JP2020094681A - Vehicular differential device - Google Patents

Abstract

To provide a differential device capable of reducing its size while suppressing an increase in its machining man-hours and also suppressing a decline in its differential restriction force.SOLUTION: A differential device 1 includes a first inner helical gear 31 to be rotated integrally with a first output shaft 11, a first outer helical gear 32 arranged on the outer periphery of the first inner helical gear 31, a second inner helical gear 41 to be rotated integrally with a second output shaft 12, a second outer helical gear 42 arranged on the outer periphery of the second inner helical gear 41, and a plurality of pinion gear sets 5 and a center washer 6 held by a housing 2. Outer helical teeth 312 formed on the outer peripheral face of the first inner helical gear 31 and inner peripheral helical teeth 321 formed on the inner peripheral face of the first outer helical gear 32, and outer peripheral helical teeth 412 formed on the outer peripheral face of the second inner helical gear 41 and inner peripheral helical teeth 421 formed on the inner peripheral face of the second outer helical gear engage with each other, respectively.SELECTED DRAWING: Figure 1

Description

The present invention relates to a vehicular differential device capable of allowing an input drive force to be differentially distributed to a pair of output shafts.

Conventionally, a differential device capable of distributing differentially the input driving force to the left and right drive shafts includes a left and right side gear that rotates integrally with each of the left and right drive shafts and a left and right side gear. And a plurality of pinion gear sets formed by meshing a pair of pinion gears arranged in parallel with each other, a housing that rotatably holds each pinion gear of the plurality of pinion gear sets, and a pair of left and right side gears that are arranged to face the shaft end surfaces of the side gears. Some have washers. In such a differential device, the left and right side gears and each pinion gear have helical teeth (twisting teeth), and an axial thrust force is generated in the left and right side gears and each pinion gear due to the meshing of these helical teeth. .. The frictional resistance force generated by the thrust force limits the differential between the left and right side gears to suppress wheel slip and, for example, a differential limiting force that makes it possible to enhance running performance on rough roads. Become.

The present applicant has proposed the differential device described in Patent Document 1 as a differential device that can be downsized. In this differential device, one pinion gear of a pair of pinion gears has two large and small gear parts with different pitch circle diameters, and the large diameter gear part meshes with the left side gear of the left and right side gears, and the small diameter gear part. Is engaged with the other pinion gear on the outer peripheral side of the right side gear. The other pinion gear meshes with a small-diameter gear portion of the one pinion gear in a part in the circumferential direction, and meshes with a right side gear in another part in the circumferential direction.

JP, 2009-197976, A

In the differential device described in Patent Document 1, the small-diameter gear portion of one pinion gear receives a radial force toward the right side gear depending on the relative rotation direction of the left and right side gears. It is necessary to form a gear support indicated by reference numeral 20F in FIG. 3 in the housing (differential case), and to interpose this gear support between the small-diameter gear part of one pinion gear and the right side gear. The man-hour was increasing. Further, since the other pinion gear meshes with the small-diameter gear portion of the one pinion gear and the right side gear at two locations in the circumferential direction, it imposes a heavy load on the transmission of the driving force, which has been a constraint for downsizing.

Further, if the diameters of the left and right side gears are reduced to reduce the size of the device, the frictional sliding diameter between the left and right side gears and the washer becomes smaller, which may make it difficult to generate a large differential limiting force. ..

Therefore, it is an object of the present invention to provide a vehicular differential device that can be downsized while suppressing an increase in processing man-hours and suppressing a reduction in differential limiting force.

