KR102543376B1 - Electric drive module with transmission having parallel twin gear pairs sharing load to a final drive gear - Google Patents

Abstract

An electric drive module comprising an electric motor, a differential assembly, and a transmission that transmits rotational power between the electric motor and the differential assembly. The transmission has first and second reduction units. The first reduction unit has a pair of first reduction gears meshingly coupled to a drive gear rotatable about a first axis and a drive gear rotatable about each second axis. The second axes are spaced from each other and parallel to the first axis. The second reduction unit has a driven gear and a pair of second reduction gears. The driven gear is rotatable about a third axis parallel to the first axis. Each second reduction gear is meshingly engaged with the driven gear and non-rotatably coupled to an associated one of the first reduction gears.

Description

ELECTRIC DRIVE MODULE WITH TRANSMISSION HAVING PARALLEL TWIN GEAR PAIRS SHARING LOAD TO A FINAL DRIVE GEAR}

Cross reference to related applications

This application benefits from US Provisional Patent Application Serial No. 62/942496, filed on December 2, 2019, the disclosure of which is incorporated by reference as if set forth in full detail herein.

Field

The present disclosure relates to an electric drive module having a transmission with parallel gear pairs that share the load on the final drive gear.

This section provides background information related to the present disclosure, which is not necessarily prior art.

It is known in the art to provide an electric drive module having an electric motor that drives a differential assembly through a transmission. Known electric drive module configurations include a coaxial arrangement in which the output shaft of the electric motor, the input and output of the differential assembly and the transmission are disposed about a common axis of rotation, or the output shaft of the electric motor, the input and output of the differential assembly and the transmission are parallel to each other. It may have an arrangement arranged around two or more rotational axes. While these configurations are well suited for their intended purpose, they can be rather difficult to package or fit into certain vehicles because there may be insufficient space in a lateral or side-to-side or radial direction. Accordingly, there remains a need in the art for an electric drive module of relatively compact design.

This section provides an overall overview of the disclosure and is not a comprehensive disclosure of the complete scope or all features of the disclosure.

In one form, the present disclosure provides an electric drive module that includes an electric motor, a differential assembly, and a transmission that transfers rotational power between the electric motor and the differential assembly. The transmission has first and second reduction units. The first reduction unit has a pair of first reduction gears meshingly coupled to a drive gear rotatable about a first axis and a drive gear rotatable about each second axis. The second axes are spaced from each other and parallel to the first axis. The second reduction unit has a driven gear and a pair of second reduction gears. The driven gear is rotatable about a third axis parallel to the first axis. Each second reduction gear is meshingly engaged with the driven gear and non-rotatably coupled to an associated one of the first reduction gears.

Additional fields of application will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only, and are not intended to limit the scope of the present disclosure.

The drawings described herein are for the purpose of illustrating only selected embodiments rather than all possible implementations, and are not intended to limit the scope of the present disclosure.
1 is a schematic diagram of an exemplary vehicle having an electric drive module constructed in accordance with the teachings of the present disclosure.
FIG. 2 is a perspective view of a partially segmented portion of the electric drive module of FIG. 1 showing the electric motor and transmission in greater detail;
3 is a cross-sectional view of a portion of the electric drive module of FIG. 1 showing a final drive gear of a transmission and differential assembly.
Figure 4 is a schematic diagram of a portion of the electric drive module of Figure 1 showing the relative positioning of the electric motor, transmission and differential assembly;
Fig. 5 is a perspective view of a portion of the electric drive module of Fig. 1 showing an optional parking lock mechanism;
6 is a plan view of a portion of a parking lock mechanism showing pawls disposed in engagement with a pair of parking gears to secure a countershaft of an electric drive module.
Fig. 7 is a cross-sectional view taken through a portion of the parking lock mechanism, showing a cam plate oriented in a first rotational position and a pair of plungers disposed in an extended position;
8 is a perspective view of a portion of the parking lock mechanism showing the pawls disengaged from the pair of parking gears to allow rotation of the countershaft of the electric drive module.
9 is a cross-sectional view taken through a portion of the parking lock mechanism, showing the cam plate oriented in a second rotational position and the pair of plungers disposed in a retracted position.
10 is a partial cross-sectional perspective view of a parking lock mechanism.
11 is a perspective view of a portion of the parking lock mechanism showing the first side of the cam plate in more detail.
12 is a cross-sectional view of a portion of the parking lock mechanism showing the lock actuator in more detail.
13 is a perspective view of a portion of the cam plate showing a locking opening formed in the second face of the cam plate.
14 is a perspective view of a portion of the parking lock mechanism showing the plunger in an extended position and the pawl in an engaged position.
Corresponding reference numerals indicate corresponding parts throughout the several views.

