5 is a cross-sectional view of the ball ramp mechanism of the present invention, taken along line IV-IV of Figure 3 with increased spacing; Figure 6 is an elevational view of the jaw clutch and the main arrow gear of the present invention; Figure 7 is a schematic diagram of the forces generated between the jaw clutch and the main arrow gear of the present invention; Figure 8 is a partial cross-sectional view of a first alternate embodiment of the ball-ramp actuator of the present invention; Figure 9 is a partial cross-sectional view of a second alternate embodiment of the ball-ramp actuator of the present invention; and Figure 10 is a cross-sectional view of a ramp actuator for use with the present invention. Detailed Description of the Preferred Embodiment Form Certain terminology will be used in the following description for convenience of reference only, and will not be limiting. For example, the terms "forward" and "backward" will refer to forward and backward directions of the transmission, as it is normally mounted on a vehicle. The terms "to the right" and "to the left" will refer to addresses in the drawings in relation to which the terminology is used. The terms "inward" and "outward" will refer to directions as they are taken in the drawings in relation to which the terminology is used. All preceding terms mentioned above include normal derivations and their equivalents. In order to promote the understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings, and specific language will be used to describe them. However, it will be understood that no limitation of the scope of the invention is intended, such alterations and further modifications to the illustrated device, and such additional applications of the principles of the invention, as illustrated herein, being contemplated as would normally occur to a person skilled in the art to which the invention relates. A gear shift transmission 2 utilizing the ball ramp actuators 14 and 16 of the present invention can be seen by reference to Figure 1. Figure 1 illustrates a partial cross-sectional view of a transmission 2 having an arrow of input 4 connected to a pulse gear 6, both supported in a transmission housing 8. The pulse gear 6 links both counter-clockwise pulse gears 12 and 13. The counter-shaft 12 rotates the counter-shaft gears 26 and 28 and the counter-shaft 13 the countershaft gears 27 and 29 rotate. The ball ramp actuator 14 and the ball ramp actuator 16 are used to selectively couple respective main arrow gears 22 and 24 to the main shaft 18. The main shaft gear 22 or the main arrow gear 24 are non-rotatably coupled to the main shaft 18 with respective jaw clutches 21 and 23. The other main arrow gears which are rotatably linked selectively to the main arrow 18 by linking their respective ball ramp actuators (not shown) are not shown. As shown in Figure 1, the countershaft gears 26 and 27 and the countershaft gears 28 and 29 are rotatably linked to the main shaft 18 by activation and axial displacement of the respective ball ramp mechanisms 30 and 31, energizing their respective electric coil assemblies 32 and 33 by introducing an electric current to electrical terminals 32A and 33A. The illustrated transmission 2 comprises an input shaft 4 carrying a pulse gear 6 which links the counter-shaft pulse gears 10 and 11 for rotation therewith. The input shaft 4 is intended to be driven by a motor (not shown) by means of a master clutch or torque converter (not shown), whose use is well known in the art. A pair of substantially identical countershafts 12 and 13 are rotatably mounted in a housing 8 and are rotated with the input shaft 4 by rotation of the countershaft pulse gears 10 and 11. An output shaft or main shaft 18 is provided, the which is preferably mounted in a floating and / or pivotal manner in the housing of the transmission 8 and is driven by the counter-arrows 12 and 13 which functionally separate the load. In this way, the main arrow 18 is not directly connected to the input shaft 4, but is driven by the counter-arrows 12 and 13 by a selected gear ratio. Each of the countershafts 12 and 13 carries a plurality of countershaft gears, including for example counter-gear gears 26 and 28 which rotate with the counter-shaft 12 and the counter-shaft gears 27 and 29 that rotate with the counter-shaft 13, all of which are fixed for rotation with them. The countershaft gears 26 and 27 are constantly engaged with the main arrow gear 22 and the counter-gear gears 28 and 29 are constantly engaged with the main shaft gear 24. Any number of gear pairs can be used to provide the desired number of impulse gear ratios in a similar theory of operation to be used to transfer power to the main shaft 18 from the countershafts 12 and 13. The main shaft gears 22 and 24, for example, are not rotationally fixed to the main shaft 18 and do not normally drive the main shaft 18 unless they rotationally engage the main shaft 18 with some type of device such as jaw clutches that are moved using shift forks controlled by the operator via a link of changes lever controlled, a technique that is known in the prior art. In accordance with the present invention, the ball ramp actuators 14 and 16 are used to move the improved