Motor case

Abstract

To provide a motor case that can promote heat transmission from a motor to a motor case.SOLUTION: A motor case comprises: a case inner wall; and an oil path which is provided in the case inner wall and in which lubricant oil flows. The case inner wall comprises: a plurality of wedge-shaped parts arranged side by side in a circumferential direction of a stator and supporting an outer periphery of the stator; and a wave-shaped part that is arranged on a radially outer side of the stator with respect to the plurality of wedge-shaped parts, and is arranged around the plurality of wedge-shaped parts. The oil path is provided between the plurality of wedge-shaped parts and the wave-shaped part, and meanders so that lubricant oil flows in the radial direction and the circumferential direction.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to a motor case. [Background technology]

[0002] Patent Document 1 discloses a configuration in which a gap is formed between the inner circumferential surface of a motor case and the outer circumferential surface of a stator core, and a lubricating oil is caused to flow in the gap to cool the motor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-122451 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration disclosed in Patent Document 1, the gap that serves as the oil passage is thin and narrow, limiting the flow rate of the lubricating oil. Also, in the configuration disclosed in Patent Document 1, the flow path of the lubricating oil in the oil passage is a laminar flow with little turbulence, so the heat transfer from the motor to the motor case is limited, leaving room for improvement.

[0005] The present disclosure has been made in consideration of the above, and has an object to provide a motor case that can promote heat transfer from a motor to the motor case. [Means for solving the problem]

[0006] The motor case of the present disclosure comprises a case inner wall and an oil passage provided in the case inner wall through which lubricating oil flows, the case inner wall comprising a plurality of wedge-shaped portions arranged in a row circumferentially of the stator and supporting the outer periphery of the stator, and a wave-shaped portion arranged radially outward of the stator relative to the plurality of wedge-shaped portions and arranged around the plurality of wedge-shaped portions, the oil passage being provided between the plurality of wedge-shaped portions and the wave-shaped portion and serpentine so that the lubricating oil flows radially and circumferentially of the stator. Effect of the Invention

[0007] According to the present disclosure, since the oil passage is serpentine, the flow of the lubricating oil is disturbed and stirred within the oil passage, thereby promoting heat transfer from the motor to the motor case. [Brief description of the drawings]

[0008] [Figure 1] FIG. 1 is a cross-sectional view showing the configuration of a motor case according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing the configuration of a modified example of the motor case according to the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] A motor case according to an embodiment of the present disclosure will be described with reference to the drawings. Note that components in the following embodiments include those that are easily replaceable by a person skilled in the art, or those that are substantially the same.

[0010] The motor case according to the embodiment is for housing a motor consisting of a stator and a rotor. The motor case according to the embodiment is formed by, for example, aluminum die casting. As described later, the motor case according to the embodiment contains lubricating oil that comes into direct contact with the motor (stator).

[0011] As shown in Fig. 1, the motor case 1 includes a case inner wall 11 and an oil passage 12. For ease of explanation, Fig. 1 shows only a portion of a cross section of the cylindrical motor case 1 and the cylindrical stator 2 taken at a predetermined position in the axial direction.

[0012] The case inner wall 11 includes a plurality of wedge-shaped portions 111 and a corrugated portion 112. The plurality of wedge-shaped portions 111 and the corrugated portion 112 are integrally configured. That is, as shown in FIG. 1, the plurality of wedge-shaped portions 111 and the corrugated portion 112 are provided spaced apart from each other at predetermined positions in the axial direction of the stator 2, but are connected at both ends (or one end) of the axial direction of the stator 2, for example. However, the plurality of wedge-shaped portions 111 and the corrugated portion 112 may be configured as separate bodies.

[0013] The wedge-shaped portions 111 are disposed on the outer periphery of the cylindrical stator 2. That is, the wedge-shaped portions 111 are disposed side by side in the circumferential direction of the stator 2. The wedge-shaped portions 111 are disposed at predetermined intervals in the circumferential direction of the stator 2. The tips of the wedge-shaped portions 111 abut against the outer periphery of the stator 2 and support the outer periphery of the stator 2. Although not shown in FIG. 1, the stator 2 is also fixed by a fastening member (such as a bolt) not shown.

[0014] The corrugated portion 112 is disposed on the radially outer side of the stator 2 relative to the plurality of wedge-shaped portions 111. The corrugated portion 112 is also disposed around the stator 2 and the plurality of wedge-shaped portions 111.

[0015] The oil passage 12 is a flow path for flowing the lubricating oil. The oil passage 12 is provided generally in the circumferential direction of the stator 2. That is, the lubricating oil in the oil passage 12 flows generally in the circumferential direction of the stator 2.

[0016] Further, oil passage 12 is provided between the multiple wedge-shaped portions 111 and corrugated portion 112. That is, oil passage 12 is made up of a space defined by the surfaces of the multiple wedge-shaped portions 111, the outer circumferential surface of stator 2 between each wedge-shaped portion 111 (see portion A in FIG. 1 ), and the surface of corrugated portion 112.