Referring to FIG. 1 of the drawings, an exemplary vehicle having a drive module constructed in accordance with the teachings of the present disclosure is indicated generally at 10 . Vehicle 10 may include a front or primary driveline 14 and a rear or secondary driveline 16 . Front driveline 14 may include engine 18 and transmission 20 and may be configured to drive a front or primary set of drive wheels 22 . The rear driveline 16 may include an electric drive module 24 that may be configured to drive a rear or secondary set of drive wheels 26 on an as-needed or “on demand” basis. . In this example, front wheels 22 are associated with primary driveline 14 and rear wheels 26 are associated with secondary driveline 16, but alternatively rear wheels may be driven by primary driveline 16. and the front wheels can be driven by a secondary driveline. Additionally, while electric drive module 24 is shown in this example as being configured to drive a secondary set of drive wheels part-time, a drive module configured in accordance with the present teachings may be used as the sole propulsion means for a vehicle or in combination with other means of propulsion. It will be appreciated that together can be employed to drive a (front, rear or other) set (eg, front or set of wheels) of driven wheels on a full time basis. The electric drive module 24 may include a drive unit 30 and a pair of axle shafts 32 .

Referring to FIGS. 2 and 3 , drive unit 30 may include housing 40 , electric motor 42 , transmission 44 , and differential assembly 46 . The housing 40 may form a structure in which other components of the drive unit 30 are mounted. The housing 40 may be formed of two or more housing elements that may be rigidly coupled together, for example via a plurality of threaded fasteners. Electric motor 42 may be any type of electric motor, such as a permanent magnet motor. An electric motor 42 may be mounted on a flange (not specifically shown) on the housing 40, and an output shaft may be received within the housing 40 and disposed along a first axis of rotation 58 (FIG. 4). (56).

Referring to FIGS. 2 and 4 , transmission 44 includes one or more transmission stages or reduction gears that provide a transmission input driven by an output shaft of electric motor 42 and a transmission output driving differential assembly 46 . can include Transmission 44 may include one or more transmission stages or reductions to provide multiple levels of gear reduction and may optionally include one or more multiple speed transmission stages. Also optionally, a clutch (not shown) may be employed between the transmission output and the differential assembly 46 to selectively de-coupling the differential assembly 46 from the electric motor 42. there is. In the example provided, the transmission 44 includes a drive gear or input pinion 60, a plurality of first reduction gears 62, a plurality of second reduction gears 64, and a driven or final drive gear 66. do. Input pinion 60 may be rotatably coupled to the output shaft of electric motor 42 . The first reduction gear 62 meshes with the input pinion 60, has more teeth than the input pinion 60, and has a relatively larger pitch diameter than the pitch diameter of the input pinion 60. Each first reduction gear 62 may be rigidly coupled to an associated one of the second reduction gears 64 to form a composite reduction gear 70 . The second reduction gear 64 has a larger pitch diameter and more teeth than the first reduction gear 62 . Each compound reduction gear 70 may be disposed on a countershaft or axle 72 mounted to the housing 40 for rotation about a second rotational axis 74 parallel to and offset from the first rotational axis 58. can Each countershaft 72 may be supported by a pair of bearings that may be mounted in the housing 40 . Each countershaft 72 can be formed as a separate component that can be assembled to a corresponding one of composite reduction gears 70, or it can be formed monolithically and integrally with a corresponding one of composite reduction gears 70. It will be understood that it can be. The final drive gear 66 may be supported by the housing 40 for rotation about an output shaft 76 parallel to and offset from the second rotational axis 74 and the first rotational axis 58 . In the example provided, the input pinion 60, the first reduction gear 62, the second reduction gear 64 and the final drive gear 66 are helical gears, and the first reduction gear 62 and the second reduction gear ( 64) is an axial direction on the composite reduction gear 70 associated with the transmission of rotational power between the input pinion 60 and the first reduction gear 62 and between the second reduction gear 64 and the final drive gear 66 Opposite handed to counterbalance forces. Although transmission 44 has been described as employing helical gears, it will be appreciated that some or all of these gears may be configured as spur gears.