jaw clutches 21 and 23 into engagement with the selected main arrow gear such as the main arrow gear 22 or the arrow gear main 24 to provide rotational engagement between the input shaft 4 and the counter-arrows 12 and 13 and the main shaft 18. Although not shown in FIG. 1, other pairs of counter-shaft gears and their respective counter-shaft gears are in constant gearing and they can similarly be coupled to the main shaft 18 by electrical excitation of their respective coil assembly. The main arrow gears 22 and 24 are rotatably supported and axially fixed in the main shaft 18. According to the present invention, the main shaft gears 22 and 24 coupled to the main shaft 18 using jaw clutches 21 and 23 are axially displaced independently to link their respective main arrow gears 22 or 24 upon activation of any of the ball ramp actuators 14 or 16, according to the desired gear ratio. The ball-ramp actuator 14 is energized upon the introduction of an electric current to the electrical terminals 32A energizing the electrical coil assembly 32, thereby activating the ball-ramp mechanism 30 contained in the ball-ramp actuator 14. Similarly, by introducing electric current to electrical terminals 33A, which are attached to the electrical coil assembly 33, an electromagnetic field is produced which activates the ball-ramp mechanism 31 contained in the ball-ramp driver 16. Typically, only one coil assembly 32 or 33 is energized at a time, because only one set of gears must be linked. For example, when the speed ratio determined by the gear set counter gear of gears 26 and 27 and the main arrow gear 22 is desired, the coil assembly 32 is energized. The electromagnetic field generated by the coil assembly 32 introduces an electromagnetic force to the ball ramp actuator 14, which activates the ball ramp mechanism 30, which expands axially to move the jaw clutch 21 to engage with the main arrow gear 22. As the jaw clutch 21 has notches extending radially inwardly to rotationally lock the jaw clutch 21 to notches 20 formed in the main arrow 18, upon engagement of the jaw clutch 21 with the main arrow gear 22, the main arrow gear 22 is engaged by non-rotating manner to the main arrow 18, resulting in rotational engagement of the main arrow 18 to both counter-arrows 12 and 13 through s of counter-gear gears 26 and 27. Similarly, the coil assembly 33 can be energized, resulting in the activation of the ball-ramp mechanism 31, thereby imparting an axial displacement of the jaw clutch 23 which then makes contact with and links the main arrow gear 24. The main shaft 24 is then rotationally coupled to the main shaft 18 and thus the main shaft 18 is rotationally coupled to the counter shaft 12 and 13 by the counter shaft gears 28 and 29. power flows back through the transmission 2 to the rest of the vehicle's driveline. Specifically, the rotational energy flows through the input shaft 4 through the pulse gear 6 which meshes outwardly with the counter-shaft pulse gears 10 and 11. The counter-arrows 12 and 13 rotate the counter-shaft gears 26, 27, 28, and 29. Depending on which of the coils 32 or 33 is energized, the rotation of the counter-arrows 12 and 13 is transferred to the main shaft 18 by any of the gear set counter-shaft pairs 26 and 27 and towards the arrow main 22 or countershaft gears 28 and 29 to the main arrow gear 24. Preferably, as is known in the art, the main arrow gears 22 and 24 are somewhat radially movable (floating) relative to the main arrow 18 The advantages of using a floating main shaft and / or floating main shaft gears are well known in the art and can be appreciated in greater detail by reference to the United States patent. No. 3,105,395 mentioned above. Referring now to Figure 2, a partial cross-sectional view of two ball-ramp actuators 14 and 16 of the present invention is shown as being installed in respective major arrow gears 22 and 24 in transmission 2. Both of ball ramp 30 and 31 use a plurality of rolling elements 34A and 35A, respectively, operating in slots 36A and 38A formed in the control ring 37 and the control ring 39 with substantially identical circumferential grooves 40A and 42A formed in the ring 43. The drive ring 43 is held in position relative to the main shaft 18 by the stabilization ring 44 which links a slot cut in the main shaft 18. The drive ring 43 is connected in a non-rotating manner to the main arrow 18 through the notch 58. The jaw clutch 21 is biased away from the main arrow gear 22 by a regress spring. 