Electronic locking differential

Abstract

A differential assembly includes helical pinions and side gears with helical gear faces. In certain cases, the helical pinions and side gears are pre-mounted to a cage and then inserted into a case of the differential assembly as a unit. In certain cases, an electronic locking arrangement is mounted to the differential assembly. The locking arrangement includes a lock plate biased away from a lock gear. Pins extend through a case of the differential assembly to actuate the lock plate upon energization of an electric coil.

Description

ELECTRONIC LOCKING DIFFERENTIALCROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 595,470, filed November 2, 2023, the disclosure of which is incorporated by reference in its entirety.BACKGROUND

[0002] Traction modifying locking differentials typically include a gear case defining a gear chamber, and disposed therein, a differential gear set. Locking differentials that require torque sharing among multiple pinions may be found in various types of vehicles (e.g., combustion engines, electric engines, hybrid vehicles, etc.).SUMMARY

[0003] Aspects of the disclosure are directed to a differential assembly and methods of use thereof.

[0004] In accordance with some aspects, a differential assembly includes a case; a stator rotationally fixed relative to the case; a gear set disposed within the case; and a locking arrangement mounted to the case. The gear set includes a plurality of helical pinions in meshing engagement with a helical face gear. The helical face gear including a lock gear. The locking arrangement includes a lock plate, a biasing member, and a plurality of pins. The biasing member biases the lock plate to a releasing position relative to the lock gear. The pins extend through the case from the lock plate towards the stator.

[0005] In accordance with other aspects, a differential assembly includes a case defining an interior; an integral cage sized to fit within the interior. The cage includes a first abutment surface recessed inwardly from a first axial end and a second abutment surface recessed inwardly from a second axial end. The cage defines a bore extending through the first and second abutment surfaces. The cage defining a plurality of first channels extending axially inwardly from the first axial end and a plurality of second channels extending axially inwardly from the second axial end.

[0006] In accordance with other aspects, a differential assembly includes a case defining a bore; an integral cage sized to fit within the bore; and a plurality of helical pinions mounted at the cage. The cage defines first and second recessed surfaces facing outwardly from first and second axial ends of the cage. The cage defining a plurality of first channels extendingaxially inwardly from the first axial end and a plurality of second channels extending axially inwardly from the second axial end.

[0007] In accordance with other aspects, a method of assembling a differential assembly includes: mounting a plurality of helical pinions to a cage; and inserting the cage and the helical pinions into a case of the differential assembly as a unit. In certain implementations, the method also includes mounting side gears to the cage prior to inserting the cage into the case. In certain examples, inserting the cage and the helical pinions into the case includes inserting the side gears into the case as a unit with the helical pinions and cage.

[0008] In accordance with other aspects, a lock gear can be formed separate from a side gear and then rotationally fixed thereto to form a face gear of a differential gear set. For example, a face gear of a differential gear set may include a side gear and a lock collar. The side gear includes a body carrying side gear teeth. The body also carries a first part of a locking interface axially spaced from the side gear teeth. The lock collar mounts to the side gear. The lock collar carries lock gear teeth. The lock collar also defines a second part of the locking interface axially spaced from the side gear teeth. The second part of the locking interface is configured to engage the first part of the locking interface to rotationally fix the lock collar to the side gear. In certain examples, the side gear teeth include helical teeth. In certain examples, the lock gear teeth include dog teeth.

[0009] 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

[0010] 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:

[0011] FIG. l is a perspective view of a first example differential assembly configured in accordance with the principles of the present disclosure;

[0012] FIG. 2 is an exploded view of the first differential assembly of FIG. 1;

[0013] FIG. 3 is a cross-sectional view of the differential assembly of FIG. 2;

[0014] FIG. 4 is an axial cross-section taken of the first differential assembly of FIG. 1;

[0015] FIG. 5 is an enlarged view of a portion of FIG. 4;

[0016] FIG. 6 is a perspective view of a second example differential assembly configured in accordance with the principles of the present disclosure;

[0017] FIG. 7 is a first perspective view of the first differential assembly of FIG. 6 with select ones of the components exploded outwardly from each other;

[0018] FIG. 8 is a second perspective view of the first differential assembly of FIG. 6 with select ones of the components exploded outwardly from each other;

[0019] FIG. 9 is an axial cross-section taken of the second differential assembly of FIG. 6;

[0020] FIG. 10 is an enlarged view of a portion of FIG. 9;

