Rotating electric machine

Abstract

To provide a technology that enables sealing between the stator and the fixed part with a simple configuration. [Solution] A rotating electric machine is constructed comprising: a housing having a fixed part having screw holes and a fixed part side refrigerant passage which is a flow path for refrigerant; an annular stator fixed to the fixed part, having a stator core having a bolt insertion hole formed through the stator in the axial direction; and a bolt inserted into the bolt insertion hole, the tip of which is inserted into the screw hole, thereby fixing the contact portion of the bolt insertion hole, including the opening on the fixed part side, to the fixed part by surface contact; wherein a supply port corresponding to the opening of the fixed part side refrigerant passage is formed in the contact portion within the distribution range of surface pressure due to the fastening of the bolt, and a stator side refrigerant passage which is a flow path for refrigerant extending axially from the supply port is formed in the stator core.

Description

Technical Field

[0001] The present invention relates to a rotating electric machine.

Background Art

[0002] Conventionally, a stator is used in a state of being fixed to a fixed part such as a housing. As a configuration for fixing the stator to the fixed part, fixing by bolts is known. For example, in Patent Document 1, bolt fixing projections protruding radially outward are formed at three positions on the radially outer surface of the stator core. In this configuration, a refrigerant flow path projection protruding radially outward is formed at one other position than the projection. Then, the refrigerant passing through the refrigerant path of the fixed part is supplied to the stator through the projection for the refrigerant flow path.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the above-described conventional technology, the bolt fixing projection and the refrigerant flow path projection are formed at different positions. Therefore, when the stator is fastened to the fixed part by bolts, the surface pressure acting between the bolt fixing projection and the fixed part does not act on the refrigerant flow path projection. Therefore, it is impossible to seal between the stator and the refrigerant flow path projection with the axial force of the bolt, and it is necessary to use another member, for example, a sealing material.

[0005] The present invention has been made in view of the above problems, and an object thereof is to provide a technique capable of sealing between a stator and a fixed part with a simple configuration.

Means for Solving the Problems

[0006] A stator according to one embodiment is an annular stator fixed to a fixed part having screw holes and a fixed part-side refrigerant passage which is a flow path for refrigerant, and comprises a stator core having a bolt insertion hole formed through the stator in the axial direction, and a bolt that is inserted into the bolt insertion hole and whose tip is inserted into the screw hole so that the contact portion of the bolt insertion hole, including the opening on the fixed part side, is in surface contact with the fixed part to fix it, and a supply port corresponding to the opening of the fixed part-side refrigerant passage is formed in the contact portion within the distribution range of surface pressure due to the fastening of the bolt, and a stator-side refrigerant passage which is a flow path for refrigerant extending in the axial direction from the supply port is formed in the stator core.

[0007] In other words, in the stator, refrigerant is supplied from the refrigerant passage on the fixed part side formed in the fixed part, through the supply port to the stator-side refrigerant passage. Therefore, there is a possibility of refrigerant leakage at the contact point where the fixed part and the stator meet. To address this, the supply port is configured to be located within the distribution range of surface pressure caused by bolt fastening, and the surface pressure caused by bolt fastening acts on the supply port, sealing the space between the supply port and the refrigerant passage on the fixed part side. This configuration reduces the possibility of leakage occurring at the contact point due to bolt fastening, making it possible to seal the space between the stator and the fixed part with a simple configuration. [Brief explanation of the drawing]

[0008] [Figure 1] This is a perspective view of the stator core. [Figure 2] This is an exploded perspective view of the stator core. [Figure 3] This diagram shows the first core as viewed along the axial direction. [Figure 4] This figure shows the second core as viewed along the axial direction. [Figure 5] This figure shows the state in which the first circumferential refrigerant passage is superimposed on the second core, viewed along the axial direction. [Figure 6] This diagram shows the third core as viewed along the axial direction. [Figure 7]This figure shows the state in which the first circumferential refrigerant passage is superimposed on the third core, viewed along the axial direction. [Figure 8] This is a perspective view showing only the refrigerant passages. [Figure 9] This diagram shows the stator core with the bolts inserted. [Figure 10] This is a cross-sectional view of the stator core and the fixed part. [Figure 11] This diagram shows the distribution of surface pressure generated by a bolt. [Figure 12] This diagram shows the first core as viewed along the axial direction. [Figure 13] This is a cross-sectional view of the stator core and the fixed part. [Figure 14] This diagram shows the third core as viewed along the axial direction. [Modes for carrying out the invention]

[0009] Here, embodiments of the present invention will be described in the following order. (1) Stator core configuration: (1-1) Configuration of the first core: (1-2) Configuration of the second core: (1-3) Configuration of the third core: (1-4) Connection to the fixed part: (2) Other embodiments, etc.:

[0010] (1) Stator core configuration: Figure 1 is a perspective view of the stator core 100 constituting the stator 1 according to this embodiment, and Figure 2 is an exploded perspective view of the stator core 100. The stator core 100 is an annular member, and in Figures 1 and 2, the central axis Ax of the ring formed by the stator core 100 is indicated by a dashed line. Figure 2 shows the stator core 100 in an exploded state in the direction of the central axis Ax.

[0011] Inside the ring formed by the stator core 100, a rotor (not shown) is disposed. The rotor is a member that rotates about the central axis Ax of the ring formed by the stator core 100 as the rotation axis. In this specification, the direction parallel to the central axis Ax is referred to as the axial direction, the direction perpendicular to the central axis Ax is referred to as the radial direction, and the rotational direction about the central axis Ax is referred to as the circumferential direction. Also, in the radial direction, the direction away from the central axis Ax is referred to as the outer radial direction, and the direction approaching the central axis Ax is referred to as the inner radial direction.