In order to achieve the above-mentioned object, the present invention is a vehicular differential device that distributes a driving force of a vehicle to first and second output shafts, the first differential device rotating integrally with the first output shaft. Outer helical gear, a first outer helical gear arranged on the outer periphery of the first inner helical gear, a second inner helical gear that rotates integrally with the second output shaft, and an outer periphery of the second inner helical gear. A second outer helical gear, a housing containing the first and second outer helical gears, a plurality of pinion gear sets held by the housing, the first outer helical gear and the second outer gear. And a friction member disposed between the helical gear and a helical gear, wherein the pinion gear set includes a first pinion gear that meshes with the first outer helical gear and a plurality of second pinion gears that mesh with the second outer helical gear. The first pinion gear integrally includes an axial direction one end side gear portion meshing with the first outer helical gear and an axial direction other end side gear portion meshing with the plurality of second pinion gears, The plurality of second pinion gears mesh with the second outer helical gear at positions spaced apart from each other in the circumferential direction of the second outer helical gear, and the axially other end side gear portion of the first pinion gear is the second Of the outer helical gears are meshed with the plurality of second pinion gears at positions radially outward of the outer helical gears, and are formed on the outer peripheral helical teeth formed on the outer peripheral surface of the first inner helical gear and the inner peripheral surface of the first outer helical gear. The outer peripheral helical teeth formed on the outer peripheral surface of the second inner helical gear and the inner peripheral helical teeth formed on the inner peripheral surface of the second outer helical gear are meshed with each other. A differential device for a vehicle is provided.

According to the vehicle differential device of the present invention, it is possible to reduce the number of processing steps and the reduction of the differential limiting force while achieving downsizing.

It is sectional drawing of the differential gear which concerns on embodiment of this invention. It is a disassembled perspective view of a differential device. It is a side view which shows the 1st pinion gear alone. (A) is a perspective view showing the center washer and the first housing member, and (b) is a configuration view of the center washer and the first housing member as seen from the axial direction.

[Embodiment]
An embodiment of the present invention will be described with reference to FIGS. 1 to 4. Note that the embodiments described below are shown as preferred specific examples for carrying out the present invention, and some parts specifically exemplify various technically preferable technical matters. The technical scope of the present invention is not limited to this specific embodiment.

FIG. 1 is a sectional view of a differential device according to an embodiment of the present invention. FIG. 2 is an exploded perspective view of the differential device.

The differential device 1 is mounted on a vehicle and allows a driving force (torque) of a vehicle driving source such as an engine, which is input from a ring gear 10, to the first and second output shafts 11 and 12 in a differential manner. Used to allocate. In FIG. 1, the ring gear 10 and the first and second output shafts 11 and 12 are shown by imaginary lines (two-dot chain lines). In FIG. 2, the rotation direction of the differential gear 1 when the vehicle is moving forward is shown by an arrow A ₁ , and the rotation direction of the differential gear 1 when moving backward is shown by an arrow A ₂ . In the present embodiment, the case where the first and second output shafts 11 and 12 are drive shafts respectively connected to the left and right wheels will be described. However, the differential device 1 is mounted on a four-wheel drive vehicle. It can also be used as a center differential that distributes the driving force to the front and rear propeller shafts.

The differential device 1 includes a housing 2 that rotates around a rotation axis O together with the ring gear 10, and a pair of first and second helical gears 3 and 4 that are housed in the housing 2 and arranged side by side along the rotation axis O. , A plurality of pinion gear sets 5 held in the housing 2, and a center washer 6 as a friction member arranged between the first helical gear pair 3 and the second helical gear pair 4, and between the center washer 6. It has first and second side washers 71, 72 sandwiching the first and second helical gear pairs 3, 4 and a gap adjusting shim 73. Hereinafter, a direction parallel to the rotation axis O will be referred to as an axial direction. The rotation of the center washer 6 and the first and second side washers 71, 72 with respect to the housing 2 is restricted.

The first helical gear pair 3 includes a first inner helical gear 31 that rotates integrally with the first output shaft 11, and a first outer helical gear 32 that is arranged on the outer circumference of the first inner helical gear 31. The first inner helical gear 31 has spline teeth 311 formed on the inner peripheral surface for connection with the first output shaft 11, and outer peripheral helical teeth 312 formed on the outer peripheral surface. The first outer helical gear 32 has inner circumferential helical teeth 321 formed on the inner circumferential surface thereof and outer circumferential helical teeth 322 formed on the outer circumferential surface thereof.

The outer peripheral helical teeth 312 of the first inner helical gear 31 and the inner peripheral helical teeth 321 of the first outer helical gear 32 mesh with each other, and torque is transmitted from the first outer helical gear 32 to the first inner helical gear 31. At this time, the axial force due to torque transmission acts on the first inner helical gear 31, and the thrust force as a reaction thereof acts on the first outer helical gear 32.

