JP2022145243A - power transmission device - Google Patents

Abstract

To improve lubrication efficiency.SOLUTION: A power transmission device includes: a case; and a shaft arranged in a direction along a rotation axis of the case within the case. The case is provided with an opening which penetrates through the case in a rotation axis direction. The case has a first guide part protruding from the opening to the inner side of the case. In the case, an oil path communicating with the shaft is formed at the outer side of the first guide part in a radial direction of the rotation axis.SELECTED DRAWING: Figure 1

Description

The present invention relates to power transmission devices.

Patent Document 1 discloses a power transmission device having a bevel gear type differential mechanism. The differential mechanism includes a pinion mate gear and a pinion mate shaft housed in a differential case.

WO2020/165620

Power transmission devices are required to improve lubrication efficiency.

A power transmission device in one aspect of the present invention includes:
a case;
a shaft disposed within the case and oriented along the axis of rotation of the case;
The case is provided with an opening penetrating in the rotation axis direction,
The case has a first guide portion that protrudes inside the case from the opening,
An oil path communicating with the shaft is formed in the case outside the first guide portion in the radial direction of the rotating shaft.

ADVANTAGE OF THE INVENTION According to the aspect of this invention, lubrication efficiency can be improved in a power transmission device.

1 is a skeleton diagram for explaining a power transmission device according to an embodiment; FIG. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram of the cross section explaining the power transmission device concerning this embodiment. 4 is an enlarged view around a planetary reduction gear of the power transmission device; FIG. It is an enlarged view around the differential mechanism of the power transmission device. It is a perspective view around the differential case of the differential mechanism. FIG. 3 is an exploded perspective view around a differential case of the differential mechanism; 3 is a perspective view of a case member 6 of the differential mechanism as viewed from the case member 7 side; FIG. 3 is a plan view of the case member 6 of the differential mechanism as seen from the case member 7 side; FIG. FIG. 9 is a schematic diagram of the AA cross section in FIG. 8; FIG. 10 is a view taken along the line AA in FIG. 9; FIG. 9 is a schematic diagram of the AA cross section in FIG. 8; The area above the rotation axis X in FIG. 9 is shown, and the stepped pinion gear is indicated by solid lines. 6 is a perspective view of the case member 7 viewed from the opposite side of the case member 6. FIG. 6 is a plan view of the case member 7 viewed from the opposite side of the case member 6. FIG. 3 is a perspective view of the case member 7 as seen from the case member 6 side; FIG. 3 is a plan view of the case member 7 viewed from the side of the case member 6. FIG. FIG. 17 is a schematic diagram of the AA cross section in FIG. 16; FIG. 18 is a view taken along line AA in FIG. 17; FIG. 17 is a schematic diagram of the AA cross section in FIG. 16; FIG. 20 is a schematic diagram of the AA cross section in FIG. 19; 4A and 4B are diagrams for explaining assembly of the case member 6 and the case member 7; FIG. 4A and 4B are diagrams for explaining assembly of the case member 6 and the case member 7; FIG. FIG. 5 is a diagram illustrating a power transmission device according to Modification 1; It is a figure explaining the guide part which concerns on the modified example 2. FIG. It is a figure explaining the guide part which concerns on the modified example 3. FIG. It is a figure explaining the guide part which concerns on the modification 4. FIG.

Embodiments of the present invention will be described below.
FIG. 1 is a skeleton diagram illustrating a power transmission device 1 according to this embodiment.
FIG. 2 is a schematic cross-sectional view illustrating the power transmission device 1 according to this embodiment.
FIG. 3 is an enlarged view around the planetary reduction gear 4 of the power transmission device 1. As shown in FIG.
FIG. 4 is an enlarged view around the differential mechanism 5 of the power transmission device 1. As shown in FIG.

As shown in FIG. 1 , the power transmission device 1 includes a motor 2 and a planetary reduction gear 4 (reduction mechanism) that reduces the output rotation of the motor 2 and inputs it to the differential mechanism 5 . The power transmission device 1 also has a drive shaft 9 and a parking lock mechanism 3 . The drive shaft 9 has a drive shaft 9A (second drive shaft) and a drive shaft 9B (first drive shaft).
In the power transmission device 1, a parking lock mechanism 3, a planetary reduction gear 4, a differential mechanism 5, and drive shafts 9 (9A, 9B) are arranged along the transmission path of the output rotation of the motor 2 about the rotation axis X. , is provided. The axes of the drive shafts 9 ( 9 A, 9 B) are coaxial with the rotation axis X of the motor 2 .

In the power transmission device 1, after the output rotation of the motor 2 is reduced by the planetary reduction gear 4 and input to the differential mechanism 5, the power transmission device 1 is mounted via the drive shafts 9 (9A, 9B). It is transmitted to the left and right drive wheels W, W of the vehicle.
Here, the planetary reduction gear 4 is connected downstream of the motor 2, the differential mechanism 5 is connected downstream of the planetary reduction gear 4, and the drive shafts 9 (9A, 9B) are connected to the differential mechanism 5 downstream.

As shown in FIG. 2 , the main body box 10 of the power transmission device 1 has a first box 11 that houses the motor 2 and a second box 12 that is externally inserted into the first box 11 . The main box 10 also has a third box 13 attached to the first box 11 and a fourth box 14 attached to the second box 12 .

The first box 11 has a cylindrical support wall portion 111 and a flange-like joint portion 112 provided at one end 111 a of the support wall portion 111 .
The first box 11 is provided with a supporting wall portion 111 oriented along the rotation axis X of the motor 2 . The motor 2 is accommodated inside the support wall portion 111 .

The joint portion 112 is provided in a direction perpendicular to the rotation axis X. As shown in FIG. The joint portion 112 is formed with an outer diameter larger than that of the support wall portion 111 .

The second box 12 includes a cylindrical peripheral wall portion 121, a flange-shaped joint portion 122 provided at one end 121a of the peripheral wall portion 121, and a flange-shaped joint portion 123 provided at the other end 121b of the peripheral wall portion 121. ,have.
The peripheral wall portion 121 is formed with an inner diameter that allows it to be externally inserted into the support wall portion 111 of the first box 11 .
The first box 11 and the second box 12 are assembled together by extrapolating the peripheral wall portion 121 of the second box 12 to the supporting wall portion 111 of the first box 11 .

A joint portion 122 on the one end 121a side of the peripheral wall portion 121 contacts the joint portion 112 of the first box 11 from the rotation axis X direction. These joints 122 and 112 are connected to each other by bolts (not shown).
In the first box 11, a plurality of grooves 111b are provided on the outer periphery of the support wall portion 111. As shown in FIG. The plurality of grooves 111b are provided at intervals in the rotation axis X direction. Each of the concave grooves 111b is provided over the entire circumference of the rotation axis X in the circumferential direction.
The peripheral wall portion 121 of the second box 12 is fitted onto the support wall portion 111 of the first box 11 . The peripheral wall portion 121 closes the opening of the groove 111b. A plurality of cooling paths CP through which cooling water flows are formed between the support wall portion 111 and the peripheral wall portion 121 .

Ring grooves 111c, 111c are formed on both sides of the region in which the concave groove 111b is provided on the outer circumference of the support wall portion 111 of the first box 11. As shown in FIG. Seal rings 113, 113 are fitted in the ring grooves 111c, 111c.
These seal rings 113 are pressed against the inner periphery of the peripheral wall portion 121 fitted on the support wall portion 111 to seal the gap between the outer periphery of the support wall portion 111 and the inner periphery of the peripheral wall portion 121 .

A wall portion 120 extending radially inward is provided at the other end 121b of the second box 12 . The wall portion 120 is provided in a direction perpendicular to the rotation axis X. As shown in FIG. An opening 120a through which the drive shaft 9A is inserted is formed in a region of the wall portion 120 intersecting with the rotation axis X. As shown in FIG.
In the wall portion 120, a cylindrical motor support portion 125 surrounding the opening 120a is provided on the surface on the side of the motor 2 (on the right side in the figure).
The motor support portion 125 is inserted inside a coil end 253b, which will be described later. The motor support portion 125 faces the end portion 21b of the rotor core 21 with a gap in the rotation axis X direction.

The peripheral wall portion 121 of the second box 12 is thicker in the radial direction in the lower region in the vertical direction than in the upper region with respect to the mounting state of the power transmission device 1 on the vehicle.
An oil reservoir portion 128 is provided to penetrate in the direction of the rotation axis X in this region having a large thickness in the radial direction.
The oil reservoir portion 128 communicates with an axial oil passage 138 provided in the joint portion 132 of the third box 13 through the communication hole 112a. The communication hole 112 a is provided in the joint portion 112 of the first box 11 .

The third box 13 has a wall portion 130 perpendicular to the axis X of rotation. A joint portion 132 having a ring shape when viewed from the rotation axis X direction is provided on the outer peripheral portion of the wall portion 130 .
As viewed from the first box 11, the third box 13 is located on the side opposite to the differential mechanism 5 (on the right side in the drawing). The joint 132 of the third box 13 is joined to the joint 112 of the first box 11 from the rotation axis X direction. The third box 13 and the first box 11 are connected to each other with bolts (not shown). In this state, the third box 13 closes the opening of the first box 11 on the joint portion 122 side (right side in the drawing) of the support wall portion 111 .

In the third box 13, an insertion hole 130a for the drive shaft 9A is provided in the central portion of the wall portion 130. As shown in FIG.
A lip seal RS is provided on the inner circumference of the insertion hole 130a. The lip seal RS brings the lip portion (not shown) into elastic contact with the outer circumference of the drive shaft 9A. A gap between the inner periphery of the insertion hole 130a and the outer periphery of the drive shaft 9A is sealed with a lip seal RS.
A peripheral wall portion 131 surrounding the insertion hole 130a is provided on the surface of the wall portion 130 on the first box 11 side (left side in the figure). A drive shaft 9A is supported on the inner periphery of the peripheral wall portion 131 via a bearing B4.

A motor support portion 135 is provided on the motor 2 side (on the left side in the figure) when viewed from the peripheral wall portion 131 . The motor support portion 135 has a tubular shape surrounding the rotation axis X with a space therebetween.
A cylindrical connection wall 136 is connected to the outer periphery of the motor support portion 135 . The connection wall 136 is formed with a larger outer diameter than the peripheral wall portion 131 on the wall portion 130 side (right side in the drawing). The connection wall 136 is oriented along the rotation axis X and extends away from the motor 2 . The connection wall 136 connects the motor support portion 135 and the wall portion 130 of the third box 13 .

The motor support portion 135 is supported by the third box 13 via the connection wall 136 . One end 20a side of the motor shaft 20 penetrates the inside of the motor support portion 135 from the motor 2 side to the peripheral wall portion 131 side.
A bearing B<b>1 is supported on the inner periphery of the motor support portion 135 . The outer circumference of the motor shaft 20 is supported by a motor support portion 135 via a bearing B1.
A lip seal RS is provided at a position adjacent to the bearing B1.

