JP7392218B2 - Lubrication structure - Google Patents

Description

The present invention relates to a lubrication structure for a planetary gear mechanism.

Patent Document 1 discloses, as a lubrication structure for a planetary gear mechanism, that a plate is installed to collect lubricating oil scattered by centrifugal force during rotation.

Japanese Patent Application Publication No. 2002-286119

Since the invention described in Patent Document 1 utilizes centrifugal force, there is a problem in improving the efficiency of collecting lubricating oil to be supplied to the planetary gear mechanism.

Therefore, there is a need to improve the efficiency of collecting lubricating oil to be supplied to the planetary gear mechanism.

The present invention
A lubrication structure having a lubricating oil passage that supplies lubricating oil from an axial side of the pinion gear to a bearing that supports the pinion gear of a planetary gear mechanism,
It has a lubricating oil introduction part that passes through an oil reservoir as the pinion gear revolves,
The lubricating oil introduction part includes an opening that opens toward the revolution direction of the pinion gear, and a guide part that guides the lubricating oil flowing from the opening in a flow along the revolution direction to the entrance of the lubricating oil path. and,
The lubricating oil introducing portion has a lubricating structure having a passage port through which the lubricating oil passes downstream of the opening in the revolution direction .

According to the present invention, the efficiency of collecting lubricating oil to be supplied to the planetary gear mechanism can be improved.

FIG. 1 is a diagram illustrating a power transmission device according to an embodiment. FIG. 3 is an enlarged view of the area around the speed reduction mechanism of the power transmission device. FIG. 3 is an enlarged view of the area around the differential device of the power transmission device. It is a figure explaining a lubrication structure. It is a figure explaining a lubrication structure. It is a figure explaining a lubrication structure. It is a figure explaining the effect|action of a lubrication structure. It is a figure explaining the lubrication structure concerning a modification.

Hereinafter, the lubrication structure 7 according to the present embodiment will be explained using an example in which the lubrication structure 7 is applied to a reduction mechanism 3 (second planetary reduction gear 5) which is one of the components of the power transmission device 1 in an electric vehicle EV. .
FIG. 1 is a diagram illustrating a power transmission device 1 according to this embodiment.
FIG. 2 is an enlarged view of the area around the speed reduction mechanism 3 of the power transmission device 1.
FIG. 3 is an enlarged view of the area around the differential device 6 of the power transmission device 1.
In addition, in the drawings, the front, rear, left, right, up and down directions are described as directions seen from a driver riding in the electric vehicle EV.

The power transmission device 1 includes a motor 2, a speed reduction mechanism 3 (first planetary reduction gear 4, second planetary reduction gear 5) that reduces the output rotation of the motor 2 and inputs it to the differential device 6, and a drive shaft 8 ( 8A, 8B).

In the power transmission device 1, along the transmission path of the output rotation of the motor 2, a reduction mechanism 3 (first planetary reduction gear 4, second planetary reduction gear 5), a differential device 6, and a drive shaft 8 (8A, 8B) are provided.
The output rotation of the motor 2 is decelerated by the deceleration mechanism 3 and input to the differential device 6, and then transmitted to the left and right drive wheels (not shown) of the electric vehicle EV via the drive shaft 8 (8A, 8B). communicated. In FIG. 1, drive shaft 8A is connected to the left wheel of electric vehicle EV so that rotation can be transmitted thereto, and drive shaft 8B is connected to the right wheel so that rotation can be transmitted to it.

Here, the first planetary reduction gear 4 is connected downstream of the motor 2, and the second planetary reduction gear 5 is connected downstream of the first planetary reduction gear 4. The differential device 6 is connected downstream of the second planetary reduction gear 5, and the drive shaft 8 (8A, 8B) is connected downstream of the differential device 6.

The motor 2 includes a cylindrical motor shaft 20, a cylindrical rotor core 21 fitted onto the motor shaft 20, and a stator core 25 surrounding the outer periphery of the rotor core 21 at predetermined intervals.

The motor shaft 20 is provided so as to be rotatable relative to the drive shaft 8B while being inserted onto the drive shaft 8B.
In the motor shaft 20, bearings B1, B1 are fitted and fixed on the outer periphery of one end 20a and the other end 20b in the longitudinal direction.
One end 20a side of the motor shaft 20 is rotatably supported by a cylindrical motor support portion 121 of the intermediate case 12 via a bearing B1.
The other end 20b side of the motor shaft 20 is rotatably supported by a cylindrical motor support portion 111 of the cover 11 via a bearing B1.

The motor 2 has a motor housing 10 that surrounds the outer periphery of a rotor core 21 at predetermined intervals. In this embodiment, an intermediate case 12 is joined to one end 10a of the motor housing 10, and a cover 11 is joined to the other end 10b of the motor housing 10.

Seal rings S, S are provided at one end 10a and the other end 10b of the motor housing 10. One end 10a of the motor housing 10 is joined to an annular base 120 of the intermediate case 12 without a gap by a seal ring S provided at the one end 10a.
The other end 10b of the motor housing 10 is joined to the annular joint 110 of the cover 11 without a gap by a seal ring S provided at the other end 10b.

As a result, a space Sa (motor chamber) surrounded by the motor housing 10, the cover 11, and the intermediate case 12 is formed inside the motor housing 10.
In this embodiment, a main body case 9 of the power transmission device 1 is composed of a motor housing 10, a cover 11, an intermediate case 12, a case 13 and an intermediate cover 14, which will be described later.
In the internal space of the main body case 9, a space Sa on the motor housing 10 side with the intermediate case 12 as a boundary serves as a motor chamber in which the motor 2 is accommodated. The spaces Sb and Sc on the side of the case 13 serve as gear chambers that accommodate the reduction mechanism 3 (first planetary reduction gear 4, second planetary reduction gear 5).
The gear chamber is partitioned into a space Sb that accommodates the first planetary reduction gear 4 and a space Sc that accommodates the second planetary reduction gear 5 and the differential case 60 by an intermediate cover 14 that will be described later.

In the cover 11, the joint portion 110 and the motor support portion 111 are provided with positions shifted in the rotation axis X direction.
In this embodiment, when the joint part 110 of the cover 11 is fixed to the other end 10b of the motor housing 10, the motor support part 111 is inserted into the inside of the motor housing 10.

In this state, the motor support portion 111 is disposed on the inner diameter side of a coil end 253b (described later), facing the other end portion 21b of the rotor core 21 with a gap in the rotation axis X direction.
The connecting portion 115 that connects the motor support portion 111 and the side wall portion 113 of the cover 11 is provided so as to avoid contact with the coil end 253b and the support tube 112, which will be described later.

In the intermediate case 12, an annular base portion 120 and a motor support portion 121 are provided with positions shifted in the rotation axis X direction.
In this embodiment, when the intermediate case 12 is fixed to one end 10a of the motor housing 10, the motor support part 121 is inserted into the inside of the motor housing 10.

In this state, the motor support portion 121 is disposed opposite to one end portion 21a of the rotor core 21 with a gap in the rotation axis X direction on the inner diameter side of a coil end 253a (described later) (see FIG. 2).
As shown in FIG. 2, the connection part 123 that connects the base part 120 and the motor support part 121 is provided so as to avoid contact with the coil end 253a and a side plate part 452, which will be described later.

Note that a bearing retainer 125 is fixed to an end surface 121a of the motor support portion 121 on the rotor core 21 side.
The bearing retainer 125 has a ring shape when viewed from the rotation axis X direction. The inner diameter side of the bearing retainer 125 is in contact with the side surface of the outer race B1b of the bearing B1 supported by the motor support part 121 from the rotation axis X direction. The bearing retainer 125 prevents the bearing B1 from falling off from the motor support section 121.