[0017] 1, the oil passage 12 meanders so that the lubricating oil flows in both the radial and circumferential directions of the stator 2. That is, when the oil passage 12 is cut at a predetermined position in the axial direction of the stator 2 as shown in the figure, a space extending in the radial direction (radially outward and radially inward) and a space extending in the circumferential direction are alternately connected. In other words, the oil passage 12 is formed in a labyrinth type (wave type) or zigzag shape. As a result, the lubricating oil in the oil passage 12 flows alternately in the radial and circumferential directions as shown in the B part of the figure.

[0018] In a typical motor case, the outer periphery of the stator is supported by, for example, a cylindrical inner wall of the case, and the inner wall of the case and the outer periphery of the stator are in close contact with each other. On the other hand, in the motor case according to the embodiment, the stator 2 is supported by the tips of the wedge-shaped portions 111, so that the lubricating oil comes into direct contact with the stator 2 between the wedge-shaped portions 111 as shown in part A of FIG. 1, and the area (liquid contact area) of the stator 2 that comes into direct contact with the lubricating oil is increased. This promotes heat transfer from the stator 2 to the motor case 1.

[0019] Furthermore, in the motor case according to the embodiment, by supporting the stator 2 at the tips of the multiple wedge-shaped portions 111, a separate stator holder or the like is not required.

[0020] In addition, the oil passages of a typical motor case are such that the lubricating oil flows only in the circumferential direction, so that the heat transfer from the stator to the motor case is limited. On the other hand, in the motor case according to the embodiment, the lubricating oil flows alternately in the radial and circumferential directions in the oil passage 12 and collides with the side surface of the wedge-shaped portion 111, the outer periphery of the stator 2, and the surface of the corrugated portion 112. This promotes the heat transfer from the stator 2 to the motor case 1.

[0021] In addition, in the motor case of the embodiment, the large surface area of ​​the corrugated portion 112 promotes heat transfer between the lubricating oil and the case inner wall 11, thereby promoting heat transfer from the stator 2 to the case inner wall 11 and air cooling via the motor case 1.

[0022] (Modification) A modified example of the motor case according to the embodiment of the present disclosure will be described with reference to Fig. 2. A motor case 1A according to this modified example includes a case inner wall 11, an oil passage 12, and a plurality of air-cooling fins 13. The configurations of the case inner wall 11 and the oil passage 12 are similar to those of the motor case 1 (see Fig. 1) described above, and therefore description thereof will be omitted.

[0023] The multiple air-cooling fins 13 are provided on the outer periphery of the motor case 1A. That is, the multiple air-cooling fins 13 are provided lined up in the circumferential direction of the stator 2. The multiple air-cooling fins 13 are also provided at predetermined intervals in the circumferential direction of the stator 2.

[0024] In this manner, by providing the motor case 1A with a plurality of air-cooling fins 13, air cooling via the motor case 1A is further promoted.

[0025] According to the motor case of the embodiment described above, the oil passage 12 is serpentine, which causes the flow of lubricating oil to be disturbed and stirred within the oil passage 12, thereby promoting heat transfer from the motor (stator 2) to the motor case 1.

[0026] In addition, in the motor case according to the embodiment, oil passage 12 consisting of a wide gap is provided between wedge-shaped portion 111 and corrugated portion 112, and lubricating oil flows at a large volume and high speed. As a result, a turbulent high-speed flow directly collides with the outer periphery of stator 2 (see part A in FIG. 1) which forms part of oil passage 12, promoting heat transfer from stator 2 to motor case 1.

[0027] Furthermore, in the motor case according to the embodiment, the lubricating oil that has received heat from the motor (stator 2) and become hot is sent to the outside of the motor case 1 and cooled, for example, by an external oil cooler (water-cooled or air-cooled). This eliminates the need for a water jacket around the motor case 1, simplifying the structure and enabling miniaturization and cost reduction.

[0028] Further advantages and modifications may readily occur to those skilled in the art. Thus, the invention in its broader aspects is not limited to the specific details and representative embodiments shown and described above. Accordingly, various modifications may be made without departing from the spirit or scope of the general inventive concept as defined by the appended claims and equivalents thereof. [Explanation of symbols]

[0029] 1,1A motor case 11 Case inner wall 111 Wedge-shaped part 112 Wave part 12 Oil road 13 Air cooling fin 2 Stator

Claims

[Claim 1] The inner wall of the case, an oil passage provided in an inner wall of the case through which lubricating oil flows; Equipped with The case inner wall is A plurality of wedge-shaped portions arranged in a circumferential direction of the stator and supporting an outer periphery of the stator; a corrugated portion disposed radially outward of the stator with respect to the plurality of wedge-shaped portions and disposed around the plurality of wedge-shaped portions; Equipped with The oil passage is provided between the plurality of wedge-shaped portions and the corrugated portion, and meanders so that the lubricating oil flows in the radial and circumferential directions of the stator. Motor case.

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