As shown in FIG. 2, the twisting direction of the tooth trace of the outer peripheral helical tooth 322 of the first outer helical gear 32 and the twisting direction of the tooth trace of the outer peripheral helical tooth 312 of the first inner helical gear 31 are opposite to each other. is there. In the present embodiment, the first outer helical gear 32 is pressed toward the center washer 6 and the first inner helical gear 31 is pressed toward the first side washer 71 when the vehicle moves forward. The twist direction of the tooth trace is set. When the vehicle retreats, the first outer helical gear 32 is pressed toward the first side washer 71, and the first inner helical gear 31 is pressed toward the center washer 6.

The second helical gear pair 4 includes a second inner helical gear 41 that rotates integrally with the second output shaft 12, and a second outer helical gear 42 that is arranged on the outer circumference of the second inner helical gear 41. The second inner helical gear 41 has spline teeth 411 formed on the inner peripheral surface for connection with the second output shaft 12, and outer peripheral helical teeth 412 formed on the outer peripheral surface. The second outer helical gear 42 has inner circumferential helical teeth 421 formed on the inner circumferential surface and outer circumferential helical teeth 422 formed on the outer circumferential surface.

The outer peripheral helical tooth 412 of the second inner helical gear 41 and the inner peripheral helical tooth 421 of the second outer helical gear 42 mesh with each other, and torque is transmitted from the second outer helical gear 42 to the second inner helical gear 41. At this time, the axial force due to the torque transmission acts on the second inner helical gear 41, and the thrust force as a reaction thereof acts on the second outer helical gear 42.

The twisting direction of the tooth trace of the inner peripheral helical tooth 421 of the second outer helical gear 42 and the twisting direction of the tooth trace of the outer peripheral helical tooth 412 of the second inner helical gear 41 are opposite to each other. In the present embodiment, the second outer helical gear 42 is pressed toward the center washer 6 and the second inner helical gear 41 is pressed toward the second side washer 72 when the vehicle moves forward. The twist direction of the tooth trace is set. When the vehicle retreats, the second outer helical gear 42 is pressed toward the second side washer 72, and the second inner helical gear 41 is pressed toward the center washer 6.

The pitch circle diameter P ₄₂ (see FIG. 2) of the second outer helical gear 42 is smaller than the pitch circle diameter P ₃₂ (see FIG. 2) of the first outer helical gear 32. The twisting direction of the tooth trace of the outer peripheral helical teeth 322 of the first outer helical gear 32 and the twisting direction of the tooth trace of the outer peripheral helical teeth 422 of the second outer helical gear 42 are opposite to each other.

Each pinion gear set 5 is composed of one first pinion gear 51 and two second pinion gears 52, 52. The first pinion gear 51 integrally includes an axial direction one end side gear portion 511 that meshes with the first outer helical gear 32 and an axial other end side gear portion 512 that meshes with the two second pinion gears 52. The second pinion gear 52 meshes with the axially other end side gear portion 512 of the first pinion gear 51 and also meshes with the second outer helical gear 42.

The axially other end side gear portion 512 of the first pinion gear 51 meshes with the two second pinion gears 52 at a position on the outer side in the radial direction of the second outer helical gear 42. A space is provided between the second outer helical gear 42 and the gear portion 512 on the other end side in the axial direction of the first pinion gear 51, and a support portion that supports the first pinion gear 51 is not formed in this space. The tilting of the first pinion gear 51 in the direction in which the gear portion 512 on the other end side in the axial direction approaches the second outer helical gear 42 is suppressed by meshing with the two second pinion gears 52. The two second pinion gears 52 mesh with the second outer helical gear 42 at positions that are separated from each other in the circumferential direction of the second outer helical gear 42.

FIG. 3 is a side view showing the first pinion gear 51 alone. The first pinion gear 51 has six helical teeth 513 spirally formed on the outer peripheral surface thereof. In each helical tooth 513, a tooth trace 513a and a tooth groove 513b are continuously formed over an axial direction one end side gear portion 511 and an axial direction other end side gear portion 512. The tooth top surface 513c of the helical tooth 513 has a predetermined width in the circumferential direction of the first pinion gear 51.