Referring to FIG. 3 , the differential assembly 46 may include a differential input member and a pair of differential output members. The differential input members can be coupled to the final drive gear 66 for rotation about and with the output shaft 76, while each differential output member is coupled to rotate with a corresponding one of the axle shafts 32. can be ringed In the particular example provided, differential assembly 46 includes differential case 80 and differential gearset 82 . Differential case 80 can function as a differential input member and can be rotatably supported on housing 40 about output shaft 76 by a pair of bearings 84 . Although bearing 84 is shown as being a tapered roller bearing in the examples provided, it will be appreciated that bearing 84 may alternatively be configured as an angular ball bearing or as a ball bearing. The differential gear set 82 may include a pair of differential pinions 90 and a pair of side gears 92 . The differential pinion 90 can be received in the differential case 80 and is rotatably disposed on a cross pin 94 mounted to the differential case 80 . Cross pin 94 may extend at least partially through differential case 80 and is oriented perpendicular to output shaft 76 . Side gear 92 is a differential output member in the example provided. The side gear 92 is accommodated in the differential case 80 and is rotatable relative to the differential case 80 about an output shaft 76 . Each side gear 92 meshes with the differential pinion 90 .

Each axle shaft 32 may be non-rotatably but axially slidably coupled to a corresponding one of the side gears 92 . In the example provided, each axle shaft 32 has a male spline segment 100 that meshingly engages an internal spline opening 102 of a corresponding one of side gears 92 . Each axle shaft 32 is configured to transmit rotational power between one of the side gears 92 and an associated one of the vehicle wheels.

The configuration of the transmission 44 is advantageous in several respects. For example, the compound reduction gear 70 allows the use of a relatively high speed electric motor and a relatively small input pinion, which lowers the pitch line speed and thus the input pinion 60 and the first reduction gear in a positive manner ( 62) affects the bending stress, load capacity and service life. As another example, the load on the final drive gear 66 is shared across the second reduction gear 64, which (as opposed to a configuration where the entire load is transmitted to the final drive gear 66 by a single gear) 2 Allows a reduction in the size of the reduction gear 64. Consequently, the arrangement of the gearing between the electric motor 42 and the final drive gear 66 allows for a reduction in the package size of the drive unit 30, and these gears are also relatively more compact than components of known electric drive units. It can be made smaller and/or made of less expensive materials, reducing the cost and mass of the electric drive module 24.

If desired, a parking lock mechanism (not shown) may be incorporated into the electric drive module 24 . 2 and 4 , the parking lock mechanism comprises a pawl pivotally coupled to the housing 40 and a differential assembly 46 rotatable on a final drive gear 66 or about an output shaft 76. It can be constructed in a conventional manner with a toothed locking wheel rotatably coupled to the component. The pawl can be pivoted into and out of engagement with the teeth on the toothed locking wheel to restrain rotation of the final drive gear 66 relative to the housing 40 . Alternatively, the parking lock mechanism may be configured to selectively lock the countershaft 72 to the housing 40 . A scissor or teeter-totter lever mechanism may be employed to simultaneously lock the countershaft 72 to the housing 40.

Referring to FIGS. 5-7 , an optional parking lock mechanism 200 may be incorporated into drive unit 30 . The parking lock mechanism 200 may include a pair of parking gears 202, a pawl 204, a pair of plungers 206, a pair of plunger bias springs 208, and an actuator 210.

Each parking gear 202 can be non-rotatably coupled to an associated one of the countershafts 72 and can form a plurality of teeth 216 and a plurality of valleys 218 . Each trough 218 is disposed between each pair of teeth 216 .

The pawl 204 includes a pawl body 220 and a pair of pawl teeth 222 disposed at both ends of the pawl body 220 . In the pawl body 220, each pawl tooth 222 is coupled to an associated one of the parking gear 202 (ie, each pawl tooth 222 is associated with one valley of the parking gear 202 ( 218) to rotationally lock the parking gear 202 and countershaft 72 relative to the housing 40 ( FIG. 6 ) and the pawl 204 to the parking gear 202 relative to the housing 40 or the disengaged position (FIG. 8) where each pawl tooth 222 is out of the teeth 216 on the associated one of the parking gears 202 so as not to inhibit rotation of the countershaft 72. It is pivotally coupled to the housing 40 of the drive unit 30 so that it can be moved. In the example provided, pivot axle 226 is mounted to housing 40 and extends through pawl 204 into actuator 210 . The pawls 204 are placed somewhat on the pivot axle 226 to ensure that the load transmitted through the parking lock mechanism 200 is shared equally by the parking gear 202 and equally by the pawl teeth 222. can be loosely accommodated. The pawl 204 can be biased about the pivot axle 226 toward a desired rotational position, such as a disengaged position. In the example provided, a helical torsion spring 258 is disposed around the pivot axle 226 and coupled to the housing 40 and pole body 220 .