In the third box 13, an oil hole 136a, which will be described later, opens in the inner circumference of the connection wall 136. As shown in FIG. The oil OL flows into the space (internal space Sc) surrounded by the connection wall 136 through the oil hole 136a. The lip seal RS is provided to prevent the oil OL in the connection wall 136 from flowing into the motor 2 side.

The fourth box 14 has a peripheral wall portion 141 surrounding the outer periphery of the planetary reduction gear 4 and the differential mechanism 5, and a flange-shaped joint portion 142 provided at the end portion of the peripheral wall portion 141 on the second box 12 side. is doing. The fourth box 14 functions as a box that accommodates the planetary reduction gear 4 and the differential mechanism 5 .
The fourth box 14 is located on the differential mechanism 5 side (left side in the figure) when viewed from the second box 12 . The joint 142 of the fourth box 14 is joined to the joint 123 of the second box 12 from the rotation axis X direction. The fourth box 14 and the second box 12 are connected to each other with bolts (not shown).

Inside the main body box 10 of the power transmission device 1, a motor chamber Sa that houses the motor 2 and a gear chamber Sb that houses the planetary reduction gear 4 and the differential mechanism 5 are formed.
The motor chamber Sa is formed inside the first box 11 between the wall 120 of the second box 12 and the wall 130 of the third box 13 .
The gear chamber Sb is formed between the wall portion 120 of the second box 12 and the peripheral wall portion 141 of the fourth box 14 on the inner diameter side of the fourth box 14 .

A plate member 8 is provided inside the gear chamber Sb.
The plate member 8 is fixed to the fourth box 14 .
The plate member 8 divides the gear chamber Sb into a first gear chamber Sb1 containing the planetary reduction gear 4 and the differential mechanism 5 and a second gear chamber Sb2 containing the parking lock mechanism 3 .
The second gear chamber Sb2 is located between the first gear chamber Sb1 and the motor chamber Sa in the rotation axis X direction.

The motor 2 has a cylindrical motor shaft 20, a cylindrical rotor core 21 fitted onto the motor shaft 20, and a stator core 25 surrounding the outer circumference of the rotor core 21 with a gap therebetween.

In the motor shaft 20 , bearings B<b>1 and B<b>1 are externally inserted and fixed on both sides of the rotor core 21 .
A bearing B<b>1 located on the one end 20 a side (right side in the drawing) of the motor shaft 20 when viewed from the rotor core 21 is supported on the inner periphery of the motor support portion 135 of the third box 13 . The bearing B1 located on the other end 20b side is supported on the inner periphery of the cylindrical motor support portion 125 of the second box 12 .

The motor support portions 135 and 125 are arranged to face one end portion 21a and the other end portion 21b of the rotor core 21 with a gap in the rotation axis X direction on the inner diameter side of coil ends 253a and 253b, which will be described later. ing.

The rotor core 21 is formed by laminating a plurality of silicon steel plates. Each of the silicon steel plates is fitted over the motor shaft 20 in a state where relative rotation with the motor shaft 20 is restricted.
The silicon steel plate has a ring shape when viewed from the rotation axis X direction of the motor shaft 20 . N-pole and S-pole magnets (not shown) are provided alternately in the circumferential direction around the rotation axis X on the outer peripheral side of the silicon steel plate.

A stator core 25 surrounding the outer periphery of the rotor core 21 is formed by laminating a plurality of electromagnetic steel sheets. The stator core 25 is fixed to the inner circumference of the cylindrical support wall portion 111 of the first box 11 .
Each of the electromagnetic steel sheets has a ring-shaped yoke portion 251 fixed to the inner periphery of the support wall portion 111 and tooth portions 252 protruding from the inner periphery of the yoke portion 251 toward the rotor core 21 side.

In this embodiment, the stator core 25 in which the windings 253 are distributed over a plurality of teeth 252 is adopted. The stator core 25 is longer than the rotor core 21 in the direction of the rotation axis X by the coil ends 253a and 253b projecting in the direction of the rotation axis X. As shown in FIG.

A stator core having a structure in which windings are concentratedly wound may be employed for each of the plurality of tooth portions 252 protruding toward the rotor core 21 side.

The wall portion 120 (motor support portion 125) of the second box 12 is provided with an opening 120a. The other end 20b side of the motor shaft 20 passes through the opening 120a to the differential mechanism 5 side (left side in the figure) and is located in the fourth box 14 .
The other end 20b of the motor shaft 20 faces a side gear 54A, which will be described later, inside the fourth box 14 with a gap in the rotation axis X direction.

As shown in FIG. 3 , the motor shaft 20 is provided with a stepped portion 201 in a region located inside the fourth box 14 . The stepped portion 201 is positioned near the motor support portion 125 . A lip seal RS supported on the inner circumference of the motor support portion 125 is in contact with the outer circumference of the region between the stepped portion 201 and the bearing B1.
The lip seal RS separates the motor chamber Sa containing the motor 2 from the gear chamber Sb in the fourth box 14 .

An oil OL for lubricating the planetary reduction gear 4 and the differential mechanism 5 is sealed in the inner diameter side of the fourth box 14 (see FIG. 2).
A lip seal RS is provided to prevent the oil OL from flowing into the motor chamber Sa.

As shown in FIG. 3, in the motor shaft 20, a region from the stepped portion 201 to the vicinity of the other end 20b serves as a fitting portion 202 having a spline on the outer periphery.
The park gear 30 and the sun gear 41 are spline-fitted to the outer periphery of the fitting portion 202 .

One side surface of the park gear 30 in the direction of the rotation axis X is in contact with the stepped portion 201 (right side in the figure). One end 410a of a cylindrical base portion 410 of the sun gear 41 is in contact with the other side surface of the park gear 30 (left side in the figure).
A nut N screwed onto the other end 20b of the motor shaft 20 is pressed against the other end 410b of the base portion 410 from the rotation axis X direction.
The sun gear 41 and the park gear 30 are sandwiched between the nut N and the stepped portion 201 so as not to rotate relative to the motor shaft 20 .

The sun gear 41 has teeth 411 on the outer circumference of the motor shaft 20 on the side of the other end 20b. A large-diameter gear portion 431 of a stepped pinion gear 43 as a pinion gear meshes with the outer periphery of the tooth portion 411 .

The stepped pinion gear 43 has a large-diameter gear portion 431 that meshes with the sun gear 41 and a small-diameter gear portion 432 smaller in diameter than the large-diameter gear portion 431 .
The stepped pinion gear 43 is a gear component in which a large-diameter gear portion 431 and a small-diameter gear portion 432 are arranged in the direction of an axis line X1 parallel to the rotation axis X and integrally provided.
The large-diameter gear portion 431 is formed with an outer diameter R<b>1 larger than the outer diameter R<b>2 of the small-diameter gear portion 432 .
The stepped pinion gear 43 is oriented along the axis X1. In this state, the large-diameter gear portion 431 is located on the motor 2 side (right side in the drawing).

The outer periphery of the small diameter gear portion 432 meshes with the inner periphery of the ring gear 42 . The ring gear 42 has a ring shape surrounding the rotation axis X with a space therebetween. A plurality of engaging teeth 421 projecting radially outward are provided on the outer periphery of the ring gear 42 . A plurality of engaging teeth 421 are provided in a circumferential direction around the rotation axis X at predetermined intervals.
The ring gear 42 has engaging teeth 421 provided on the outer periphery thereof spline-fitted to tooth portions 146 a provided on the support wall portion 146 of the fourth box 14 . The rotation of the ring gear 42 around the rotation axis X is restricted.

The stepped pinion gear 43 has a through hole 430 passing through the inner diameter side of the large diameter gear portion 431 and the small diameter gear portion 432 in the direction of the axis X1.
The stepped pinion gear 43 is rotatably supported on the outer periphery of the pinion shaft 44 passing through the through hole 430 via needle bearings NB, NB as bearings.

On the outer circumference of the pinion shaft 44, an intermediate spacer MS is interposed between the needle bearing NB supporting the inner circumference of the large-diameter gear portion 431 and the needle bearing NB supporting the inner circumference of the small-diameter gear portion 432. .

As shown in FIG. 4, inside the pinion shaft 44, shaft internal oil passages 440A and 440B are provided. As a first pinion shaft internal oil passage, the shaft internal oil passage 440A extends from one end 44a (right side in the figure) of the pinion shaft 44 to the inner diameter side of the large diameter gear portion 431 along the axis X1. As a second pinion shaft internal oil passage, the shaft internal oil passage 440B extends from the other end 44b (left side in the figure) of the pinion shaft 44 to the inner diameter side of the small diameter gear portion 432 along the axis X1.
The pinion shaft 44 is provided with oil holes 441 and 442 for communicating between the in-shaft oil passage 440A and the outer circumference of the pinion shaft 44, and oil holes 443 and 444 for communicating between the in-shaft oil passage 440B and the outer circumference of the pinion shaft 44. It is

The oil hole 441 opens in a region where the needle bearing NB that supports the inner circumference of the large-diameter gear portion 431 is provided. The oil hole 441 in the pinion shaft 44 opens in a region where the stepped pinion gear 43 is externally inserted. The oil hole 442 opens into a gap CL1 between the axial side surface 431a of the large-diameter gear portion 431 and the facing surface 61b of the case member 6 of the differential case 50 in the direction of the axis X1.

Oil OL, which is raked up by the differential case 50 described later, flows into the oil hole 442 . The oil OL that has flowed into the oil hole 442 flows into the in-shaft oil passage 440A of the pinion shaft 44 . The oil OL that has flowed into the in-shaft oil passage 440A is discharged radially outward from the oil hole 441 . The oil OL discharged from the oil hole 441 lubricates the needle bearing NB externally fitted on the pinion shaft 44 .

Also, the oil hole 443 opens in a region where the needle bearing NB that supports the inner periphery of the small diameter gear portion 432 is provided. The oil hole 443 in the pinion shaft 44 opens in a region where the stepped pinion gear 43 is externally inserted.

The oil hole 444 allows the in-shaft oil passage 440B and the outer circumference of the pinion shaft 44 to communicate with each other. The oil hole 444 opens into a gap CL2 between a side wall portion 432a of the small-diameter gear portion 432 in the direction of the axis X1 and a plate portion 68 of the case member 6, which will be described later.

Oil OL, which is raked up by a differential case 50 described later and directed toward the outer diameter side, flows into the gap CL2. The oil OL that has flowed into the oil hole 444 through the clearance CL2 flows into the in-shaft oil passage 440B of the pinion shaft 44 . The oil OL that has flowed into the in-shaft oil passage 440B is discharged radially outward from the oil hole 443 . The oil OL discharged from the oil hole 443 lubricates the needle bearing NB externally fitted on the pinion shaft 44 . That is, the clearance CL2 functions as an oil path that guides the oil OL that has been scraped up by the differential case 50 to the pinion shaft 44 .