As shown in FIG. 1, inside the motor housing 10, the rotor core 21 is arranged between the motor support part 111 on the cover 11 side and the motor support part 121 on the intermediate case 12 side.

The rotor core 21 is formed by laminating a plurality of silicon steel plates, and each of the silicon steel plates is fitted onto 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 direction of the rotation axis It is set in.

One end portion 21 a of the rotor core 21 in the direction of the rotation axis X is positioned by the large diameter portion 203 of the motor shaft 20 . The other end 21b of the rotor core 21 is positioned by a stopper 23 press-fitted into the motor shaft 20.

The stator core 25 is formed by laminating a plurality of electromagnetic steel plates, and each of the electromagnetic steel plates includes a ring-shaped yoke portion 251 fixed to the inner periphery of the motor housing 10 and a rotor core from the inner periphery of the yoke portion 251. It has teeth portions 252 that protrude toward the 21 side.
In this embodiment, the stator core 25 has a structure in which the winding 253 is distributed over a plurality of teeth portions 252, and the stator core 25 has coil ends 253a and 253b that protrude in the rotation axis X direction. Therefore, the length in the rotation axis X direction is longer than that of the rotor core 21.

Note that a stator core having a configuration in which windings are concentratedly wound on each of a plurality of teeth portions protruding toward the rotor core 21 side may be employed.

In the motor shaft 20, a bearing B1 is press-fitted into the outer periphery of a region closer to the one end 20a than the large diameter portion 203.
As shown in FIG. 2, one side surface of the inner race B1a of the bearing B1 in the direction of the rotation axis X is in contact with a stepped portion 204 provided on the outer periphery of the motor shaft 20. A ring-shaped stopper 205 press-fitted onto the outer periphery of the motor shaft 20 is in contact with the other side surface of the inner race B1a.
The bearing B1 is positioned by the stopper 205 at a position where the inner race B1a is brought into contact with the stepped portion 204.

One end 20a of the motor shaft 20 is located closer to the differential device 6 than the stopper 205 (on the left side in the figure). In the direction of the rotation axis X, one end 20a faces the side surface 41a of the sun gear 41 of the first planetary reduction gear 4 with an interval therebetween.

On the one end 20a side of the motor shaft 20, a cylindrical wall 122 is located on the radially outer side of the motor shaft 20.
The cylindrical wall 122 protrudes from the motor support portion 121 toward the differential device 6, and a tip 122a of the cylindrical wall 122 faces the side surface 41a of the sun gear 41 of the first planetary reduction gear 4 with an interval therebetween.

The cylindrical wall 122 surrounds the outer periphery of the motor shaft 20 at predetermined intervals, and a lip seal RS is installed between the cylindrical wall 122 and the motor shaft 20.
The lip seal RS is provided to partition a space Sa on the inner diameter side of the motor housing 10 (see FIG. 1) and a space Sb on the inner diameter side of the intermediate case 12 (see FIG. 1).

A space Sb on the inner diameter side of the intermediate case 12 communicates with a space Sc in the case 13 that accommodates a differential device 6, which will be described later, and is filled with lubricating oil OL for the differential device 6. The lip seal RS is provided to prevent the lubricating oil OL from flowing into the space Sa on the inner diameter side of the motor housing 10.

As shown in FIG. 2, a region 202 on the one end 20a side of the motor shaft 20 is formed with a larger inner diameter than a region 201 into which the rotor core 21 is inserted.
A cylindrical connecting portion 411 of the sun gear 41 is inserted inside the region 202 on the one end 20a side. In this state, the region 202 on the one end 20a side of the motor shaft 20 and the connecting portion 411 of the sun gear 41 are spline-fitted so as to be unable to rotate relative to each other.

Therefore, the output rotation of the motor 2 is input to the sun gear 41 of the first planetary reduction gear 4 via the motor shaft 20, and the sun gear 41 rotates around the rotation axis X by the rotational driving force of the motor 2.
The first planetary reduction gear 4 includes a sun gear 41, a ring gear 42, a pinion gear 43, and a carrier 45.

Sun gear 41 has a connecting portion 411 extending in the rotation axis X direction from a side surface 41a on the inner diameter side. The connecting portion 411 is formed integrally with the sun gear 41 , and a through hole 410 is formed across the inner diameter side of the sun gear 41 and the inner diameter side of the connecting portion 411 .
Sun gear 41 is rotatably supported on the outer periphery of drive shaft 8B passing through through hole 410.

A ring gear 42 is located on the outer diameter side of the sun gear 41 in the radial direction of the rotation axis X. The ring gear 42 is spline-fitted to the inner periphery of the base 120 of the intermediate case 12.
Since the intermediate case 12 is a stationary member, the ring gear 42 is provided in such a manner that rotation about the rotation axis X is restricted.

In the radial direction of the rotation axis X, between the sun gear 41 and the ring gear 42, a pinion gear 43 rotatably supported by a pinion shaft 44 meshes with the outer periphery of the sun gear 41 and the inner periphery of the ring gear 42. .

The pinion gear 43 is rotatably supported on the outer periphery of the pinion shaft 44 via a needle bearing NB. The pinion shaft 44 passes through the pinion gear 43 in the direction of the axis X1 parallel to the rotation axis X. One end and the other end of the pinion shaft 44 in the longitudinal direction are supported by a pair of side plate parts 451 and 452 of the carrier 45.

The side plate portions 451 and 452 are provided parallel to each other with an interval in the rotation axis X direction.
Between the side plate portions 451 and 452, a plurality of (for example, four) pinion gears 43 are provided at predetermined intervals in the circumferential direction around the rotation axis X.

A cylindrical connecting portion 453 is provided on the side plate portion 451 located on the differential gear 6 side.
In the side plate portion 451, the connecting portion 453 is arranged concentrically with respect to the rotation axis X, and protrudes along the rotation axis X in a direction approaching the differential device 6 (leftward in the figure).

A ring-shaped intermediate cover 14 is located on the differential gear 6 side when viewed from the intermediate case 12.
The base portion 143 on the outer diameter side of the intermediate cover 14 is sandwiched between the intermediate case 12 and the case 13.
The connecting portion 453 provided on the inner diameter side of the side plate portion 451 passes through the central opening 140 of the intermediate cover 14 from the motor 2 side to the differential device 6 side (left side in the figure).
A tip 453a of the connecting portion 453 is located inside the intermediate cover 14. A meshing portion between the sun gear 51 of the second planetary reduction gear 5 and the stepped pinion gear 53 (large diameter gear portion 531) is located on the extension of the tip 453a of the connecting portion 453 in the rotation axis X direction.

A cylindrical connecting portion 511 extending from the sun gear 51 is inserted into the inside of the connecting portion 453 and is spline-fitted between the connecting portion 453 on the first planetary reduction gear 4 side and the connecting portion 511 on the second planetary reduction gear 5 side. The connecting portion 511 is connected to the connecting portion 511 so as not to be relatively rotatable.
In the first planetary reduction gear 4, the sun gear 41 serves as an input section for the output rotation of the motor 2, and the carrier 45 (connection section 453) that supports the pinion gear 43 serves as an output section for the input rotation. There is.

In the second planetary reduction gear 5 , the sun gear 51 serves as an input portion for the output rotation of the motor 2 .
Sun gear 51 has a connecting portion 511 extending in the direction of rotation axis X from a side surface 51a on the inner diameter side. The connecting portion 511 is formed integrally with the sun gear 51, and a through hole 510 is formed across the inner diameter side of the sun gear 51 and the inner diameter side of the connecting portion 511.
Sun gear 51 is rotatably supported on the outer periphery of drive shaft 8B passing through through hole 510.

A side surface 51b of the sun gear 51 on the side of the differential device 6 (left side in the figure) faces a cylindrical support portion 601 of a differential case 60, which will be described later, with a gap in the rotation axis X direction, and the side surface 51b and the support A needle bearing NB is interposed between the portion 601 and the portion 601.