[0021] FIG. 11 is a perspective view of an example gear assembly including a plurality of gears mounted to a cage;

[0022] FIG. 12 is a first perspective view of an example implementation of a cage suitable for use with the gear assembly of FIG. 11;

[0023] FIG. 13 is a second perspective view of the cage of FIG. 12;

[0024] FIG. 14 is an end view of the cage of FIG. 12;

[0025] FIG. 15 is a side elevational view of the cage of FIG. 12;

[0026] FIG. 16 is a perspective view of an alternative example implementation of a cage suitable for use with the gear assembly of FIG. 11;

[0027] FIG. 17 is an end view of the differential case of FIG. 6 oriented to look into an interior of the case;

[0028] FIG. 18 is a perspective view of an example side gear and an example lock collar suitable for use as the lock gear of the gear set of any of FIGS. 1-17; and

[0029] FIG. 19 shows the lock gear of FIG. 18 assembled.DETAILED DESCRIPTION

[0030] 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.

[0031] Referring to the figures in general, a differential assembly 100, 200 has a first end 102, 202 from which a first axle shaft (not shown) extends and an opposite second end 104, 204 from which a second axle shaft (not shown) extends. The differential assembly 100, 200 includes a case 106, 206 that holds a gear set 112, 212 (e.g., see FIGS. 2 and 7) that controls rotation of the first and second axle shafts relative to the case 106, 206. The case 106, 206 includes a flange 108, 208 at which a rotor (not shown) can be attached to the case 106, 206 toapply torque to the case 106, 206. In certain examples, one or more end caps 110, 210 attach to the case 106, 206 to enclose the gear set 112, 212. In certain examples, the differential assembly 100, 200 includes a limited slip differential assembly. Details of the gear set 112, 212 can be found in U.S. Patent No. 8,133,146, the disclosure of which is hereby incorporated herein by reference in its entirety.

[0032] In accordance with certain aspects of the disclosure, the differential assembly 100, 200 includes an electronic locking arrangement 120, 220 to selectively lock the rotation of the first and second axle shafts. In certain implementations, the locking arrangement 120, 220 includes an electric coil 125, 225 disposed at a stator 114, 214, which remains rotationally fixed relative to a surrounding framework (not shown) in which the case 106, 206 is installed. The case 106, 206 rotates relative to the stator 114, 214 and relative to the framework upon application of torque from the rotor. The gear set 112, 212 includes a lock gear 122, 222 configured to selectively engage a lock plate 124, 224.

[0033] The lock gear 122, 222 is carried with a side gear. In some examples, the lock gear 122, 222 is integrally formed with the side gear. In other examples, the lock gear 122, 222 is a separate piece mounted to the side gear. FIGS. 18 and 19 illustrate an example helical face gear 300 including a side gear 302 and a lock gear 122, 222. The side gear 302 carries side gear teeth 304 (e.g., helical teeth) and a lock collar 310 carries lock gear teeth 312 (e.g., dog teeth) that form the lock gear 122, 222. The side gear 302 includes a body 306 extending axially outwardly from the side gear teeth 304. The lock collar 310 is configured to mount to the body 306 to be rotationally fixed relative to the body 306. For example, the body 306 may define a first part 308 of an interlock interface and the lock collar 310 may define a second part 314 of the interlock interface. When aligned, the first and second parts 308, 314 engage to rotationally fix the lock collar 310 to the side gear 302 (e.g., see FIG. 19). In certain examples, the first part 308 includes a ring of teeth extending radially outwardly and the second part 314 includes an inner ring gear. In certain examples, the lock collar 310 axially slides over the body 306 until the second part 314 of the interface meshes with the first part 308. In other implementations, the helical face gear 300 can be formed as a single piece or can be otherwise formed from multiple pieces.

[0034] The lock plate 124, 224 is rotationally fixed to the case 106, 206 (e.g., by engagement between ears 127, 227 of the lock plate 124, 224 and grooves 129 of the case 106, 206). The lock plate 124, 224 is axially movable relative to the case 106, 206 and relative to the gear set 112, 212 between a locking position and a releasing position. When disposed in the locking position, the lock plate 124, 224 engages the lock gear 122, 222 to rotationally fixthe lock gear 122, 222 to the case 106, 206. In certain examples, the lock plate 124, 224 and lock gear 122, 222 include dog teeth that mesh together when engaged. When disposed in the releasing position, the lock plate 124, 224 is spaced sufficient from the lock gear 122, 222 to enable relative rotation therebetween. In certain implementations, the lock plate 124, 224 is biased to the releasing position. In certain examples, a biasing member 126, 226 (e.g., one or more wave springs) biases the lock plate 124, 224 away from the lock gear 122, 222 towards the releasing position.

