Electronic locking differential

Abstract

A locking differential transitions between a locking configuration and a non-locking configuration via an axially movable locking arrangement. The locking arrangement includes pins maintaining a constant distance between a locking plate and a magnetizable armature. Energizing an electro-magnet attracts the armature so that the entire locking arrangement is pulled to the locking configuration. A spring biases the locking arrangement back to the non-locking configuration when energization ceases.

Description

ELECTRONIC LOCKING DIFFERENTIALCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to Indian Provisional Application Nos. 202311065490, filed September 29, 2023; and 202411065511, filed August 30, 2024; the disclosures of which are hereby incorporated by reference in their entireties.BACKGROUND

[0002] During normal operation of a motor vehicle, it is common that all four wheels are not turning at an identical rate of speed. Different wheel turn rates are most commonly encountered when the vehicle is making a turn, but may also be caused by braking or non- uniform road surface conditions. In order to accommodate differing wheel turning rates while continuing to direct power to two wheels, a differential is configured to allow for different wheel turn rates between the powered wheels. The differential allows the wheels to spin at different rates while transmitting torque to each wheel.

[0003] While this solution may be satisfactory in some driving conditions, it is unsatisfactory under conditions where one of the driven wheels experiences a surface having a much lower coefficient of friction than a surface engaged by the other wheel(s). Such conditions may prevent the application of torque to a wheel with more traction, thereby resulting in undesired vehicle performance. A locking mechanism may be provided to lock the differential and prevent different wheel spin rates and transmit torque uniformly between two wheels in at least some circumstances.SUMMARY

[0004] In accordance with certain aspects of the disclosure, a differential assembly comprising: a stator including an electro-magnet; a gear housing configured to rotate relative to the stator; a differential gear set disposed within the gear housing, the differential gear set including a locking gear; and a locking arrangement disposed at the gear housing. The locking arrangement includes: a locking member, an armature, a biasing member, and a pin. The locking member is disposed within the gear housing. The locking member is movable relative to the locking gear between a locking position and a non-locking position. The armature is disposed external of the gear housing. The armature is axially movable relative to the stator between first and second positions. The armature is configured to move to the second position when the electro-magnet is energized. The biasing member is configured tobias the armature to the first position. The pin extends between the locking member and the armature. The pin is configured to maintain a separation distance between the locking member and the armature so that the locking arrangement travels axially as a unit relative to the gear housing. The locking member is disposed in the non-locking position when the armature is disposed in the first position and the locking member is disposed in the locking position when the armature is disposed in the second position.

[0005] In some examples, the biasing member is disposed external of the gear housing. In other examples, the biasing member is disposed within the gear housing.

[0006] In some examples, the locking member includes a locking collar having radial teeth. In other examples, the locking member includes a locking plate having axial teeth.

[0007] In accordance with certain aspects of the disclosure, a differential assembly includes a locking arrangement that is moveable relative to a gear housing. The locking arrangement includes a locking plate; an armature; and a pin. The locking plate is movable relative to a locking gear within the gear housing between a locking position and a nonlocking position. The locking plate engages the locking gear to rotationally fix the locking plate and locking gear together when in the locking position. The locking plate is rotatable relative to the locking gear when in the non-locking position. The armature includes an armature that is axially movable between first and second positions. The armature is biased to the first position. The armature is formed of a magnetizable material (e.g., a ferrous material). A first end of the pin is axially fixed to the locking plate and a second end of the pin is axially fixed to the armature.

[0008] In certain implementations, the locking plate is disposed at an opposite side of the differential gear set from the armature. In certain examples, the locking plate is disposed within the differential housing and the armature is disposed external of the gear case. In certain examples, the pin extends through the differential housing between the locking plate and the armature.

[0009] In certain implementations, the pin is one of a plurality of pins. A first end of each pin is axially fixed to the locking plate and a second end of each pin is axially fixed to the armature.

[0010] In certain implementations, the pin can be threaded, clipped (e.g., using a circlip), press-fit, welded, fastened (e.g., with threaded screw, with set screw, with split pin or other peg), or otherwise secured to the armature and / or locking plate.

[0011] In accordance with other aspects of the disclosure, a method of operating a locking differential includes: energizing an electro-magnet to attract a ferrous armature from a first position to a second position against a biasing force; and moving a locking plate in unison with the armature by pulling on a pin connecting the locking plate with the armature so that the locking plate moves from a non-locking position to a locking position.