As shown in FIG. 4 , on the side of one longitudinal end 44 a of the pinion shaft 44 , a first shaft portion 445 protrudes from the stepped pinion gear 43 . The first shaft portion 445 is supported by a support hole 61 a provided in the case member 6 of the differential case 50 .
On the other end 44 b side of the pinion shaft 44 in the longitudinal direction, a region protruding from the stepped pinion gear 43 serves as a second shaft portion 446 . The second shaft portion 446 is supported by a support hole 68 a provided in the case member 6 of the differential case 50 . Although the details will be described later, the second shaft portion 446 is press-fitted into the support hole 68a and supported relative to the case member 6 so as not to rotate.

Here, the first shaft portion 445 means a region (right side in FIG. 4) on the one end 44a side of the pinion shaft 44 where the stepped pinion gear 43 is not externally inserted. The second shaft portion 446 means a region (left side in FIG. 4) on the other end 44b side of the pinion shaft 44 where the stepped pinion gear 43 is not externally inserted.
In the pinion shaft 44, the second shaft portion 446 is longer than the first shaft portion 445 in the direction of the axis X1.

The main configuration of the differential mechanism 5 will be described below.
5 is a perspective view around the differential case 50 of the differential mechanism 5. FIG.
6 is an exploded perspective view around the differential case 50 of the differential mechanism 5. FIG. In FIG. 6 , one stepped pinion gear 43 is omitted to expose the inside of the differential mechanism 5 .
As shown in FIGS. 4 to 6 , a differential case 50 as a case accommodates the differential mechanism 5 . The differential case 50 is formed by assembling the case member 6 (second case member) and the case member 7 (first case member) in the rotation axis X direction. In this embodiment, the case member 6 of the differential case 50 functions as a carrier that supports the pinion shaft 44 of the planetary reduction gear 4 .

As shown in FIG. 6 , three pinion mate gears 52 and a pinion mate shaft 51 are provided between the case members 6 and 7 of the differential case 50 . The pinion mate shaft 51 functions as a support shaft that supports the pinion mate gear 52 .
The pinion mate shaft 51 includes three shaft members 511 that are circumferentially spaced around the rotation axis X (see FIG. 6).
An inner diameter side end of each of the shaft members 511 is connected to a central member 510 arranged on the rotation axis X. As shown in FIG. That is, the shaft members 511 are radially arranged with the central member 510 as the center. As the pinion mate shaft 51, one obtained by integrally molding the central member 510 and the shaft member 511 can be used.

One pinion mate gear 52 is fitted onto each of the shaft members 511 . Each of the pinion mate gears 52 is in contact with the central member 510 from the radially outer side of the rotation axis X. As shown in FIG.
In this state, each pinion mate gear 52 is rotatably supported by the shaft member 511 .

As shown in FIG. 4 , a spherical washer 53 is fitted onto the shaft member 511 . The spherical washer 53 is in contact with the spherical outer periphery of the pinion mate gear 52 .

In the differential case 50, the side gear 54A is positioned on one side of the central member 510 in the direction of the rotation axis X, and the side gear 54B is positioned on the other side. The side gear 54A is rotatably supported by the case member 6. As shown in FIG. The side gear 54B is rotatably supported by the case member 7. As shown in FIG.
The side gear 54A meshes with the three pinion mate gears 52 from one side in the rotation axis X direction. The side gear 54B meshes with the three pinion mate gears 52 from the other side in the rotation axis X direction.

7 to 12 are diagrams for explaining the case member 6. FIG.
FIG. 7 is a perspective view of the case member 6 of the differential mechanism 5 viewed from the case member 7 side.
FIG. 8 is a plan view of the case member 6 of the differential mechanism 5 viewed from the case member 7 side.
In FIGS. 7 and 8, the plate portion 68 is cross-hatched for clarity.
FIG. 9 is a schematic diagram of the AA cross section in FIG. FIG. 9 shows the arrangement of the shaft member 511 of the pinion mate shaft 51 in phantom lines.
10 is a view taken along the line AA in FIG. 9. FIG.
FIG. 11 is a schematic diagram of the AA cross section in FIG. FIG. 11 shows the arrangement of the side gear 54A, the stepped pinion gear 43, and the drive shaft 9A in phantom lines while omitting the illustration of the plate portion 68 and the connecting beam 62 on the far side of the paper surface.
FIG. 12 shows the upper region of the rotation axis X in FIG. 9 and shows the stepped pinion gear 43 with a solid line.

As shown in FIGS. 7 and 9, the case member 6 has a ring-shaped base portion 61 . The base 61 is a plate-like member having a thickness W61 in the rotation axis X direction.
As shown in FIG. 9, an opening 60 is provided in the central portion of the base portion 61 . A cylindrical wall portion 611 surrounding the opening 60 is provided on the surface of the base portion 61 opposite to the case member 7 (on the right side in FIG. 9). The outer circumference of the cylinder wall portion 611 is supported by the plate member 8 via the bearing B3 (see FIG. 2).

Three connecting beams 62 extending toward the case member 7 are provided on the surface of the base portion 61 on the side of the case member 7 (on the left side in FIG. 9).
The three connecting beams 62 are provided at regular intervals in the circumferential direction around the rotation axis X (see FIGS. 7 and 8).
As shown in FIG. 7 , the connecting beam 62 has a base portion 63 connected to the base portion 61 and extending in a direction orthogonal to the base portion 61 . The connecting beam 62 also has a connecting portion 64 that is connected to the base portion 63 on the side of the case member 7 (on the left side in the drawing) and is wider than the base portion 63 . The connecting portion 64 has a larger circumferential width around the rotation axis X than the base portion 63 .

A circular space is formed on the inner diameter side of the connecting portion 64 when viewed from the rotation axis X direction. As shown in FIG. 6 , this space accommodates the central member 510 of the pinion mate shaft 51 , the pinion mate gear 52 and the spherical washer 53 . A spherical washer 53 is positioned on the outer circumference of the pinion mate gear 52 , and a central member 510 is positioned on the inner circumference of the pinion mate gear 52 .

The connecting portions 64 are provided at regular intervals in the circumferential direction around the rotation axis X, as shown in FIG. Three plate portions 68 are arranged between the connecting portions 64 . The plate portion 68 extends along the circumferential direction around the rotation axis X and connects adjacent connecting portions 64 . The plate portion 68 has an arc shape when viewed from the rotation axis X direction. As shown in FIG. 9 , the plate portion 68 protrudes further toward the case member 7 (to the left in the drawing) than the connecting portion 64 . The plate portion 68 faces the base portion 61 with a gap therebetween. A stepped pinion gear 43 and a pinion shaft 44 are accommodated in this gap (see FIG. 5).

As shown in FIG. 7, the outer peripheral surface of the base portion 63 is formed with a stepped portion 63a along the circumferential direction around the rotation axis X. As shown in FIG. As shown in FIG. 4, with this stepped portion 63a as a boundary, the case member 7 side of the case member 6 (the left side in the drawing) is defined as a first portion 6A, and the base portion 61 side (the right side in the drawing) away from the case member 7 is the first portion 6A. ) is the second portion 6B.

The diameter of the outer peripheral surface of the second portion 6B is larger than the diameter of the outer peripheral surface of the first portion 6A. By making the thickness of the first portion 6A in the radial direction of the rotation axis X smaller than the thickness of the second portion 6B, the weight of the case member 6 is reduced. As shown in FIG. 7, the stepped portion 63a is formed near the center of the base portion 63 in the direction of the rotation axis X, but the position where the stepped portion 63a is formed can be changed as appropriate.

As shown in FIG. 8, a recess 640 is provided in the center of the connecting portion 64 in the circumferential direction around the rotation axis X. As shown in FIG. As shown in FIG. 7, the concave portion 640 is recessed toward the base portion 61 with respect to the plate portion 68 . The concave portion 640 includes an arc-shaped bottom portion 643 extending along the circumferential direction around the rotation axis X, and a side wall portion 644 extending from the bottom surface portion 643 toward the plate portion 68 in the rotation axis X direction.

A groove portion 645 extending in the radial direction of the rotation axis X is formed at the boundary between the bottom portion 643 and the side wall portion 644 . A bottom surface portion 643 of the concave portion 640 is a surface extending along a direction perpendicular to the rotation axis X. As shown in FIG. The bottom surface portion 643 is provided with a support groove 65 (second cutout portion) for supporting the shaft member 511 of the pinion mate shaft 51 .

As shown in FIG. 8 , the support groove 65 is linearly formed along the radial line L of the ring-shaped base portion 61 when viewed from the rotation axis X direction. The support groove 65 crosses the central portion of the concave portion 640 in the circumferential direction around the rotation axis X from the inner diameter side to the outer diameter side.
As shown in FIG. 9 , the support groove 65 is formed by cutting the bottom surface portion 643 into a semicircular shape along the outer diameter of the shaft member 511 of the pinion mate shaft 51 . The support groove 65 is formed with a depth capable of accommodating half of the cylindrical shaft member 511 . That is, the support groove 65 is formed with a depth corresponding to half the diameter Da of the shaft member 511 (=Da/2).

A circular arc portion 641 is formed along the outer circumference of the pinion mate gear 52 on the inner diameter side (the rotation axis X side) of the connecting portion 64 .
The arc portion 641 supports the outer periphery of the pinion mate gear 52 via the spherical washer 53 .
In the circular arc portion 641, an oil groove 642 is provided along the radial line L described above. The oil groove 642 is provided in a range from the support groove 65 that supports the shaft member 511 to the gear support portion 66 fixed to the inner circumference of the connecting portion 64 .

The gear support portion 66 is connected to the boundary portion between the base portion 63 and the connecting portion 64 . The gear support portion 66 is provided in a direction orthogonal to the rotation axis X. As shown in FIG. The gear support portion 66 has a through hole 660 in its central portion.
As shown in FIG. 8 , the outer circumference of the gear support portion 66 is connected to the inner circumferences of the three connecting portions 64 . The center of the through hole 660 is located on the rotation axis X in this state.

As shown in FIGS. 9 and 11 , the gear support portion 66 is provided with a concave portion 661 surrounding the through hole 660 on the surface opposite to the base portion 61 (left side in the drawing). The recess 661 accommodates a ring-shaped washer 55 that supports the back surface of the side gear 54A.
A cylindrical wall portion 541 is provided on the back surface of the side gear 54A. The washer 55 is externally inserted on the cylinder wall portion 541 .

Three oil grooves 662 are provided on the surface of the gear support portion 66 on the concave portion 661 side when viewed from the rotation axis X direction. The oil grooves 662 are provided circumferentially around the rotation axis X at predetermined intervals.
The oil groove 662 extends from the inner periphery to the outer periphery of the gear support portion 66 along the radial line L described above. The oil groove 662 communicates with the oil groove 642 on the arc portion 641 side.