[0035] The movement of the lock plate 124, 224 relative to the lock gear 122, 222 is controlled using the electric coil 125, 225 of the stator 114, 214. In some implementations, the stator 114 is axially movable relative to the case 106 between an actuated position and a nonactuated position (see FIGS. 1-5). In other implementations, the stator 214 is axially fixed relative to the case 206 while an armature 235 is axially movable relative to the case 206 between actuated and non-actuated positions (e.g., see FIGS. 6-10). In some implementations, the stator 114 is disposed at the first end 102 of the differential assembly 100 (e.g., see FIGS. 1-5). In other implementations, the stator 214 and armature 235 are disposed at the second end 204 of the differential assembly 200 (e.g., see FIGS. 6-10).

[0036] Referring to FIGS. 1-5, axial movement of the stator 114 is controlled through energization of the electric coil 125. In particular, the case 106 or an end cap or other component thereof includes a magnetizable material (e.g., iron). When the coil 125 is energized, the coil 125 is attracted to the case 106, which moves the stator 114 axially towards the case 106 to the actuated position. One or more pins 128 (e.g., rods or other structures) extend through the case 106 (e.g., through apertures 105) between the stator 114 and the lock plate 124. In some examples, the pins 128 are separate parts from the lock plate 124. In other examples, the pins 128 may be integrally formed with the lock plate 124. In some examples, the pins 128 are separate parts from the stator 114. In other examples, the pins 128 may be integrally formed with the stator 114.

[0037] Accordingly, when the stator 114 is moved to the actuated position, the stator 114 presses against the one or more pins 128, which thereby press the lock plate 124 towards the locking position against the bias of the biasing member 126. When the electric coil 125 is deenergized (i.e., turned off), the biasing member 126 presses the lock plate 124 away from the lock gear 122 to the releasing position. Interaction between the lock plate 124 and the one or more pins 128 presses the stator 114 back to the non-actuated position. In certain examples, a snap-ring 130 or other retainer limits the axial movement of the stator 114 away from the case 106. In some examples, the interaction between the stator 114 and a groove 132 in the outersurface of the case 106 limits the axial movement of the stator 114 towards the case 106. In other examples, the interaction between the lock plate 124 and the lock gear 122 limits the axial movement of the stator 114 towards the case 106 (e.g., the lock plate 124 bottoms out on the lock gear 122).

[0038] Referring to FIGS. 6-10, axial movement of the armature 235 is controlled through energization of the electric coil 225. In particular, the armature 235 includes a magnetizable material (e.g., iron). When the coil 225 is energized, the coil 225 attracts the armature 235, which moves the armature 235 axially towards the coil 225, and hence towards the case 206, to the actuated position. One or more pins 228 (e.g., rods or other structures) extend through the case 206 (e.g., through apertures 205) between the armature 235 and the lock plate 224. In some examples, the pins 228 are separate parts from the lock plate 224. In other examples, the pins 228 may be integrally formed with the lock plate 224. In some examples, the pins 228 are separate parts from the armature 235. In other examples, the pins 228 may be integrally formed with the armature 235.

[0039] Accordingly, when the armature 235 is moved to the actuated position, the armature 235 presses against the one or more pins 228, which thereby press the lock plate 224 towards the locking position against the bias of the biasing member 226. When the electric coil 225 is de-energized (i.e., turned off), the biasing member 226 presses the lock plate 224 away from the lock gear 222 to the releasing position. Interaction between the lock plate 224 and the one or more pins 228 presses the armature 235 back to the non-actuated position.

[0040] In certain examples, a snap-ring 230 or other retainer limits the axial movement of the armature 235 away from the case 206. In some examples, the interaction between the armature 235 and the stator 214 limits the axial movement of the armature 235 towards the case 206. In other examples, the interaction between the lock plate 224 and the lock gear 222 limits the axial movement of the armature 235 towards the case 206 (e.g., the lock plate 224 bottoms out on the lock gear 222).