[0012] In certain implementations, the method also includes deenergizing the electromagnet to enable the biasing force to move the armature back to the first position.

[0013] In accordance with other aspects of the disclosure, a locking differential includes a stator including an electro-magnet; a gear housing configured to rotate relative to the stator; a differential gear set including a locking gear; and a locking arrangement mounted to the gear housing. The locking arrangement includes a locking plate; an armature; a biasing member; and a pin. The locking plate is disposed within the gear housing. The locking plate is movable relative to the locking gear between a locking position and a non-locking position. The armature is disposed external of the gear housing. The armature is configured to rotate with the gear housing relative to the stator. The armature is axially movable relative to the stator between first and second positions. The armature is configured to move to the second position when the electro-magnet is energized. The biasing member is disposed between the stator and the armature to bias the armature to the first position. The pin extends between the locking plate and the armature. The pin is configured to maintain a separation distance between the locking plate and the armature so that the locking plate is disposed in the nonlocking position when the armature is disposed in the first position and the locking plate is disposed in the locking position when the armature is disposed in the second position.

[0014] In certain implementations, the biasing member is disposed external of the differential housing.

[0015] A variety of additional inventive aspects will be set forth in the description that follows. The inventive aspects can relate to individual features and to combinations of features. It is to be understood that both the forgoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the broad inventive concepts upon which the embodiments disclosed herein are based.BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The accompanying drawings, which are incorporated in and constitute a part of the description, illustrate several aspects of the present disclosure. A brief description of the drawings is as follows:

[0017] FIG. l is a cross-sectional view of an example locking differential including a locking arrangement configured in accordance with the principles of the present disclosure.

[0018] FIG. 2 is a perspective view of the locking differential of FIG. 1 with the case housing removed for ease in viewing the locking arrangement.

[0019] FIG. 3 is an enlarged view of a portion of FIG. 1.

[0020] FIG. 4 is a perspective view of an example pin suitable for use with the locking arrangement of FIG. 1.

[0021] FIG. 5 is a perspective view of an example locking plate suitable for use with the locking arrangement of FIG. 1.

[0022] FIG. 6 is a perspective view of an example locking gear suitable for use with the locking arrangement of FIG. 1.

[0023] FIG. 7 is a perspective view of an example armature suitable for use with the locking arrangement of FIG. 1.

[0024] FIG. 8 is an enlarged view of a portion of FIG. 3, except with the second end of the pin modified to press-fit into the mounting station of the armature.

[0025] FIG. 9 shows a weld disposed at the mounting station of FIG. 8.

[0026] FIG. 10 shows a pin held at the armature mounting station using a first type fastener.

[0027] FIG. 11 shows a pin held at the armature mounting station using a second type fastener.

[0028] FIG. 12 shows a pin held at the armature mounting station using a third type fastener.

[0029] FIG. 13 shows the pin being disposed loosely within the passage of the locking differential housing.

[0030] FIG. 14 is a perspective view of another example locking differential including a locking arrangement configured in accordance with the principles of the present disclosure.

[0031] FIG. 15 is a first perspective view of the components of the locking differential of FIG. 14 exploded away from each other.

[0032] FIG. 16 is a second perspective view of the components of the locking differential of FIG. 14 exploded away from each other.

[0033] FIG. 17 is a first perspective view of an example locking arrangement suitable for use with the locking differential of FIG. 14, the locking arrangement including a locking plate, an armature, and a plurality of pins.

[0034] FIG. 18 is a second perspective view of the locking arrangement of FIG. 17.

[0035] FIG. 19 is a cross-sectional view of the locking differential of FIG. 14.

[0036] FIG. 20 is a perspective view of another example locking differential including a locking arrangement configured in accordance with the principles of the present disclosure.

[0037] FIG. 21 is a first perspective view of the components of the locking differential of FIG. 20 exploded away from each other.

[0038] FIG. 22 is a second perspective view of the components of the locking differential of FIG. 20 exploded away from each other.

[0039] FIG. 23 is a first perspective view of an example locking arrangement suitable for use with the locking differential of FIG. 20, the locking arrangement including a locking plate, an armature, and a plurality of pins.

[0040] FIG. 24 is a second perspective view of the locking arrangement of FIG. 23.

[0041] FIG. 25 is a cross-sectional view of the locking differential of FIG. 20.

[0042] FIG. 26 is a perspective view of a gear case having a travel limiting physical stop.