As shown in FIGS. 7 and 9, the base portion 61 has a support hole 61a for the pinion shaft 44. As shown in FIGS. The support hole 61a opens in a region between the connecting beams 62, 62 which are spaced apart in the circumferential direction around the rotation axis X. As shown in FIG.
The base portion 61 is provided with a boss portion 616 surrounding the support hole 61a. A washer Wc (see FIG. 11) externally fitted on the pinion shaft 44 contacts the boss portion 616 from the rotation axis X direction.

An oil groove 617 is provided in the base portion 61 in a range from the central opening 60 to the boss portion 616 .
As shown in FIG. 7 , the oil groove 617 is formed in a tapered shape in which the width in the circumferential direction around the rotation axis X becomes narrower as it approaches the boss portion 616 . Oil groove 617 communicates with oil groove 618 provided in boss portion 616 .

Bolt holes 67 , 67 are provided on both sides of the support groove 65 in the connecting portion 64 .
As shown in FIG. 6, the connecting portion 74 on the side of the case member 7 is joined to the connecting portion 64 of the case member 6 from the rotation axis X direction. The case member 6 and the case member 7 are joined together by screwing a bolt B (see FIG. 5) passing through the connecting portion 74 on the case member 7 side into the bolt holes 67 , 67 .

As shown in FIG. 8 , the plate portion 68 includes an arc-shaped base portion 680 and an outer peripheral wall 681 provided on the outer peripheral edge of the base portion 680 when viewed from the rotation axis X direction.
As shown in FIG. 9, the base 680 is a plate-like member arranged with its thickness direction along the rotation axis X direction. One end surface 680a and the other end surface 680b of the base 680 in the rotation axis X direction are flat surfaces orthogonal to the rotation axis X. As shown in FIG. The outer peripheral wall 681 protrudes from one end surface 680a of the base 680 in the rotation axis X direction.

As shown in FIG. 8, the outer peripheral wall 681 is formed over the entire length of the base portion 680 in the circumferential direction around the rotation axis X when viewed from the rotation axis X direction. The three plate portions 68 are formed so that the inner peripheral surfaces 681a of the outer peripheral walls 681 overlap the virtual circles Im1 having the diameter D1. In addition, the three plate portions 68 are formed such that the inner peripheral surfaces 680c of the base portions 680 are overlapped with the virtual circle Im2 having the diameter D2.

As shown in FIG. 9, the plate portion 68 is formed with a support hole 68a penetrating through the base portion 680 in the rotation axis X direction. The support hole 68a and the support hole 61a are arranged concentrically along an axis X1 parallel to the rotation axis X. As shown in FIG.
As shown in FIG. 8, the support hole 68a is formed in the central portion of the base portion 680 in the circumferential direction around the rotation axis X. As shown in FIG.

Although the details will be described later, in the base portion 680 of the plate portion 68, a region on the inner diameter side of the support hole 68a in the radial direction of the rotation axis X is an oil receiving portion that receives the oil OL that has been raked up by the rotation of the differential case 50. 682 (see FIG. 9).
In the following description, with respect to a region of the base portion 680 on the inner diameter side of the support hole 68a, the one end surface 680a, the other end surface 680b, and the inner peripheral surface 680c of the base portion 680 are the one end surface 680a, the other end surface 680b, and the Also referred to as inner peripheral surface 680c.

As shown in FIG. 10, an inner peripheral surface 680c of the oil receiving portion 682 is provided with a recess 683 formed by notching the central portion in the circumferential direction around the rotation axis X. As shown in FIG.
As viewed from the rotation axis X direction, the recess 683 opens radially inward. The recessed portion 683 has inclined surfaces 683a and 683b that narrow the opening width W68 in the circumferential direction from the inner peripheral surface 680c toward the outer diameter side. A vertex P at which the inclined surface 683a and the inclined surface 683b of the recess 683 intersect is located on the diameter line Lr passing through the rotation axis X and the axis X1.

As shown in FIG. 9, the inner peripheral surface 680c and recessed portion 683 of the oil receiving portion 682 are inclined radially outward from one end surface 680a toward the other end surface 680b in the rotation axis X direction.
In the concave portion 683, inclined surfaces 683a and 683b are inclined radially outward from one end surface 680a to the other end surface 680b in the rotation axis X direction.

As shown in FIG. 9, an oil groove 685 is formed in the other end surface 680b of the oil receiving portion 682 in the rotation axis X direction. The oil groove 685 connects the recess 683 and the support hole 68a. The oil groove 685 linearly extends from the vertex P of the recess 683 along the diameter line Lr (see FIG. 10).

As shown in FIG. 12, the stepped pinion gear 43 is assembled to the case member 6 by disposing the stepped pinion gear 43 in the space between the base portion 61 and the plate portion 68 in the rotation axis X direction. This is done by inserting the shaft 44 from the side of the support hole 61a (the direction of the arrow in the figure). Washers Wc are interposed between the large-diameter gear portion 431 and the base portion 61 and between the small-diameter gear portion 432 and the base portion 680 in the direction of the rotation axis X, respectively.

One end 44a side and the other end 44b side of the pinion shaft 44 are supported by support holes 61a and 68a, respectively. The diameter of the support hole 61 a is set to be slightly larger than the outer diameter of the pinion shaft 44 , and the diameter of the support hole 68 a is set to substantially match the outer diameter of the pinion shaft 44 . The other end 44b of the pinion shaft 44 is press-fitted into the support hole 68a. Thereby, the pinion shaft 44 is fixed to the case member 6 so as not to rotate relative to it. The stepped pinion gear 43 externally fitted on the pinion shaft 44 is rotatably supported by the pinion shaft 44 about the axis X1.

As shown in the enlarged area of FIG. 12, when the stepped pinion gear 43 is assembled to the case member 6, the other end surface 680b of the base portion 680 and the side wall portion 432a of the small diameter gear portion 432 sandwich the washer Wc in the rotation axis X direction. opposite.

In the region of the base portion 680 where the oil groove 685 of the oil receiving portion 682 is formed, there is a gap between the oil groove 685 in the rotation axis X direction and the side wall portion 432a of the small diameter gear portion 432 with the washer Wc therebetween. CL2 is formed. The oil hole 444 of the pinion shaft 44 opens into the clearance CL2.

As shown in the enlarged area of FIG. 12, the case member 7 (see the phantom line in the drawing) is attached to the case member 6 from the plate portion 68 side in the rotation axis X direction.

13 to 20 are diagrams for explaining the case member 7. FIG.
13 is a perspective view of the case member 7 viewed from the opposite side of the case member 6. FIG.
14 is a plan view of the case member 7 viewed from the opposite side of the case member 6. FIG.
FIG. 15 is a perspective view of the case member 7 viewed from the case member 6 side.
FIG. 16 is a plan view of the case member 7 viewed from the case member 6 side. In FIG. 16, cross-hatching is added to facilitate understanding of the position of the guide portion 78 .
FIG. 17 is a schematic diagram of the AA cross section in FIG. FIG. 17 shows the arrangement of the pinion mate gear 52 in phantom lines. In FIG. 17, the boundary between the oil hole 710 and the guide portion 78 is indicated by a dashed line for easy understanding.
18 is a view taken along line AA in FIG. 17. FIG. In FIG. 18, cross-hatching is added to facilitate understanding of the position of the guide portion 78 .
FIG. 19 is a schematic diagram of the AA cross section in FIG. FIG. 19 illustrates the arrangement of the stepped pinion gear 43, the plate portion 68, the side gear 54B, and the drive shaft 9B in phantom lines while omitting the illustration of the connecting portion 74 on the far side of the paper surface.
FIG. 20 is a schematic diagram of the AA cross section in FIG.

As shown in FIGS. 13 and 14, the case member 7 has a ring-shaped base portion 71 (plate) when viewed from the rotation axis X direction.
The base portion 71 is a plate-like member having a thickness W71 (see FIG. 19) in the rotation axis X direction. A through hole 70 is provided in the central portion of the base portion 71 so as to pass through the base portion 71 in the thickness direction. The diameter (2R4, see FIG. 14) of the outer peripheral surface 71c of the base portion 71 is slightly smaller than the diameter D1 of the imaginary circle Im1 (see FIG. 8) along the inner peripheral surface 681a of the outer peripheral wall 681 of the plate portion 68. (2R4<D1).

As shown in FIG. 17, one end surface 71a and the other end surface 71b of the base 71 in the rotation axis X direction are flat surfaces perpendicular to the rotation axis X. As shown in FIG. A cylindrical wall portion 72 surrounding the through hole 70 and a guide portion 73 (second guide portion) surrounding the cylindrical wall portion 72 are provided on one end surface 71 a of the base portion 71 . As shown in FIG. 14, the guide portion 73 has an annular shape when viewed from the rotation axis X direction.

As shown in FIGS. 13 and 14 , three ribs 711 are provided on the inner diameter side of the guide portion 73 in the base portion 71 . The three ribs 711 are provided circumferentially around the rotation axis X at intervals. These ribs 711 are formed on one end face 71 a of the base portion 71 . The rib 711 extends linearly in the radial direction of the rotation axis X. As shown in FIG. The rib 711 is provided across the guide portion 73 on the outer diameter side and the tubular wall portion 72 on the inner diameter side.

As shown in FIG. 14, between three ribs 711 arranged in the circumferential direction around the rotation axis X, oil holes 710 (openings) are provided that penetrate the base portion 71 in the thickness direction. The oil hole 710 opens to the outside and the inside of the differential case 50 in the rotation axis X direction.

Three ribs 713 are provided on the outer diameter side of the guide portion 73 in the base portion 71 . The three ribs 713 are provided circumferentially around the rotation axis X at intervals. These ribs 713 are formed on one end surface 71 a of the base portion 71 . The rib 713 linearly extends in the radial direction of the rotation axis X from the guide portion 73 toward the outer peripheral surface 71 c of the base portion 71 .

The base portion 71 is provided with bolt accommodating portions 76 , 76 recessed toward the back side of the paper between adjacent ribs 713 . These bolt accommodating portions 76, 76 are provided in a symmetrical positional relationship with the radius line L interposed therebetween. The bolt accommodating portion 76 opens to the outer peripheral surface 71 c of the base portion 71 .
A bolt insertion hole 77 is opened inside the bolt accommodating portion 76 . The insertion hole 77 penetrates the base portion 71 in the thickness direction (rotational axis X direction).

In the base portion 71, three ribs 713 are formed on the outer diameter side of the oil hole 710 in the radial direction of the rotation axis X. As shown in FIG.

As shown in FIG. 14, the oil holes 710 are provided in the case member 7 at intervals in the circumferential direction around the rotation axis X. As shown in FIG.

As shown in the enlarged area of FIG. 14, the oil hole 710 has a substantially rectangular shape when viewed from the rotation axis X direction. The oil hole 710 includes long side portions 710a and 710b along the circumferential direction around the rotation axis X, and short side portions 710c and 710d connecting ends of the long side portions 710a and 710b. In the oil hole 710, the long side portion 710a is located on the outer diameter side of the long side portion 710b.