The axial one end side gear portion 511 is formed to have a larger outer diameter than the axial other end side gear portion 512. The pitch circle diameter of the one axial end side gear section 511 and _{P 1,} when the pitch circle diameter of the other axial end side gear section 512 and _{P 2, P 1} is greater than _{P 2,} the ratio of _{P 1} against _{P 2 (P} 1 / _{P 2)} is 1.05 to 1.15, for example. In the illustrated example of FIG. 3, this ratio is set to about 1.1. Further, the twist angle of the tooth trace 513a in the axial direction one end side gear section 511 and theta _1, when the twist angle of the tooth trace 513a in the axial end gear portion 512 and theta _2, theta ₁ is greater than theta ₂ The ratio is, for example, the same as the ratio of the pitch circle diameters of both gear parts 511 and 512.

Further, in the central portion 510 of the first pinion gear 51, the pitch circle diameter and the twist angle gradually decrease from the axial one end side gear portion 511 to the axial other end side gear portion 512 so that stress is not concentrated. .. The second pinion gear 52 has six helical teeth 521 that mesh with the helical teeth 513 of the gear portion 512 on the other axial side of the first pinion gear 51, and its pitch circle diameter is equal to P ₂ . The twist angle is equal to θ ₂ .

As described above, the pitch circle diameter P ₂ of the axial other end side gear portion 512 is smaller than the pitch circle diameter P _{1 of the} axial one end side gear portion 511, and the tooth trace in the axial other end side gear portion 512 is twisted. When the first helical gear pair 3 rotates faster than the second helical gear pair 4 because the angle θ ₂ is smaller than the torsion angle θ ₁ of the tooth trace in the axial one end side gear portion 511 (for example, when turning right). 2) TBR (torque bias ratio) and the TBR when the second helical gear pair 4 rotates faster than the first helical gear pair 3 (for example, when turning left).

That is, in the present embodiment, since the pitch circle diameter P ₃₂ of the first outer helical gear ₃₂ is larger than the pitch circle diameter P ₄₂ of the second outer helical gear ₄₂ , the tooth trace of the gear portion 511 in the axial direction on the one side is temporarily assumed. When the twist angle θ ₁ and the twist angle θ ₂ of the tooth trace of the gear portion 512 on the other end in the axial direction are equal, the difference in diameter between the first outer helical gear 32 and the second outer helical gear 42 causes the vehicle to move. A difference occurs in the differential limiting force that limits the differential rotation of the first and second outer helical gears 32 and 42 between right turning and left turning. However, in the present embodiment, the first pinion gear is used. By configuring 51 as described above, such an imbalance in TBR is suppressed.

The housing 2 has a bottomed cylindrical first housing member 21 and a second housing member 22 fixed to the opening side of the first housing member 21. The first housing member 21 houses the first and second pinion gear pairs 3 and 4. Further, the first housing member 21 is formed with a bore 20 as a pinion gear accommodating space for holding the first pinion gear 51 and the two second pinion gears 52. In the present embodiment, as shown in FIG. 2, since the differential device 1 has four pinion gear sets 5, four bores 20 are formed in the first housing member 21.

The bore 20 has a first accommodation space 201 for accommodating the first pinion gear 51 and two second accommodation spaces 202 for accommodating the two second pinion gears 52, respectively. The two second accommodating spaces 202 are formed at both ends of the bore 20 in the circumferential direction of the first housing member 21. The first accommodation space 201 is formed between two second accommodation spaces 202. The first housing space 201 and the two second housing spaces 202 are both open at the end on the opening side of the first housing member 21.

When the first pinion gear 51 rotates in the bore 20, the tooth crests 513c of the helical teeth 513 of the first pinion gear 51 slide on the inner surface 201a of the first accommodation space 201. When the second pinion gear 52 rotates in the bore 20, the tooth crests 521c of the helical teeth 521 of the second pinion gear 52 slide on the inner surface 202a of the second accommodation space 202. The frictional force generated on the tooth top surfaces 513c and 521c of the first and second pinion gears 51 and 52 due to these sliding movements is the differential limiting force that limits the differential between the first and second output shafts 11 and 12. Becomes

The first housing member 21 includes a cylindrical portion 211 in which four bores 20 are formed, a bottom portion 212 formed by projecting inward from one end of the cylindrical portion 211, and an outer portion from the other end of the cylindrical portion 211. It integrally has a flange portion 213 that is formed so as to project from the central portion of the bottom portion 212, and a conduit portion 214 that axially projects from the center portion of the bottom portion 212 for inserting the first output shaft 11. An oil groove 214a that allows the lubricating oil to flow is formed on the inner surface of the conduit portion 214.

