Vehicle drive device

Patent metadata

Field	Value
Publication number	US-11434977-B2
Application number	US-201716323350-A
Country	US
Kind code	B2
Filing date	Jul 27, 2017
Priority date	Sep 30, 2016
Publication date	Sep 6, 2022
Grant date	Sep 6, 2022

Abstract

A vehicle drive device that includes a rotary electric machine, a power transfer mechanism that transfers a rotational drive force between the rotary electric machine and a plurality of wheels, a case that houses at least a part of the power transfer mechanism and the rotary electric machine, and a hydraulic pump.

First claim

The invention claimed is:

1. A vehicle drive device comprising
a rotary electric machine,
a power transfer mechanism that transfers a rotational drive force between the rotary electric machine and a plurality of wheels,
a case that houses at least a part of the power transfer mechanism and the rotary electric machine, and
a hydraulic pump, wherein:
the power transfer mechanism includes a differential gear mechanism that distributes torque input from a rotary electric machine side to the plurality of wheels,
the case is provided with a first reservoir that stores oil suctioned by the hydraulic pump inside the case, and a second reservoir that stores oil inside the case;
the hydraulic pump is a pump driven always in conjunction with rotation of the differential gear mechanism;
a delivery port of the hydraulic pump communicates with a supply through which oil is supplied to the second reservoir;
at least a part of the differential gear mechanism is housed in the first reservoir;
a first height is a height of an oil surface in the first reservoir in a state in which rotation of the plurality of wheels is stopped, and the first height is such a height that at least a part of the differential gear mechanism is immersed in oil stored in the first reservoir;
the differential gear mechanism includes a differential input gear meshed with a gear that is used to input torque of the rotary electric machine to the differential gear mechanism; and
a supply oil path through which oil splashed from the first reservoir by the differential input gear which rotates forward is supplied to the second reservoir is formed inside the case.

2. The vehicle drive device according to claim 1 , wherein
a second height is a height of the oil surface in the first reservoir in a state in which the plurality of wheels are rotating, and the second height is a height below a lowermost part of a rotor core of the rotary electric machine.

3. The vehicle drive device according to claim 2 , wherein
a sum of an oil storable capacity of the second reservoir and a capacity of an oil path through which oil stored in the first reservoir is led to an oil supply target through drive of the hydraulic pump is equal to or more than a value obtained by subtracting an amount of oil stored in the first reservoir in a case where the height of the oil surface in the first reservoir is the second height from an amount of oil stored in the first reservoir in a case where the height of the oil surface in the first reservoir is the first height.

4. The vehicle drive device according to claim 1 , wherein:
the second reservoir is disposed above the first reservoir; and
the second reservoir includes a discharge which is provided in a bottom of the second reservoir and through which oil is discharged from the second reservoir.

5. The vehicle drive device according to claim 1 , wherein:
the plurality of wheels include a first wheel;
the power transfer mechanism includes an output shaft that couples the differential gear mechanism and the first wheel to each other;
the output shaft is supported so as to be rotatable with respect to the case in a state of being inserted into a communication hole that communicates between an inside and an outside of the case;
a seal is disposed on an inner peripheral surface of the communication hole, the seal having a contact surface that contacts an outer peripheral surface of the output shaft, or an outer peripheral surface of a member that rotates together with the output shaft, in a slidable state; and
the first height is a height above a lowermost part of the contact surface.

6. The vehicle drive device according to claim 1 , wherein:
the plurality of wheels include a first wheel;
the power transfer mechanism includes an output shaft that couples the differential gear mechanism and the first wheel to each other;
the differential gear mechanism includes a differential output gear that rotates together with the output shaft, a differential case that houses the differential output gear and that rotates together with the differential input gear, and a washer disposed between the differential case and the differential output gear in an axial direction of the output shaft; and
the first height is such a height that at least a part of the washer is immersed in oil stored in the first reservoir.

7. The vehicle drive device according to claim 1 , wherein:
the second reservoir and the differential input gear are disposed such that respective regions of arrangement of the second reservoir and the differential input gear overlap each other in an axial direction of the differential input gear;
a second height is a height of the oil surface in the first reservoir in a state in which the plurality of wheels are rotating, and the second height is such a height that a lower part of the differential input gear is immersed in oil stored in the first reservoir;
the second reservoir is partitioned into two chambers arranged in a horizontal direction that is orthogonal to the axial direction of the differential input gear;
each of the two chambers is formed in a shape of a tank that opens upward;
the closer of the two chambers to the supply oil path is a first chamber, the other chamber is a second chamber, and an upper end of a peripheral wall that defines the first chamber is disposed at a position below an upper end of a peripheral wall that defines the second chamber;
a capacity of the first chamber is smaller than a capacity of the second chamber; and
a delivery port of the hydraulic pump communicates with a supply through which oil is supplied to the second chamber.

8. The vehicle drive device according to claim 1 , wherein:
the power transfer mechanism includes a counter gear mechanism that transfers a rotational drive force between the rotary electric machine and the differential gear mechanism;
the counter gear mechanism includes a first gear meshed with an output gear of the rotary electric machine, the gear meshed with the differential input gear of the differential gear mechanism, and a coupling shaft that couples the first gear and the second gear to each other; and
the second reservoir includes a discharge through which oil stored in the second reservoir is supplied to at least one of the output gear and the first gear.

9. The vehicle drive device according to claim 1 , wherein
a delivery port of the hydraulic pump communicates with at least one of a bearing disposed inside the case and a cooling oil path that is used to cool the rotary electric machine not via the second reservoir.

10. The vehicle drive device according to claim 1 , wherein:
the case includes a separation wall that separates a first space that houses the differential gear mechanism and a second space that houses the rotary electric machine from each other; and
a second height is a height of the oil surface in the first reservoir in a state in which the plurality of wheels are rotating, and a communication that allows communication between the first space and the second space is formed in the separation wall at a position below the second height.

11. The vehicle drive device according to claim 1 , wherein:
the rotary electric machine includes a rotor core and a stator core disposed on an outer side in a radial direction with respect to the rotor core;
the stator core has a cylindrical inner peripheral surface that faces an outer peripheral surface of the rotor core in the radial direction; and
the first height is a height above a lowermost part of the inner peripheral surface of the stator core.

12. The vehicle drive device according to claim 11 , wherein
a second height is a height

Assignees

• Aisin Corp
• Toyota Motor Co Ltd

Inventors

• Takahashi Katsutoshi
• Sasaki Yoshihiko
• Nemoto Hiroki
• Kawamura Tatsuya
• Kaneko Kazunori

Classifications

• H02K9/19 Primary

  for machines with closed casing and closed-circuit cooling using a liquid cooling medium, e.g. oil · CPC title

• F16H57/037

  Gearboxes for accommodating differential gearings (rotating cases for differential gearings F16H48/40) · CPC title

• F16H57/04

  Features relating to lubrication or cooling {or heating} (control of lubrication or cooling in hydrostatic gearing F16H61/4165) · CPC title

• H02K7/116

  with gears · CPC title

• F16H57/0423

  Lubricant guiding means mounted or supported on the casing, e.g. shields or baffles for collecting lubricant, tubes or pipes · CPC title