As shown in FIGS. 15 and 16, the other end surface 71b of the base portion 71 on the case member 6 side is provided with three guide portions 78 (first guide portions) surrounding the three oil holes 710, respectively. These three guide portions 78 are spaced apart in the circumferential direction around the rotation axis X. As shown in FIG.

The guide portion 78 is a continuous wall that surrounds the oil hole 710 and opens toward the inner diameter side. Specifically, as shown in the enlarged area of FIG. 15, the guide portion 78 has a long wall portion 781 along the long side portion 710a of the oil hole 710 and short wall portions along the short side portions 710c and 710d of the oil hole 710. 783, 784. The long wall portion 781 and the short wall portions 783 and 784 are integrally formed.

As shown in FIG. 16, in the long wall portion 781, the outer peripheral surface 781b is formed so as to overlap the virtual circle Im3 having a diameter D4. The diameter D4 of the virtual circle Im3 is smaller than the diameter D2 of the virtual circle Im2 (see FIG. 8) along the inner peripheral surface 680c of the base portion 680 of the plate portion 68 of the case member 6 (D4<D2).

As shown in FIG. 18, the long wall portion 781 of the guide portion 78 is an arc-shaped wall along the circumferential direction around the rotation axis X when viewed from the rotation axis X direction. The short wall portions 783 and 784 extend radially inward from both ends of the long wall portion 781 in the circumferential direction around the rotation axis X, respectively. The short wall portions 783 and 784 extend linearly along straight lines Lm2 and Lm3 parallel to a straight line Lm1 passing through the rotation axis X and an intermediate point C of the inner peripheral surface 781a of the long wall portion 781 in the circumferential direction around the rotation axis X. extended.

Here, in the enlarged area of FIG. 15, the boundary between the oil hole 710 and the guide portion 78 is indicated by a broken line.
As shown in the enlarged area of FIG. 15, the inner peripheral surface 781a of the long wall portion 781 and the inner peripheral surfaces 783a and 784a of the short wall portions 783 and 784 (the front side of the paper surface from the dashed line in the figure) are the same as the oil hole 710. The long side portion 710a and the short side portions 710d and 710c (in the drawing, the back side of the paper from the broken line) are connected without a step.

As shown in FIG. 17, the guide portions 73 and 78 extend away from the base portion 71 in the rotation axis X direction. The inner peripheral surface 731 of the guide portion 73 is a flat surface parallel to the rotation axis X when viewed from the radial direction of the rotation axis X. As shown in FIG. A long side portion 710a of the oil hole 710 is connected to an inner peripheral surface 731 of the guide portion 73 on the one end surface 71a side of the base portion 71 in the rotation axis X direction. A long side portion 710a of the oil hole 710 forms an inclined surface that inclines toward the outer diameter side as it separates from the inner peripheral surface 731 of the guide portion 73 in the rotation axis X direction. The long side portion 710a of the oil hole 710 is connected to the inner peripheral surface 781a of the long wall portion 781 of the guide portion 78 on the other end surface 71b side of the base portion 71 in the rotation axis X direction.
An inner peripheral surface 781a of the long wall portion 781 of the guide portion 78 is also an inclined surface that slopes radially outward as it separates from the inner peripheral surface 731 of the guide portion 73 in the rotation axis X direction. The inclination angle of the inner peripheral surface 781 a of the long wall portion 781 is the same as the inclination angle of the long side portion 710 a of the oil hole 710 .

As shown in FIGS. 15 and 16, the other end surface 71b of the base portion 71 on the case member 6 side is provided with three connecting portions 74 (convex portions) that protrude toward the case member 6 side.
The connecting portions 74 are provided at regular intervals in the circumferential direction around the rotation axis X. As shown in FIG. As shown in FIG. 15 , the connecting portion 74 has a tip surface 743 protruding toward the case member 6 . The connecting portion 74 also has side wall portions 744 that connect both end portions of the distal end surface 743 in the circumferential direction around the rotation axis X and the base portion 71 .

As shown in FIG. 5 and FIG. 21 described later, the connecting portion 74 is formed with a circumferential width W2 that is smaller than the circumferential width W1 (see FIG. 5) of the recess 640 of the connecting portion 64 on the case member 6 side. there is The circumferential width W1 of the concave portion 640 means the length from the side wall portion 644 connected to one end in the circumferential direction of the bottom portion 643 around the rotation axis X to the side wall portion 644 connected to the other end. The circumferential width W2 of the connecting portion 74 means the length from the side wall portion 744 connected to one end in the circumferential direction of the distal end surface 743 around the rotation axis X to the side wall portion 744 connected to the other end.

As shown in FIG. 16, the distal end surface 743 of the connecting portion 74 is an arc-shaped surface extending along the circumferential direction around the rotation axis X when viewed from the rotation axis X direction. As shown in FIG. 15, the side wall portion 744 extends from the distal end surface 743 toward the base portion 71 along the rotation axis X direction. A bolt insertion hole 77 is opened in the tip surface 743 . One end of the bolt insertion hole 77 is open to the bolt accommodating portion 76 (see FIG. 13), the base 71 is penetrated in the thickness direction (rotational axis X direction), and the other end is open to the tip surface 743. there is As shown in FIG. 16 , the tip surface 743 is provided with a support groove 75 (first notch) for supporting the pinion mate shaft 51 . The support groove 75 is formed between the bolt insertion holes 77 in the circumferential direction around the rotation axis X. As shown in FIG.

As shown in FIG. 17 , the support groove 75 is linearly formed along the radius line L of the base portion 71 when viewed from the rotation axis X direction. The support groove 75 is formed across the connecting portion 74 from the inner diameter side to the outer diameter side.

The support groove 75 has a semicircular shape along the outer diameter of the shaft member 511 by cutting the tip surface 743 .
As shown in FIG. 17, the support groove 75 is formed with a depth capable of accommodating half of the cylindrical shaft member 511 . That is, the support groove 75 is formed with a depth corresponding to half the diameter Da of the shaft member 511 (=Da/2).

As shown in FIG. 13 , the outer peripheral surface 74 a of the connecting portion 74 protrudes radially outward of the rotation axis X from the outer peripheral surface 71 c of the base portion 71 . The outer peripheral surface 74 a of the connecting portion 74 and the outer peripheral surface 71 c of the base portion 71 are connected by a stepped portion 79 . That is, the stepped portion 79 is provided on the outer peripheral surface of the boundary between the connecting portion 74 and the base portion 71 . As shown in FIG. 14, the diameter R3 of the outer peripheral surface of the stepped portion 79 on the connecting portion 74 side, that is, the outer peripheral surface 74a, is longer than the diameter R4 of the outer peripheral surface on the base portion 71 side, that is, the outer peripheral surface 71c. Here, the radii R3 and R4 mean radii from the rotation axis X, respectively.

As shown in FIGS. 15 and 16 , an arc portion 741 along the outer circumference of the pinion mate gear 52 is provided on the inner diameter side (rotational axis X side) of the connecting portion 74 .
The arc portion 741 supports the outer periphery of the pinion mate gear 52 via the spherical washer 53 (see FIG. 17).
In the circular arc portion 741, an oil groove 742 is provided along the radial line L described above. The oil groove 742 is provided in a range from the support groove 75 of the shaft member 511 to the base portion 71 positioned on the inner circumference of the connecting portion 74 .

The oil groove 742 communicates with the oil groove 712 provided in the other end surface 71 b of the base portion 71 . As shown in FIG. 16 , the oil groove 712 is provided along the radius line L when viewed from the rotation axis X direction, and is formed up to the through hole 70 provided in the base portion 71 .
As shown in the enlarged lower area of FIG. 19, on the other end surface 71b of the base portion 71, a ring-shaped washer 55 that supports the back surface of the side gear 54B is placed. A cylindrical wall portion 540 is provided on the back surface of the side gear 54B. The washer 55 is externally inserted on the cylinder wall portion 540 .

As shown in FIG. 19 , an oil groove 721 is formed at a position intersecting with the oil groove 712 on the inner periphery of the cylindrical wall portion 72 surrounding the through hole 70 . An oil groove 721 is provided on the inner periphery of the cylindrical wall portion 72 along the rotation axis X over the entire length of the cylindrical wall portion 72 in the rotation axis X direction.

21A and 21B are diagrams for explaining the assembly of the case member 6 and the case member 7. FIG.
22A and 22B are diagrams for explaining the assembly of the case member 6 and the case member 7. FIG.
21 shows the state before the case members 6 and 7 are assembled, and FIG. 22 shows the state after the case members 6 and 7 are assembled. 21 and 22 show the differential case 50 viewed from the AA direction in FIG. Also, the connecting portions 64 and 74 are hatched for easy viewing. Also, the shaft member 511 of the pinion mate shaft 51 is indicated by a dashed line.

As shown in FIG. 21, the differential case 50 is constructed by assembling the case member 6 and the case member 7 in the rotation axis X direction. In other words, the rotation axis X direction is along the assembly direction of the differential case 50 . As shown in FIG. 22 , the connection portion 74 (projection) of the case member 7 is inserted into the recess 640 of the connection portion 64 of the case member 6 .
Here, the length L2 of the side wall portion 744 of the case member 7 in the rotation axis X direction has a length matching the length L1 of the side wall portion 644 of the case member 6 in the rotation axis X direction. Therefore, the tip surface 743 of the connecting portion 74 inserted into the recess 640 contacts the bottom surface portion 643 . Thereby, the case member 7 and the case member 6 are positioned in the rotation axis X direction.

By fitting the outer peripheral surface 71c of the base portion 71 of the case member 7 into the inner peripheral surface 681a of the outer peripheral wall 681 of the plate portion 68 of the case member 6, the case member 7 and the case member 6 are concentrically aligned on the rotation axis X. placed.

As described above, the case member 6 and the case member 7 are connected by screwing the bolt B (see FIG. 5) passing through the connecting portion 74 on the case member 7 side into the bolt holes 67, 67 on the case member 6 side. spliced together

As shown in FIG. 22, the support groove 65 of the bottom surface portion 643 and the support groove 75 of the tip end surface 743 are formed at overlapping positions in the rotation axis X direction. When the bottom surface portion 643 and the tip surface 743 are in contact with each other, the semi-circular support grooves 65 and 75 face each other and become line symmetric with the bottom surface portion 643 and the tip surface 743 interposed therebetween. The openings of the support grooves 65 and 75 communicate with each other to form a circular hole along the outer diameter of the shaft member 511 as a whole. The shaft member 511 is held by passing through this circular hole.

As shown in FIG. 21, the circumferential width W1 of the concave portion 640 around the rotation axis X is greater than the circumferential width W2 of the connecting portion 74 (W1>W2). Therefore, as shown in FIG. 22, the side wall portion 644 of the recess 640 faces the side wall portion 744 of the connecting portion 74 with a gap therebetween. This gap serves as an oil passage 56 that communicates the inside and outside of the differential case 50 . The oil passages 56 are formed at both ends in the circumferential direction around the rotation axis X. As shown in FIG. The length of each oil passage 56 in the circumferential direction around the rotation axis X is (W1-W2)/2.