The sun gear 51 meshes with the large-diameter gear portion 531 of the stepped pinion gear 53 on the extension of the connecting portion 453 on the side of the first planetary reduction gear 4 described above.

The stepped pinion gear 53 has a large-diameter gear portion 531 that meshes with the sun gear 51 and a small-diameter gear portion 532 that has a smaller diameter than the large-diameter gear portion 531.
The stepped pinion gear 53 is a gear component in which a large-diameter gear portion 531 and a small-diameter gear portion 532 are aligned in the axis X2 direction parallel to the rotation axis X and are integrally provided.

The stepped pinion gear 53 has a through hole 530 passing through the inner diameter side of the large diameter gear portion 531 and the small diameter gear portion 532 in the direction of the axis X2.
The stepped pinion gear 53 is rotatably supported on the outer periphery of the pinion shaft 54 passing through the through hole 530 via a needle bearing NB.
One end and the other end in the longitudinal direction of the pinion shaft 54 are supported by a side plate portion 651 formed integrally with the differential case 60 and a side plate portion 551 arranged at intervals on the side plate portion.

The side plate portions 651, 551 are provided parallel to each other with an interval in the rotation axis X direction.
Between the side plate parts 651, 551, a plurality of stepped pinion gears 53 are provided at predetermined intervals in the circumferential direction around the rotation axis X (for example, three).

Each of the small diameter gear portions 532 meshes with the inner periphery of the ring gear 52. The ring gear 52 is spline-fitted to the inner periphery of the case 13, and relative rotation with the case 13 is restricted.

A cylindrical portion 552 extending toward the first planetary reduction gear 4 is provided on the inner diameter side of the side plate portion 551 . The cylindrical portion 552 passes through the central opening 140 of the intermediate cover 14 from the differential gear 6 side to the motor 2 side (right side in the figure). In the direction of the rotation axis X, the tip 552a of the cylindrical portion 552 faces the side plate portion 451 of the carrier 45 of the first planetary reduction gear 4 with an interval therebetween.

The cylindrical portion 552 is located on the radially outer side of the engagement portion between the connecting portion 453 on the first planetary reduction gear 4 side and the connecting portion 511 on the second planetary reduction gear 5 side. A bearing B3 fixed to the inner periphery of the opening 140 of the intermediate cover 14 is in contact with the outer periphery of the cylindrical portion 552. The cylindrical portion 552 of the side plate portion 551 is rotatably supported by the intermediate cover 14 via a bearing B3.

In the second planetary reduction gear 5 , one of the side plate portions 551 and 651 that constitute the carrier 55 is formed integrally with the differential case 60 of the differential device 6 .

In the second planetary reduction gear 5 , the output rotation of the motor 2 reduced by the first planetary reduction gear 4 is input to the sun gear 51 .
The output rotation input to sun gear 51 is input to stepped pinion gear 53 via large diameter gear portion 531 meshing with sun gear 51, and stepped pinion gear 53 rotates around axis X2.

Then, the small diameter gear part 532 formed integrally with the large diameter gear part 531 rotates around the axis X2 together with the large diameter gear part 531.
Here, the small diameter gear portion 532 meshes with a ring gear 52 fixed to the inner circumference of the case 13. Therefore, when the small diameter gear portion 532 rotates around the axis X2, the stepped pinion gear 53 revolves around the rotation axis X while rotating around the axis X2.

Then, as shown in FIG. 3, one end of the pinion shaft 54 is supported by a side plate portion 651 formed integrally with the differential case 60, so the differential case 60 rotates in conjunction with the revolution of the stepped pinion gear 53. Rotates around axis X.

Here, in the stepped pinion gear 53, the outer diameter R2 of the small diameter gear portion 532 is smaller than the outer diameter R1 of the large diameter gear portion 531 (see FIG. 3).
In the second planetary reduction gear 5, the sun gear 51 serves as an input section for the output rotation of the motor, and the carrier 55 that supports the stepped pinion gear 53 serves as an output section for the input rotation.
Then, the rotation input to the sun gear 51 of the second planetary reduction gear 5 is largely reduced by the stepped pinion gear 53 and then output to the differential case 60 with which the side plate portion 651 of the carrier 55 is integrally formed.

As shown in FIG. 3, the differential case 60 is formed into a hollow shape that accommodates the shaft 61, bevel gears 62A, 62B, and side gears 63A, 63B therein.
In the differential case 60, cylindrical support parts 601 and 602 are provided on both sides in the direction of the rotation axis X (in the left-right direction in the figure). The support parts 601 and 602 extend along the rotation axis X in a direction away from the shaft 61.

A connecting piece 56 that connects the side plate parts 651 of the carrier 55 and the side plate parts 551 is provided on the outer diameter side of the support part 601.
One end of the connecting piece 56 on the differential case 60 side is provided across the side plate portion 651 and the outer periphery of the differential case 60, and the other end is connected to the side plate portion 551 from the rotation axis X direction.

The connecting piece 56 is provided at a position that avoids interference with the stepped pinion gear 53 described above. As described above, a plurality (for example, three) of stepped pinion gears 53 are provided at predetermined intervals in the circumferential direction around the rotation axis X.
The connecting piece 56 is provided between stepped pinion gears 53 that are adjacent to each other in the circumferential direction around the rotation axis X.

The inner race B2a of the bearing B2 is press-fitted into the outer periphery of the support portion 602.
The outer race B2b of the bearing B2 is held by a ring-shaped support part 131 of the case 13, and the support part 602 of the differential case 60 is rotatably supported by the case 13 via the bearing B2.

A drive shaft 8A passing through the opening 130 of the case 13 is inserted into the support portion 602 from the rotation axis X direction, and the drive shaft 8A is rotatably supported by the support portion 602.
A lip seal RS is fixed to the inner periphery of the opening 130, and a lip portion (not shown) of the lip seal RS elastically contacts the outer periphery of the drive shaft 8A, thereby causing a gap between the outer periphery of the drive shaft 8A and the opening. A gap with the inner periphery of the portion 130 is sealed.

As shown in FIG. 1, the drive shaft 8B, which passes through the opening 114 of the cover 11, is inserted into the support portion 601 from the rotation axis X direction.
The drive shaft 8B is provided across the motor shaft 20 of the motor 2, the inner diameter side of the sun gear 41 of the first planetary reduction gear 4, and the inner diameter side of the sun gear 51 of the second planetary reduction gear 5 in the direction of the rotation axis X. The distal end side of the drive shaft 8B is rotatably supported by a support portion 601.

A lip seal RS is fixed to the inner periphery of the opening 114 of the cover 11, and a lip portion (not shown) of the lip seal RS elastically contacts the outer periphery of the drive shaft 8B, thereby causing the drive shaft 8B to A gap between the outer periphery and the inner periphery of the opening 114 is sealed.

Inside the differential case 60, side gears 63A, 63B are spline-fitted to the outer periphery of the tips of the drive shafts 8A, 8B, and the side gears 63A, 63B and the drive shaft 8 (8A, 8B) are connected around the rotation axis X. It is rotatably connected to the .

As shown in FIG. 3, the differential case 60 is provided with shaft holes 60a and 60b that penetrate in a direction perpendicular to the rotation axis X and are provided at symmetrical positions with the rotation axis X in between.
The shaft holes 60a and 60b are located on an axis Y that is perpendicular to the rotation axis X, and one end 61a side and the other end 61b side of the shaft 61 are inserted into the shaft holes 60a and 60b.

One end 61a side and the other end 61b side of the shaft 61 are fixed to the differential case 60 with a pin P, and the shaft 61 is prohibited from rotating around the axis Y.

The shaft 61 is located between the side gears 63A and 63B within the differential case 60, and is arranged along the axis Y.
Inside the differential case 60, bevel gears 62A and 62B are fitted onto a shaft 61 and rotatably supported.