48 and in a similar manner, the jaw clutch 23 is biased away from the main arrow gear 24 by the return spring 49 where both return springs 48 and 49 are held in position and in a compression state by their respective stops of spring 50 and 51, which are held in place on the main arrow 18. Annular clutch plates 52 and 53 operate in proximity to their respective main arrow gears 22 and 24 such that when the coil assembly 32 or 33 is energized, the chuck plate 52 or the clutch plate 53 is electromagnetically attracted to the main arrow gear 22 or the main arrow gear 24, thereby frictionally engaging the clutch plate 52 or the clutch plate 53 to its respective main arrow gear 22 or 24. The clutch plates 52 and 53 have their respective plate fingers 54 and 55 which link their respective control rings 37 and 39 so as to allow axial movement of the attachment plates 52 and 53 relative to the main arrow gears 22 and 24 while rotationally linking the clutch plates 52 and 53 to their respective control rings 37 and 39. For example, the relative rotation between the main arrow gear 22 and the main arrow 18 causes relative rotation between the drive ring 43 and the control ring 39, thereby causing the ball ramp mechanism 31 to expand axially, thereby moving the jaw clutch 23 to engage with the main arrow gear 24 In Figure 2, electrical coils 32 and a second coil assembly 64 having electrical terminals 64A are structurally connected to housing 8 via coil support 56. Additional coil assemblies 64 and 65 illustrate an arrangement whereby two sets The coil assembly 64 is mounted to the transmission housing 8 using a coil support 56. The coil assembly 64 may be used to provide control of a third ball-ramp actuator (not shown) to link another main shaft engagement (not shown). . The coil assembly 33 is attached to the housing 8 by a coil support 60 which also similarly holds a coil assembly 65 having electrical terminals 65A for activation of a fourth ball-ramp actuator (not shown) for control of the Linkage of its own associated main arrow gear. In this way, depending on the desired gear ratio, the electric coils 32 or 33 or 64 or 65 can be energized electrically through the electrical terminals 32A, 33A, 64A or 65A, thereby activating the associated ball-ramp actuators. 30, 31, or the two ball ramp actuators not shown in Figure 2, thereby causing the jaw clutch 21 or 23 or one of the other two jaw clutches not shown in Figure 2, to be moved to link of the main arrow gears 22 or 24 or to the main arrow gears not shown in figure 2, one at a time, to link the desired main arrow gear to the main arrow 18. All the main arrow gears are driven in continuously by its associated counter-gear, such as the main shaft gear 22 which is continuously rotated and meshes with the counter-gear gears 26 and 27 and identically the main shaft gear 24 is rotated and connects the countershaft gears 28 and 29. Segmented flow slots 80A are formed in the chuck plates 52 and 53 and segmented flow slots 80B are formed in the main shaft gears 22 and 24 which jointly act to intensify the forces electromagnetic generated by the coil assemblies 32 and 33 to more effectively attract the clutch plates 52 and 53 to their respective main arrow gears 22 and 24. This technique is known in the art and used for vehicle air conditioning compressor clutches . Referring now to FIGS. 3, 4 and 5 to describe the operation of the ball ramp mechanism 31, a cross-sectional view of the control ring 39 taken along the line III-III of FIG. 2 is shown in FIG. Figure 3, and a view taken along the line IV-IV of Figure 3 of the control ring 39 and the drive ring 43 separated by a bearing element 35A is shown in Figures 4 and 5. Three elements Spherical bearing 35A35B and 35C are spaced approximately 120 ° apart from each other in three variable depth grooves 42A, 42B and 42C, respectively, when the control ring 39 rotates relative to the drive ring 43. Any number of spherical bearing elements can be used and respective ramps, depending on the desired angle of rotation and axial movement of the ball ramp actuator 16. It is desirable to employ at least three spherical bearing elements 35A, 35B and 35C traveling over a similar number of opposite depth slots, spaced apart from each other. identical and identically equal intervals 40A and 42A, 40B and 42B, and 40C and 42C, formed in the control ring 39 and the drive ring 43, respectively, to provide stability to the control ring 39 and the drive ring 43. It can be used any type of low friction device that rolls along the slots 42A, 42B, 42C for the bearing elements 35A, 35B and 35C of such It's balls or rollers. Three variable-depth, circumferential, semi-circular grooves 42A, 42B and 42C are formed on the face of the control ring 39 with opposite, identical depth slots 40A, 40B and 40C (when the slots 40B and 40C are not shown) formed on the face of the drive ring 43, as shown in FIGS. 4 and 5. Also formed on an opposite face of the drive ring 31 are slots 38A, 38B and 38C, where 38B and 38C are not shown but are substantially identical to the slots 42B and 42C. The variable depth slots 40A, 40B, 40C, 42A, 42B and 42C vary in axial depth in accordance with the circumferential position in the slot and extend circumferentially by approximately 120 ° (actually, slightly less than 120 ° to allow a section of separation between the ramps). Any number of opposing grooves and associated bearing elements can be used, depending on the desired range of rotation and the necessary axial displacement of the ball-ramp mechanism 31. The groove depth is at a maximum at the center of its extension. The control ring 39 and the drive ring 43 can be made of a high strength steel or high strength powdered metal with the variable depth grooves 38A, 38B, 38C, 40A, 40B, 40C and 42A, 42B and 42C carburized and hardened to Rc 55-60. The axial spacing 70, shown at a minimum in FIG. 4, between the control ring 39 and the drive ring 43 is determined by