The oil passage 56 is located between the recess 640 and the connecting portion 74 in the circumferential direction around the rotation axis X of the differential case 50 . In FIG. 6, the positions of the oil passages 56 are indicated by hatching in the case member 6. As shown in FIG. The oil passage 56 extends radially outward of the rotating shaft X from the inner diameter side end of the connecting portion 64 and opens to the outer peripheral surface of the differential case 50 . The oil passage 56 discharges the oil OL stirred by the pinion mate gear 52 and the side gear 54</b>B accommodated on the inner diameter side of the connecting portion 64 to the outside of the differential case 50 .

As shown in FIG. 22, the oil passage 56 has a longitudinal shape extending along the rotation axis X direction. A groove portion 645 formed at the boundary between the bottom portion 643 and the side wall portion 644 is positioned at one end of the oil passage 56 in the direction of the rotation axis X. As shown in FIG. A base portion 71 of the case member 7 is positioned at the other end of the oil passage 56 in the rotation axis X direction.

As shown in the enlarged area of FIG. 19 , the outer peripheral surface 71 c of the base portion 71 of the case member 7 is fitted to the inner peripheral surface 681 a of the outer peripheral wall 681 of the plate portion 68 of the case member 6 .
The guide portion 78 of the case member 7 is arranged on the inner diameter side of the oil receiving portion 682 of the case member 6 . In this state, the tip end surface 78a of the guide portion 78 is arranged between one end surface 680a and the other end surface 680b of the oil receiving portion 682 in the rotation axis X direction. The guide portion 78 of the case member 7, the oil receiving portion 682 of the case member 6, and the pinion shaft 44 overlap in the radial direction of the rotation axis X. As shown in FIG.

As shown in FIG. 20, when viewed from the radial direction of the rotation axis X, the oil hole 710 and the guide portion 78 of the case member 7, the recess 683 and oil groove 685 of the case member 6, the oil hole 444 and the oil hole 444 of the pinion shaft 44, and The in-shaft oil passages 440B are arranged in order along the diameter line Lr passing through the rotation axis X and the axis X1. A vertex P of the recess 683 is arranged on the diameter line Lr.

As shown in FIG. 19, in the differential case 50, a bearing B2 is externally fitted on the tubular wall portion 72 of the case member 7. As shown in FIG. The inner race of the bearing B2 abuts against a stepped portion 722 provided on the outer periphery of the cylindrical wall portion 72 from the rotation axis X direction. The bearing B<b>2 externally inserted into the cylindrical wall portion 72 is held by the support portion 145 of the fourth box 14 . A tubular wall portion 72 of the differential case 50 is rotatably supported by the fourth box 14 (see FIG. 4) via a bearing B2.

As shown in FIG. 4, the drive shaft 9B penetrating through the opening 145a of the fourth box 14 is inserted into the supporting portion 145 from the rotation axis X direction. The drive shaft 9B is rotatably supported by a support portion 145. As shown in FIG. The cylinder wall portion 72 functions as a shaft support portion that supports the outer circumference of the drive shaft 9B.
A lip seal RS is fixed to the inner circumference of the opening 145a. A lip portion (not shown) of the lip seal RS is in elastic contact with the outer circumference of the cylinder wall portion 540 of the side gear 54B externally fitted on the drive shaft 9B.
As a result, the gap between the outer circumference of the cylindrical wall portion 540 of the side gear 54B and the inner circumference of the opening 145a is sealed.

The case member 6 of the differential case 50 is supported by the plate member 8 via a bearing B3 externally inserted into the tubular wall portion 611 (see FIG. 2).

A drive shaft 9A passing through the insertion hole 130a of the third box 13 is inserted into the case member 6 from the rotation axis X direction.
The drive shaft 9A is provided across the inner diameter side of the motor shaft 20 of the motor 2 and the sun gear 41 of the planetary reduction gear 4 in the rotation axis X direction.

As shown in FIG. 4, inside the differential case 50, side gears 54A and 54B are spline-fitted to the outer periphery of the tip portion of the drive shaft 9 (9A and 9B). The side gears 54A, 54B and the drive shafts 9 (9A, 9B) are connected to each other so as to rotate about the rotation axis X together.

In this state, the side gears 54A and 54B are arranged opposite to each other with a gap in the rotation axis X direction. A central member 510 of the pinion mate shaft 51 is positioned between the side gears 54A, 54B.
In this embodiment, a total of three shaft members 511 extend radially outwardly from central member 510 . A pinion mate gear 52 is supported on each of the shaft members 511 of the pinion mate shaft 51 . The pinion mate gear 52 is assembled to a side gear 54A positioned on one side in the direction of the rotation axis X and a side gear 54B positioned on the other side in such a manner that the teeth thereof are meshed with each other.

As shown in FIG. 2 , lubricating oil OL is stored inside the fourth box 14 . The lower side of the differential case 50 is positioned within the stored oil OL.
In this embodiment, the oil OL is stored up to a height where the connecting beam 62 is positioned within the oil OL when the connecting beam 62 is positioned at the lowest side.
The stored oil OL is raked up by the differential case 50 rotating around the rotation axis X when the output rotation of the motor 2 is transmitted.

As shown in FIG. 2 , an oil catch portion 15 is provided on the upper portion of the fourth box 14 . A portion of the oil OL that is raked up by the differential case 50 rotating around the rotation axis X flows into the oil catch portion 15 .
The oil catch portion 15 communicates with an oil passage 151a extending radially inside the fourth box 14 . As shown in FIG. 2, the inner diameter side end of the oil passage 151a opens between the lip seal RS and the bearing B2.

The oil catch portion 15 also communicates with an oil hole 136a (see FIG. 2) provided in a cylindrical connection wall 136 of the third box 13 via a pipe (not shown).

Part of the oil OL that has been scraped up by the differential case 50 rotating around the rotation axis X and reaches the oil catch portion 15 is supplied to the internal space Sc of the connection wall 136 through the guide portion 154 and the pipe 127. .

The third box 13 is provided with a radial oil passage 137 communicating with the internal space Sc.
The radial oil passage 137 extends radially downward from the internal space Sc. The radial oil passage 137 communicates with an axial oil passage 138 provided inside the joint portion 132 .

The axial oil passage 138 communicates with an oil reservoir 128 provided in the lower portion of the second box 12 via a communication hole 112a provided in the joint portion 112 of the first box 11 .
The oil reservoir portion 128 penetrates the inside of the peripheral wall portion 121 in the rotation axis X direction. The oil reservoir portion 128 communicates with the second gear chamber Sb2 provided in the fourth box 14 .

The operation of the power transmission device 1 having such a configuration will be described.
As shown in FIG. 1, in the power transmission device 1, a planetary reduction gear 4, a differential mechanism 5, and a drive shaft 9 (9A, 9B) are provided along the transmission path of the output rotation of the motor 2. ing.

As shown in FIG. 2 , when the rotor core 21 rotates around the rotation axis X by driving the motor 2 , rotation is input to the sun gear 41 of the planetary reduction gear 4 via the motor shaft 20 that rotates together with the rotor core 21 . be.

As shown in FIG. 3 , in the planetary reduction gear 4 , the sun gear 41 serves as an input portion for the output rotation of the motor 2 . A differential case 50 that supports the stepped pinion gear 43 serves as an output portion for the input rotation.

When the sun gear 41 rotates around the rotation axis X due to the input rotation, the stepped pinion gear 43 (the large-diameter gear portion 431 and the small-diameter gear portion 432) rotates around the axis X1 due to the rotation input from the sun gear 41 side. do.
Here, the small diameter gear portion 432 of the stepped pinion gear 43 meshes with the ring gear 42 fixed to the inner circumference of the fourth box 14 . Therefore, the stepped pinion gear 43 revolves around the rotation axis X while rotating around the axis X1. The drive shaft 9B is positioned on the inner circumference of the revolution track of the stepped pinion gear 43 .

Here, the outer diameter R2 of the small-diameter gear portion 432 of the stepped pinion gear 43 is smaller than the outer diameter R1 of the large-diameter gear portion 431 (see FIG. 3).
As a result, the differential case 50 (case member 6, case member 7) supporting the stepped pinion gear 43 rotates around the rotation axis X at a rotation speed lower than the rotation input from the motor 2 side.
Therefore, the rotation input to the sun gear 41 of the planetary reduction gear 4 is greatly reduced by the stepped pinion gear 43 . The reduced rotation is output to the differential case 50 (differential mechanism 5).

When the differential case 50 rotates around the rotation axis X due to the input rotation, the drive shafts 9 ( 9 A, 9 B) meshing with the pinion mate gear 52 rotate around the rotation axis X within the differential case 50 . As a result, the left and right drive wheels W, W (see FIG. 1) of the vehicle on which the power transmission device 1 is mounted are rotated by the transmitted rotational driving force.

As shown in FIG. 2 , lubricating oil OL is stored inside the fourth box 14 . Therefore, the stored oil OL is raked up by the differential case 50 rotating around the rotation axis X when the output rotation of the motor 2 is transmitted.
The raking oil OL forms a meshing portion between the sun gear 41 and the large diameter gear portion 431, a meshing portion between the small diameter gear portion 432 and the ring gear 42, and a meshing portion between the pinion mate gear 52 and the side gears 54A and 54B. is lubricated. Most of the oil OL scraped up by the differential case 50 flows into the oil catch portion 15 .

A portion of the oil OL that has flowed into the oil catch portion 15 flows into an oil passage 151 a that is open at one end on the upper surface of the support base portion 151 .

An end portion on the inner diameter side of the oil passage 151a opens to the inner circumference of the support portion 145 (see FIG. 2). Therefore, the oil OL that has flowed into the oil passage 151a is discharged into the clearance Rx between the inner periphery of the support portion 145 of the fourth box 14 and the tubular wall portion 540 of the side gear 54B.

A part of the oil OL discharged into the clearance Rx lubricates the bearing B2 supported by the support portion 145 . The oil OL that has lubricated the bearing B2 moves outside the differential case 50 (bearing B2 side) toward the outer diameter side due to the centrifugal force generated by the rotation of the differential case 50 .
A guide portion 73 having an annular shape when viewed from the rotation axis X direction is provided on the outer diameter side of the differential case 50 . Therefore, the oil OL that has moved to the outer diameter side is captured by the guide portion 73 . As shown in FIG. 14, a rib 711 is provided on the inner peripheral side of the guide portion 73 . A recess is formed between the guide portion 73 , the rib 711 and the cylindrical wall portion 72 . This depression makes it easier for the oil OL to accumulate on the inner peripheral side of the guide portion 73 .
As shown in FIG. 19 , in the base portion 71 of the case member 7 , an oil hole 710 is provided along the inner peripheral surface 731 of the guide portion 73 . Further movement of the oil OL to the outer diameter side is prevented by the guide portion 73 . The oil OL whose movement is hindered passes through an oil hole 710 opening on the inner circumference of the guide portion 73 toward the case member 6 .