The first accommodation space 201 and the second accommodation space 202 extend in the axial direction from the end of the cylindrical portion 211 on the opening side of the first housing member 21 toward the bottom portion 212. The axial length of the second accommodation space 202 is shorter than the axial length of the first accommodation space 201. An oil hole 212 a is formed in the bottom portion 212 for allowing lubricating oil to flow between the first accommodation space 201 and the outside of the housing 2.

At the center of the cylindrical portion 211 of the first housing member 21, there is a first hollow portion 203 that is a housing space that houses the first helical gear pair 3, and a housing space that houses the second helical gear pair 4. The second hollow portions 204 are formed side by side in the axial direction. The first hollow portion 203 is provided on the back side (bottom portion 212 side) of the first housing member 21, and the second hollow portion 204 is provided on the opening side of the first housing member 21. The first hollow portion 203 communicates with the first accommodation space 201 of the bore 20 and does not communicate with the second accommodation space 202. The second hollow portion 204 communicates with the first accommodation space 201 and the second accommodation space 202 of the bore 20. The first side washer 71 is arranged between the first inner helical gear 31 and the bottom portion 212 of the first housing member 21.

The second housing member 22 includes an annular plate portion 221 that closes one end of the bore 20 on the opening side of the first housing member 21, and a flange portion 222 that is attached to the flange portion 213 of the first housing member 21. , And a conduit portion 223 that projects in the axial direction from the ring plate portion 221 and allows the second output shaft 12 to be inserted therethrough. An oil groove 223a that allows the lubricating oil to flow is formed on the inner surface of the conduit portion 223. The second side washer 72 is arranged between the second inner helical gear 41 and the ring plate portion 221 of the second housing member 22. An oil hole 221a for circulating lubricating oil is formed in the ring plate portion 221 so as to penetrate therethrough in the axial direction.

The flange portion 213 of the first housing member 21 and the flange portion 222 of the second housing member 22 are fastened by a plurality of bolts 23. The housing 2 is rotatably supported by the differential carrier by a bearing (not shown) and rotates about the rotation axis O. Bolt insertion holes 213a and 222a through which the shaft portion of the bolt 100 for fixing the ring gear 10 is inserted are formed in the flange portions 213 and 222 of the first and second housing members 21 and 22, respectively.

FIG. 4A is a perspective view showing the center washer 6 and the first housing member 21, and FIG. 4B is a configuration diagram of the center washer 6 and the first housing member 21 seen from the axial direction.

The center washer 6 is arranged between the first outer helical gear 32 and the second outer helical gear 42. Further, the center washer 6 includes a ring-shaped plate-shaped main body portion 61 with which the shaft end surfaces 32 a and 42 a of the first outer helical gear 32 and the second outer helical gear 42 come into contact with each other when the center washer 6 moves forward, A plurality of fitting protrusions 62 and a plurality of abutting protrusions 63 projecting in one direction are integrally provided. A through hole 610 is formed in the center of the main body 61.

The first housing member 21 is formed with a plurality of recessed fitting portions 215 into which the plurality of fitting protrusions 62 of the center washer 6 are fitted. In the present embodiment, the center washer 6 has four fitting protrusions 62, and the first housing member 21 is formed with the same number of concave fitting portions 215. Further, in the present embodiment, the recessed fitting portion 215 is formed so as to be recessed in the axial direction from the bottom surface 202b of the second accommodation space 202. The center washer 6 is prevented from rotating with respect to the housing 2 by fitting the fitting protrusion 62 into the concave fitting portion 215.

The plurality of contact protrusions 63 of the center washer 6 are provided between the plurality of fitting protrusions 62 in the circumferential direction of the main body 61. The contact projection 63 has a distal end surface 63 a formed in an arc shape with a curvature corresponding to the curvature of the inner peripheral surface 203 a of the first hollow portion 203 of the first housing member 21. The center washer 6 is positioned in the radial direction with respect to the housing 2 by the contact projections 63 contacting the inner peripheral surface 203 a of the first hollow portion 203.