Referring to FIG. 7 , each plunger 206 may have a plunger body with a guide portion 230, a first body portion 232, a transition portion 234, and a second body portion 236. . Guide portion 230 may be disposed on a first axial end of plunger 206 and may be cylindrical in shape with a first diameter. The first body portion 232 may be disposed between the guide portion 230 and the transition portion 234 and may be sized in any desired manner. For example, first body portion 232 can be generally cylindrical in shape with a desired diameter equal to the first diameter. In the example provided, the first body portion 232 has a diameter equal to the first diameter and the outer surface of the first body portion 232 by a desired amount, such as 2 degrees to 30 degrees, preferably 5 degrees to 15 degrees, the guide portion. Between 230 and transition portion 234 is a base (where first body portion 232 intersects guide portion 230) with a relatively shallow cone angle that tapers inward toward the central axis of plunger 206. It has the shape of a truncated cone.

The second body portion 236 can also be cylindrical in shape, but has a second diameter smaller than the first diameter. Transition portion 234 may be formed in a truncated cone shape tapering between first body portion 232 and second body portion 236 . A spring opening 240 may be formed in the first axial end of the plunger 206 and is sized to receive a corresponding one of the plunger bias springs 208 therein. In the examples provided, each plunger bias spring 208 is a helical coil compression spring, but it will be appreciated that other types of springs may be used in place of or in addition to helical coil compression springs.

Each plunger 206 and plunger bias spring 208 are received within a plunger opening 244 of housing 40 . In the illustrated example, housing 40 includes any pair of plunger bushings 246 that may be formed from any suitable material, such as hardened steel. Each plunger bushing 246 defines a plunger opening 244 sized to receive a first body portion 232 of a corresponding one of the plungers 206 and a corresponding one of the plunger bias spring 208. The plunger opening 244 may be a blind hole such that the plunger bushing 246 forms an inner wall 248 against which the end of a corresponding one of the plunger bias springs 208 may abut.

Each plunger 206 has an extended position (shown in FIGS. 6 and 7 ) and a retracted position (shown in FIGS. 6 and 7 ) and a retracted position (shown in FIGS. 8 and 9) relative to the housing 40 along its longitudinal axis. To position the plunger 206 in the extended position, the pawl teeth 222 must engage the parking gear 202. When the outer surface of the first body portion 232 is tapered (truncated conical), the plunger bias spring 208 causes the outer surface of the first body portion 232 of each plunger 206 to form a pole body 220. will press the plunger 206 outwardly from the plunger opening 244 to contact the . When plunger 206 is placed in its retracted position, pawl 204 can be rotated via torsion spring 258 to its disengaged position. When the pawl 204 is in the disengaged position, the pawl 204 may contact the second body portion 236 of one or both of the plungers 206 .

7 and 10, actuator 210 is configured to control movement of plunger 206 between extended and retracted positions. The actuator 210 includes a pair of cam followers 250, an actuator hub 252, a cam plate 254, a bearing 256, a torsion spring 258, a rotary actuator 260, and a locking actuator 262. can include

Referring to FIGS. 7 and 9 , each cam follower 250 may be disposed in series with an associated one of the plungers 206 . In the example provided, each cam follower 250 is monolithically and integrally formed with an associated one of the plungers 206 . More specifically, the cam follower 250 can be a spherical radius on the second axial end of the plunger 206 opposite the first axial end.

Actuator hub 252 may be fixedly coupled to housing 40 concentrically about an axis about which pole 204 pivots. In the example provided, actuator hub 252 is press-fitted to pivot axle 226 . The actuator hub 252 may include a central portion 270 , a bearing mount 272 and a lock actuator mount 274 . The central portion 270 may define a pivot axle opening 280 and a threaded opening 282 aligned along a common axis. The pivot axle opening 280 is formed through the first axial side of the central portion 270 and is sized to engage the pivot axle 226 in a press fit manner. A threaded opening 282 is formed through the second opposing axial side of the central portion 270 . A bearing mount 272 may be concentrically disposed about the central portion 270 and coupled to the central portion 270 through a flange member 284 or alternatively through a plurality of spokes or webs. can The bearing mount 272 has an outer circumferential surface 286, a shoulder 288 extending radially outward from the outer circumferential surface, and a retaining ring groove 290 formed into the outer circumferential surface 286. The lock actuator mount 274 may have a bean-shaped (i.e., bean) shape, best seen in FIG. 5, and may be fixedly coupled to the bearing mount 272 radially offset from the central portion 270. (eg, may be formed monolithically with it).