[0041] Referring to FIGS. 11-19, the gear set 212 of a distribution assembly may be insertable into the case 206 as a unit. For example, gears of the gear set 212 may be assembled at a cage 250 or other framework outside of the case 206 to form a gear assembly 240. The gear assembly 240 may then be inserted into the case 206. Pre-assembling the gears at the cage 250 facilitates blind insertion of certain ones of the gears. For example, the cage 250 allows the gear set 212 to be installed within a case 206 having a sufficiently large bore to accommodate the lock gear 222 and pin 228 of the locking arrangement 220.

[0042] In certain implementations, the gear set 212 includes first and second side gears 242, 244 that engage the first and second axle shafts, respectively. The gear set 212 also includes a first set of pinions 246 that engage the first side gear 242 and a second set of pinions 248 that engage the second side gear 244. The pinions 246, 248 are disposed circumferentially around the side gears 242, 244 as disclosed in U.S. Patent No. 8,133,146, incorporated by reference above.

[0043] The cage 250 is configured to hold the side gears 242, 244 and pinions 246, 248 of the gear set 212. The cage 250 includes a body 252 defining a first part of a retention structure and the differential case 206 defines a second part of the retention structure. The first and second parts engage each other to retain the cable body 252 within the case 206. In certain implementations, the cage body 252 is configured to mount within the case 206 at a rotationally fixed position. For example, the first part of the retention structure may include rails 270 or other protrusions that mate with grooves 290 (e.g., see FIG. 17) of the second part. In another example, the first part may define grooves while the second part includes rails or other protrusions. In certain examples, the cage 250 or gear assembly 240 also is configured to mount at an axially fixed position relative to the case 206. In an example, one axial end of the cage 150 abuts the lock gear component of the gear set 212 while the other axial end abuts the end cover 210 (e.g., see FIG. 9).

[0044] As shown in FIGS. 12-16, the body 252 of the cage 250 defines a center bore 254 that extends axially therethrough. In some examples, the body 252 also defines a passage 280 leading from the bore 254 to an exterior of the cage body 252 intermediate the axial ends (e.g., see FIGS. 12-15). In such examples, the cage 250 is oriented within the case 206 to align the passage 280 with a window 207 (e.g., see FIG. 6) through an annular side of the case 206. In other examples, however, the cage body 252 does not define such a passage (e.g., see FIG. 16).

[0045] The body 252 has a first abutment surface 256 recessed inwardly from a first axial end of the body 252 and second abutment surface 258 recessed inwardly from a second axial end of the body 252. The bore 254 extends through the first and second abutment surfaces 256, 258. The first side gear 242 is disposed at the first abutment surface 256 and the second side gear 244 is disposed at the second abutment surface 258 when the side gears 242, 244 are mounted to the cage 250. In certain examples, a spacer 245 may be disposed within the bore 254 between the first and second side gears 242, 244.

[0046] In certain implementations, the cage body 252 includes one or more channels 260, 262 configured to receive the pinions 246, 248, respectively. The channels 260, 262 face radially outwardly from the body 252. Each channel 260, 262 extends inwardly from one ofthe axial ends of the cage body 252 towards a respective stop surface 266, 268 defined by the cage body 252. Each channel 260, 262 receives one of the pinions 246, 248. The first set of pinions 246 abut the first stop surfaces 266 and the second set of pinions 248 abut the second stop surfaces 268. The stop surfaces 266, 268 allow the pinions to be properly axially positioned relative to each other and relative to the side gears 242, 244 outside of the differential case 206.

[0047] In certain implementations, the stop surfaces 266, 268 are formed by stop members 282 formed integral with the cage body 252. In certain examples, each stop member 282 defines a groove 284 facing an adjacent one of the channels 260, 262 to accommodate the pinion 246, 248 of the adjacent channel 260, 262. For example, as shown in FIG. 14, the cage body 252 defines a first channel 262 and an adjacent channel 264. The first channel 262 extends inwardly from the first axial end of the cage body 252 and the second channel 264 extends inwardly from the second axial end. Each channel 262, 264 terminates at a respective stop member 282 defining a respective stop surface 266, 268. The stop member 282 of the first channel 262 defines a groove 284 that faces the adjacent channel 264. The stop member 282 of the second channel 264 defines a groove that 284 that faces the adjacent channel 262.