The oil OL reaches the inner peripheral surface 731 of the guide portion 73 due to the centrifugal force caused by the rotation of the differential case 50 . Most of the oil OL that reaches the inner peripheral surface 731 of the guide portion 73 flows into the oil hole 710 that opens in the rotation axis X direction without getting over the guide portion 73 .

As shown in FIG. 19 , oil OL supplied to oil hole 710 moves to guide portion 78 . The long side portion 710a of the oil hole 710 and the inner peripheral surface 781a of the long wall portion 781 of the guide portion 78 form an inclined surface that slopes radially outward as it separates from the inner peripheral surface 731 of the guide portion 73 in the rotation axis X direction. there is
Therefore, the oil OL passing through the oil hole 710 and the guide portion 78 is moved along the inclination while being subjected to centrifugal force, thereby promoting the movement toward the case member 6 . In addition, this inclination prevents the oil OL, which has moved from the guide portion 73 toward the case member 6 , from returning to the guide portion 73 side and being discharged to the outside of the differential case 50 .

Here, as described above, the guide portion 78 is a continuous wall composed of a long wall portion 781 and short wall portions 783 and 784 (see FIG. 18). When viewed from the rotation axis X direction, the guide portion 78 opens toward the inner diameter side. As a result, in addition to the oil OL flowing from the oil hole 710, the oil OL scattering inside the differential case 50 can also be caught (white arrow in FIG. 19).

As shown in FIGS. 19 and 20, the oil OL that has moved through the guide portion 78 from the oil hole 710 toward the case member 6 is discharged from the tip surface 78a. The inner peripheral surface 680c of the oil receiving portion 682 and the recessed portion 683 cross the tip end surface 78a of the guide portion 78 from the base portion 71 side of the case member 7 in the rotation axis X direction to the pinion gear 43 side.
Accordingly, the oil OL discharged from the tip surface 78a of the guide portion 78 moves radially outward due to centrifugal force, and is then caught by the inner peripheral surface 680c of the oil receiving portion 682 and the recess 683 (see FIG. 20).

The inner peripheral surface 680c and the recessed portion 683 are inclined surfaces that are inclined radially outward as they move away from the guide portion 78 in the rotation axis X direction. The oil OL caught by the recessed portion 683 moves along the inclination from the one end surface 680a side of the oil receiving portion 682 to the other end surface 680b side. Also, most of the oil OL caught by the inner peripheral surface 680c gathers in the recess 683 in the process of moving along the slope.

As shown in FIG. 20, when viewed from the direction of the rotation axis X, the oil OL in the recess 683 moves on the inclined surfaces 683a and 683b in the circumferential direction about the rotation axis X due to centrifugal force and gathers around the vertex P. .

The concave portion 683 communicates at the vertex P with the oil groove 685 (clearance CL2). The oil OL in the recessed portion 683 is discharged to the oil groove 685 after gathering at the apex P by centrifugal force. The oil OL in the oil groove 685 moves radially outward due to centrifugal force and flows into the oil hole 444 of the pinion shaft 44 . At this time, the washer Wc is also lubricated.

The oil OL that has flowed into the oil hole 444 of the pinion shaft 44 moves to the in-shaft oil passage 440B and is finally discharged from the oil hole 443 (see FIG. 4) to lubricate the needle bearing NB.

Further, part of the oil OL discharged into the clearance Rx passes through an oil groove 721 provided in the inner circumference of the cylindrical wall portion 72 of the case member 7, as shown in FIG. The oil OL that has passed through the oil groove 721 is supplied to the washer 55 that supports the back surface of the side gear 54B and lubricates the washer 55 .
Furthermore, the oil OL passes through an oil groove 712 provided in the base portion 71 of the case member 7 and an oil groove 742 provided in the arc portion 741 . The oil OL that has passed through the oil groove 742 is supplied to the spherical washer 53 that supports the back surface of the pinion mate gear 52 to lubricate the spherical washer 53 .

A portion of the oil OL captured by the oil catch portion 15 is supplied to an oil hole 136a (see FIG. 2) provided in the cylindrical connection wall 136 of the third box 13 through a pipe (not shown). be.
The oil OL discharged from the oil hole 136a into the internal space Sc is stored in the internal space Sc. Oil OL also lubricates bearing B4 supported by peripheral wall portion 131 of third box 13 .

A portion of the oil OL discharged into the internal space Sc moves to the other end 20b side of the motor shaft 20 through the gap between the outer circumference of the drive shaft 9A and the inner circumference of the motor shaft 20 .
As shown in FIG. 11, the other end 20b of the motor shaft 20 is inserted inside the cylindrical wall portion 541 of the side gear 54A. A communication path 542 is provided on the inner periphery of the cylindrical wall portion 541 to communicate with the back surface of the side gear 54A.
Therefore, part of the oil OL that has moved to the other end 20 b side of the motor shaft 20 and is discharged inside the cylinder wall portion 541 passes through the communication path 542 . The oil OL that has passed through the communication path 542 is supplied to the washer 55 on the back surface of the side gear 54A to lubricate the washer 55 .

Furthermore, as shown in FIG. 11, the oil OL that has lubricated the washer 55 on the back surface of the side gear 54A passes through an oil groove 662 provided in the gear support portion 66 of the case member 6 and an oil groove 642 provided in the arc portion 641. . The oil OL that has passed through the oil groove 642 is supplied to the spherical washer 53 that supports the back surface of the pinion mate gear 52 to lubricate the spherical washer 53 .

2, the internal space Sc of the third box 13 includes a radial oil passage 137, an axial oil passage 138, a communication hole 112a, and an oil reservoir provided in the lower portion of the second box 12. 128 and the second gear chamber Sb<b>2 provided in the fourth box 14 .
Therefore, the oil OL inside the internal space Sc is held at the same height position as the oil OL stored inside the fourth box 14 .

In this way, most of the oil OL that has been raked up by the differential case 50 rotating around the rotation axis X flows into the oil catch portion 15 . The oil OL is supplied from the oil catch portion 15 into the support portion 145 of the fourth box 14 to lubricate the bearing B2. The oil OL is also supplied to the internal space Sc inside the third box 13 to lubricate the bearing B4.
The oil OL that has lubricated these bearings B2 and B4 is finally returned into the fourth box 14 and raked up by the rotating differential case 50 .

Therefore, in the power transmission device 1, the oil OL in the fourth box 14 is scooped up when the drive wheels W rotate, and is used to lubricate the bearings and the meshing portions of the gears. The oil OL used for lubrication is returned into the fourth box 14 and raked up again.

Further, in the power transmission device 1 , the connecting portion 74 of the case member 7 is inserted into the concave portion 640 of the case member 6 and brought into contact therewith, so that the support grooves 65 and 75 face each other to support the shaft member 511 . A circular hole is formed.

Therefore, as shown in FIG. 21 , in the embodiment, the case members 6 and 7 can be assembled with the shaft member 511 previously arranged in the support groove 65 of the recess 640 .

Also, the three shaft members 511 can be arranged in the case member 6 in a state where they are connected to the central member 510 in advance. In this case, a pinion mate shaft 51 in which the shaft member 511 and the central member 510 are integrally molded can also be used.

Also, the circumferential width W2 of the connecting portion 74 around the rotation axis X is set smaller than the circumferential width W1 of the recess 640 . Therefore, the connecting portion 74 can be easily inserted into the concave portion 640 .

As shown in FIG. 22 , when the case member 6 and the case member 7 are assembled, a gap that becomes the oil passage 56 is formed between the concave portion 640 and the connecting portion 74 . The oil passage 56 improves the ability of the oil OL to be discharged from the inside of the differential case 50 to the outside. As a result, the stirring resistance of the oil OL by the pinion mate gear 52 and the side gears 54A and 54B (see FIG. 5) located on the inner diameter side of the connecting portion 64 and the connecting portion 74 can be reduced.

Further, as shown in FIG. 8, a groove portion 645 is formed at the boundary between the bottom portion 643 and the side wall portion 644 of the case member 6 . The groove portion 645 extends along the oil passage 56 from the inner diameter side of the rotating shaft X to the outer diameter side. The oil OL stirred by the pinion mate gear 52 and the side gears 54A and 54B enters the groove portion 645 and flows along the groove portion 645 toward the outer diameter side. This improves the ability of the oil OL to be discharged from the inside of the differential case 50 to the outside.

As described above, the power transmission device 1 according to this embodiment has the following configuration.
(1) The power transmission device 1 is
a differential case 50 (case);
and a pinion shaft 44 (shaft) arranged in the differential case 50 in a direction along the rotation axis X of the differential case 50 .
The differential case 50 is provided with an oil hole 710 (opening) penetrating in the rotation axis X direction.
Differential case 50 has a guide portion 78 (first guide portion) protruding inwardly of differential case 50 from oil hole 710 .
A gap CL<b>2 (oil path) communicating with the pinion shaft 44 is formed outside the guide portion 78 in the radial direction of the rotation axis X in the differential case 50 .

With this configuration, the lubrication efficiency in the power transmission device 1 can be improved.
Specifically, the oil OL that has flowed into the oil hole 710 is supplied to the pinion shaft 44 from the guide portion 78 through the clearance CL2 due to the centrifugal force generated by the rotation of the differential case 50 .
By interposing the guide portion 78 and the clearance CL2 between the oil hole 710 and the pinion shaft 44, the amount of the oil OL guided to the pinion shaft 44 can be increased. This improves lubrication efficiency.

The power transmission device 1 according to this embodiment has the following configuration.
(2) A long side portion 710a (inner peripheral wall) of the oil hole 710 is inclined so as to widen radially outward as it approaches the gap CL2.

With this configuration, centrifugal force can be used to positively guide the oil OL that has flowed into the oil hole 710 to the clearance CL2.

The power transmission device 1 according to this embodiment has the following configuration.
(3) The differential case 50 has a guide portion 73 (second guide portion) that protrudes from the oil hole 710 to the outside of the differential case 50 .

With this configuration, the oil OL that scatters outside the differential case 50 can be taken in by the guide portion 73, so the amount of the oil OL that is guided to the pinion shaft 44 can be increased. This improves lubrication efficiency.

The power transmission device 1 according to this embodiment has the following configuration.
(4) When viewed from the rotation axis X direction, the guide portion 73 is annular, and the guide portion 78 is non-annular.

The differential case 50 accommodates the differential mechanism 5 inside. Therefore, inside the differential case 50 , the space in which the guide portion 78 is provided is limited to a portion that avoids interference with the differential mechanism 5 . On the other hand, outside the differential case 50, there is enough space for the guide portion 73 to be provided.
Therefore, the flexibility of the layout of the differential mechanism 5 is ensured by configuring as described above and making the guide portion 78 non-annular inside the differential case 50 . Further, on the outside of the differential case 50, the guide portion 73 is annular so that a large amount of the oil OL can be taken in.