[0043] FIG. 27 shows how the physical stop of FIG. 26 maintains a gap between the armature and the stator.DETAILED DESCRIPTION

[0044] Reference will now be made in detail to exemplary aspects of the present disclosure that are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

[0045] FIG. 1 shows a locking differential 100, 200, 300 for a vehicle. The locking differential 100, 200, 300 includes a gear housing 102, 202, 302 (e.g., a gear case 104, 204, 304 and an end cap 106, 206, 306) configured to rotate about a longitudinal axis L of the gear housing 102, 202, 302. Torque input to the locking differential 100, 200, 300 can be provided by an input ring gear (not shown) to a flange 105, 205, 305 of the gear housing 102, 202, 302. The rotatable housing 102, 202, 302 defines a gear chamber 112, 212, 312 in which a differential gear set 114, 214, 314 is disposed. The differential gear set 114, 214, 314 includes a first side gear 126, 226, 326 and a second side gear 128, 228, 328 coupled together by pinion gears.

[0046] The gear housing 102, 202, 302 defines annular hub portions 108, 208, 308 and 110, 210, 310 at which left and right axle shafts, respectively, are coupled. A pair of bearing sets (not shown) disposed at the annular hub portions 108, 208, 308, 110, 210, 310 providerotational support for the rotating differential device 100, 200, 300 relative to an outer differential housing or "carrier" (also not shown). In certain implementations, a thrust sleeve 207, 307 is disposed between the first side gear 226 and the housing 202 (e.g., the end cap 206). The thrust sleeve 207, 307 inhibits wear and tear on the end cap 206, 306.

[0047] The locking differential 100, 200, 300 can be operated in a locked mode or an unlocked mode. When operated in the locked mode, one or both side gears of the differential gear set 114, 214, 314 are locked against rotation relative to the gear housing 102, 202, 302. When operated in the unlocked mode, the side gears 126, 128 are free to spin relative to the gear housing 102, 202, 302. For example, a first side gear 126, 226, 326 and a second side gear 128, 228, 328 may be configured to independently rotate about the longitudinal axis L of the gear housing 102, 202, 302. In some implementations, the locking differential 100, 200, 300 is transitioned between locked and unlocked modes manually by a user. In other implementations, the locking differential 100, 200, 300 is transitioned between locked and unlocked modes automatically (e.g., by a microprocessor of the vehicle based on a sensed operational condition of the vehicle).

[0048] The locking differential 100, 200, 300 includes a locking arrangement 118, 218, 318 that can be transitioned between a locking configuration and a non-locking configuration. When disposed in the locking configuration, the locking arrangement 118, 218, 318 inhibits independent rotation of the side gear 126, 226, 326 from the gear housing 102, 202, 302. When disposed in the non-locking configuration, the locking arrangement 118, 218, 318 allows independent rotation of the side gear 126, 226, 326 relative to the gear housing 102, 202, 302.

[0049] In certain implementations, the locking arrangement 118, 218, 318 includes an armature 119, 219, 319 and a locking member 122, 222, 322 spaced apart by one or more pins 124, 224, 324 (e.g., pull / push rods). In the examples shown in FIGS. 1-19, the locking arrangement 118, 218, 318 includes three pins 124, 224, 324. In the example shown in FIGS. 20-26, the locking arrangement 118, 218, 318 includes four pins 124, 224, 324. Other configurations are possible. The pins 124, 224, 324 are configured to maintain a constant spacing between the armature 119, 219, 319 and the locking member 122, 222, 322. The locking member 122, 222, 322 is engaged with the gear housing 102, 202, 302 so that the locking member 122, 222, 322 spins in unison with the gear housing 102, 202, 302. The locking member 122, 222, 322 is configured to engage a locking gear 130, 230, 330 when the locking arrangement 118, 218, 318 is disposed in the locking configuration. The lockingmember 122, 222, 322 is disengaged from the locking gear 130, 230, 330 when the locking arrangement 118, 218, 318 is disposed in the non-locking configuration. In certain implementations, the locking gear 130, 230, 330 is integral with the side gear 126, 226, 326.

[0050] In certain implementations, the pins 124, 224, 324 extend through passages 103, 203, 303 defined in the gear housing 102, 202, 302 between the locking member 122, 222, 322 and the armature 119, 219, 319 (e.g., see FIG. 13). In some implementations, the pins 124, 224, 324 fit tightly within the passages 103, 203, 303 (e.g., see FIG. 1). In other implementations, the pins 124, 224, 324 fit loosely within the passages 103, 202, 303 (e.g., see FIG. 13). In some examples, the passages 103, 203, 303 extend through most of the gear chamber 112, 212, 312. In other examples, the passages 103, 203, 303 are interrupted at the gear chamber 112, 212, 312 (e.g., see FIG. 26). In certain examples, the passages 103, 203, 303 are interrupted by windows in the housing 302.

