Transaxle

Patent metadata

Field	Value
Publication number	US-11279218-B2
Application number	US-202117142621-A
Country	US
Kind code	B2
Filing date	Jan 6, 2021
Priority date	Jan 9, 2020
Publication date	Mar 22, 2022
Grant date	Mar 22, 2022

Abstract

A transaxle includes a planetary gear reducer and a differential device. The planetary gear reducer includes a stepped pinion, a first needle bearing, a second needle bearing, and a carrier. The stepped pinion includes a pinion shaft with which a large diameter pinion and a small diameter pinion are integrated. The first needle bearing is fitted to a part of the pinion shaft outside the large diameter pinion. The second needle bearing is fitted to a part of the pinion shaft outside the small diameter pinion. The carrier is configured to support the stepped pinion via the first needle bearing and the second needle bearing such that the stepped pinion is rotatable with respect to the carrier, and to couple the stepped pinion and the differential device.

First claim

What is claimed is:

1. A trans axle comprising:
a planetary gear reducer;
a differential device; and
a transaxle case for housing the planetary gear reducer and the differential device, wherein:
the transaxle is configured to transmit drive force of an electric motor to an axle via the planetary gear reducer and the differential device; and
the planetary gear reducer includes
a stepped pinion including a pinion shaft with which a large diameter pinion and a small diameter pinion are integrated, the large diameter pinion configured to mesh with a sun gear provided in an output shaft of the electric motor, and the small diameter pinion configured to mesh with a ring gear fixed to the transaxle case,
a first needle bearing fitted to a part of a shaft surface between a first end of the pinion shaft and a side surface of the large diameter pinion, the first end located closer to the large diameter pinion than to the small diameter pinion,
a second needle bearing fitted to a part of the shaft surface between a second end of the pinion shaft and a side surface of the small diameter pinion, the second end located closer to the small diameter pinion than to the large diameter pinion, and
a carrier configured to support the stepped pinion via the first needle bearing and the second needle bearing such that the stepped pinion is rotatable with respect to the carrier, and to couple the stepped pinion and the differential device.

2. The transaxle according to claim 1 , further comprising a first oil introducing portion and a second oil introducing portion, wherein:
the transaxle case includes a case internal oil passage;
the carrier includes a carrier internal oil passage communicating with the differential device;
the pinion shaft includes a shaft internal oil passage that extends along an axis of the pinion shaft, and the shaft internal oil passage includes an opening at the second end and is configured to communicate with the first needle bearing and the second needle bearing;
the first oil introducing portion is configured to introduce oil from the case internal oil passage to the carrier internal oil passage; and
the second oil introducing portion is configured to introduce oil from the case internal oil passage to the shaft internal oil passage through the opening of the shaft internal oil passage at the second end, the second oil introducing portion provided further upstream than the first oil introducing portion of the case internal oil passage.

3. The transaxle according to claim 1 , further comprising
a first thrust washer or a first thrust bearing and a second thrust washer or a second thrust bearing, wherein:
the carrier includes a first stopper and a second stopper, the first stopper configured to restrict movement of the stepped pinion in a direction toward the first end, and the second stopper configured to restrict movement of the stepped pinion in a direction toward the second end;
the stepped pinion includes a first facing surface facing the first stopper and a second facing surface facing the second stopper;
the first thrust washer or the first thrust bearing is provided between the first stopper and the first facing surface; and
the second thrust washer or the second thrust bearing is provided between the second stopper and the second facing surface.

4. The transaxle according to claim 3 , wherein:
the first stopper is a first bearing boss portion into which the first needle bearing is fitted; and
the first facing surface is provided in the large diameter pinion.

5. The transaxle according to claim 3 , wherein:
the second stopper is a second bearing boss portion into which the second needle bearing is fitted; and
the second facing surface is provided in the small diameter pinion.

6. The transaxle according to claim 3 , wherein:
the second stopper is provided further outside than the second end in an axial direction of the stepped pinion; and
the second facing surface is provided in the second end.

7. The transaxle according to claim 6 , wherein the second stopper is a parking gear attached to the carrier.

8. The transaxle according to claim 6 , wherein:
the carrier includes a first bearing boss portion into which the first needle bearing is fitted;
the first bearing boss portion includes no protrusion protruding radially inward, and the first bearing boss portion and the first needle bearing are fixed by press fitting; and
the second stopper is provided in the carrier.

9. A transaxle comprising:
a planetary gear reducer;
a differential device; and
a transaxle case for housing the planetary gear reducer and the differential device, wherein:
the transaxle is configured to transmit drive force of an electric motor to an axle via the planetary gear reducer and the differential device; and
the planetary gear reducer includes
a stepped pinion including a pinion shaft with which a large diameter pinion and a small diameter pinion are integrated, the large diameter pinion configured to mesh with a sun gear provided in an output shaft of the electric motor, and the small diameter pinion configured to mesh with a ring gear fixed to the transaxle case,
a first needle bearing fitted to a part of a shaft surface from a first end of the pinion shaft to the large diameter pinion, the first end located closer to the large diameter pinion than to the small diameter pinion,
a second needle bearing fitted to a part of the shaft surface from a second end of the pinion shaft to the small diameter pinion, the second end located closer to the small diameter pinion than to the large diameter pinion, and
a carrier configured to support the stepped pinion via the first needle bearing and the second needle bearing such that the stepped pinion is rotatable with respect to the carrier, and to couple the stepped pinion and the differential device, the carrier including a first stopper configured to restrict movement of the stepped pinion in a direction toward the first end, the first stopper being a first bearing boss portion into which the first needle bearing is fitted.

10. The transaxle according to claim 9 , further comprising a first oil introducing portion and a second oil introducing portion, wherein:
the transaxle case includes a case internal oil passage;
the carrier includes a carrier internal oil passage communicating with the differential device;
the pinion shaft includes a shaft internal oil passage that extends along an axis of the pinion shaft, and the shaft internal oil passage includes an opening at the second end and is configured to communicate with the first needle bearing and the second needle bearing;
the first oil introducing portion is configured to introduce oil from the case internal oil passage to the carrier internal oil passage; and
the second oil introducing portion is configured to introduce oil from the case internal oil passage to the shaft internal oil passage through the opening of the shaft internal oil passage at the second end, the second oil introducing portion provided further upstream than the first oil introducing portion of the case internal oil passage.

11. The transaxle according to claim 9 , further comprising
a first thrust washer or a first thrust bearing and a second thrust washer or a second thrust bearing, wherein:
the carrier includes a second stopper, the second stopper configured to restrict movement of the stepped pinion in a direction toward the second end;
the stepped pinion includes a first facing surface facing the first stopper and a second facing surface facing the second stopper;
the first thrust washer or the first thrust bearing is provided between the first stopper and the first facing su

Assignees

• Toyota Motor Co Ltd

Inventors

• Hibino Akira
• Shiina Takahiro

Classifications

• F16H48/38

  Constructional details (the outer casing comprising the differential and supporting input and output shafts F16H57/037) · CPC title

• B60K17/08

  of mechanical type · CPC title

• F16H57/04

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

• F16H57/0482

  Gearings with gears having orbital motion · CPC title

• F16H57/0424

  Lubricant guiding means in the wall of or integrated with the casing, e.g. grooves, channels, holes · CPC title