5, 7, and 11, the cam plate 254 includes an annular plate 300, a gear portion 302, a torsion spring mounting portion 304, and a pair of sensor targets 306a and 306b. can include The annular plate 300 may be formed of any suitable material. The annular plate 300 may have an inner circumferential surface 310 and may form a pair of cams 312 . Each cam 312 is formed into a first face of the annular plate 300 facing the cam follower 250 and the plunger 206 . Each cam 312 may be a circumferentially extending groove in the first face of the annular plate 300 . Each cam 312 may taper between a first circumferential end 320 ( FIG. 11 ) of the deepest groove and a second opposing circumferential end 322 ( FIG. 11 ) of the shallowest groove. there is. Each cam follower 250 has a cam 312 (i.e., a groove) such that rotation of the cam plate 254 about the axis about which the pawl 204 pivots causes a corresponding linear motion of the plunger 206. ) can be accommodated into the corresponding one of More specifically, the cam longitudinal into the deepest portion of the associated one of the cams 312 (ie, the first circumferential end 320 of the groove forming the associated one of the cams 312) as shown in FIG. 7 . The placement of the east portion 250 allows a corresponding one of the plunger bias springs 208 to urge the associated one of the plungers 206 into its extended position while the associated one of the cams 312 as shown in FIG. The placement of the cam follower 250 at the shallowest portion of the (i.e., the second circumferential end of the groove forming the associated one of the cams 312) counteracts the deflection of the corresponding one of the plunger bias springs 208. A corresponding one of the plungers 206 is positioned in its retracted position. Gear portion 302 may include a plurality of gear teeth that may be fixedly coupled to annular plate 300 such that the gear teeth are concentric with inner circumferential surface 310 . In the example provided, the gear teeth are monolithically and integrally formed with the annular plate 300 . The gear teeth may be disposed around the entire circumference of the annular plate 300 as shown in the example provided, or may be formed around one sector of the annular plate 300. The torsion spring mount 304 may be a cylindrical post or protrusion that may extend from a second side of the annular plate 300 opposite the first side. Each sensor target 306a, 306b can be mounted on annular plate 300 and is activated by sensor 328 (FIG. 10) when cam plate 254 is in a predetermined rotational position relative to housing 40. configured to be detected. In the example provided, each sensor target 306a, 306b is a magnet, and sensor 328 is a Hall effect sensor coupled to housing 40.

Referring to FIG. 7 , a bearing 256 is configured to support the cam plate 254 for rotation relative to the actuator hub 252 . The bearing 256 can include an inner bearing race 330, an outer bearing race 332, and a plurality of bearing elements 334 received between the inner bearing race 330 and the outer bearing race 332. The inner bearing race 330 can be received onto the outer circumferential surface 286 of the bearing mount 272 and can abut against the shoulder 288 . If desired, the inner bearing race 330 can be press-fitted to the outer circumferential surface 286 of the bearing mount 272 . An outer retaining ring 336 may be received within the retaining ring groove 290 and may inhibit axial movement of the inner bearing race 330 on the actuator hub 252 in a direction away from the shoulder 288 . The outer bearing race 332 can be coupled to the cam plate 254 in any desired manner. For example, the outer bearing race 332 may be press-fit or adhesively bonded to the inner circumferential surface 310 of the annular plate 300 . Alternatively, where the annular plate is formed from a plastic material, the annular plate 300 can be overmolded onto the outer bearing race 332 such that the outer bearing race 332 is adhesively bonded to the annular plate 300. .