A part of the main body 61 of the center washer 6 is arranged between the annular protrusion 323 of the first outer helical gear 32 and the annular protrusion 423 of the second outer helical gear 42, and the inner diameter of the through hole 610 is It is smaller than the inner diameter of the annular protrusion 323 of the first outer helical gear 32 and the inner diameter of the annular protrusion 423 of the second outer helical gear 42. Thereby, as compared with the case where the first and second outer helical gears 32 and 42 do not have the annular protrusions 323 and 423, for example, the shaft end surfaces of the first outer helical gear 32 and the second outer helical gear 42 are respectively formed. The contact area between the center washers 6 and 32a, 42a is increased, and wear of these surfaces is suppressed.

(Operation of the differential device 1)
When the housing 2 is rotated by the driving force input from the ring gear 10, the driving force is transmitted to the pinion gear set 5 held by the cylindrical portion 211 of the first housing member 21, and the first pinion gear 51 to the first outer member. The driving force is distributed to the helical gear 32 and from the second pinion gear 52 to the second outer helical gear 42. Then, the driving force is output from the first outer helical gear 32 to the first output shaft 11 via the first inner helical gear 31, and the second outer helical gear 42 passes from the second inner helical gear 41 to the second inner helical gear 41. The driving force is output to the output shaft 12.

When the vehicle is moving forward, the first outer helical gear 32 receives the thrust force toward the center washer 6 side due to the meshing with the first pinion gear 51, and the center outer washer 6 side due to the meshing with the first inner helical gear 31. Receive thrust force to. Due to these thrust forces, a frictional force is generated between the shaft end surface 32a of the first outer helical gear 32 and the center washer 6. Further, the first inner helical gear 31 receives the thrust force to the first side washer 71 due to the meshing with the first outer helical gear 32, and the shaft end surface 31 a of the first inner helical gear 31 and the first side washer 71. A frictional force is generated between and.

Similarly, the second outer helical gear 42 receives a thrust force toward the center washer 6 side by meshing with the second pinion gear 52, and also thrusts toward the center washer 6 side by meshing with the second inner helical gear 41. Receive power. Due to these thrust forces, a frictional force is generated between the shaft end surface 42a of the second outer helical gear 42 and the center washer 6. Further, the second inner helical gear 41 receives a thrust force to the second side washer 72 due to the meshing with the second outer helical gear 42, and the shaft end surface 41 a of the second inner helical gear 41 and the second side washer 72 are received. A frictional force is generated between and.

These frictional forces serve as a differential limiting force that limits the differential between the first and second output shafts 11 and 12, and the slippage of the left and right wheels is suppressed, so that the running performance on rough roads is enhanced.

(Operation and Effect of Embodiment)
According to the embodiment described above, the thrust force generated by the meshing of the first outer helical gear 32 and the first inner helical gear 31, and the meshing of the second outer helical gear 42 and the second inner helical gear 41 The generated thrust force enhances the differential limiting force during forward traveling.

Moreover, since the first pinion gear 51 and the second pinion gear 52 mesh with each other on the outer peripheral side of the second outer helical gear 42, the device size can be reduced in the axial direction. Further, since the two second pinion gears 52 mesh with the one first pinion gear 51, the load on each of the second pinion gears 52 can be reduced when the driving force is transmitted, and the second pinion gear 52 can be miniaturized. It becomes possible to do.

Furthermore, without the need for a structure (a member interposed between the first pinion gear 51 and the second outer helical gear 42) corresponding to the gear support portion 20F that was necessary in the differential device described in Patent Document 1. Since it is possible to avoid the interference between the first pinion gear 51 and the second outer helical gear 42, it is possible to suppress an increase in the number of processing steps of the housing 2.

(Appendix)
The present invention has been described above based on the embodiment, but the embodiment does not limit the invention according to the claims. It should be noted that not all combinations of the features described in the embodiments are essential to the means for solving the problems of the invention.

Further, the present invention can be appropriately modified and implemented without departing from the spirit of the present invention. For example, in the above-described embodiment, the case where the differential device 1 has four pinion gear sets 5 has been described, but the present invention is not limited to this, and the differential device 1 may have two, three, or five or more pinion gear sets 5. May have.

