US-12620873-B2 - Drive device

US12620873B2US 12620873 B2US12620873 B2US 12620873B2US-12620873-B2

Abstract

A drive device includes a motor, a transmission, a housing, and a flow path. The transmission includes first to third shafts, and first to third bearings supporting the first to third shafts, respectively. The housing includes a side wall covering a gear chamber from one side in an axial direction, and having first to third bearing holding portions for holding the first to third bearings, respectively. The flow path includes a supply flow path portion that supplies a fluid to the inside of the second bearing holding portion, a first flow path portion that connects the inside of the second bearing holding portion and the inside of the first bearing holding portion, and a second flow path portion that connects the inside of the second bearing holding portion and the inside of the third bearing holding portion.

Inventors

Ryosuke Matsuzaki
Taishi Satoda
Sota Doi
Jinnosuke Ikushima
Daichi Sukemori

Assignees

NIDEC CORPORATION

Dates

Publication Date: 20260505
Application Date: 20240329
Priority Date: 20230331

Claims (12)

1 . A drive device comprising: a motor; a transmission mechanism configured to transmit power of the motor; a housing provided with a gear chamber that accommodates the transmission mechanism; and a flow path at least a part of which is provided in the housing and through which a fluid can flow, wherein the transmission mechanism includes: a first shaft rotatable about a first axis extending in an axial direction; a second shaft rotatable about a second axis extending in parallel with the first axis; a third shaft rotatable about a third axis extending in parallel with the first axis and the second axis; a first bearing that supports the first shaft; a second bearing that supports the second shaft; and a third bearing that supports the third shaft, the housing includes: a side wall covering the gear chamber from one side in the axial direction; a first bearing holding portion that is provided in the side wall and holds the first bearing; a second bearing holding portion that is provided in the side wall and holds the second bearing; and a third bearing holding portion that is provided in the side wall and holds the third bearing, and the flow path includes: a supply flow path portion that supplies the fluid to an inside of the second bearing holding portion; a first flow path portion connecting the inside of the second bearing holding portion and an inside of the first bearing holding portion; and a second flow path portion connecting the inside of the second bearing holding portion and an inside of the third bearing holding portion.
2 . The drive device according to claim 1 , wherein the second bearing holding portion includes: a facing surface positioned on one side in an axial direction with respect to an end portion on one side in the axial direction of the second shaft and extending in a direction orthogonal to the axial direction; and an inner side surface that extends in the axial direction and supports the second bearing from radially outside, and the inner side surface is provided with: a first opening that is an end portion of the first flow path portion; a second opening that is an end portion of the second flow path portion; and a wall that is positioned between the first opening and the second opening and protrudes radially inward.
3 . The drive device according to claim 2 , wherein the inner side surface is provided with a third opening that is an end portion of the supply flow path portion, a direction intersecting both an up-down direction and the axial direction is defined as a first direction, the first opening is positioned on one side in a first direction with respect to the wall, the second opening is positioned on an other side in the first direction with respect to the wall, and the third opening is positioned on one side in the first direction with respect to the wall.
4 . The drive device according to claim 3 , wherein the transmission mechanism includes a differential device including the third shaft.
5 . The drive device according to claim 2 , wherein the inner side surface is provided with a third opening that is an end portion of the supply flow path portion, a direction intersecting both an up-down direction and the axial direction is defined as a first direction, the first opening is positioned on one side in a first direction with respect to the wall, the second opening is positioned on an other side in the first direction with respect to the wall, and the third opening is positioned on the other side in the first direction with respect to the wall.
6 . The drive device according to claim 1 , wherein a cross-sectional area of the first flow path portion is larger than a cross-sectional area of the second flow path portion.
7 . The drive device according to claim 1 , wherein a cross-sectional area of the second flow path portion is larger than a cross-sectional area of the first flow path portion.
8 . The drive device according to claim 1 , wherein the second bearing holding portion has a facing surface located on one side in the axial direction with respect to the end portion on one side in the axial direction of the second shaft and extending in the direction orthogonal to the axial direction, the facing surface is provided with a recess recessed to one side in the axial direction, and the first flow path portion and the second flow path portion are connected to an inside of the recess.
9 . The drive device according to claim 8 , wherein the second bearing holding portion has an inner side surface extending in the axial direction and supporting the second bearing from a radially outer side, and the inner side surface is provided with: the first opening that is the end portion of the first flow path portion; the second opening that is the end portion of the second flow path portion; the wall that is positioned between the first opening and the second opening and protrudes radially inward, and the wall extends to an inside of the recess and is disposed on a side of the second opening with respect to a circumferential center of the recess.
