Stator structure and rotating electric motor

Abstract

The present application aims at improving the degree of freedom of the position of the flow path of refrigerant liquid in the frame of a rotary electric machine. The stator structure is provided with: a stator having a stator core and a stator coil wound on the stator core; a current collector ring having a bus bar connected to the stator coil, and an outer diameter larger than that of the stator core; a frame accommodating the stator core on the radially inner side, and having a flow path of refrigerant liquid opened at the axial one side and extending toward the axial other side; and a cover member arranged on the axial one side of the frame and on the axial other side of the current collector ring, blocking the opening of the flow path and holding the current collector ring, the cover member being fixed to the frame.

Description

Technical Field

[0001] This invention relates to stator structures and rotary electric machines. Background Technology

[0002] For example, in a three-phase AC motor, there is a known structure in which the stator coils of each phase wound on the stator core are connected by a busbar for each phase, and the busbars of each phase are concentrated by a slip ring (e.g., Patent Document 1). The busbar is a ring-shaped conductor.

[0003] In addition, as a cooling structure for motors, there is a known structure in which a flow path is provided on a frame covering the outer periphery of the stator, and the stator is cooled by allowing a refrigerant liquid such as water to flow in the flow path (for example, Patent Document 2).

[0004] Existing technical documents

[0005] Patent documents

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

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

[0008] The problem that the invention aims to solve

[0009] The motor frame is manufactured using a mold, for example, like an aluminum die-casting. In this case, when flow paths are formed within the frame, they need to be shaped to open externally on the frame for demolding. To cool the stator axially, the flow paths need to extend axially; in this case, the opening for demolding is located at the axial end of the frame. This opening at the axial end of the frame is blocked circumferentially by covering it with a bracket that covers the axial end of the stator.

[0010] However, it is desirable to prevent an increase in the axial dimension of the motor by placing the slip rings radially outside the coil ends, which are the axial ends of the stator coils. Furthermore, the slip rings require axial thickness and radial width depending on the magnitude of the flowing current and the required mechanical strength. Since the bracket needs to cover the size of the slip rings, if the slip rings are large radially, the flow path through which the bracket blocks the opening must also be placed radially outside.

[0011] The outer periphery of the stator core contacts the inner periphery of the frame and is cooled by liquid refrigerant flowing in the flow path of the frame. However, as mentioned above, if the flow path is arranged radially outward, it moves away from the stator core, resulting in decreased cooling efficiency. Furthermore, if the flow path is arranged radially outward, the frame becomes radially thicker, leading to increased weight and size.

[0012] The purpose of this invention is to improve the degree of freedom in the position of the refrigerant liquid flow path in the frame of a rotating electric motor.

[0013] Methods for solving problems

[0014] One aspect of the stator structure of the present invention comprises: a stator having a stator core and a stator coil wound on the stator core; a slip ring having a busbar connected to the stator coil and having an outer diameter larger than the outer diameter of the stator core; a frame housing the stator core radially inward and having a flow path for refrigerant liquid that is open at one end in the axial direction and extends to the other side in the axial direction; and a cover member disposed on one side of the frame and the other side in the axial direction of the slip ring, blocking the opening of the flow path and retaining the slip ring, the cover member being fixed to the frame.

[0015] In one of the stator structures described above, the opening of the flow path is located radially inward than the outer diameter of the slip ring.

[0016] In one of the above-described stator structures, a bracket is also provided that covers the axial side of the stator core from both the axial side and the radial side, the bracket being fixed to the frame or the cover component.

[0017] One aspect of the present invention provides a rotating electric motor comprising: the aforementioned stator structure, a rotor disposed radially inside the stator core, and an inverter unit disposed on one axial side of the stator structure and driving the rotating electric motor.

[0018] The rotary motor described above is used to drive a car.

[0019] Invention Effects

[0020] According to one aspect of the invention, the objective is to improve the degree of freedom in the position of the refrigerant liquid flow path in the frame of the rotating electric motor. Attached Figure Description

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

[0022] Figure 2 It means that it has been assembled. Figure 1 A side sectional view of the state of the stator structure 100.

[0023] Figure 3 It means Figure 1 A perspective view of the cover component 120. Detailed Implementation

[0024] Hereinafter, the stator structure according to an embodiment of the present invention will be described with reference to the accompanying drawings. It should be noted that, in the following drawings, for ease of understanding of each structure, the actual structure and the scale and quantities in each structure may sometimes differ. Furthermore, for ease of observation of each structure, approximations different from the actual shapes are used.