Two bevel gears 62A, 62B are provided at intervals in the longitudinal direction of the shaft 61 (in the axial direction of axis Y), and the bevel gears 62A, 62B are arranged with their teeth facing each other. ing. The bevel gears 62A and 62B are provided on the shaft 61 so that the axes of the bevel gears 62A and 62B coincide with the axis of the shaft 61.

Inside the differential case 60, side gears 63A and 63B are located on both sides of the bevel gears 62A and 62B in the axial direction of the rotation axis X.
The side gears 63A, 63B are provided in two spaced apart in the axial direction of the rotation axis X, with their teeth facing each other, and the bevel gears 62A, 62B and the side gears 63A, 63B are It is assembled with the teeth meshing.

An oil reservoir T of lubricating oil OL is formed in the lower part of the case 13 (space Sc). The lower side of the differential case 60 is immersed in an oil reservoir T (see FIG. 3).
In this embodiment, the oil reservoir T is stored to a height at which one end 61a or the other end 61b of the shaft 61 is located at least in the oil reservoir T when the one end 61a or the other end 61b of the shaft 61 is located at the lowest side. has been done.

As described above, the differential case 60 rotates around the rotation axis X by the output rotation of the motor 2 input via the reduction gear mechanism 3. At this time, the lubricating oil OL in the case 13 is taken into the hollow differential case 60, and the bevel gears 62A, 62B and the side gears 63A, 63B in the differential case 60 are lubricated.

Furthermore, the carrier 55 of the second planetary reduction gear 5 is formed integrally with the differential case 60. Therefore, when the differential case 60 rotates around the rotation axis X, the stepped pinion gear 53 supported by the carrier 55 of the second planetary reduction gear 5 revolves around the rotation axis Raise up.
As a result, the components of the second planetary reduction gear 5 (sun gear 51, ring gear 52, stepped pinion gear 53) are lubricated.

As shown in FIG. 3, the stepped pinion gear 53 of the second planetary reduction gear 5 is rotatably supported on the outer periphery of the pinion shaft 54 supported by the side plates 651, 551 of the carrier 55 via a needle bearing NB. has been done.
On the outer periphery of the pinion shaft 54, needle bearings NB are provided on the inner diameter side of the large diameter gear portion 531 and on the inner diameter side of the small diameter gear portion 532, respectively. On the outer periphery of the pinion shaft 54, the needle bearings NB are arranged in series in the direction of the axis X2.

An oil hole 541 is provided at the center of the pinion shaft 54. The oil hole 541 passes through the pinion shaft 54 from one end to the other end along the axis X2 passing through the center of the pinion shaft 54.
An oil hole 542 is provided inside the pinion shaft 54 in a direction perpendicular to the axis X2. One oil hole 542 is provided at a position corresponding to the needle bearing NB that supports the large diameter gear portion 531 and the needle bearing NB that supports the small diameter gear portion 532. In this embodiment, the oil hole 542 is provided at approximately the center of the length of the needle bearing NB in the direction of the axis X2.

In the lubrication structure 7 of the second planetary reduction gear 5 according to this embodiment, the side plate of the carrier 55 is used to supply lubricating oil to the stepped pinion gear 53, which is one of the components of the second planetary reduction gear 5. A lubricating oil introduction section 70 is provided in the section 651.

[Lubricating oil introduction part]
FIG. 4 is a diagram illustrating the lubrication structure 7. FIG. 4A is a diagram illustrating the lubricating oil introduction section 70, and is a perspective view of the carrier 55 seen from the differential case 60 side in the rotation axis X direction. FIG. 4(b) is a view taken along the line AA in FIG. 4(a). Note that the stepped pinion gear 53 is not shown in FIG. 4.
FIG. 5 is a diagram illustrating the lubrication structure 7, and is a schematic cross-sectional view taken along line BB in FIG. 4(b). Note that FIG. 5 shows the stepped pinion gear 53 and its surroundings.
FIG. 6 is a diagram illustrating the guide portion 72 in the lubrication structure 7. As shown in FIG. FIG. 6(a) is an enlarged view of area A in FIG. FIG. 6B is a perspective view of the guide portion 72. FIG. FIG. 6(c) is a schematic diagram of the AA cross section in FIG. 6(a).

As shown in FIGS. 4A and 4B, the lubricating oil introduction section 70 includes a base 71 and a guide section 72 fixed to the base 71. As shown in FIGS. The base 71 has a ring shape when viewed from the rotation axis X direction. The outer diameter R3 of the base portion 71 substantially matches the outer diameter of the side plate portion 651.

The base 71 is attached to the side surface 651a of the side plate 651 on the differential case 60 side with the center line of the base 71 aligned with the rotation axis X (see FIG. 3).
The base 71 is provided with an arcuate wall 711 provided on the outer periphery of the base 71 and a cylindrical wall 712 that surrounds the entire inner periphery of the base 71 .

The arcuate wall 711 and the cylindrical wall 712 extend in a direction away from the side plate portion 651 in the rotation axis X direction. The arcuate walls 711 are provided at three locations at equal intervals in the circumferential direction (revolution direction) around the rotation axis X.

A through hole 713 passing through the base 71 is formed between the arcuate wall 711 and the cylindrical wall 712 in the radial direction of the rotation axis X (see the imaginary line in FIG. 4(b)). Similar to the arcuate wall 711, the through holes 713 are also provided at three equal intervals in the revolution direction.

Further, a bolt hole (not shown) is formed between the through holes 713 in the revolution direction. There are also three bolt holes provided at equal intervals in the direction of revolution. The base portion 71 is fixed to the side plate portion 651 of the carrier 55 by screwing a bolt B into a bolt hole. Note that the base portion 71 may be formed integrally with the side plate portion 651.

As shown in FIG. 5, the center line of the through hole 713 coincides with the center line (axis X2) of the support hole 651b of the pinion shaft 54 provided in the side plate portion 651. The through hole 713 has a hole diameter that substantially matches the hole diameter of the support hole 651b.

The through hole 713 and the support hole 651b communicate the oil holes 541 and 542 of the pinion shaft 54 with the space Sc. The through hole 713 serves as an inlet through which lubricating oil OL flows into the oil holes 541 and 542.

The opening of the through hole 713 is closed by the guide portion 72 from the differential case 60 side in the direction of the axis X2. The guide portion 72 is arranged between the arcuate wall 711 and the cylindrical wall 712 in the radial direction of the axis X2.
In this state, the arcuate wall 711 of the base portion 71 extends upstream in the revolution direction from the guide portion 72 (see (b) in FIG. 4).

As shown in FIGS. 6(a) to 6(c), the guide portion 72 is composed of a pair of plate-like members 73 and 74. As shown in FIGS. The pair of plate-like members 73 and 74 are elastic members, and are connected by a connecting pin P1, which will be described later, and a spring Sp, which will be described later.
Although details will be described later, one plate member 73 is fixed to the base 71 (hereinafter referred to as a fixed plate 73). The other plate member 74 is rotatably provided with respect to the base 71 (fixed plate 73) (hereinafter referred to as movable plate 74).

As shown in FIG. 5, the fixed plate 73 and the movable plate 74 are provided side by side in the revolution direction. When the base 71 rotates around the rotation axis X, the fixed plate 73 and the movable plate 74 revolve around the rotation axis X.

In this embodiment, a case will be described in which when the electric vehicle EV moves forward, the output rotation of the motor 2 causes the differential case 60 to rotate in the clockwise direction of the rotation axis X (the direction of the arrow in FIG. 4B) in the normal direction.
In this case, the movable plate 74 and the fixed plate 73 are arranged so that the lubricating oil OL flows from the movable plate 74 side to the fixed plate 73 side during revolution (see white arrow in FIG. 5).
In the following description, the movable plate 74 side of the guide portion 72 is assumed to be the upstream side in the revolution direction, and the fixed plate 73 side is assumed to be the downstream side in the revolution direction.

