Stator structure and rotating electrical machine

Abstract

The purpose of the present invention is to improve the degree of freedom in the position of a flow path for a refrigerant liquid in a frame of a rotating electrical machine. The stator structure includes: a stator having a stator core and a stator coil wound around the stator core; a collector ring having a bus bar connected to the stator coil and having an outer diameter larger than an outer diameter of the stator core; a frame that accommodates the stator core on the inside in the radial direction, and that has a flow path for a refrigerant liquid that opens at one end in the axial direction and extends toward the other end in the axial direction; and a cover member that is disposed on one side of the frame in the axial direction and on the other side of the collector ring in the axial direction, that closes the opening of the flow path and holds the collector ring, and that is fixed to the frame.

Description

Technical Field

[0001] The present invention relates to a stator structure and a rotating electric machine. Background Art

[0002] For example, in a three-phase AC motor, the following structure is known: stator coils of each phase wound around a stator core are connected by busbars of each phase, and the busbars of each phase are collected through slip rings (for example, Patent Document 1). The busbar is a ring-shaped conductor.

[0003] In addition, as a cooling structure of an electric machine, the following structure is known: a flow path is provided on a frame covering the outer periphery of the stator, and a refrigerant liquid such as water is made to flow through the flow path to cool the stator and the like (for example, Patent Document 2).

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2019-154084

[0007] Patent Document 2: International Publication No. 2013 / 069321 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] The frame of the electric machine is manufactured using a mold, such as an aluminum die-cast part. In this case, when forming a flow path in the frame, in order to perform demolding, the flow path needs to be formed in a shape that opens to the outside of the frame. In order to cool the stator in the axial direction, the flow path needs to extend along the axial direction. In this case, the opening for demolding is arranged at the axial end of the frame. The opening at the axial end of the frame can be blocked in the entire circumferential direction by covering it with a bracket that covers the axial end of the stator.

[0010] However, it is desired to prevent an increase in the axial dimension of the electric machine by arranging the slip ring on the radially outer side of the coil end, which is the axial end of the stator coil. In addition, the slip ring requires an axial thickness and a radial width according to the magnitude of the flowing current and the required mechanical strength. Since the bracket needs to cover the size of the slip ring, when the slip ring is large in the radial direction, the flow path for blocking the opening with the bracket also has to be arranged on the radially outer side.

[0011] The outer periphery of the stator core is in contact with the inner periphery of the frame and is cooled by a refrigerant liquid flowing in the flow path of the frame. However, as described above, if the flow path is arranged on the radially outer side, the flow path is far from the stator core, and there is a problem that the cooling efficiency deteriorates. In addition, if the flow path is arranged on the radially outer side, the frame becomes thicker in the radial direction, and thus there are problems of an increase in weight and size.

[0012] An object of the present invention is to improve the degree of freedom in the position of the flow path of the refrigerant liquid in the frame of the rotating electric machine.

[0013] Means for Solving the Problem

[0014] A stator structure according to one aspect of the present invention includes: a stator having a stator core and a stator coil wound around the stator core; a slip ring having a bus bar connected to the stator coil and an outer diameter larger than the outer diameter of the stator core; a frame that houses the stator core on the radially inner side and has a flow path for the refrigerant liquid that opens at one axial end and extends to the other axial side; and a cover member that is disposed on the one axial side of the frame and on the other axial side of the slip ring, closes the opening of the flow path, and holds the slip ring, and the cover member is fixed to the frame.

[0015] In the stator structure according to the above aspect, the opening of the flow path is located at a position radially inside the outer diameter of the slip ring.

[0016] In the stator structure according to the above aspect, there is also a bracket that covers the one axial side of the stator core from the one axial side and the radially outer side, and the bracket is fixed to the frame or the cover member.

[0017] A rotating electric machine according to one aspect of the present invention includes: the above-described stator structure, a rotor disposed radially inside the stator core, and an inverter unit disposed on the one axial side of the stator structure and driving the rotating electric machine.