5 and 7 , a torsion spring 258 may be wound around a central portion 270 and may include a cam plate and a first tang 340 that may react against the actuator hub 252. It may have a second tang 342 that can counteract the torsion spring mount 304 on 254 . In the example provided, first tang 340 is received into a hole formed in flange member 284 . Torsion spring 258 may be secured to central portion 270 via washer 346 and threaded fastener 348 threaded into threaded opening 282 of central portion 270 . The torsion spring 258 is configured to rotationally bias the cam plate 254 about its axis of rotation toward a first rotational position, the deepest portion of the cam 312 at the cam follower 250. It may be a position for orientation with respect to. Alternatively, torsion spring 258 may be configured to rotationally bias cam plate 254 about its axis of rotation into a position where the shallowest portion of cam 312 is oriented relative to cam follower 250. .

Referring to FIG. 10 , the rotary actuator 260 is configured to control the rotation of the cam plate 254 about the axis of rotation of the cam plate between a first rotational position and a second rotational position. Rotary actuator 260 may include a rotary electric motor (not specifically shown) and an output pinion (not specifically shown) meshingly coupled to gear teeth of gear portion 302 of cam plate 254. . An electric motor may be coupled (eg, mounted) to the housing 40 . The output pinion is either directly driven by the electric motor (eg, the output pinion is mounted on the output shaft of the electric motor) or one or more gears (not shown) disposed in the power transmission path between the electric motor and the output pinion. It can be driven through a transmission (not shown) having.

The electric motor can be operated to drive the cam plate 254 to a second rotational position, which position the opposite circumferential end of the cam 312, eg, the shallowest portion of the cam 312, to the cam follower ( 250) may be a position for orientation. In some forms, an electric motor may be employed to drive the cam plate 254 to a desired rotational position and thereafter hold the cam plate 254 in this rotational position. Optionally, the cam plate 254 is a stop member (not shown) that abuts a mating stop member (not shown) coupled to the housing 40 when the electric motor rotates or drives the cam plate 254 to a desired rotational position. not) can be configured to have. However, in the example provided, sensor target 306b, sensor 328, and lock actuator 262 are employed to hold cam plate 254 in a desired rotational position so that power to the electric motor does not need to be maintained. .

The placement of cam plate 254 into each of the first and second rotational positions can be sensed by sensor 328 , which can respond to this and generate a corresponding sensor signal. For example, placement of cam plate 254 in a first rotational position orients sensor target 306a relative to sensor 328 and sensor 328 generates a first sensor signal in response, while generating a first sensor signal. Placing the cam plate 254 in the two rotational position orients the sensor target 306b relative to the sensor 328 and the sensor 328 generates a second sensor signal in response. In response to receiving the second sensor signal, a controller (not shown) is configured to inhibit rotation of the cam plate 254 out of the second rotational position (i.e., to the cam plate 254 by the torsion spring 258). (due to the applied moment) may control the lock actuator 262 to engage the lock actuator 262 with the cam plate 254.

Referring to FIGS. 10 and 12 , the lock actuator 262 may include any means for inhibiting rotation of the cam plate 254 relative to the housing 40 . In the example provided, lock actuator 262 includes solenoid assembly 400 and lock opening 402 . Solenoid assembly 400 may be coupled to housing 40 and may include solenoid 410 , solenoid plunger 412 and solenoid spring 414 . Solenoid plunger 412 is movable on solenoid 410 between an extended or latched position and a retracted or unlatched position. Solenoid spring 414 biases solenoid plunger 412 into an extended or latched position. The locking opening 402 is formed in the second side of the annular plate 300 and is configured to receive the solenoid plunger 412 therein when the cam plate 254 is in the second rotational position. In the example shown, the solenoid plunger 412 has a tip 420 formed by a spherical radius, and the locking opening 402 has a truncated conical sidewall 422 . The tip 420 of the solenoid plunger 412 and the contours of the sidewall 422 of the locking opening 402 are coupled to the solenoid plunger 412 via the torsion spring 258 when the solenoid 410 or electric motor is not energized. is driven towards the retracted or unlatched position.

5, 7, and 12, when power is not provided to the electric motor or solenoid 410 during operation of the drive unit 30, the torsion spring 258 is cam as shown in FIG. The deepest portion of 312 biases the cam plate 254 to a first rotational position aligned with the cam follower 250, so as shown in FIG. ) is disposed in its extended position to contact the pawl body 220 and the pawl 204 is disposed around the pivot axle 226 such that the pawl teeth 222 engage the parking gear 202. In this state, the countershaft 72 is substantially non-rotatably locked to the housing 40 and is transmitted through each pawl tooth 222 and each parking gear 202 due to the construction of the parking lock mechanism 200. load is the same. In this state, sensor target 306a is aligned with sensor 328, and sensor 328 generates a first sensor signal in response thereto. The first sensor signal may be received by a controller (not shown), indicating that the cam plate 254 is in a rotational position that causes the parking lock mechanism 200 to lock the countershaft 72 to the housing 40. can be employed to determine The solenoid spring 414 of the lock actuator 262 biases the tip 420 of the solenoid plunger 412 against the second face of the annular plate 300 .