[Fixed plate 73]
As shown in FIGS. 6A and 6C, the fixing plate 73 of the guide portion 72 has a substrate 730. As shown in FIGS. The substrate 730 is arranged with the thickness direction of the substrate 730 aligned along the axis X2 direction.

As shown in FIGS. 6A and 6B, the substrate 730 is provided with a connecting piece 731 and an abutting piece 732 at a portion facing the movable plate 74 in the revolution direction. These connecting pieces 731 and abutting pieces 732 are provided side by side in the axis X2 direction. The contact piece 732 is provided closer to the through hole 713 than the connecting piece 731 (on the right side in FIG. 6A) in the direction of the axis X2. The substrate 730, the connecting piece 731, and the abutting piece 732 are integrally formed.

As shown in FIG. 6C, the connecting pieces 731 are provided at opposing portions of the arcuate wall 711 and the cylindrical wall 712 in the direction orthogonal to the axis X2 of the substrate 730, respectively.

[Movable plate 74]
As shown in FIGS. 6A and 6C, the movable plate 74 of the guide section 72 has a substrate 740. The substrate 740 is arranged with the thickness direction of the substrate 740 aligned along the axis X2 direction.

As shown in FIGS. 6A and 6B, the board 740 is provided with a connecting piece 741 and an abutting piece 742 at a portion facing the fixed plate 73 in the revolution direction. These connecting pieces 741 and abutting pieces 742 are provided side by side in the axis X2 direction. The contact piece 742 is provided closer to the through hole 713 than the connecting piece 741 (on the right side in FIG. 6A) in the direction of the axis X2. The substrate 740, the connecting piece 741, and the contact piece 742 are integrally formed.

As shown in FIG. 6C, the connecting piece 741 is provided at an intermediate position between the arcuate wall 711 and the cylindrical wall 712 in the direction perpendicular to the axis X2 of the substrate 740. As shown in FIG.

As shown in FIGS. 6(b) and 6(c), in the guide portion 72, the connecting piece 741 of the movable plate 74 is accommodated between the connecting pieces 731, 731 of the fixed plate 73 in the direction perpendicular to the axis X2. The situation is as follows. One connecting pin P1 is inserted into the connecting pieces 731, 731 of the fixed plate 73 and the connecting piece 741 of the movable plate 74. Thereby, the fixed plate 73 and the movable plate 74 cannot be separated.

As shown in FIG. 6C, the connecting pin P1 is provided across the arcuate wall 711 and the cylindrical wall 712 in a direction perpendicular to the axis X2. The fixed plate 73 and the movable plate 74 are connected to the base 71 via a connecting pin P1. The movable plate 74 is fixed to the base 71 so as to be rotatable around the central axis Y2 of the connecting pin P1.

Further, a support pin P2 is inserted into the base plate 730 of the fixed plate 73.
As shown in FIG. 6C, the support pin P2 is provided across the arcuate wall 711 and the cylindrical wall 712, and is arranged parallel to the connecting pin P1. The fixed plate 73 is fixed non-rotatably to the base 71 by a connecting pin P1 and a support pin P2.

As shown in FIG. 6C, a spring Sp is housed inside the connecting piece 741 of the movable plate 74. As shown in FIG. This spring Sp is fitted onto the connecting pin P1, and has one end connected to a connecting piece 731 of the fixed plate 73 and the other end connected to a connecting piece 741 of the movable plate 74.

The spring Sp acts on the movable plate 74 with a biasing force F toward the through hole 713 in the circumferential direction around the rotation axis Y2 (see (a) in FIG. 6). In this state, the contact pieces 732 and 742 of the fixed plate 73 and the movable plate 74 are in contact with each other.

The guide portion 72 according to this embodiment has a basic shape in which the contact pieces 732 and 742 are in contact with each other due to the biasing force F of the spring Sp. In the basic shape, the guide portion 72 covers the opening of the through hole 713.

As shown in FIG. 6A, the substrate 730 of the fixed plate 73 and the substrate 740 of the movable plate 74 have a tapered shape that becomes thinner as they move away from each other in the direction of revolution.
The guide portion 72 is arranged such that the tip end 730a side of the base plate 730 of the fixed plate 73 is spaced apart from the base portion 71 by a predetermined distance CL1 in the axis X2 direction. Further, the guide portion 72 is arranged such that the tip end 740a side of the substrate 740 of the movable plate 74 is spaced apart from the base portion 71 by a predetermined distance CL2 in the axis X2 direction. In the basic shape of the guide portion 72, the intervals CL1 and CL2 are set to be approximately the same size.

The substrate 730 of the fixed plate 73 has a surface 730b facing the through hole 713 in the direction of the axis X2. The opposing surface 730b is an inclined surface that is inclined toward the through hole 713 in the axis X2 direction as it goes downstream in the revolution direction (hereinafter, the opposing surface 730b will be referred to as an inclined surface 730b).

The substrate 740 of the movable plate 74 has a surface 740b facing the through hole 713 in the direction of the axis X2. The opposing surface 740b includes a first opposing surface 740c on the tip 740a side in a direction perpendicular to the axis X2, and a second opposing surface 740d on the fixed plate 73 side.

The first opposing surface 740c is an intake surface that takes the lubricating oil OL into an oil chamber R to be described later (hereinafter, the first opposing surface 740c will be referred to as an intake surface 740c). In the basic shape of the guide portion 72, the intake surface 740c is a flat surface perpendicular to the axis X2.

The second opposing surface 740d is an inclined surface that is inclined away from the through hole 713 in the axis X2 direction as it goes downstream in the revolution direction (upper side in the figure). (denoted as surface 740b).

A space surrounded by the guide portion 72, the through hole 713, the side plate portion 651, and the pinion shaft 54 in the direction of the axis X2 constitutes an oil chamber R that supplies lubricating oil OL to the stepped pinion gear 53. .

As shown in FIG. 3, the case 13 that houses the second planetary reduction gear 5 and the differential device 6 includes a differential housing section 132, a first housing section 133, and a second housing section 134. .
The differential accommodating portion 132 is formed with an inner diameter that can accommodate the differential case 60. The first accommodating portion 133 has an inner diameter that can accommodate the ring gear 52 of the second planetary reduction gear 5 . The second accommodating portion 134 is formed with an inner diameter that can accommodate the large diameter gear portion 531.

The case 13 is fixed to the intermediate cover 14 with the flange portion 135 provided on the second accommodating portion 134 being joined to the outer peripheral portion of the base portion 143 of the intermediate cover 14 .

The operation of the power transmission device 1 having such a configuration will be explained.
In the power transmission device 1, along the transmission path of the output rotation of the motor 2, a reduction mechanism 3 (first planetary reduction gear 4, second planetary reduction gear 5), a differential device 6, and a drive shaft 8 (8A, 8B) are provided.

When the rotor core 21 rotates around the rotation axis X by driving the motor 2, the rotation is input to the sun gear 41 of the first planetary reduction gear 4 via the motor shaft 20 that rotates together with the rotor core 21.

In the first planetary reduction gear 4, the sun gear 41 serves as an input part for the output rotation of the motor 2, and the carrier 45 that supports the pinion gear 43 serves as an output part for the input rotation.

When the sun gear 41 rotates around the rotation axis X by the output rotation of the motor 2, the pinion gear 43 meshed with the outer periphery of the sun gear 41 and the inner periphery of the ring gear 42 rotates around the axis X1.
Here, the ring gear 42 is spline-fitted to the inner periphery of the intermediate case 12 (fixed side member), and relative rotation with the intermediate case 12 is restricted.
Therefore, the pinion gear 43 revolves around the rotation axis X while rotating around the axis X1. Thereby, the carrier 45 (side plate parts 451, 452) that supports the pinion gear 43 rotates around the rotation axis X at a rotation speed lower than the output rotation of the motor 2.