Further, if the interference between the first pinion gear 51 and the second outer helical gear 42 can be avoided, the pitch circle diameter of the second outer helical gear 42 can be made the same as the pitch circle diameter of the first outer helical gear 32. Alternatively, the pitch circle diameter of the other axial end gear portion 512 of the first pinion gear 51 may be the same as the pitch circle diameter of the one axial end gear portion 511.

DESCRIPTION OF SYMBOLS 1... Differential device 11... 1st output shaft 12... 2nd output shaft 2... Housing 31... 1st inner helical gear 312... Outer peripheral helical tooth 32... 1st outer helical gear 321... Inner peripheral helical tooth 323... Annular Protrusion 32a... Shaft end face 41... Second inner helical gear 412... Outer peripheral helical tooth 42... Second outer helical gear 421... Inner peripheral helical tooth 423... Annular protrusion 42a... Shaft end face 5... Pinion gear set 51... First pinion gear 511... Axial one end side gear portion 512... Axial other end side gear portion 513... Helical tooth 52... Second pinion gear 521... Helical tooth 6... Center washer (friction member)
61... Main body part 62... Fitting protrusion 63... Abutting protrusion

Claims (6)

A differential device for a vehicle, which distributes a driving force of a vehicle to first and second output shafts,
A first inner helical gear that rotates integrally with the first output shaft;
A first outer helical gear arranged on the outer periphery of the first inner helical gear;
A second inner helical gear that rotates integrally with the second output shaft;
A second outer helical gear arranged on the outer periphery of the second inner helical gear;
A housing for housing the first and second outer helical gears;
A plurality of pinion gear sets held in the housing,
A friction member disposed between the first outer helical gear and the second outer helical gear,
The pinion gear set includes a first pinion gear that meshes with the first outer helical gear and a plurality of second pinion gears that mesh with the second outer helical gear,
The first pinion gear integrally has an axial direction one end side gear portion that meshes with the first outer helical gear and an axial direction other end side gear portion that meshes with the plurality of second pinion gears,
The plurality of second pinion gears mesh with the second outer helical gear at positions spaced apart from each other in the circumferential direction of the second outer helical gear,
The axially other end side gear portion of the first pinion gear meshes with the plurality of second pinion gears at a position corresponding to the radial outer side of the second outer helical gear,
The outer peripheral helical teeth formed on the outer peripheral surface of the first inner helical gear mesh with the inner peripheral helical teeth formed on the inner peripheral surface of the first outer helical gear,
Outer peripheral helical teeth formed on the outer peripheral surface of the second inner helical gear and inner peripheral helical teeth formed on the inner peripheral surface of the second outer helical gear mesh with each other.
Vehicle differential. The friction member includes an annular plate-shaped main body portion with which the respective axial end surfaces of the first outer helical gear and the second outer helical gear are in contact, and a plurality of fittings that project radially outward from the main body portion. A protrusion, and the fitting protrusion is prevented from rotating with respect to the housing by fitting into a recessed fitting portion formed in the housing.
The vehicle differential device according to claim 1. The friction member has a plurality of abutment projections that project radially outward from the main body portion between the plurality of fitting projections, and the plurality of abutment projections abut the inner peripheral surface of the housing. Thereby being positioned in the radial direction with respect to the housing,
The vehicle differential device according to claim 2. The first outer helical gear and the second outer helical gear each have an annular protrusion protruding inward in the radial direction at an end on the friction member side,
A part of the friction member is arranged between the annular protrusions of the first outer helical gear and the second outer helical gear, respectively.
The vehicle differential device according to any one of claims 1 to 3. A pitch circle diameter of the second outer helical gear is smaller than a pitch circle diameter of the first outer helical gear,
The vehicle differential device according to claim 1. The first pinion gear and the second pinion gear have helical teeth on their outer peripheral surfaces,
In the first pinion gear, the pitch circle diameter of the gear portion on the other end side in the axial direction is smaller than the pitch circle diameter of the gear portion on the one end side in the axial direction, and the tooth of the helical tooth in the gear portion on the other end side in the axial direction is The twist angle of the muscle is smaller than the twist angle of the tooth trace of the helical tooth in the gear portion on the one end side in the axial direction,
The vehicle differential device according to any one of claims 1 to 5.

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