Cam plate 254 in a first direction of rotation about the axis of rotation of the cam plate to unlock the countershaft 72 from the housing 40 to allow rotation of the countershaft 72 relative to the housing 40. ) may be energized to an electric motor to drive the output pinion to cause a corresponding rotation of . Rotation of the cam plate 254 in the first direction of rotation aligns the progressively shallower portion of the groove or cam 312 relative to the cam follower 250 as shown in FIG. 9 so that the plunger 206 It moves from its extended position toward its retracted position. Due to the tapered configuration of the first body portion 232 and the transition portion 234 of the plunger 206 and the moment applied to the pawl 204 by the torsion spring 258, the pawl teeth 222 are 206 is progressively moved away from the teeth 216 of the parking gear 202 as it progressively moves toward its retracted position. As shown in FIGS. 8 and 9 , the placement of the pawl 204 in contact with the second body portion 236 of the plunger 206 is such that the parking gear 202 and consequently the countershaft 72 are connected to the housing 40. Position the pawl teeth 222 away from the parking gear 202 in a position where they can rotate freely with respect to . Further rotation of the cam plate 254 in the first rotational direction positions the cam plate 254 in a second rotational position, which orients the sensor target 306b relative to the sensor 328 to make the sensor ( 328) in response to generate a second sensor signal. In response to receiving the second sensor signal, the controller can provide power to solenoid 410 to drive solenoid plunger 412 into lock opening 402 and hold solenoid plunger 412 in this position. Optionally, the controller may also terminate supply of power to the motor. The moment applied to the cam plate 254 by the torsion spring 258 to urge the cam plate 254 toward the first rotational position causes the solenoid plunger 412 to open the lock opening ( 402) is insufficient to press out.

To lock the countershaft 72 back to the housing 40 to inhibit rotation of the countershaft 72 relative to the housing 40, the supply of power to the solenoid 410 is terminated. The moment applied to the cam plate 254 by the torsion spring 258 to urge the cam plate 254 toward the first rotational position overcomes the force applied by the solenoid spring 414 to the solenoid plunger 412 and This is sufficient to force the solenoid plunger 412 out of the lock opening 402. A moment applied to cam plate 254 by torsion spring 258 causes cam plate 254 to rotate in a second rotational direction opposite to the first rotational direction. Rotation of the cam plate 254 in the second rotational direction causes the gear teeth of the gear portion 302 to back-drive the output pinion as the cam plate 254 rotates toward and into the first rotational position. (back-drive). Rotation of the cam plate 254 in the second direction of rotation also aligns the progressively deeper portion of the groove or cam 312 with respect to the cam follower 250 so that the plunger 206 extends from its retracted position. move to position Due to the tapered configuration of the first body portion 232 and the transition portion 234 of each plunger 206, the pole body 220 and the plunger when the cam plate 254 is rotated in the second rotational direction ( Contact between 206 drives pawls 204 about pivot axle 226 such that pawl teeth 222 rotate toward their respective parking gears 202 . The pawl teeth 222 can move directly into the valleys 218 of the parking gear 202 in situations where the parking gear 202 is oriented in the stowed position. In another situation, movement of the pawl teeth 222 into the trough 218 is such that the parking gear 202 is at a position where each pawl tooth 222 contacts an associated one of the teeth of the parking gear 202. Since it is oriented as , it can be blocked. However, the plunger bias spring 208 moves the plunger 206 to its extended position when the countershaft 72 is slightly rotated (the outer surface of the first body portion 232 is engaged with the pawl 204 so that the pawl teeth ( 222) to be driven into engagement with the parking gear 202) to provide compliance.

The foregoing description of the embodiments has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment and, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same can also be varied in numerous ways. Such changes are not to be regarded as a departure from this disclosure, and all such changes are intended to be included within the scope of this disclosure.