[0051] The armature 119, 219, 319 includes mounting stations 148, 248, 348 at which the pins 124, 224, 324 are received. The armature 119, 219, 319 is configured to rotate with the gear housing 102, 202, 302 relative to the stator 134, 234, 334. The pins 124, 224, 324 supply torque to the armature 119, 219, 319. The armature 119, 219, 319 is axially movable relative to the stator 134, 234, 334 between first and second positions. The stator 134, 234, 334 is disposed external to the gear housing 102, 202, 302. For example, the stator 134, 234, 334 may form a ring surrounding the annular hub portion 110, 210, 310. The gear housing 102, 202, 302 rotates relative to the stator 134, 234, 334. A snap-ring 136, 236 axially retains the stator 134, 234, 334 at the gear housing 102, 202, 302 (e.g., at the annular hub portion 110, 210, 310). The locking member 122, 222, 322 is disposed within the gear housing 102, 202, 302.

[0052] In certain implementations, the locking arrangement 118, 218, 318 is biased to the non-locking configuration by a biasing member 140, 240, 340 (e.g., wave spring). In certain implementations, the locking arrangement 118, 218, 318 is transitioned from the nonlocking configuration to the locking configuration against the bias of the biasing member 140, 240, 340 using an electro-magnet 132, 232, 332. In certain examples, the armature 119, 219, 319 is formed of ferrous material or other magnetizable material. When the electromagnet 132, 232, 332 is energized, the electro-magnet 132, 232, 332 attracts the armature 119, 219, 319, causing the armature 119, 219, 319 to move axially along the axis L relative to the gear housing 102, 202, 302. The armature 119, 219, 319 axially moves with a remainder of the locking arrangement 118, 218, 318 as a unit, thereby axially moving the lockingmember 122, 222, 322 to the locking configuration. Because the locking arrangement 118, 218, 318 moves unitarily with the armature 119, 219, 319, the state of the locking arrangement (e.g., locked or unlocked) can be determined from the position of the armature 119, 219, 319. In certain implementations, the position of the armature 119, 219, 319 can be determined based on the inductance.

[0053] In certain examples, the electro-magnet 132, 232, 332 is disposed at the stator 134, 234, 334. The stator 134, 234, 334 is disposed external of the gear housing 102, 202, 302. The armature 119, 219, 319 also is disposed external of the gear housing 102, 202, 302. For example, the armature 119, 219, 319 may be annular member surrounding the annular hub portion 110. In such examples, the armature 119, 219, 319 may ride over the gear housing 102, 202, 302 during axial movement.

[0054] In certain implementations, the locking arrangement 118, 218, 318 and gear housing 102, 202, 302 are configured to inhibit contact between the armature 119, 219, 319 and the stator 134, 234, 334. For example, the gear housing 102, 202, 302 may be configured to limit travel of the locking member 122, 222, 322 — and hence the locking arrangement 118,218, 318 — via a physical stop. In an example, the physical stop includes a shoulder 109, 209, 309 defined by the differential housing 102, 202, 302 (e.g., see FIGS. 26 and 27). In an example, the shoulder 109, 209, 309 is spaced a distance D from the lock member 122, 222, 322 when the locking arrangement 118, 218, 318 is disposed in the non-locking configuration. The distance D is less than a distance between the armature 119, 219, 319 and the stator 134, 234, 334 (e.g., see FIG. 27). Accordingly, the limited travel stops the locking arrangement 118, 218, 318 from sliding a sufficient distance for the armature 119, 219, 319 to contact the stator 134, 234, 334. Maintaining a gap (e.g., an air cap) between the armature 119, 219, 319 and the stator 134, 234, 334 reduces frictional drag on the torque being applied to the gear housing 102, 202, 302.