10 . The drive device according to claim 8 , wherein the second bearing holding portion has an inner side surface extending from the facing surface to an other side in the axial direction and supporting the second bearing from a radially outer side, the inner side surface is provided with: the first opening that is the end portion of the first flow path portion; the second opening that is the end portion of the second flow path portion; and the wall that is positioned between the first opening and the second opening and protrudes radially inward, and the wall extends to the inside of the recess and is disposed on a side of the first opening with respect to a circumferential center of the recess.
11 . The drive device according to claim 1 , wherein the second bearing holding portion includes: a facing surface positioned on one side in the axial direction with respect to an end portion on one side in the axial direction of the second shaft and extending in a direction orthogonal to the axial direction; and an inner side surface that extends in the axial direction and supports the second bearing from radially outside, the inner side surface is provided with: a first opening that is an end portion of the first flow path portion; a second opening that is an end portion of the second flow path portion; and a third opening that is an end portion of the supply flow path portion, the facing surface is provided with a rib that protrudes to an other side in an axial direction and covers at least a part of the third opening, a direction intersecting both an up-down direction and an axial direction is defined as a first direction, the first opening and the second opening are positioned on one side in the first direction with respect to the second opening, and at least a part of the rib is provided on one side in the first direction with respect to the second opening.
12 . The drive device according to claim 11 , wherein the facing surface is provided with a recess recessed to one side in the axial direction, and the rib extends toward the recess.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present invention claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2023-058151 filed on Mar. 31, 2023 and Japanese Patent Application No. 2024-013441 filed on Jan. 31, 2024, the entire contents of which are incorporated herein by reference. FIELD OF THE INVENTION The present invention relates to a drive device. BACKGROUND A drive device is mounted on a vehicle such as an electric vehicle and a hybrid vehicle. A fluid such as oil is stored in such a drive device, and the fluid lubricates gears and bearings in the drive device. The bearing is held by a bearing holding portion provided in the housing. When a plurality of bearings are provided, it is required to stably supply fluid to each bearing and to suppress shortage of supply to some of the bearings. SUMMARY A drive device according to an embodiment of the present invention includes a motor, a transmission mechanism configured to transmit power of the motor, a housing provided with a gear chamber that accommodates the transmission mechanism, and a flow path at least a part of which is provided in the housing and through which a fluid can flow. The transmission mechanism includes a first shaft rotatable about a first axis extending in an axial direction, a second shaft rotatable about a second axis extending in parallel with the first axis, a third shaft rotatable about a third axis extending in parallel with the first axis and the second axis, a first bearing that supports the first shaft, a second bearing that supports the second shaft, and a third bearing that supports the third shaft. The housing includes a side wall covering the gear chamber from one side in an axial direction, and a first bearing holding portion that is provided on the side wall and holds the first bearing. A second bearing holding portion that is provided on the side wall and holds the second bearing is provided. A third bearing holding portion that is provided on the side wall and holds the third bearing is provided. The flow path includes a supply flow path portion that supplies a fluid to the inside of the second bearing holding portion, a first flow path portion that connects the inside of the second bearing holding portion and the inside of the first bearing holding portion, and a second flow path portion that connects the inside of the second bearing holding portion and the inside of the third bearing holding portion. The above and other elements, features, steps, characteristics and advantages of the present disclosure will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a conceptual diagram of a drive device of an embodiment; FIG. 2 is a front view of a side wall according to a drive device of an embodiment; FIG. 3 is a front view of a second bearing holding portion according to an embodiment; FIG. 4 is a schematic cross-sectional view of the second bearing holding portion taken along line IV-IV in FIG. 3; FIG. 5 is a schematic view of a second bearing holding portion according to a first modification; FIG. 6 is a schematic view of a second bearing holding portion according to a second modification; FIG. 7 is a schematic view of a second bearing holding portion according to a third modification; FIG. 8 is a schematic view of a second bearing holding portion according to a fourth modification; FIG. 9 is a schematic view of a second bearing holding portion according to a fifth modification; FIG. 10 is a schematic view of a second bearing holding portion of a sixth modification; FIG. 11 is a schematic view of a second bearing holding portion of a seventh modification; and FIG. 12 is a schematic cross-sectional view of the second bearing holding portion taken along line XII-XII in FIG. 11. DETAILED DESCRIPTION A drive device according to an embodiment of the present invention will be described below with reference to the drawings. In description below, an up-down direction is defined based on a positional relationship when a drive device 1 of the present embodiment is mounted on a vehicle (not illustrated) positioned on a horizontal road surface. In the drawings, an XYZ coordinate system is illustrated appropriately as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, a Z-axis direction corresponds to the up-down direction. The up-down direction is, for example, a vertical direction. A +Z side corresponds to an upper side in the vertical direction, while a −Z side corresponds to a lower side in the vertical direction. In the present embodiment, the upper side in the vertical direction will be referred to simply as the “upper side” and the lower side in the vertical direction will be simply referred to as the “lower side”. An X-axis direction is a direction orthogonal to the Z-axis direction and is a vehicle front-rear direction on which the drive device 1 is