Claims (10)

An electric drive module 24 for a vehicle,
an electric motor (42) with a motor output shaft (56);
driven gear 66;
differential assembly 46 driven by driven gear 66;
As a transmission 44 that transmits rotational power between the electric motor 42 and the driven gear 66, the transmission 44 includes a driving gear 60, a pair of first reduction gears 62, and a pair of a second reduction gear (64), drive gears (60) coupled to the motor output shaft (56) for rotation together about a first axis (58), each first reduction gear (62) having meshingly coupled to the drive gear 60 and rotatable about respective second shafts 74, the second shafts 74 being spaced from each other and parallel to the first shaft 58; gear 64 meshingly coupled to driven gear 66 and fixedly and non-rotatably coupled to an associated one of first reduction gears 62 to form a compound reduction gear 70;
housing 40 in which transmission 22 and differential assembly 46 are housed;
a pair of parking gears (202), each parking gear (202) non-rotatably coupled to an associated one of the second reduction gears (64);
A pawl 204 having a pair of pawl teeth 222, the pawls 204 coupled to the housing 40, each pawl tooth 222 to a corresponding one of the parking gears 202. a pawl 204 pivotable between an engaged position in which it is engaged and a disengaged position in which the pawl teeth 222 are disengaged from the parking gear 202; and
A pair of plungers (206) movable between first and second positions, each plunger (206) having a smaller diameter than the first body portion (232) and the second body portion (232). 236, contact between the first body portion 232 of the plunger 206 and the pawl 204 places the pawl 204 in the engaged position, and the pawl 204 has the second body portion 232 of the plunger 206. a pair of plungers (206), disposed in a disengaged position when the body portion (236) contacts the pawl (204);
The driven gear 66 is rotatable about the third axis 76,
Each composite reduction gear 70 is disposed on each countershaft 72 rotating about each second shaft 74 and is integrally formed with each countershaft 72 for a vehicle electric drive module 24 ). According to claim 1,
When the pawl 204 is in the engaged position, the first load transmitted between the first pawl tooth of the pawl teeth 222 and the first parking gear of the parking gear 202 is the first of the pawl teeth 222. The vehicle electric drive module 24 equal to the second load transmitted between the two pole teeth and the second parking gear of the parking gear 202. According to claim 1,
The pawl 204 is pivotably disposed on the pivot axle 226, and the fit between the pawl 204 and the pivot axle 226 is the load transmitted between the pawl teeth 222 and the parking gear 202. An electric drive module (24) for a vehicle that allows non-rotational movement of the pawl (204) relative to the pivot axle (226) such that According to claim 1,
The vehicle electric drive module (24), wherein the first body portion (232) of the plunger (206) is truncated cone-shaped. According to claim 4,
Each plunger 206 further includes a transition portion 234 disposed between the first body portion 232 and the second body portion 236, the transition portion 234 being shaped like a truncated cone, and The vehicular electric drive module (24) wherein the cone angle of the portion (232) is smaller than the cone angle of the transition portion (234). According to claim 1,
It further includes an actuator 210 for controlling movement of the plunger 206 between the first and second positions, the actuator 210 comprising an actuator hub 252, a cam plate 254, and a plurality of cams. comprising a follower 250, an actuator hub 252 coupled to the housing 40, and a cam plate 254 rotatable about the actuator hub 252 and forming a pair of cams 312 And, each cam 312 is a circumferentially extending groove having a depth that tapers between the first circumferential end 320 and the second circumferential end 322, and each cam follower 250 has a cam ( 312) and disposed in line with the associated one of the plungers 206. According to claim 6,
Each cam follower (250) is rigidly coupled to an associated one of the plungers (206). According to claim 6,
The actuator 210 further includes a torsion spring 258 disposed between the actuator hub 252 and the cam plate 254, the torsion spring 258 holding the cam plate 254 relative to the actuator hub 252. Electric drive module 24 for vehicles biasing towards the 1 turn position. According to claim 6,
The actuator 210 further includes a locking actuator 262, the locking actuator 262 having a solenoid assembly 400 and a locking opening 402, the solenoid assembly 400 having a solenoid plunger 412, locking An aperture 402 is formed in the cam plate 254 and the solenoid assembly 400 allows the cam plate 254 to align the second circumferential end 322 of the cam 312 relative to the cam follower 250. A vehicle electric drive module (24) that, when rotated to a rotational position, is energized to cause the solenoid plunger (412) to be received into the lock opening (402) and engaged to the cam plate (254). According to claim 6,
An electric drive module (24) for a vehicle in which a bearing (256) is disposed radially between the actuator hub (252) and the cam plate (254).

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