the rotational orientation between the corresponding opposite grooves such as 40A and 42A, where the spherical bearing element 35A wheel on each ramp 40A and 42A when the control ring 39 rotates relative to the drive ring 43 on the same axis of rotation C. The relative rotation forces the control ring 39 and the drive ring 43 to separate or allow them to be closer together, as determined by the position of the bearing elements 35A, 35B and 35C in their respective slot pairs 40A, 42A and 40B, 42B and 40C, 42C, thereby providing axial movement of the jaw clutch 23 for attachment with the main arrow gear 24. Note that the slots are dual ramp with its deepest point at its center, which provides an increase in axial separation 70 when turning the ring of control 39 in any direction from a starting point as shown in Figure 4. This double action capability provides main arrow gear lock 24 in the vehicle operating modes of both free running and descending. Figure 4 illustrates the rotational orientation of the control ring 39 and the drive ring 43 when the axial separation distance 70 is at a minimum, since the grooves 40A and 42A are directly opposite and the bearing element 35A is in the upper section. deep of the slots 40A and 42A as indicated by the alignment of the reference points 66 and 68. Rotation of the control ring 39 in either direction would result in an increased axial separation distance 70. FIG. 5 illustrates the separation distance 70 increased when the control ring 39 is rotated relative to the ring. drive 43. The reference points 66 and 68 are no longer opposite each other and the bearing element 35A has traversed both the groove 42A in the control ring 39 and the groove 40A in the drive ring 43, thereby increasing the axial separation distance 70. As illustrated in FIG. 2, the control ring 39 is rotated relative to the drive ring 43 by application of a torsion input created by the clutch plate 53 which makes contact with the main arrow gear 24 when the electric current is supplied to the coil assembly 33. The clutch plate 53 has plate fingers 55 which extend and rotationally connect the clutch plate 53 to the control ring 39, thereby rotationally locking the main arrow gear 24 to control ring 39. If there is relative rotational movement between control ring 39 and drive ring 43, clutch plate 53 applies a force to control ring 39, causing it to rotate relative to the ring drive 43, for example to the position shown in Figure 5. The reference point 66 relative to the reference point 68 in the slots 42A and 40A, shown s respectively aligned in Figure 4, is moved to the position shown in Figure 5, where the separation distance 70 is increased due to the bearing of the bearing element 35A relative to the slots 40A and 42A. In this way, the relative movement between the control ring 39 and the drive ring 43, when the bearing elements 35A, 35B and 35C assume new positions in their respective slots 42A, 42B and 42C and 40A, 40B and 40C, increases its axial separation between the control ring 39 and the drive ring 43. The increased axial clearance 70 of the ball ramp mechanism 31 causes the jaw clutch 23 to be axially displaced towards the main arrow gear 24, thereby linking the main arrow gear 24 and rotationally engaging the main arrow gear 24 to the main arrow 18. As the main arrow gear 24 is continuously engaged and rotated with the counter-gear gears 28 and 29, the main shaft 18 is rotationally coupled to the input shaft 4, thereby completing the power flow through the transmission 2 and eventually to the traction shaft (not shown) of the vehicle for transport nference to the rest of the vehicle's drive line. Figure 6 is an elevational view of the jaw clutch 23 and the main arrow gear 24 of the present invention. The jaw clutch 23 consists of a plurality of jaw clutch teeth 72 shown forming a main body 73 of the jaw clutch 23 and which are shown as equally spaced along the periphery of the jaw clutch 23. The clutch teeth jaw 74 are bevelled axially and radially so as to link pairing clutch cavities 78 formed in the main arrow gear 24. The jaw clutch teeth 74 may also extend axially from one face of the annular clutch jaw 23 instead to train in the periphery. The design of the beveled jaw clutch teeth 74 and the linking cavities 78 allows the control ring 39 to continue to rotate relative to the drive ring 43 to axially further displace the jaw clutch 23 toward the main arrow gear 24 for increased engagement of the jaw clutch teeth 74 to the linking cavities 78. Referring now to Fig. 7, a schematic of the jaw clutch 23 is shown which links the main arrow gear 24, where the clutch teeth 72 have engaged the main arrow gear 24 in the jaw clutch teeth 74, linking the clutch engagement cavity 78. The angle T is used to calculate the forces generated on the jaw clutch 23 where a tending force is created to allow the ball ramp mechanism 31 to be additionally activated, thereby providing increased axial force on the clutch of which flange 23 which tends to further link the jaw clutch teeth 74 in the clutch engagement cavities 78. The geometry of the jaw clutch teeth 74 does not allow the forces generated by the jaw clutch 23 to retro-urge the mechanism of 31 ball ramp.