[0018] The rotating electric machine according to the above aspect is used to drive an automobile.

[0019] Effects of the Invention

[0020] According to one aspect of the present invention, an object is to improve the degree of freedom in the position of the flow path of the refrigerant liquid in the frame of the rotating electric machine. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic exploded perspective view showing the stator structure of the first embodiment of the present invention.

[0022] Figure 2 is a side cross-sectional view showing the state of the assembled Figure 1 stator structure 100.

[0023] Figure 3 is a perspective view showing Figure 1 the cover member 120. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, with reference to the drawings, the stator structure of the embodiment of the present invention will be described. It should be noted that in the following drawings, in order to facilitate understanding of each structure, sometimes the actual structure, the scale, the quantity, etc. in each structure are different. In addition, in order to easily observe each structure, it is represented by a schematic different from the actual shape.

[0025] In addition, in the drawings, the XYZ coordinate system is appropriately shown as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the X-axis direction is the direction parallel to the axial direction of the central axis J shown in Figure 1 the figure. The Y-axis direction is the up-and-down direction in the radial direction with respect to the central axis J among Figure 1 them. The Z-axis direction is the direction orthogonal to both the X-axis direction and the Y-axis direction. In any one of the X-axis direction, the Y-axis direction, and the Z-axis direction, the side indicated by the arrow shown in the figure is set as the + side, and the opposite side is set as the - side.

[0026] In addition, in the following description, the negative side (-X side) of the X-axis direction is referred to as "one side", and the positive side (+X side) of the X-axis direction is referred to as "the other side". It should be noted that one side and the other side are only names used for explanation and do not limit the actual positional relationship and direction. In addition, unless otherwise specified, the direction parallel to the central axis J (X-axis direction) is simply referred to as the "axial direction", the radial direction centered on the central axis J is simply referred to as the "radial direction", and the circumferential direction centered on the central axis J, that is, the direction around the axis of the central axis J is simply referred to as the "circumferential direction". The side closer to the central axis J in the radial direction is referred to as the "radial inner side", and the side farther from the central axis J is referred to as the "radial outer side".

[0027] It should be noted that in this specification, "extending along the axial direction" includes not only the case of strictly extending along the axial direction (X-axis direction), but also the case of extending along a direction inclined within a range of less than 45° with respect to the axial direction. In addition, in this specification, "extending along the radial direction" includes not only the case of strictly extending along the radial direction, that is, the direction perpendicular to the axial direction (X-axis direction), but also the case of extending along a direction inclined within a range of less than 45° with respect to the radial direction. In addition, "parallel" includes not only the case of strictly parallel, but also the case where the angle formed with each other is inclined within a range of less than 45°.

[0028] <First Embodiment>

[0029] Figure 1It is a schematic exploded perspective view showing the stator structure of the first embodiment of the present invention. The stator structure 100 constitutes the periphery of the stator of an electric machine as an example of a rotating electric machine. The stator structure 100 constitutes, for example, a three-phase AC electric machine. The stator structure 100 is configured to include a stator 110, a cover member 120, a frame 130, a slip ring 113, and a terminal block 114. The electric machine having the stator structure 100 has a rotor disposed radially inside the stator 110, but the illustration of the rotor is omitted.

[0030] The stator 110 has a cylindrical stator core 111 and stator coils 112 of each phase wound around the stator core 111. The slip ring 113 has busbars 113a of each phase. Each end of the stator coils 112 of each phase is electrically connected to each of the busbars 113a of each phase. The outer diameter of the slip ring 113 is larger than the outer diameter of the stator core 111. The outer peripheral end of the slip ring 113 is located at a position radially outside the outer peripheral end of the stator core 111.