[0048] Examples of the disclosure may be described according to the following aspects:

[0049] Aspect 1. A differential assembly comprising:

[0050] a case;

[0051] a stator rotationally fixed relative to the case;

[0052] a gear set disposed within the case, the gear set including a plurality of helical pinions in meshing engagement with a helical face gear, the helical face gear including a lock gear; and

[0053] a locking arrangement mounted to the case, the locking arrangement including a lock plate, a biasing member, and a plurality of pins, the biasing member biasing the lock plate to a releasing position relative to the lock gear, the pins extending through the case from the lock plate towards the stator.

[0054] Aspect 2. The differential assembly of aspect 1, wherein the stator is configured to move axially relative to the case between actuated and de-actuated positions, the stator pressing the lock plate to the lock gear against the bias of the biasing member via the pins when disposed in the actuated position.

[0055] Aspect s. The differential assembly of aspect 1, further comprising an armature configured to move axially relative to the case between actuated and de-actuated positions, thearmature pressing the lock plate to the lock gear against the bias of the biasing member via the pins when disposed in the actuated position.

[0056] Aspect 4. The differential assembly of any of aspects 1-3, further comprising a cage holding the gear set.

[0057] Aspect s. The differential assembly of aspect 4, wherein the gear set is preassembled at the cage before being mounted within the case.

[0058] Aspect 6. The differential assembly of aspect 4, wherein the gear set and the cage are mountable within the case as a unit.

[0059] Aspect 7. A method of assembling a differential assembly, the method comprising:

[0060] mounting a plurality of helical pinions to a cage;

[0061] inserting the cage and the helical pinions into a case of the differential assembly as a unit.

[0062] Aspect 8. The method of aspect 7, further comprising mounting side gears to the cage prior to inserting the cage into the case; and wherein inserting the cage and the helical pinions into the case includes inserting the side gears into the case as a unit with the helical pinions and cage.

[0063] Aspect 9. The method of aspect 7 or aspect 8, further comprising rotationally aligning the cage with the case prior to inserting the cage into the case.

[0064] Aspect 10. A differential assembly comprising:

[0065] a case defining an interior;

[0066] an integral cage sized to fit within the interior, the cage extending between opposite first and second axial ends, the cage including a first abutment surface recessed inwardly from the first axial end and a second abutment surface recessed inwardly from the second axial end, the cage defining a bore extending through the first and second abutment surfaces, the cage also defining a plurality of first channels extending axially inwardly from the first axial end and a plurality of second channels extending axially inwardly from the second axial end; and

[0067] a plurality of helical pinions mounted at the first and second channels.

[0068] Aspect 11. The differential assembly of aspect 10, wherein the first and second channels are radially offset from the bore.

[0069] Aspect 12. The differential assembly of aspect 10, wherein the first channels are circumferentially offset from the second channels.

[0070] Aspect 13. The differential assembly of aspect 10, wherein the first and second channels face radially outwardly from the cage.

[0071] Aspect 14. The differential assembly of aspect 10, wherein the cage includes first stop members terminating the first channels and second stop members terminating the second channels.

[0072] Aspect 15. The differential assembly of aspect 10, wherein the first and second channels face radially outwardly from the cage; and wherein the first and second stop members extend radially outwardly from the respective first and second channels.

[0073] Aspect 16. The differential assembly of aspect 10, further comprising first and second side gears mounted at the first and second abutment surfaces, respectively.

[0074] Aspect 17. The differential assembly of aspect 16, wherein the first side gear includes a lock gear.

[0075] Aspect 18. The differential assembly of aspect 10, wherein the cage defining a first part of a retention structure and the case defines a second part of the retention structure, wherein the first and second parts engage each other to retain the cage within the case.

[0076] Aspect 19. The differential assembly of aspect 18, wherein the first part of the retention structure includes rails; and the second part of the retention structure defines grooves.

[0077] Aspect 20. The differential assembly of aspect 10, wherein the cage also defines a passage leading from the bore to an exterior of the cage intermediate the first and second abutment surfaces.

[0078] Aspect 21. The differential assembly of aspect 1, wherein the helical face gear is formed from multiple pieces.

[0079] Aspect 22. The differential assembly of aspect 21, wherein the helical face gear is formed from a side gear and a lock collar that are rotationally fixed together.

[0080] Aspect 23. The differential assembly of claim 22, wherein the lock collar is configured to slide onto the side gear.

[0081] Aspect 24. The differential assembly of aspect 17, wherein the lock gear is formed as a separate piece from the side gear.