The force Ft is calculated by the equation: Ft = FnsenT + uFncosT and Fa is calculated by the equation: Fa = FncosT - uFnsenT. Therefore, Ft / Fa = tan (T + B) where B = tan "1 (u) where Ft is the driving force applied by the jaw clutch 23; Fa is the axial force applied by the control ring 39 of the ball ramp mechanism 31, Fn is the normal force component, Fu is the tangential force component, u is the coefficient of friction, T is the bevelled jaw clutch tooth angle 74, B is the friction angle. Fig. 8 is a partial cross-sectional view of a first alternate embodiment of the transmission shift system of the present invention, the configuration and orientation of the electric coil assemblies 32 and 33 have been changed where the sets of electrical coil 32 and 33 are mounted on the drive ring holder 59 and electromagnetically supply a force to attract the clutch plates 52 and 53 to their respective main arrow gears 22 and 24, thereby providing relative movement between The control ring 37 and the drive ring 43 and the control ring 39 and the drive ring 43.

The flow slots 80A are formed as segmented circumferential grooves in the clutch plates 52 and 53 and flow slots 80B are formed in the main arrow gears 22 and 24, such that the magnetic flux does not flow through the clutch plates. 52 and 53 and instead flow through the main arrow gears 22 and 24, thereby providing frictional connection between the clutch plate 52 and the main arrow gear 22 and the clutch plate 53 and the main shaft gear 24. The flow slots 80A and 80B are similar to those used in vehicle air conditioning clutches and prevent the clutch plates 52 and 53 from short-circuiting the magnetic path when electric current is applied. In this way, the geometry of the jaw clutch teeth 74 and the linking cavities 78 allows the control ring 39 to continue to move relative to the drive ring 43 until the jaw clutch teeth 74 fully engage the cavities of the jaw. linking 78. Referring now to Figure 9, a partial cross-sectional view of a second alternative embodiment of the transmission shifting system of the present invention is shown. Again as shown in Figure 8, the coil assemblies 32 and 33 are mounted in the housing 8 using a support member 86. The coil assemblies 32 and 33 electromagnetically connect the clutch plate 84 to the main arrow gear 22. and similarly the coil assembly 33 electromagnetically connects, causing the clutch plate 85 to contact and frictionally engage the main arrow gear 24. The clutch plates 84 and 85 are non-rotationally linked to control rings 82. and 83 respective. In this manner, the control rings 82 and 83 in the second alternative embodiment of Figure 9 are frictionally linked to the main arrow gears 22 and 24. Rather than being separate parts, as shown in previous embodiments, the jaw clutches 94 and 96 now extend and form the drive rings 90 and 92. The ball ramp mechanisms 30 and 31 operate in a manner similar to the previous embodiments with the exception that the slots 38A, 38B and 38C are formed in the control ring 82 and the slots 40A, 40B and 40C are formed in the control ring 83 and the slots 38A, 38B and 38C are formed in the drive ring 90 and the slots 42A, 42B and 42C They are formed in the drive ring 92. In this way, with these changes, the operation is identical to that described with reference to FIGS. 3, 4 and 5. Again, relative movement is created when there is a difference in the speed of rotation between s main arrow gears 22 or 24 selected and the main arrow 20, wherein the electrical energization of the coil assembly 32 results in frictional engagement between the clutch plate 84 and the main arrow gear 22, which in turn drives the control ring 82 such that the relative rotation of the control ring 82 and the drive ring 90 and the jaw clutch 94 results in the activation of the ball ramp mechanism 30, thereby causing the jaw clutch 94 to move axially towards the main arrow gear 22, causing teeth to be engaged of jaw clutch 74 with the linking cavities 78. When electrical power to the coil assembly 32 ceases, the return spring 48 causes the jaw clutch 94 to move axially back to its original position, thereby collapsing the mechanism of ball ramp 30 to a state as shown in figure 4, where the separation distance 70 is at a minimum. The stabilization ring 44 maintains the geometry of the control ring 82 and the control ring 83, both with each other and with respect to the main arrow 18. Referring now to FIG. 10, a top elevational view of an embodiment alternative of the drive ring 43 'and the control ring 39' is shown, which can be used with the shift mechanisms shown in Figures 2 and 8. As a relatively moderate force (approximately 300 pounds force) is required to force the jaw clutches 21 and 23 to engage with their respective main arrow gears 22 and 24, the ball ramp mechanisms 30 and 31 are not necessary to generate this level of force. As an alternative to the ball ramp mechanism 31, a drive ring 43 'and a control ring 39' having cam ramps 102 and 104, respectively, can be used to generate the axial force required to link the jaw clutch 23 with the main arrow gear 24. Similarly, the ball ramp mechanism 30 is replaced with the main arrow gear 37 'which operates against the drive ring 43'. Figure 10 shows the control ring 37 'in a non-active mode where the separation 70A is at a minimum and the control ring 39' in an intermediate position relative to the drive ring 43 ', where the cam ramp 104 has partially traveled on the cam ramp 102, thereby increasing the spacing 70B, which would also move the jaw clutch 23 into engagement with the main arrow gear 24. In this way, since when using the jaw clutch 23 of the present invention, a drive ring 43 'and a control ring 39' having cam ramps 102 and 104, respectively, can generate the required force without using a ball-ramp mechanism 31. This invention has been described in detail, enough to allow a technician in the field to make and use it.