[0025] Furthermore, in the accompanying drawings, the XYZ coordinate system is appropriately represented as a three-dimensional orthogonal coordinate system. In the XYZ coordinate system, the X-axis direction is perpendicular to the x-axis. Figure 1 The direction parallel to the axial direction of the central axis J is shown. The Y-axis direction is radially relative to the central axis J. Figure 1 The Z-axis is the vertical direction. It is orthogonal to both the X-axis and Y-axis. In any of the X-axis, Y-axis, and Z-axis directions, the side indicated by the arrow in the diagram is designated as the "+" side, and the opposite side is designated as the "-" side.

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

[0027] It should be noted that, in this specification, "extending axially" includes not only the case of extending strictly along the axial direction (X-axis direction), but also the case of extending in a direction inclined relative to the axial direction within a range of less than 45°. Furthermore, in this specification, "extending radially" includes not only the case of extending strictly in the radial direction, i.e., perpendicular to the axial direction (X-axis direction), but also the case of extending in a direction inclined relative to the radial direction within a range of less than 45°. Additionally, "parallel" includes not only the case of being strictly parallel, but also the case of the angle between them being inclined within a range of less than 45°.

[0028] <First Implementation Method>

[0029] Figure 1This is an exploded perspective view showing a schematic stator structure according to a first embodiment of the present invention. The stator structure 100 forms the stator surrounding an electric motor, an example of a rotating electric motor. The stator structure 100, for example, forms a three-phase AC motor. The stator structure 100 is configured to include a stator 110, a cover member 120, a frame 130, slip rings 113, and terminal blocks 114. The motor having the stator structure 100 has a rotor disposed radially inside the stator 110, but the rotor is omitted from the illustration.

[0030] The stator 110 has a cylindrical stator core 111 and stator coils 112 for each phase wound on the stator core 111. Slip rings 113 have a busbar 113a for each phase. Each end of the stator coil 112 for each phase is electrically connected to each busbar 113a for each phase. The outer diameter of the slip rings 113 is larger than the outer diameter of the stator core 111. The outer peripheral end of the slip rings 113 is located radially outward from the outer peripheral end of the stator core 111.

[0031] Terminal block 114 holds the respective terminals 113b of each phase busbar 113a, enabling easy connection to external devices. An inverter section for driving the motor is disposed on one axial side of the motor having stator structure 100, and the terminals of terminal block 114 are electrically connected to this inverter section. The motor having stator structure 100 is used, for example, to drive an automobile.

[0032] The frame 130 is cylindrical and houses the stator core 111 radially inward. The frame 130 and the stator core 111 are fixed, for example, by thermoforming. The frame 130 has a flow path 131, which serves as a flow path for a refrigerant liquid, such as water. The flow path 131 opens at one axial end of the frame 130 and extends axially to the other side. The frame 130 is manufactured using a mold, for example, like an aluminum die casting. Because the flow path 131 has an opening at one axial end of the frame 130, the shape of the flow path 131 can be molded during the manufacture of the frame 130.

[0033] The cover member 120 is a component that, when refrigerant liquid flows in the flow path 131, covers and blocks the opening at one axial end of the frame 130 to prevent refrigerant liquid from leaking out. The cover member 120 is disposed on one axial side of the frame 130 and the other axial side of the slip ring 113. The cover member 120 is an annular component that blocks the opening at one axial end of the frame 130 by having a surface at a position facing the opening. A sealing portion, preferably made of a liquid gasket or the like, is preferably provided between the frame 130 and the cover member 120 around the opening. The stator 110 is cooled by allowing refrigerant liquid to flow in the flow path 131. The refrigerant liquid in the flow path 131 is circulated, for example, by a pump or the like, through an inlet and an outlet provided on the side of the frame 130.

[0034] The stator structure 100 has bolts 120c. The cover member 120 has bolt holes 120b for inserting the bolts 120c. The frame 130 has bolt holes 130a for inserting the bolts 120c. The bolts 120c securely hold the cover member 120 to the frame 130 such that the axial side of the cover member 120 contacts the axial side of the frame 130. The bolts 120c, bolt holes 120b, and bolt holes 130a are an example of a retaining structure for holding the cover member 120 to the frame 130. Multiple bolts 120c, bolt holes 120b, and bolt holes 130a are provided circumferentially.