[0082] Aspect 25. The differential assembly of aspect 24, wherein the lock gear is slidably mounted to the side gear in a rotationally fixed position.

[0083] Aspect 26. A face gear of a differential gear set, the face gear comprising:

[0084] a side gear including a body carrying side gear teeth, the body also carrying a first part of a locking interface axially spaced from the side gear teeth;

[0085] a lock collar that mounts to the side gear, the lock collar carrying lock gear teeth, the lock collar also defining a second part of the locking interface axially spaced from the sidegear teeth, the second part of the locking interface being configured to engage the first part of the locking interface to rotationally fix the lock collar to the side gear.

[0086] Aspect 27. The face gear of aspect 26, wherein the side gear teeth include helical teeth.

[0087] Aspect 28. The face gear of aspect 26 or aspect 27, wherein the lock gear teeth include dog teeth.

[0088] 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. For example, other types of gear sets (e.g., other than helical gears) can be used with the cage to mount into the differential case as a unit. Further, other types of locking arrangements can be used with the gear assembly including the cage. 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 case; a stator rotationally fixed relative to the case; a gear set disposed within the case, the gear set including a plurality of helical pinions in meshing engagement with a helical face gear, the helical face gear including a lock gear; and a locking arrangement mounted to the case, the locking arrangement including a lock plate, a biasing member, and a plurality of pins, the biasing member biasing the lock plate to a releasing position relative to the lock gear, the pins extending through the case from the lock plate towards the stator.

2. The differential assembly of claim 1, wherein the stator is configured to move axially relative to the case between actuated and de-actuated positions, the stator pressing the lock plate to the lock gear against the bias of the biasing member via the pins when disposed in the actuated position.

3. The differential assembly of claim 1, further comprising an armature configured to move axially relative to the case between actuated and de-actuated positions, the armature pressing the lock plate to the lock gear against the bias of the biasing member via the pins when disposed in the actuated position.

4. The differential assembly of any of claims 1-3, further comprising a cage holding the gear set.

5. The differential assembly of claim 4, wherein the gear set is pre-assembled at the cage before being mounted within the case.

6. The differential assembly of claim 4, wherein the gear set and the cage are mountable within the case as a unit.

7. The differential assembly of any of claims 1-6, wherein the helical face gear includes a lock collar rotationally fixed to a side gear, the lock collar carrying the lock gear.

8. A method of assembling a differential assembly, the method comprising: mounting a plurality of helical pinions to a cage; inserting the cage and the helical pinions into a case of the differential assembly as a unit.

9. The method of claim 8, further comprising mounting side gears to the cage prior to inserting the cage into the case; and wherein inserting the cage and the helical pinions into the case includes inserting the side gears into the case as a unit with the helical pinions and cage.

10. The method of claim 8 or claim 9, further comprising rotationally aligning the cage with the case prior to inserting the cage into the case.

11. A differential assembly comprising: a case defining an interior; an integral cage sized to fit within the interior, the cage extending between opposite first and second axial ends, the cage including a first abutment surface recessed inwardly from the first axial end and a second abutment surface recessed inwardly from the second axial end, the cage defining a bore extending through the first and second abutment surfaces, the cage also defining a plurality of first channels extending axially inwardly from the first axial end and a plurality of second channels extending axially inwardly from the second axial end; and a plurality of helical pinions mounted at the first and second channels.

12. The differential assembly of claim 11, wherein the first and second channels are radially offset from the bore.

13. The differential assembly of claim 11, wherein the first channels are circumferentially offset from the second channels.

14. The differential assembly of claim 11, wherein the cage includes first stop members terminating the first channels and second stop members terminating the second channels.

15. The differential assembly of claim 11, wherein the first and second channels face radially outwardly from the cage; and wherein the first and second stop members extend radially outwardly from the respective first and second channels.

16. The differential assembly of claim 11, further comprising first and second side gears mounted at the first and second abutment surfaces, respectively.

17. The differential assembly of claim 16, wherein the first side gear includes a lock gear.

18. The differential assembly of claim 11, wherein the cage defining a first part of a retention structure and the case defines a second part of the retention structure, wherein the first and second parts engage each other to retain the cage within the case.

19. The differential assembly of claim 18, wherein the first part of the retention structure includes rails; and the second part of the retention structure defines grooves.

20. The differential assembly of claim 11, wherein the cage also defines a passage leading from the bore to an exterior of the cage intermediate the first and second abutment surfaces.

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