[0031] The terminal block 114 holds terminals 113b of the busbars 113a of each phase and enables easy connection to the outside. On one axial side of the electric machine having the stator structure 100, an inverter unit for driving the electric machine is disposed, and the terminals of the terminal block 114 are electrically connected to the inverter unit. The electric machine having the stator structure 100 is used, for example, to drive an automobile.

[0032] The frame 130 has a cylindrical shape and houses the stator core 111 radially inside. The frame 130 and the stator core 111 are fixed, for example, by thermal press fitting. The frame 130 has a flow path 131 that is a flow path for a refrigerant liquid. The refrigerant liquid is, for example, water. The flow path 131 opens at one axial end of the frame 130 and extends from the opening to the other axial side. The frame 130 is manufactured, for example, using a mold like an aluminum die casting. Since the flow path 131 has an opening at one axial end of the frame 130, the shape of the flow path 131 can be demolded when manufacturing the frame 130.

[0033] The cover member 120 is a member that covers and blocks the opening at the axial one - side end of the frame 130 to prevent the refrigerant liquid from leaking when the refrigerant liquid flows in the flow path 131. The cover member 120 is arranged on the axial one - side of the frame 130 and on the axial other - side of the slip ring 113. The cover member 120 is an annular member, and by having a surface at a position facing the opening at the axial one - side end of the frame 130, it blocks the opening when fixed to the axial one - side end of the frame 130. Around the opening, it is preferable to provide a sealing portion composed of a liquid gasket or the like between the frame 130 and the cover member 120. The stator 110 is cooled by making the refrigerant liquid flow in the flow path 131. The refrigerant liquid in the flow path 131 circulates, for example, through a pump via an inlet and an outlet provided on the side surface of the frame 130.

[0034] The stator structure 100 has a bolt 120c. The cover member 120 has a bolt hole 120b for inserting the bolt 120c. The frame 130 has a bolt hole 130a for inserting the bolt 120c. The bolt 120c fixes and holds the cover member 120 to the frame 130 so that the surface on the axial other - side of the cover member 120 contacts the surface on the axial one - side of the frame 130. The bolt 120c, the bolt hole 120b, and the bolt hole 130a are an example of a holding structure for holding the cover member 120 to the frame 130. The bolt 120c, the bolt hole 120b, and the bolt hole 130a are provided in a plurality along the circumferential direction.

[0035] The stator structure 100 has a bolt 113d. The slip ring 113 has a bolt hole 113c for inserting the bolt 113d. The cover member 120 has a bolt hole 120a for inserting the bolt 113d. The bolt 113d fixes and holds the slip ring 113 to the cover member 120 so that the surface on the axial other - side of the slip ring 113 contacts the surface on the axial one - side of the cover member 120. The bolt 113, the bolt hole 113c, and the bolt hole 120a are an example of a holding structure for holding the slip ring 113 to the cover member 120. The bolt 113, the bolt hole 113c, and the bolt hole 120a are provided in a plurality along the circumferential direction.

[0036] The stator structure 100 has a bolt 114a. The cover member 120 has a bolt hole 120d for inserting the bolt 114a. The terminal block 114 is fixed to the cover member 120 by the bolt 114a. The bolt 114a and the bolt hole 120d are provided on both circumferential sides of the terminal block 114.

[0037] Figure 2 It shows a side cross - sectional view of the stator structure 100 in a state where Figure 1 is assembled. Figure 2It is shown by a section taken along a plane passing through the central axis J and orthogonal to the Z-axis. One axial side of the stator core 112 can also be covered by a bracket from the axial side and the radial outside. The bracket is bolted to the frame 130 or the cover member 120 at a position different from the bolt fixing positions of the frame 130 and the cover member 120.

[0038] The slip ring 113 is arranged on the radial outside of the coil end on the axial one side of the stator coil 112. At least a part of the slip ring 113 overlaps with the cover member 120 in the axial direction. At least a part of the cover member 120 overlaps with the frame 130 in the axial direction. In addition, the radial length of the other axial side of the flow path 131 is shorter than the radial length of the axial one side. By forming such a shape, the demolding of the shape of the flow path 131 can be smoothly performed when manufacturing the frame 130.