Various alterations and modifications of the invention will occur to those skilled in the art upon reading and understanding the foregoing description, and it is intended to include all such alterations and modifications as part of the invention, insofar as they fall within the scope of the appended claims.

Claims (16)

1. A transmission shift system for a transmission having a main arrow and at least one counterthrust disposed substantially within a housing having axes of rotation parallel to each other; at least two pairs of gears, each pair comprising a countershaft gear non-rotatably attached to said countershaft in permanent gear engaged with a corresponding main shaft gear rotationally supported on said main shaft, said main shaft gear sustained on said shaft main being able to be connected to said main shaft by means of an axially movable jaw clutch, the gear system comprising: a ball-ramp mechanism comprising a drive ring connected non-rotatably to said main shaft and a control ring arranged adjacent to the main shaft; said driving ring, both surrounding said main arrow and having opposite faces provided with circumferentially extending grooves, arranged as at least three opposite pairs of grooves, including portions of variable depth, and bearing members disposed in each opposite pair of grooves, said slots in said drive ring and said control ring being arranged so that the relative angular movement of said drive ring and said control ring in any direction, from a starting position, causes axial movement of said control ring away from said ring of control. drive to axially displace said jaw clutch, thereby pivotally coupling said main arrow gear to said main arrow; a coil assembly mounted in said housing and electrically energized to create an electromagnetic field for frictionally coupling said control ring to said main arrow gear, thereby causing relative rotation between said control ring and said drive ring; wherein said jaw clutch makes axial contact with said control ring and has axially beveled clutch teeth formed therein, adapted to engage a corresponding plurality of axially bevelled linking cavities formed in said main arrow gear.