[0055] In some examples, the biasing member 140, 240, 340 is disposed external of the gear housing 102, 202, 302 (e.g., see FIG. 1). For example, the biasing member 140, 240, 340 can be disposed between the stator 134, 234, 334 and the armature 119, 219, 319. In an example, one axial end of the biasing member 140, 240, 340 may contact the armature 119,219, 319 while the opposite axial end of the biasing member 140, 240, 340 contacts the stator 134, 234, 334 or a bushing 141 (e.g., washer) abutting the stator 134, 234, 334 (e.g., see FIG. 3). In an example, the bushing 141 inhibits wear and tear on the biasing member 140, 240, 340 that would be caused by relative rotation between the biasing member and the stator. Inother examples, the biasing member 140, 240, 340 can be disposed internal of the gear housing 102, 202, 302 (e.g., see FIG. 13). For example, the biasing member 140, 240, 340 can be disposed between the locking member 122, 222, 322 and the gear housing 102, 202, 302. In certain examples, the biasing member 140, 240, 340 is disposed around the side gear 126, 226, 326.

[0056] In certain implementations, the locking arrangement 118, 218, 318 is assembled to move as a unit relative to the gear set 114, 214, 314 and gear housing 102, 202, 302. In certain implementations, the locking member 122, 222, 322 has an outer periphery configured to engage an inner surface of the gear housing 102, 202, 302 to rotationally fix the locking member 122, 222, 322 to the gear housing 102, 202, 302 while allowing the locking member 122, 222, 322 to move axially relative to the gear housing 102, 202, 302. In certain examples, the locking member 122, 222, 322 includes one or more ears 142, 242, 342 that slide along respective grooves 144, 244, 344 defined by the gear housing 102, 202, 302 (e.g., by the gear case 104, 204, 304). Engagement between the ears 142, 242, 342 and the grooves 144, 244, 344 inhibits rotation between the locking member 122, 222, 322 and the gear housing 102, 202, 302. The grooves 144, 244, 344 are sufficiently long to accommodate movement of the locking member 122, 222, 322 between the locking and non-locking configurations.

[0057] In certain implementations, the locking member 122, 222, 322 also is configured to engage the locking gear 130, 230, 330 when disposed in the locking configuration. In some implementations, the locking member 122 includes a locking collar having an inner periphery defining teeth 146 or other protrusions that intermesh with teeth of the locking gear 130. In certain examples, the locking gear 130 is formed around an outer periphery of the side gear 126. When in the locking configuration, the locking member 122 is axially positioned to radially align sufficiently with the locking gear 130 to mesh the teeth 146 with the locking gear 130. Cooperating between the teeth 146 and the locking gear 130 and cooperating between the ears 142and the grooves 144 causes the locking gear 130, and hence the side gear 126, to rotate in unison with the gear housing 102. When in the non-locking configuration (e.g., see FIG. 1), the locking member 122 is axially spaced out of radial alignment with the locking gear 130 so that the teeth 146 of the locking member 122 do not mesh with the locking gear 130. Accordingly, the locking gear 130, and hence the side gear 126, can spin independently of the gear housing 102 and locking member 122.

[0058] In other implementations, the locking member 222, 322 includes a locking plate having teeth 246, 346 (e.g., dog teeth) that axially engage with teeth of the locking gear 230, 330. In certain examples, the locking gear 230, 33 Ois disposed at an opposite side of the side gear 226, 326 from the gear teeth. When in the locking configuration, the locking member 222, 322 is axially positioned to mesh the axial teeth 246, 346 with the locking gear 230, 330. Cooperation between the teeth 246, 346 and the locking gear 230, 330 and cooperation between the ears 242, 342 and the grooves 244, 344 causes the locking gear 230, 330, and hence the side gear 226, 326, to rotate in unison with the gear housing 202, 302. When in the non-locking configuration, the locking member 222, 322 is axially spaced from the locking gear 230, 330 so that the teeth 246, 346 of the locking member 222, 322 do not engage with the locking gear 230, 330 (e.g., see FIGS. 19 and 25). Accordingly, the locking gear 230, 330, and hence the side gear 226, 326, can spin independently of the gear housing 202, 302, and locking member 222, 322.

[0059] In certain implementations, the locking member 122, 222, 322 includes a plurality of mounting stations 148, 248, 348 at which first ends 123 of the pins 124, 224, 324 are fixedly received. In some implementations, the first end 123 of the pins 124, 224, 324 extend through the mounting stations 148, 248, 348 and are clipped to the locking member 122, 222, 322 (e.g., using a circlip or other retainer). In other implementations, the first ends 123 of the pins 124, 224, 324 can be press-fit, welded, fastened, or otherwise secured at the mounting stations 148, 248, 348. In some implementations, the mounting stations 148, 248, 348 are formed in the ears 142, 242, 342 of the locking member 122, 222, 322. In certain examples, only some of the ears 142, 242, 342 form mounting stations 148, 248, 348. In certain implementations, the ears 142, 242, 342 forming the mounting stations 148, 248, 348 are larger than the other ears 142, 242, 342. In other implementations, the mounting stations 148, 248, 348 can be spaced from the ears 142, 242, 342.