[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 securely holds the slip ring 113 to the cover member 120 such that the axially opposite side of the slip ring 113 contacts the axially side of the cover member 120. The bolt 113, bolt hole 113c, and bolt hole 120a are an example of a holding structure for holding the slip ring 113 to the cover member 120. Multiple bolts 113, bolt holes 113c, and bolt holes 120a are provided circumferentially.

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

[0037] Figure 2 It means that it has been assembled. Figure 1 A side sectional view of the state of the stator structure 100. Figure 2It is shown by a section cut through the central axis J and orthogonal to the Z-axis. The axial side of the stator core 112 can also be covered by a bracket from the axial side and the radially outer side. The bracket is bolted to the frame 130 or the cover component 120 at a location different from the bolt fixing position of the frame 130 and the cover component 120.

[0038] A slip ring 113 is disposed radially outward of the coil end on one axial side of the stator coil 112. At least a portion of the slip ring 113 overlaps axially with the cover member 120. At least a portion of the cover member 120 overlaps axially with the frame 130. Furthermore, the radial length on the other axial side of the flow path 131 is shorter than the radial length on the axial side. By forming this shape, the shape of the flow path 131 can be easily demolded during the manufacture of the frame 130.

[0039] Figure 3 It means Figure 1 A perspective view of the cover component 120. In this embodiment, six bolt holes 120b are arranged circumferentially on the cover component 120. That is, six combinations of bolts 120c, bolt holes 120b, and bolt holes 130a are arranged circumferentially. The number of bolts 120c, bolt holes 120b, and bolt holes 130a is not limited to this, as long as the cover component 120 can stably block the opening of the flow path 131 of the frame 130.

[0040] Furthermore, in this embodiment, three bolt holes 120a are arranged circumferentially on the cover member 120. That is, three combinations of bolts 113d, bolt holes 113c, and bolt holes 120a are arranged circumferentially. The number of bolts 113d, bolt holes 113c, and bolt holes 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 the protrusion 120aa that protrudes from the axial side of the cover member 120. With the configuration described above, the cover member 120 can hold the slip ring 113 separately in the axial direction, which can improve the degree of freedom of the shape of the slip ring 113.

[0042] In this embodiment, the slip ring 113 is not held directly to the frame 130, but rather to the cover member 120. Therefore, the holding structure for the slip ring 113 does not need to avoid the opening of the flow path 131 in the radial direction, improving the freedom of movement of the slip ring and the frame. This allows for miniaturization of the motor and reduction of its weight.

[0043] Furthermore, in this embodiment, the opening of the flow path 131 in the frame 130 can be blocked by the cover member 120 without being blocked by the bracket. Therefore, the radial position of the flow path 131 can be determined independently 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, the side close to the stator core 111, which can improve cooling efficiency and enable the miniaturization and weight reduction of the motor.

[0044] This invention is not limited to the embodiments described above, and various modifications and design changes can be made without departing from the spirit of the invention. Furthermore, the embodiments disclosed herein should be considered illustrative rather than restrictive in all respects. The scope of this invention is defined not by the foregoing description but by the claims, and is intended to include all modifications equivalent to and within the scope of the claims.

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

[0046] Explanation of reference numerals in the attached figures

[0047] 100 stator structure, 110 stator, 120 cover component, 113 slip ring, 130 frame.

Claims

1. A stator structure, characterized by, The stator structure includes: a stator having a stator core and a stator coil wound on 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 housing the stator core on an inner side in a radial direction, and having a flow path of refrigerant liquid extending from an opening at one axial end to the other axial end; and a cover member arranged on the one axial end of the frame and on the other axial end of the collector ring, blocking the opening of the flow path and holding the collector ring, the cover member is fixed to the frame, the cover member blocks the opening of the flow path by having a surface at a position facing the opening at the one axial end of the frame when the cover member is fixed to the frame.

2. The stator structure according to claim 1, wherein the opening of the flow path is located at a position inside in the radial direction than the outer diameter of the collector ring.

3. The stator structure according to claim 1, wherein the stator structure further includes a bracket covering the one axial end of the stator core from the one axial end and from an outer side in the radial direction, the bracket is fixed to the frame or the cover member.

4. A rotary electric machine characterized by The rotating electric machine includes: the stator structure according to claim 1; a rotor arranged inside in the radial direction of the stator core; and an inverter section arranged on the one axial end of the stator structure, and driving the rotating electric machine.

5. The rotating electric machine according to claim 4, wherein the rotating electric machine is used for driving an automobile.

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