The transmission shift system of claim 1, further comprising a clutch plate adapted to frictionally link said coil assembly upon electrical energization of said coil assembly, said clutch plate being non-rotatably linked to said control ring .

3. The transmission shift system of claim 2, wherein said clutch plate has axially extending clutch plate fingers to engage said control ring, thereby allowing axial movement between said clutch plate and said ring of said clutch plate. control and non-rotatably coupling said clutch plate to said control ring.

The transmission shift system of claim 1, wherein said clutch teeth and said engagement cavities are beveled both axially and radially.

The transmission shift system of claim 2, wherein said clutch plate is disposed on a first side of said main arrow gear and said coil assembly is disposed on a second side of said main arrow gear.

6. A transmission shifting system having a main arrow and at least one countershaft disposed substantially within a housing having rotational axes parallel to each other; at least two pairs of gears, each pair comprising a counter-gear engaged non-rotatably to said counter-shaft permanently in engagement with a corresponding main shaft gear rotationally supported on said main shaft, said main shaft gear sustained in said main shaft being able to be connected to said main shaft by an axially movable jaw clutch, the shift system comprising: a cam ramp mechanism comprising a drive ring connected non-rotatably to said main arrow and a control ring disposed adjacent said drive ring, both surrounding said main arrow and having opposite faces provided with cam ramps disposed as at least three opposite pairs of cam ramps, including variable depth portions, said cam ramps in said drive ring and said control ring being arranged such that the relative angular movement of said drive ring and said control ring in any direction, from a starting position, causes axial movement of said control ring away from said drive ring to axially displace said jaw clutch, thereby non-rotatably engaging said main arrow gear to said main arrow; a coil assembly mounted in said housing and electrically energized to create an electromagnetic field for frictionally coupling said control ring to said housing, thereby causing relative rotation between said control ring and said drive ring; wherein said jaw clutch makes axial contact with said control ring and has axially bevelled clutch teeth formed therein, adapted to engage a plurality of axially bevelled linking cavities, formed in said main arrow gear.

7. The transmission shift system of claim 6, further comprising a clutch plate adapted to frictionally link said coil assembly upon electrical energization of said coil assembly, said clutch plate being non-rotatably linked with said control ring.

The transmission shifting system of claim 7, wherein said clutch plate has axially extending chuck fingers to engage said control ring, thereby allowing relative axial movement between said clutch plate and said shifting ring. control and non-rotatably coupling said chuck to said control ring.

The transmission shift system of claim 6, wherein said clutch teeth and said engagement cavities are beveled both axially and radially.

The transmission shift system of claim 7, wherein said control ring extends axially to rotationally engage said clutch plate.

The transmission shift system of claim 7, further comprising a plurality of segmented flow slots formed in said clutch plate facing said main arrow gear.

The transmission shifting system of claim 6, further comprising a plurality of flux slots formed in said main arrow gear facing said clutch plate.

13. A jaw clutch, comprising: an annular main body having notches extending radially inwardly; a plurality of clutch teeth formed on a surface of said main body, said clutch teeth having an axially bevelled section for linking a corresponding plurality of linking cavities formed in a main arrow gear in a transmission.

The jaw clutch of claim 13, wherein said clutch teeth are beveled both axially and radially.

15. The jaw clutch of claim 13, wherein said clutch teeth are formed on a peripheral surface of said main body.

16. The jaw clutch of claim 13, wherein said clutch teeth are formed on a face surface of said main body.