[0060] In certain implementations, the armature 119, 219, 319 of the locking arrangement 118, 218, 318 has a first axial end facing towards the gear set and an opposite second axial end facing away from the gear set. The armature 119, 219, 319 defines a plurality of mounting stations 160, 260, 360 at the first axial end. The mounting stations 160, 260, 360 are configured to receive and axially fix second ends 125 of the pins 124, 224, 324. In certain implementations, the mounting stations 160, 260, 360 are configured to form positive connections with the second ends 125 of the pins 124, 224, 324. In certain implementations, each mounting station 160, 260, 360 defines an aperture sized to receive thesecond end 125 of a pin 124, 224, 324. In certain implementations, each mounting station 160, 260, 360 includes a raised rim surrounding the aperture. In some examples, a mounting station 160, 260, 360 can be straight. In other examples, a mounting station 160, 260, 360 can be tapered.

[0061] In some examples, the mounting stations 160, 260, 360 provide threaded apertures into which the second ends 125 of the pins 124, 224, 324 can be secured (e.g., see FIG. 3). In other examples, the mounting stations 160, 260, 360 define apertures into which the second ends 125 of the pins 124, 224, 324 can be press-fit (e.g., see FIG. 8). In other examples, the second ends of the pins 124, 224, 324 can be welded (see weld 150) to the armature 119, 219, 319 at the mounting stations 160, 260, 360 (e.g., see FIG. 9). For example, the pins 124, 224, 324 can be press-fit into the mounting stations 160, 260, 360 with welds 150. In other examples, the second ends 125 of the pins 124, 224, 324 can be fastened to the armature 119, 219, 319 using fasteners 152. A screw type fastener 152a is shown in FIG. 10 to secure a pin 124, 224, 324 to the armature 119, 219, 319 at the mounting station 160, 260, 360. A set screw type fastener 152a is shown in FIG. 11 to secure a pin 124, 224, 324 to the armature 119, 219, 319 at the mounting station 160, 260, 360. A split pin type fastener 152c is shown in FIG. 12 to secure a pin 124, 224, 324 to the armature 119, 219, 319 at the mounting station 160, 260, 360.

[0062] Examples of the disclosure may be described according to the following aspects.

[0063] Aspect 1. A differential assembly comprising: a stator including an electromagnet; a gear housing configured to rotate relative to the stator; a differential gear set disposed within the gear housing, the differential gear set including a locking gear; and a locking arrangement disposed at the gear housing. The locking arrangement includes: a locking member, an armature, a biasing member, and a pin. The locking member is disposed within the gear housing. The locking member is movable relative to the locking gear between a locking position and a non-locking position. The armature is disposed external of the gear housing. The armature is axially movable relative to the stator between first and second positions. The armature is configured to move to the second position when the electro-magnet is energized. The biasing member is configured to bias the armature to the first position. The pin extends between the locking member and the armature. The pin is configured to maintain a separation distance between the locking member and the armature so that the locking arrangement travels axially as a unit relative to the gear housing. The locking member is disposed in the non-locking position when the armature is disposed in thefirst position and the locking member is disposed in the locking position when the armature is disposed in the second position.

[0064] Aspect 2. The differential assembly of aspect 1, wherein the biasing member is disposed external of the gear housing.

[0065] Aspect 3. The differential assembly of aspect 1, wherein the biasing member is disposed within the gear housing.

[0066] Aspect 4. The differential assembly of aspect 1, wherein the locking member includes a locking collar having radial teeth.

[0067] Aspect 5. The differential assembly of aspect 1, wherein the locking member includes a locking plate having axial teeth.

[0068] Aspect 6. The differential assembly of any of aspects 1-5, wherein travel of the locking arrangement is limited to provide a gap between the armature and the stator when the armature is disposed in the second position.

[0069] Aspect 7. The differential assembly of any of aspects 1-6, wherein the armature includes a first mounting station configured to receive a first end of the pin; and wherein the locking member includes a second mounting station configured to receive the locking member.

[0070] Aspect 8. The differential assembly of aspect 7, wherein the first mounting station includes threads.