As described above, the connecting portion 453 of the carrier 45 is connected to the connecting portion 511 of the sun gear 51 on the second planetary reduction gear 5 side, and the rotation of the carrier 45 (output rotation of the first planetary reduction gear 4) is 2 is input to the sun gear 51 of the planetary reduction gear 5.

In the second planetary reduction gear 5, the sun gear 51 serves as an input part for the output rotation of the second planetary reduction gear 5, and the carrier 55 supporting the stepped pinion gear 53 serves as an output part for the input rotation. ing.

When the sun gear 51 rotates around the rotation axis X with input rotation, the stepped pinion gear 53 (large diameter gear part 531, small diameter gear part 532) rotates around the axis X2 with the rotation input from the sun gear 51 side. do.
Here, the small diameter gear portion 532 of the stepped pinion gear 53 meshes with the ring gear 52 fixed to the inner circumference of the case 13. Therefore, the stepped pinion gear 53 rotates around the rotation axis X while rotating around the axis X2.

As a result, the carrier 55 (side plate portions 551, 651) supporting the stepped pinion gear 53 rotates around the rotation axis X at a lower rotation speed than the rotation input from the first planetary reduction gear 4 side.
Here, in the stepped pinion gear 53, the outer diameter R1 of the small diameter gear portion 532 is smaller than the outer diameter R2 of the large diameter gear portion 531 (see FIG. 2).
Therefore, the rotation input to the sun gear 51 of the second planetary reduction gear 5 is reduced by the stepped pinion gear 53 to a greater extent than in the case of the first planetary reduction gear 4, and then the side plate portion 651 of the carrier 55 is integrated. The signal is output to a differential case 60 (differential device 6) formed in .

Then, as the differential case 60 rotates around the rotation axis X with the input rotation, the drive shafts 8 (8A, 8B) rotate around the rotation axis X, and the drive shafts 8 (8A, 8B) rotate around the rotation axis communicated.

When the differential case 60 rotates around the rotation axis X, the second planetary reduction gear 5, in which the carrier 55 is integrally formed with the differential case 60, rotates around the rotation axis X together with the differential case 60.
As a result, the lubricating oil OL in the oil reservoir T is scooped up by the components (stepped pinion gear 53, carrier 55) of the second planetary reduction gear 5.
At this time, the guide portion 72 of the lubricating oil introducing portion 70 revolves around the rotation axis X in conjunction with the rotation of the carrier 55 around the rotation axis X. The guide portion 72 repeatedly enters and escapes from the oil reservoir T.

FIG. 7 is a diagram illustrating the operation of the lubrication structure 7. FIG. 7A is a diagram showing a state in which the guide portion 72 is in the oil reservoir T. FIG. 7B is a diagram showing a state in which the guide portion 72 is outside the oil reservoir T.

In this embodiment, when the electric vehicle EV moves forward, the differential case 60 rotates in the normal direction due to the output rotation of the motor 2. The guide portion 72 revolves along the normal rotation direction.
As described above, the oil reservoir T in which the lubricating oil OL is collected is formed in the lower part of the case 13 (inside the space Sc) (see FIG. 3).

The guide portion 72 sequentially enters the following states (A) to (D) during one revolution (revolution) along the normal rotation direction.
(A) Entering into oil sump T from outside oil sump T (B) Movement within oil sump T (C) Escape from inside oil sump T to outside oil sump T (D) Movement outside oil sump T

In the present embodiment, in the guide portion 72, the movable plate 74 is located upstream of the fixed plate 73 in the revolution direction (see FIG. 5).
Then, in the above state (A), the tip 740a of the movable plate 74 enters the oil reservoir T. In this state, lubricating oil flows into the oil chamber R from between the tip 740a of the movable plate 74 and the base 71 (see the white arrow in FIG. 7(a)).

The movable plate 74 receives resistance from the lubricating oil OL that has entered between the tip 740a and the base 71 of the movable plate 74, and is biased by the biasing force F of the spring Sp around the central axis Y2 (see (a) in FIG. 6). It rotates in the opposing direction (see the black arrow in FIG. 7(a)). As a result, the oil chamber R is opened to the upstream side in the revolution direction.

Here, as described above, in the basic shape of the guide portion 72, the intake surface 740c of the movable plate 74 is a flat surface perpendicular to the axis X2 (see (a) of FIG. 6).
As shown in FIG. 7A, when the movable plate 74 rotates around the central axis Y2, the intake surface 740c tilts away from the through hole 713 in the axis X2 direction as it moves upstream in the revolution direction. . The distance between the tip 740a of the movable plate 74 and the base 71 in the direction of the axis X2 increases from CL2 to CL3 (CL3>CL2).

In this embodiment, by providing the intake surface 740c on the movable plate 74, the opening area of the oil chamber R is made larger than in the case where the intake surface 740c is not provided, and the amount of lubricating oil OL taken in (inflow amount) is increasing.

Here, the arcuate wall 711 of the base 71 extends upstream in the revolution direction from the movable plate 74 (see (b) in FIG. 4). The lubricating oil OL is rectified by passing between the arcuate wall 711 and the cylindrical wall 712 so as to flow along the revolution direction, and then taken into the oil chamber R from the opening. The lubricating oil OL scattered in the radial direction of the rotation axis X can also be captured by the arc-shaped wall 711.

In the above state (B), since the lubricating oil OL is sequentially taken into the oil chamber R from the opening, the oil chamber R is maintained in a state where it is opened toward the upstream side in the revolution direction. In this state, the inclined surface 740d of the movable plate 74 and the inclined surface 730b of the fixed plate 73 are inclined in a direction closer to the through hole 713 in the axis X2 direction as they go downstream in the revolution direction.

Specifically, after the lubricating oil OL is taken in from the opening of the oil chamber R, it is guided toward the through hole 713 side (pinion shaft 54 side) in the oil chamber R by the inclined surface 740d and the inclined surface 730b.
Further, a part of the lubricating oil OL in the oil chamber R flows out of the oil chamber R from between the tip 730a side of the fixed plate 73 and the base 71 having a predetermined interval CL1 ((a in FIG. 7). ). This suppresses an increase in stirring resistance due to the revolution of the stepped pinion gear 53.

In this embodiment, the distance CL3 between the tip 740a side of the movable plate 74 and the base 71 in the direction of the axis X2 is made to be sufficiently larger than the predetermined distance CL1 between the tip 730a of the fixed plate 73 and the base 71. is set (CL3>CL1).

Therefore, the amount of lubricating oil OL taken into the oil chamber R is greater than the amount of lubricating oil OL flowing out from the oil chamber R. This is because it is blocked by the inclined surface 730b of the fixed plate 73.
Thereby, the pressure inside the oil chamber R is increased while suppressing an increase in stirring resistance. The lubricating oil OL whose pressure has increased in the oil chamber R is released into the oil holes 541 and 542 of the pinion shaft 54 (see hatched arrows in (a) of FIG. 7).
Therefore, the lubricating oil OL is efficiently supplied from the oil chamber R to the stepped pinion gear 53 side.

Here, the stirring resistance due to the revolution of the stepped pinion gear 53 is concentrated on the fixed plate 73 that dams up the lubricating oil OL in the oil chamber R. The higher the revolution speed of the stepped pinion gear 53, the more the stirring resistance increases.
As described above, since the fixed plate 73 is an elastic member, when the stirring resistance increases beyond a predetermined value, the fixed plate 73 is elastically deformed. Specifically, the tip 730a side of the fixing plate 73 deforms in the direction away from the base 71. The amount of deformation of the fixed plate 73 increases as the stirring resistance increases.
When the stirring resistance increases, the distance between the tip 730a of the fixed plate 73 and the base 71 becomes wider than CL1. This increases the amount of lubricating oil OL released from the oil chamber R to the outside. Therefore, even if the revolution speed of the stepped pinion gear 53 becomes high, it is possible to suppress an increase in stirring resistance.

