US-20260128644-A1 - ROTATING ELECTRIC MACHINE SYSTEM

US20260128644A1US 20260128644 A1US20260128644 A1US 20260128644A1US-20260128644-A1

Abstract

In a rotating electric machine system, a rotor internal flow path allowing a liquid coolant to flow is formed in an interior of a rotor. A support member includes a supporting tubular part that abuts against an inner peripheral surface of a first sleeve end part. The rotor internal flow path includes a first flow through space, a second flow through space allowing the liquid coolant to flow more outwardly in a radial direction than the first flow through space, and a direction changing portion that serves to direct the liquid coolant outwardly in the radial direction. A fitting portion, which is a contact location between an inner peripheral surface of a first tubular part of a sleeve and an outer peripheral surface of the supporting tubular part, is positioned more inwardly in the radial direction than an inner peripheral surface of a second tubular part of the sleeve.

Inventors

Tsubasa Nakatomi
Tatsuya Choji

Assignees

HONDA MOTOR CO., LTD.

Dates

Publication Date: 20260507
Application Date: 20251029
Priority Date: 20241101

Claims (7)

1 . A rotating electric machine system, comprising: a rotating electric machine including a rotor, the rotor including a permanent magnet and a rotating shaft; a rotating electric machine housing configured to rotatably support the rotating shaft; and a first bearing and a second bearing each interposed between the rotating electric machine housing and the rotating shaft, and configured to be spaced apart from each other in an axial direction of the rotor; wherein a rotor internal flow path through which a liquid coolant is allowed to flow is formed in an interior of the rotor; the rotor further includes a sleeve interposed between the rotating shaft and the permanent magnet in a radial direction of the rotating shaft, and at least a portion of the rotor internal flow path is formed between an outer peripheral surface of the rotating shaft and an inner peripheral surface of the sleeve; a support member configured to support a first sleeve end part, which is one end part of the sleeve, is disposed between the first bearing and the sleeve; the support member includes a supporting tubular part configured to abut against an inner peripheral surface of the first sleeve end part; the rotor internal flow path includes: a first flow through space; a second flow through space formed on a more downstream side than the first flow through space, and configured to allow the liquid coolant to flow more outwardly in the radial direction than the first flow through space; and a direction changing portion configured to connect the first flow through space and the second flow through space and to direct the liquid coolant outwardly in the radial direction; the sleeve includes a first tubular part that is the first sleeve end part, and a second tubular part that forms the second flow through space between the second tubular part and the rotating shaft; and a fitting portion, which is a contact location between an inner peripheral surface of the first tubular part and an outer peripheral surface of the supporting tubular part, is positioned more inwardly in the radial direction than the inner peripheral surface of the second tubular part.
2 . The rotating electric machine system according to claim 1 , wherein when the liquid coolant in an amount corresponding to a volume of the first flow through space moves into the second flow through space, the fitting portion is configured to be positioned more inwardly in the radial direction than a liquid surface of the liquid coolant in the second flow through space while the rotor is rotating.
3 . The rotating electric machine system according to claim 2 , wherein an opening area of the second flow through space in a cross section perpendicular to an axial line of the rotor is configured to be larger than an opening area of the first flow through space.
4 . The rotating electric machine system according to claim 1 , wherein the sleeve is configured to be formed seamlessly from between the rotating shaft and the permanent magnet to the first sleeve end part that is supported by the support member.
5 . The rotating electric machine system according to claim 1 , wherein the supporting tubular part is configured to form one portion of the direction changing portion and one portion of the first flow through space.
6 . The rotating electric machine system according to claim 1 , wherein a holder member having a hollow tubular shape and configured to surround the first sleeve end part is disposed outwardly of the first sleeve end part in the radial direction; and a seal member configured to face in the radial direction toward the holder member is disposed on an outer peripheral part of the first sleeve end part.