[0071] Aspect 9. The differential assembly of aspect 7, wherein the first end of the pin is press-fit at the first mounting station.

[0072] Aspect 10. The differential assembly of aspect 7, wherein the first end of the pin is welded to the armature at the mounting station.

[0073] Aspect 11. The differential assembly of aspect 7, wherein the first end of the pin is held at the first mounting station using a fastener.

[0074] Aspect 12. The differential assembly of aspect 11, wherein the fastener includes a horizontal screw.

[0075] Aspect 13. The differential assembly of aspect 11, wherein the fastener includes a set screw.

[0076] Aspect 14. The differential assembly of aspect 11, wherein the fastener includes a split pin.

[0077] Aspect 15. The differential assembly of any of aspects 1-15, wherein the pin is one of a plurality of pins that extend between the locking member and the armature.

[0078] Aspect 16. A method of operating a locking differential comprising: energizing an electro-magnet to attract a ferrous armature from a first position to a second position against a biasing force; and moving a locking plate in unison with the armature by pulling on a pin connecting the locking plate with the armature so that the locking plate moves from a non-locking position to a locking position.

[0079] Aspect 17. The method of aspect 16, further comprising deenergizing the electro-magnet to enable the biasing force to move the armature back to the first position.

[0080] Aspect 18. A locking arrangement for a locking differential, the locking arrangement including: a locking plate movable between a locking position and a nonlocking position relative to a locking gear of a locking differential, the locking plate engaging the locking gear to rotationally fix the locking plate and locking gear together when in the locking position, the locking plate being rotatable relative to the locking gear when in the non-locking position; an armature that is axially movable between first and second positions, the armature being biased to the first position, and the armature being formed of ferrous material; and a pin extending between opposite first and second ends, the first end of the pin being axially fixed to the locking plate and the second end of the pin being axially fixed to the armature.

[0081] Aspect 19. The locking arrangement of aspect 18, wherein the first end of the pin is clipped to the locking plate and the second end of the pin is threaded to the armature.

[0082] Aspect 20. The locking arrangement of any of aspects 18-19, further comprising a stator holding an electro-magnet, the electro-magnet configured to move the armature to the second position when the electro-magnet is energized, wherein the armature is biased to the first position by a biasing member disposed at an opposite side of the armature from the pin.

[0083] Aspect 21. A differential assembly comprising: a stator including an electromagnet; a gear housing configured to rotate relative to the stator; a differential gear set disposed within the gear housing, the differential gear set including a locking gear; a locking arrangement mounted to the gear housing, the locking arrangement including: a locking collar disposed within the gear housing, the locking collar being movable relative to the locking gear between a locking position and a non-locking position; an armature disposed external of the gear housing, the armature being configured to rotate with the gear housing relative to the stator, the armature being axially movable relative to the stator between first and second positions, the armature being configured to move to the second position when the electro-magnet is energized; a biasing member disposed between the stator and the armatureto bias the armature to the first position; and a pin extending between the locking collar and the armature, the pin being configured to maintain a separation distance between the locking collar and the armature so that the locking arrangement travels axially as a unit relative to the gear housing, wherein the locking collar is disposed in the non-locking position when the armature is disposed in the first position and the locking collar is disposed in the locking position when the armature is disposed in the second position.

[0084] Aspect 22. The differential assembly of aspect 1, wherein the biasing member is disposed external of the gear housing.

[0085] Aspect 23. The differential assembly of aspect 1, further comprising a bushing disposed between the biasing member and the stator.

[0086] Aspect 24. The differential assembly of aspect 1, wherein the biasing member includes a wave spring.

[0087] Aspect 25. The differential assembly of any of aspects 1-4, wherein travel of the locking arrangement is limited to provide a gap between the armature and the stator when the armature is disposed in the second position.

[0088] Aspect 26. The differential assembly of any of aspects 1-5, wherein one of the armature includes a mounting station, the mounting station being configured to receive a first end of the pin.

[0089] Aspect 27. The differential assembly of aspect 6, wherein the mounting station includes threads.

[0090] Aspect 28. The differential assembly of aspect 6, wherein the mounting station defines an aperture into which the first end of the pin can be press-fit.

[0091] Aspect 29. The differential assembly of aspect 6, wherein the first end of the pin is welded to the armature at the mounting station.

[0092] Aspect 30. The differential assembly of aspect 6, wherein the first end of the pin is held at the mounting station using a fastener.