As shown in FIG. 7B, in the states (C) and (D) above, the lubricating oil OL is no longer taken into the oil chamber R, so the resistance of the lubricating oil OL acting on the movable plate 74 is also eliminated. Then, the movable plate 74 rotates around the central axis Y2 due to the biasing force F of the spring Sp (see the black arrow in FIG. 7(b)). Then, the guide portion 72 returns to its basic shape and covers the opening of the through hole 713.

This prevents the lubricating oil OL remaining in the oil chamber R and the oil holes 541 and 542 from leaking to the outside from the through hole 713 side, and from the oil hole 542 to the outside on the stepped pinion gear 53 side. leaks (see white arrow in FIG. 7(b)).
Therefore, even if the lubricating oil OL is not sequentially taken into the oil chamber R, the lubricating oil OL remaining in the oil chamber R and the oil holes 541 and 542 is used to supply the lubricating oil OL to the stepped pinion gear 53 side. can be supplied.

As described above, the lubrication structure 7 of the second planetary reduction gear 5 according to the present embodiment has the following configuration.
(1) Lubricating oil OL is supplied from the axis X2 direction side of the stepped pinion gear 53 to the pinion shaft 54 (bearing) that supports the stepped pinion gear 53 of the second planetary reduction gear 5 (planetary gear mechanism) It has oil holes 541 and 542 (lubricating oil passages).
It has a lubricating oil introduction part 70 that includes a guide part 72 that passes through the oil reservoir T as the stepped pinion gear 53 revolves around the rotation axis X.
The guide portion 72 of the lubricating oil introducing portion 70 has a movable plate 74 (opening) that opens toward the revolution direction around the rotation axis The fixed plate 73 (guide portion) guides the lubricating oil OL to the through hole 713 (entrance of the lubricating oil path).

With this configuration, the lubricating oil OL can be introduced directly from the oil reservoir T into the oil holes 541 and 542 by utilizing the rotational force of the stepped pinion gear 53 during revolution. Therefore, compared to the invention disclosed in Patent Document 1 that uses centrifugal force, the collection efficiency of the lubricating oil OL supplied to the second planetary reduction gear 5 can be improved.

The lubrication structure 7 of the second planetary reduction gear 5 according to this embodiment has the following configuration.
(2) The guide portion 72 has an inclined surface 740d and an inclined surface 730b (wall portion) that are inclined so as to approach the through hole 713 as it goes downstream in the revolution direction.
The inclined surface 740d (at least a portion of the wall portion) is provided on the movable plate 74 that constitutes the guide portion 72.

With this configuration, the inclined surface 740d functions as a guide portion that guides the lubricating oil OL to the through hole 713. The distance CL3 (clearance near the opening) when the movable plate 74 opens is wider than the distance CL1 (clearance near the opening entrance) between the fixed plate 73 and the through hole 713. This allows a large amount of lubricating oil OL to flow in, and also increases the pressure in the oil chamber R (as it approaches the entrance of the oil hole 541), so that the lubricating oil OL can be effectively stepped. It can be supplied to the pinion gear 53.

The lubrication structure 7 of the second planetary reduction gear 5 according to this embodiment has the following configuration.
(3) The guide portion 72 of the lubricating oil introducing portion 70 has an inclined surface 730b (damping portion) located downstream in the direction of revolution of the movable plate 74.
The inclined surface 730b is provided on the fixed plate 73 that constitutes the guide section 72.

With this configuration, the lubricating oil OL is dammed up on the downstream side (the fixed plate 73 side) of the movable plate 74 in the revolution direction. As a result, the pressure within the oil chamber R increases, so that the lubricating oil OL can be efficiently supplied to the stepped pinion gear 53.

In addition, in this embodiment, although the inclined surface 730b (damming part) has the space|interval CL1 and the base 71 on the front-end|tip 730a side (separated), the state where it is exemplified is the case where it is in close contact with the base 71. Also good. Further, when the base 71 is formed integrally with the side plate 651, the tip 730a side of the inclined surface 730b may be in close contact with the side plate 651 of the carrier 55.

The lubrication structure 7 of the second planetary reduction gear 5 according to this embodiment has the following configuration.
(4) The guide part 72 of the lubricating oil introduction part 70 has a predetermined interval CL1 (a passage hole through which the lubricating oil OL passes) between the tip 730a side of the fixed plate 73 and the base 71 (downstream of the opening in the revolution direction). ) are spaced apart.

The guide portion 72 causes stirring resistance when passing through the oil reservoir T. Therefore, by configuring as described above and providing a passage port through which the lubricating oil OL escapes downstream in the revolution direction, it is possible to suppress an increase in stirring resistance.

In addition, in this embodiment, the case where the passage opening is formed by arranging the tip 730a of the fixing plate 73 and the base 71 with a predetermined interval CL1 is illustrated, but the passage opening is not limited to this. For example, a hole formed directly in the guide portion 72 may be used.

The lubrication structure 7 of the second planetary reduction gear 5 according to this embodiment has the following configuration.
(5) The fixing plate 73 of the guide portion 72 is an elastic member. As the revolution speed of the stepped pinion gear 53 increases, the fixed plate 73 is elastically deformed, and the predetermined distance CL1 (area of the passage opening) from the base 71 becomes wider.

With this configuration, even if the revolution speed of the stepped pinion gear 53 increases, it is possible to suppress the stirring resistance from increasing.
In this embodiment, the case where the guide member 72 (fixed plate 73 and movable plate 74) is an elastic member is illustrated, but the guide member 72 is not limited to this. For example, a hinge may be provided on the tip 730a side of the fixed plate 73. As a result, when the revolution speed of the stepped pinion gear 53 increases and the stirring resistance increases, the hinge portion of the fixed plate 73 opens (deforms) and the distance CL1 between the tip 730a and the base 71 of the fixed plate 73 is reduced. Can be expanded.

In addition, when the revolution of the stepped pinion gear 53 is stopped, the predetermined distance CL1 between the tip 730a of the fixed plate 73 and the base 71 may be 0 (zero). In this case, the guide portion 72 has a predetermined distance CL1 between the fixed plate 73 and the base portion 71 when the revolution speed of the stepped pinion gear 53 is equal to or higher than a predetermined speed.

The lubrication structure 7 of the second planetary reduction gear 5 according to this embodiment has the following configuration.
(6) The power of the motor 2 is transmitted to the speed reduction mechanism 3 (planetary gear mechanism).

Electric vehicles (EVs) are often not equipped with a pump for lubrication. The lubrication structure 7 according to this embodiment is particularly suitable for such cases. Furthermore, even if a pump is installed, it is useful in that the capacity of the pump can be reduced.

The lubrication structure 7 of the second planetary reduction gear 5 according to this embodiment has the following configuration.
(7) The lubricating oil introduction section 70 has an arcuate wall 711 (first wall) and a cylindrical wall 712 (second wall).
The guide portion 72 is disposed between an arcuate wall 711 and a cylindrical wall 712 in the radial direction of the rotation axis X (direction intersecting the revolution direction).

With this configuration, a part of the lubricating oil OL scattered in the radial direction of the rotation axis X can be captured by the arcuate wall 711 and the cylindrical wall 712.

[Modified example]
A lubrication structure 7A according to a modification will be explained.
FIG. 8 is a diagram illustrating a lubrication structure 7A according to a modified example, and is a diagram illustrating a lubricating oil introduction portion 70A viewed from the differential case 60 side in the rotation axis X direction.