[0039] Figure 3 It is shown as Figure 1 A perspective view of the cover member 120. In the present embodiment, six bolt holes 120b are arranged on the cover member 120 in the circumferential direction. That is, six combinations of the bolt 120c, the bolt hole 120b, and the bolt hole 130a are arranged in the circumferential direction. The number of the bolt 120c, the bolt hole 120b, and the bolt hole 130a is not limited to this, as long as the opening of the flow path 131 of the frame 130 can be stably blocked by the cover member 120.

[0040] In addition, in the present embodiment, three bolt holes 120a are arranged on the cover member 120 in the circumferential direction. That is, three combinations of the bolt 113d, the bolt hole 113c, and the bolt hole 120a are arranged in the circumferential direction. The number of the bolt 113d, the bolt hole 113c, and the bolt hole 120a is not limited to this, as long as the slip ring 113 can be stably held on the cover member 120.

[0041] It should be noted that the bolt hole 120a is provided in a protruding portion 120aa that protrudes from the axial one side of the cover member 120 toward the axial one side. By configuring as described above, the cover member 120 can hold the slip ring 113 separately in the axial direction, and the degree of freedom of the shape of the slip ring 113 can be improved.

[0042] In the present embodiment, the slip ring 113 is not directly held on the frame 130, but is held on the cover member 120. Thus, the holding structure for holding the slip ring 113 does not need to avoid the position of the opening of the flow path 131 in the radial direction, and the degrees of freedom of the slip ring and the frame can be improved. Thereby, the size of the motor can be miniaturized and the weight can be reduced.

[0043] In addition, in the present embodiment, the opening of the flow path 131 in the frame 130 can be blocked by the cover member 120 instead of being blocked by the bracket. Therefore, the radial position of the flow path 131 can be determined regardless of the shape of the slip ring 113. Thus, the flow path 131 can be arranged on the inner diameter side of the frame 130, that is, on the side closer to the stator core 111, which can improve the cooling efficiency and enable miniaturization and weight reduction of the motor.

[0044] The present invention is not limited to the above-described embodiments, and various improvements and design changes can be made without departing from the gist of the present invention. In addition, the embodiments disclosed this time should be considered illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and is intended to include the meaning equivalent to the claims and all changes within the scope.

[0045] This application claims priority based on Japanese Patent Application No. 2023-004920 filed on January 17, 2023, and incorporates by reference all the contents described in the Japanese patent application.

[0046] Description of Reference Numerals

[0047] 100 Stator structure, 110 Stator, 120 Cover member, 113 Slip ring, 130 Frame.

Claims

1. A stator structure, characterized in that: The stator structure has: A stator, the stator comprising a stator core and a stator coil wound on the stator core; A collector ring, wherein the collector ring has a busbar connected to the stator coil and has an outer diameter larger than an outer diameter of the stator core; a frame that accommodates the stator core radially inwardly and has a refrigerant liquid flow path that is open at one axial end and extends toward the other axial end; and a cover member, the cover member being arranged on one axial side of the frame and on the other axial side of the collector ring, blocking the opening of the flow path and holding the collector ring, The cover member is fixed to the frame.

2. The stator structure according to claim 1, characterized in that: The opening of the flow path is located radially inward of the outer diameter of the slip ring.

3. The stator structure according to claim 1, characterized in that: The stator structure further comprises a bracket, which covers one axial side of the stator core from one axial side and from the radial outer side. The bracket is fixed to the frame or the cover member.

4. A rotating electrical machine, characterized in that: have: The stator structure according to claim 1; a rotor disposed radially inward of the stator core; and An inverter unit is arranged on one side of the stator structure in an axial direction and drives the rotating electric machine.

5. The rotating electrical machine according to claim 4, characterized in that: The rotating electric machine is used to drive a vehicle.

Images