The power transmission device 1 according to this embodiment has the following configuration.
(5) When viewed from the rotation axis X direction, the guide portion 78 is a continuous wall with an opening facing the inner diameter side. Specifically, the guide portion 78 includes a long wall portion 781 provided along the circumferential direction around the rotation axis X, and short wall portions 783 and 784 extending radially inward from both ends of the long wall portion 781 . , consists of

With this configuration, the guide portion 78 can take in not only the oil OL passing through the oil hole 710 but also the oil OL scattering inside the differential case 50 .

The power transmission device 1 according to this embodiment has the following configuration.
(6) The differential case 50 is composed of the case member 7 (first case member) having the guide portion 78 and the case member 6 (second case member) having the clearance CL2.
The case member 6 has an oil receiving portion 682 arranged on the outer diameter side of the guide portion 78 while being joined to the case member 7 in the rotation axis X direction.
An inner peripheral surface 680c of the oil receiving portion 682 crosses the tip end surface 78a of the guide portion 78 in the rotation axis X direction from the case member 7 side to the stepped pinion shaft 44 side.

With this configuration, the oil OL discharged from the guide portion 78 of the case member 7 can be received by the inner peripheral surface 680 c of the oil receiving portion 682 of the case member 6 . As a result, the oil OL that has passed through the guide portion 78 of the case member 7 can be caught without scattering.

The power transmission device 1 according to this embodiment has the following configuration.
(7) The inner peripheral surface 680c of the oil receiving portion 682 is formed with a recess 683 (notch) that opens radially inward when viewed from the rotation axis X direction.

With this configuration, the oil OL caught by the inner peripheral surface 680 c of the oil receiving portion 682 from the guide portion 78 can be collected in the recess 683 .

The power transmission device 1 according to this embodiment has the following configuration.
(8) The inner peripheral surface 680c of the oil receiving portion 682 is positioned on the inner diameter side of the clearance CL2.
The inner peripheral surface 680c and the recessed portion 683 of the oil receiving portion 682 are inclined so as to widen radially outward from the guide portion 78 toward the clearance CL2.

With this configuration, centrifugal force can be used to positively guide the oil OL caught by the inner peripheral surface 680c and the recessed portion 683 to the clearance CL2.

The power transmission device 1 according to this embodiment has the following configuration.
(9) The clearance CL2 is configured as a clearance between the other end surface 680b (side wall) of the oil receiving portion 682 and the side wall portion 432a (side wall) of the small diameter gear portion 432 (pinion gear) supported by the pinion shaft 44. be.
Specifically, the clearance CL2 is the clearance between the oil groove 685 that communicates the recess 683 and the support hole 68a in the other end surface 680b of the oil receiving portion 682 and the side wall portion 432a of the small diameter gear portion 432.

For example, in order to guide the oil OL caught by the oil receiving portion 682 to the pinion shaft 44 side, it is conceivable to form an oil hole penetrating the oil receiving portion 682 in the radial direction. When forming the oil hole, the oil hole is formed after the case member 6 is cast.
On the other hand, in the present embodiment, an oil groove 685 is provided in the other end surface 680b of the oil receiving portion 682 to communicate the recess 683 and the support hole 68a, and the oil groove 685 is provided between the oil groove 685 and the side wall portion 432a of the small diameter gear portion 432. It has a configuration in which a clearance is formed at
With this configuration, the oil groove 685 can be formed when the case member 6 is cast. As a result, the number of steps can be reduced as compared with the case of forming oil holes.

In addition, in the present embodiment, the case where the gap CL2 is formed by providing the oil groove 685 was exemplified, but the present invention is not limited to this. For example, the gap CL2 may be formed by offsetting the other end surface 680b of the oil receiving portion 682 over the entire circumferential surface around the rotation axis X in a direction away from the side wall portion 432a of the small-diameter gear portion 432.

[Modification 1]
In the power transmission device 1 according to the present embodiment, the case where the oil OL received by the oil receiving portion 682 is guided to the pinion shaft 44 side through the gap CL2 has been exemplified, but the present invention is not limited to this. For example, the following modifications may be used.

23A and 23B are diagrams illustrating a power transmission device 1A according to Modification 1. FIG.
In the power transmission device 1A according to Modification 1, only the parts that are different from the power transmission device 1 according to the present embodiment will be described.

As shown in FIG. 23, in the power transmission device 1A according to Modification 1, the oil receiving portion 682A of the plate portion 68A is provided with a wall portion 688 protruding radially inward from the inner peripheral surface 680c. The wall portion 688 is provided on the other end surface 680b side of the oil receiving portion 682A in the rotation axis X direction.
The wall portion 688 is provided over the entire length of the inner peripheral surface 680c in the circumferential direction around the rotation axis X. As shown in FIG. The wall portion 688 faces the guide portion 78 with a gap in the rotation axis X direction. The wall portion 688 constitutes an opposing side wall portion of the guide portion 78 .

A communication hole 689 is formed in the oil receiving portion 682A to communicate the recess 683 and the support hole 68a. The communication hole 689 functions as an oil path. The communication hole 689 opens in a region between the wall portion 688 of the concave portion 683 in the rotation axis X direction and the guide portion 78 . The communication hole 689 opens to the support hole 68a and communicates with the oil hole 444A of the pinion shaft 44A.

In the power transmission device 1A, the oil OL discharged from the guide portion 78 is caught by the recessed portion 683 of the inner peripheral surface 680c of the oil receiving portion 682A. The oil OL caught by the recess 683 moves along the slope on the recess 683 in the direction of the rotation axis X (the direction of the arrow in FIG. 23).

The flow of the oil OL moving over the recessed portion 683 is finally blocked by the wall portion 688 . As a result, the oil OL is stored in the space surrounded by the recess 683 and the wall 688 in the oil receiving portion 682A. The stored oil OL is discharged from the communication hole 689 to the oil hole 444A of the pinion shaft 44A by centrifugal force. Thereby, the oil OL can be guided to the pinion shaft 44A.

A power transmission device 1A according to a modification has the following configuration.
(10) The oil receiving portion 682A has a wall portion 688 (opposing side wall portion) that faces the guide portion 78 in the rotation axis X direction and protrudes radially inward.
The oil receiving portion 682A has a communication hole 689 (oil path) between the guide portion 78 and the wall portion 688 that communicates with the pinion shaft 44A.

With this configuration, the oil OL caught in the recessed portion 683 of the inner peripheral surface 680c is blocked by the wall portion 688 and discharged from the communication hole 689 toward the pinion shaft 44A. Thereby, the amount of oil OL guided to the pinion shaft 44 side can be increased.

[Modifications 2 to 4]
FIG. 24 is a diagram illustrating a guide portion 78A according to Modification 2. As shown in FIG.
FIG. 25 is a diagram illustrating a guide portion 78B according to Modification 3. As shown in FIG.
FIG. 26 is a diagram illustrating a guide portion 78C according to Modification 4. As shown in FIG.

In the present embodiment, the long wall portion 781 of the guide portion 78 is provided in a direction along the imaginary circle Im3 (see FIG. 16), and the short wall portions 783 and 784 are arranged along straight lines Lm2 and Lm3 (see FIG. 18) parallel to the radial direction. Although the case where it is provided in the direction along is illustrated, it is not limited to this.

For example, as in Modified Example 2 shown in FIG. 24, the guide portion 78A may be configured to have short wall portions 783A and 784A that are inclined away from each other toward the radially inner side.

Further, as in Modified Example 3 shown in FIG. 25, the guide portion 78B may be configured to have short wall portions 783B and 784B that are slanted toward each other toward the inner side in the radial direction.

26, the guide portion 78C may be configured to have an arc-shaped wall portion 780 that covers the oil hole 710 over the entire length in the circumferential direction around the rotation axis X. As shown in FIG. The wall portion 780 is recessed radially outward toward the central portion in the circumferential direction around the rotation axis X, and has an opening directed radially inward.

Further, in the present embodiment, the concave portion 683 provided in the plate portion 68 is configured by the inclined surfaces 683a and 683b, but the present invention is not limited to this.
Although illustration is omitted, for example, the concave portion 683 may be recessed toward the outer diameter side with a curvature larger than the curvature of the inner peripheral surface 680c when viewed from the rotation axis X direction. By doing so, the oil OL can also be collected at the apex of the concave portion 683 .

Although the embodiments of the present invention have been described above, the present invention is not limited only to the aspects shown in these embodiments. It can be changed as appropriate within the scope of the technical idea of the invention.

1, 1A power transmission device 6 case member (second case member)
7 case member (first case member)
43 stepped pinion gear (pinion gear)
44 Pinion axis (shaft)
50 differential case (case)
68, 68A plate portion 73 guide portion (second guide portion)
78, 78A to 78C guide portion (first guide portion)
432 Small-diameter gear portion 432a Side wall portion 680c Inner peripheral surface (inclined surface)
682, 682A Oil receiving portion 683 Recess (notch)
685 oil groove 688 wall portion (opposing side wall portion)
689 Communication hole 710 Oil hole (opening)
710a long side (inner peripheral wall)
CL2 clearance (oil path)
OL oil (lubricating oil)
X rotation axis

Claims (10)

a case;
a shaft disposed within the case and oriented along the axis of rotation of the case;
The case is provided with an opening penetrating in the rotation axis direction,
The case has a first guide portion that protrudes inside the case from the opening,
A power transmission device, wherein an oil path communicating with the shaft is formed in the case outside the first guide portion in a radial direction of the rotating shaft. In claim 1,
A power transmission device, wherein an inner peripheral wall of the opening is inclined in a direction that widens radially outward as it approaches the oil path. In claim 1 or 2,
The power transmission device, wherein the case has a second guide portion protruding outside the case from the opening. In claim 3,
A power transmission device, wherein the second guide portion is annular and the first guide portion is non-annular when viewed from the rotation axis direction. In any one of claims 1 to 4,
The power transmission device, wherein the first guide portion is a continuous wall with an opening facing the inner diameter side when viewed from the direction of the rotating shaft. In any one of claims 1 to 5,
The case is composed of a first case member having the first guide portion and a second case member having the oil path,
The power transmission device, wherein the second case member has an oil receiving portion on the outer diameter side of the first guide portion. In claim 6,
A power transmission device according to claim 1, wherein the oil receiving portion is formed with a notch portion that opens radially inward when viewed from the direction of the rotating shaft. In claim 6 or 7,
The power transmission device, wherein the oil receiving portion has an inclined surface that inclines in a direction that widens radially outward from the first guide portion toward the oil path. In any one of claims 6 to 8,
A power transmission device, wherein the oil path is configured as a clearance between a side wall of the oil receiving portion and a side wall of a pinion gear supported by the shaft. In any one of claims 6 to 8,
The power transmission device, wherein the oil receiving portion has a facing side wall portion that faces the first guide portion in the direction of the rotation axis and protrudes radially inward.

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