[0093] Aspect 31. The differential assembly of aspect 10, wherein the fastener includes a horizontal screw.

[0094] Aspect 32. The differential assembly of aspect 10, wherein the fastener includes a set screw.

[0095] Aspect 33. The differential assembly of aspect 10, wherein the fastener includes a split pin.

[0096] Aspect 34. The differential assembly of aspect 1, wherein a second end of the pin is clipped to the locking collar.

[0097] Aspect 35. The differential assembly of any of aspects 1-14, wherein the pin is one of a plurality of pins that extend between the locking collar and the armature.

[0098] Having described the preferred aspects and implementations of the present disclosure, modifications and equivalents of the disclosed concepts may readily occur to one skilled in the art. However, it is intended that such modifications and equivalents be included within the scope of the claims which are appended hereto.

Claims

What is claimed is:

1. A differential assembly comprising: a stator including an electro-magnet; a gear housing configured to rotate relative to the stator; a differential gear set disposed within the gear housing, the differential gear set including a locking gear; a locking arrangement disposed at the gear housing, the locking arrangement including: a locking member disposed within the gear housing, the locking member being movable relative to the locking gear between a locking position and a non-locking position; an armature disposed external of the gear housing, the armature being axially movable relative to the stator between first and second positions, the armature being configured to move to the second position when the electro-magnet is energized; a biasing member configured to bias the armature to the first position; and a pin extending between the locking member and the armature, the pin being configured to maintain a separation distance between the locking member and the armature so that the locking arrangement travels axially as a unit relative to the gear housing, wherein the locking member is disposed in the non-locking position when the armature is disposed in the first position and the locking member is disposed in the locking position when the armature is disposed in the second position.

2. The differential assembly of claim 1, wherein the biasing member is disposed external of the gear housing.

3. The differential assembly of claim 1, wherein the biasing member is disposed within the gear housing.

4. The differential assembly of claim 1, wherein the locking member includes a locking collar having radial teeth.

5. The differential assembly of claim 1, wherein the locking member includes a locking plate having axial teeth.

6. The differential assembly of any of claims 1-5, wherein the gear housing defines a stop to limit travel of the locking arrangement to provide a gap between the armature and the stator when the armature is disposed in the second position.

7. The differential assembly of any of claims 1-6, wherein the armature includes a first mounting station configured to receive a first end of the pin; and wherein the locking member includes a second mounting station configured to receive the locking member.

8. The differential assembly of claim 7, wherein the first mounting station includes threads.

9. The differential assembly of claim 7, wherein the first end of the pin is press-fit at the first mounting station.

10. The differential assembly of claim 7, wherein the first end of the pin is welded to the armature at the mounting station.

11. The differential assembly of claim 7, wherein the first end of the pin is held at the first mounting station using a fastener.

12. The differential assembly of claim 11, wherein the fastener includes a horizontal screw.

13. The differential assembly of claim 11, wherein the fastener includes a set screw.

14. The differential assembly of claim 11, wherein the fastener includes a split pin.

15. The differential assembly of any of claims 1-15, wherein the pin is one of a plurality of pins that extend between the locking member and the armature.

16. A method of operating a locking differential comprising: energizing an electro-magnet to attract an armature from a first position to a second position against a biasing force, the armature being rotatable relative to the electro-magnet; and moving a locking member in unison with the armature by pulling on a pin connecting the locking member to the armature so that the locking member moves from a non-locking position to a locking position.

17. The method of claim 16, further comprising deenergizing the electro-magnet to enable the biasing force to move the armature back to the first position.

18. A locking arrangement for a locking differential having a locking gear, the locking arrangement including: a locking member movable between a locking position and a non-locking position relative to the locking gear of the locking differential, the locking member engaging the locking gear to rotationally fix the locking plate and the locking gear together when in the locking position, the locking member being rotatable relative to the locking gear when in the non-locking position; an armature that is axially movable between first and second positions, the armature being biased to the first position, and the armature being formed of magnetizable material; and a pin extending between opposite first and second ends, the first end of the pin being axially fixed to the locking member and the second end of the pin being axially fixed to the armature.

19. The locking arrangement of claim 18, wherein the first end of the pin is clipped to the locking member and the second end of the pin is threaded to the armature.

20. The locking arrangement of any of claims 18-19, further comprising a stator holding an electro-magnet, the electro-magnet configured to move the armature to the second position when the electro-magnet is energized, wherein the armature is biased to the first position by a biasing member disposed at an opposite side of the armature from the pin.

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