7 . The rotating electric machine system according to claim 6 , wherein the support member includes a supporting base part adjacent to the first bearing, and the supporting tubular part configured to project out from the supporting base part along an axial direction of the rotating shaft; an outer peripheral surface of the supporting tubular part supports an inner peripheral surface of the first sleeve end part of the sleeve; and a preload applying member configured to apply a load to an outer ring of the first bearing is disposed in a manner so as to surround the holder member, the seal member, and the supporting tubular part.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2024-192808 filed on Nov. 1, 2024, the contents of which are incorporated herein by reference. BACKGROUND OF THE INVENTION Field of the Invention The present invention relates to a rotating electric machine system. Description of the Related Art A rotating electric machine is equipped with a rotor having a rotating shaft, and a stator positioned on an outer periphery of the rotor. The rotor includes permanent magnets that are retained on the rotating shaft. When the rotating shaft rotates, an induced electrical current is generated in an electromagnetic coil that makes up the stator. In this case, the rotating electric machine functions as a generator. When the temperature of the permanent magnets becomes too high during the operation of the rotating electric machine, the magnetic force of the permanent magnets decreases. For example, in JP 2011-097784 A, in order to cool the permanent magnets, a configuration is disclosed in which a cooling medium (oil) is supplied to the interior of the rotating shaft. SUMMARY OF THE INVENTION It is undesirable for the cooling medium to leak out from any location other than a normal discharge outlet. The present invention has the object of solving the aforementioned problem. An aspect of the present disclosure is characterized by a rotating electric machine system, equipped with a rotating electric machine including a rotor, the rotor including a permanent magnet and a rotating shaft, a rotating electric machine housing configured to rotatably support the rotating shaft, and a first bearing and a second bearing each interposed between the rotating electric machine housing and the rotating shaft, and configured to be spaced apart from each other in an axial direction of the rotor, wherein a rotor internal flow path through which a liquid coolant is allowed to flow is formed in an interior of the rotor, the rotor further includes a sleeve interposed between the rotating shaft and the permanent magnet in a radial direction of the rotating shaft, and at least a portion of the rotor internal flow path is formed between an outer peripheral surface of the rotating shaft and an inner peripheral surface of the sleeve, a support member configured to support a first sleeve end part, which is one end part of the sleeve, is disposed between the first bearing and the sleeve, the support member includes a supporting tubular part configured to abut against an inner peripheral surface of the first sleeve end part, the rotor internal flow path includes a first flow through space, a second flow through space formed on a more downstream side than the first flow through space, and configured to allow the liquid coolant to flow more outwardly in the radial direction than the first flow through space, and a direction changing portion configured to connect the first flow through space and the second flow through space and to direct the liquid coolant outwardly in the radial direction, the sleeve includes a first tubular part that is the first sleeve end part, and a second tubular part that forms the second flow through space between the second tubular part and the rotating shaft, and a fitting portion, which is a contact location between an inner peripheral surface of the first tubular part and an outer peripheral surface of the supporting tubular part, is positioned more inwardly in the radial direction than the inner peripheral surface of the second tubular part. According to the rotating electric machine system of the present disclosure, leakage of the liquid coolant to the exterior of the rotor via the fitting portion can be effectively suppressed. In accordance therewith, leakage of the liquid coolant from any location other than the outlet of the rotor internal flow path can be suppressed. Therefore, it is possible to suppress a situation in which an area inside the rotating electric machine housing into which the liquid coolant is not intended to flow becomes contaminated by the liquid coolant. The above and other objects, features, and advantages of the present invention will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which a preferred embodiment of the present invention is shown by way of illustrative example. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of a combined motive power system; FIG. 2 is a schematic cross-sectional view of a rotating electric machine system; FIG. 3 is a schematic cross-sectional view of the rotating electric machine system as viewed from another angle; FIG. 4 is an enlarged cross-sectional view in the vicinity of a first bearing; FIG. 5 is a schematic diagram of a rotor internal flow path and the vicinity thereof; and FIG. 6 is an enlarged cross-sectional view in the vicinity of a second bearing. DETAILED DESCRIPTION OF THE INVENTIO