In the above-described lubrication structure 7, the cylindrical wall 712 illustrated the lubricating oil introduction part 70 provided so as to surround the entire inner peripheral edge of the base 71, but the present invention is not limited to this.

For example, as shown in FIG. 7, a lubrication structure 7A may be provided having a lubricant introduction portion 70A provided with an arcuate wall 712A along the inner peripheral edge of the base 71. Three arcuate walls 712A are provided at intervals in the revolution direction. The arcuate walls 712A, 712A, and 712A are arranged within an angular range that overlaps with the arcuate walls 711, 711, and 711, respectively, in the radial direction of the rotation axis X.

Therefore, the total length of the arcuate walls 712A, 712A, 712A in the revolution direction is shorter than the total length of the cylindrical wall 712. Thereby, the weight of the lubricating oil introducing part 70A becomes lighter than in the case of using the lubricating oil introducing part 70 (cylindrical wall 712) according to this embodiment, and the cost can be reduced.

When the stepped pinion gear 53 revolves, the lubricating oil OL is scattered radially outward of the rotation axis X by centrifugal force. More of the scattered lubricating oil OL is captured by the arcuate wall 711 than by the arcuate wall 712A, rectified toward the oil chamber R, and then taken into the oil chamber R. Therefore, even if the arcuate wall 712A becomes shorter, the amount of lubricating oil OL taken into the oil chamber R does not decrease compared to this embodiment.

A lubrication structure 7A of the second planetary reduction gear 5 according to the modification has the following configuration.
(8) The lubricating oil introducing portion 70A has an arcuate wall 711 (first wall portion) and an arcuate wall 712A (second wall portion).
The arcuate wall 711 is located on the outer peripheral side than the arcuate wall 712A.
The length of the arcuate wall 711 in the revolution direction is longer than the length of the arcuate wall 712A in the revolution direction.

With this configuration, the arcuate wall 711 can respond to the dominant force in the centrifugal force direction (direction toward the outer circumferential side) of the rotation axis X. On the other hand, by using the arcuate walls 712A, 712A, 712A, cost and weight can be reduced compared to the case where the cylindrical wall 712 is used.

Here, the term "downstream connected" in this specification means a connection relationship in which power is transmitted from a component located upstream to a component located downstream.
For example, the first planetary reduction gear 4 connected downstream of the motor 2 means that power is transmitted from the motor 2 to the first planetary reduction gear 4.
In addition, the term "direct connection" in this specification means that members are connected to each other so that power can be transmitted without intervening a member whose reduction ratio is converted, such as another reduction mechanism, speed increase mechanism, or transmission mechanism. means.

Further, in this embodiment, the reduction mechanism 3 includes a first planetary reduction gear 4 including a pinion gear 43 without a step, a second planetary reduction gear 5 including a stepped pinion gear 53, and a second planetary reduction gear 5 including a stepped pinion gear 53. The case where the first planetary reduction gear 4 and the second planetary reduction gear 5 are arranged in series on the transmission path of the output rotation of the motor 2 is illustrated. However, it is not limited only to this embodiment. For example, the reduction mechanism may include only the second planetary reduction gear 5 including the stepped pinion gear 53.

Furthermore, the revolution direction is preferably set as the forward rotation direction when the electric vehicle EV is moving forward, but is not limited thereto. The revolution direction may be set as the forward rotation direction when the electric vehicle EV is traveling backwards.

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

1 Power Transmission Device 10 Motor Housing 11 Cover 110 Joint 111 Motor Support 112 Support Cylinder 113 Side Wall 114 Opening 115 Connection 12 Intermediate Case 120 Base 121 Motor Support 122 Cylindrical Wall 123 Connection 125 Bearing Retainer 13 Case 130 Opening Part 131 Support part 132 Differential housing part 133 First housing part 134 Second housing part 135 Flange part 14 Intermediate cover 140 Opening 143 Base part 2 Motor 20 Motor shaft 203 Large diameter part 204 Step part 205 Stopper 21 Rotor core 23 Stopper 25 Stator core 251 Yoke Part 252 Teeth part 253 Winding 253a, 253b Coil end 3 Reduction mechanism 4 First planetary reduction gear (planetary gear)
41 Sun gear 410 Through hole 411 Connection portion 42 Ring gear 43 Pinion gear 44 Pinion shaft 45 Carrier 451, 452 Side plate portion 453 Connection portion 5 Second planetary reduction gear (planetary gear)
51 Sun gear 510 Through hole 511 Connecting portion 52 Ring gear 53 Stepped pinion gear 530 Through hole 531 Large diameter gear portion 532 Small diameter gear portion 54 Pinion shaft 541, 542 Oil hole 55 Carrier 551 Side plate portion 552 Cylindrical portion 56 Connection piece 6 Difference Movement device 60 differential case 601 Support Department 602 Support Department 61 Shaft 62a, 62B Gear 63A, 63B side gear 651 side board 651a side support 6, 7A Lubricating structure 70, 70A lubricating oil introduction section 71 弧 弧 基 基 基 基 基 基 基 基2 -yen cylindrical wall 712A Arc-shaped wall 713 Through hole 72 Guide part 73 Fixed plate 730 Substrate 730a Tip 730b Inclined surface 731 Connection piece 732 Contact piece 74 Movable plate 740 Substrate 740a Tip 740b Opposing surface 740c Intake surface 740d Inclined surface 741 Connection piece 742 Contact piece 8 (8A, 8B) Drive shaft 9 Main case B1, B2, B3 Bearing B1b, B2b Outer race B1a, B2a Inner race NB Needle bearing F Biasing force OL Lubricating oil P Pin P1 Connecting pin P2 Support pin R Oil chamber RS Lip seal S Seal Ring Sa space (motor room)
Sb space (gear room)
Sc space (gear room)
Sp Spring T Oil sump X Rotating axis X1, X2, Y Axis Y2 Center axis

Claims (6)

A lubrication structure having a lubricating oil passage that supplies lubricating oil from an axial side of the pinion gear to a bearing that supports the pinion gear of a planetary gear mechanism,
It has a lubricating oil introduction part that passes through an oil reservoir as the pinion gear revolves,
The lubricating oil introduction part includes an opening that opens toward the revolution direction of the pinion gear, and a guide part that guides the lubricating oil flowing from the opening in a flow along the revolution direction to the entrance of the lubricating oil path. and,
The lubricant structure is characterized in that the lubricating oil introduction part has a passage port through which the lubricating oil passes downstream of the opening in the revolution direction. In claim 1 ,
The lubricant structure is characterized in that the lubricating oil introducing portion is configured such that the area of the passage opening increases as the revolution speed of the pinion gear increases. A lubrication structure having a lubricating oil passage that supplies lubricating oil from an axial side of the pinion gear to a bearing that supports the pinion gear of a planetary gear mechanism,
It has a lubricating oil introduction part that passes through an oil reservoir as the pinion gear revolves,
The lubricating oil introduction part includes an opening that opens toward the revolution direction of the pinion gear, and a guide part that guides the lubricating oil flowing from the opening in a flow along the revolution direction to the entrance of the lubricating oil path. and,
It has a first wall part and a second wall part,
The lubricant structure is characterized in that the lubricating oil introduction part is disposed between the first wall part and the second wall part in a direction intersecting the revolution direction. In claim 3 ,
The first wall portion is located on the outer peripheral side of the second wall portion,
A lubrication structure characterized in that the length of the first wall portion in the revolution direction is greater than the length of the second wall portion. In any one of claims 1 to 4 ,
The lubricating oil introduction part has a dam part located downstream of the opening part in the revolution direction,
A lubrication structure characterized in that at least a portion of the guide portion is constituted by the dam. In any one of claims 1 to 5 ,
A lubrication structure characterized in that power of a drive motor is transmitted to the planetary gear mechanism.