[0012] The stator core 100 has a plurality of teeth 40 arranged in the circumferential direction and a plurality of slots 41 formed between the teeth 40 in the circumferential direction. In the present embodiment, the teeth 40 are portions that protrude radially inward from the radially inner surface of the stator core 100. The teeth 40 are formed at regular intervals in the circumferential direction over the entire inner circumference of the stator core 100. The number of teeth 40 may be various numbers. In the present embodiment, the cross-sectional shape of the teeth 40 in the direction perpendicular to the axial direction is the same at any position in the axial direction. Therefore, the teeth 40 are portions that protrude from the outer radial direction toward the inner radial direction in the radial direction and extend in the axial direction while having the same cross-sectional shape in the direction perpendicular to the axial direction.

[0013] The space formed between the teeth 40 in the circumferential direction is the slot 41. A coil (not shown) is disposed in the slot 41.

[0014] In the present embodiment, the stator core 100 is composed of a first core 10, a second core 20, and a third core 30. The first core 10 and the second core 20 are present in the central portion in the axial direction, and in the present embodiment, the boundary line between the first core 10 and the second core 20 is located at the center in the axial direction. The first core 10 and the second core 20 are sandwiched by the third core 30. That is, the first core 10 and the second core 20 are in contact with each other on one surface perpendicular to the axial direction and are in contact with the third core 30 on the other surface.

[0015] In this embodiment, the stator core 100 is provided with protrusions 100a that project radially outward from the radially outer surface of the annular portion. In this embodiment, the protrusions 100a are formed at three locations on the stator core 100, and their distances in the circumferential direction are equal. That is, each protrusion 100a is positioned at a distance of 120° from each other with respect to the central axis Ax.

[0016] The protrusion 100a has a circumferential distance on the radially inner side that is longer than the circumferential distance on the radially outer side, and is approximately trapezoidal in shape when viewed along the axial direction. In this embodiment, the first core 10, the second core 20, and the third core 30 all have protrusions 10a, 20a, and 30a with the same radially outer circumference shape. That is, the protrusion 100a is formed by the overlapping of the protrusions 10a, 20a, and 30a in the circumferential direction.

[0017] The outer circumferential shapes of the protrusions 10a, 20a, and 30a are identical, but their inner structures differ from each other. The stator core 100 is fixed to a fixed part, which will be described later. A fixed part-side refrigerant passage, described later, is formed in the fixed part, and the stator core 100 is cooled by the refrigerant supplied from this fixed part-side refrigerant passage. The first core 10, the second core 20, and the third core 30 will be described in detail below.

[0018] (1-1) Configuration of the first core: Next, the configuration of the first core 10 will be described. In this embodiment, the first core 10 is constructed by laminating electrical steel sheets of a certain thickness. Figure 3 is a diagram showing the electrical steel sheets constituting the first core 10 as viewed along a direction parallel to the central axis Ax. The first core 10 has a refrigerant passage for flowing the refrigerant in the axial direction and a refrigerant passage for flowing in the circumferential direction. In this embodiment, the first core 10 has a plurality of first circumferential refrigerant passages 11 formed at intervals of a certain distance in the circumferential direction. The first circumferential refrigerant passages 11 are refrigerant flow paths that extend in the circumferential direction with a radial length that is substantially constant.

[0019] Furthermore, in the first core 10, a plurality of first circumferential refrigerant passages 11 are formed at positions radially outward from the teeth 40. As shown in Figure 3, the first circumferential refrigerant passages 11 are formed at six locations in the first core 10. In this embodiment, the sum of the lengths of the plurality of first circumferential refrigerant passages 11 in the circumferential direction is longer than half of the total circumferential length. In addition, the first circumferential refrigerant passages 11 penetrate the first core 10 in the axial direction.

[0020] In this embodiment, the first core 10 has a plurality of axial refrigerant passages 13 formed on the radially outer side of the teeth 40. Specifically, a substantially rectangular hole is formed on the radially outer side of the teeth 40, radially inward from the first circumferential refrigerant passage 11, with the radial direction being the longer side and the circumferential direction being the shorter side, constituting the axial refrigerant passage 13. The axial refrigerant passage 13 is a substantially rectangular hole and has the same shape at any position in the axial direction. That is, the axial refrigerant passage 13 is a refrigerant passage with the same cross-sectional shape extending in the axial direction. The axial refrigerant passage 13 is connected to the axial refrigerant passage 31 of the third core 30, which will be described later.

[0021] In this embodiment, a plurality of connecting portions 12 are formed on the radially inner wall surface of the first circumferential refrigerant passage 11. The connecting portions 12 are radially extending holes, and four are formed for each of the first circumferential refrigerant passages 11. In this embodiment, the connecting portions 12 are portions that narrow in stages toward the radially inward direction, with the radially outer portion connected to the first circumferential refrigerant passage 11 and the radially inner portion connected to the axial refrigerant passage 31 of the third core 30, which will be described later. That is, the radially inner portion of the connecting portion 12 has a shape that overlaps with the axial refrigerant passage 31 when viewed along the axial direction.

[0022] A bolt insertion hole 14 is formed in the protruding portion 10a. This bolt insertion hole 14 constitutes a part of the bolt insertion hole that penetrates the stator 1 in the axial direction. The bolt insertion hole 14 is a circular hole that penetrates the first core 10. Screw threads may or may not be formed in the bolt insertion hole 14.

[0023] A radial refrigerant passage 15, which is a refrigerant flow path extending in the radial direction, is formed in one of the protruding portions 10a. The radial refrigerant passage 15 is a hole formed radially outward from the teeth 40 and the axial refrigerant passage 13, extending from the protruding portion 10a to the annular portion of the first core 10.

[0024] The radial refrigerant passage 15 has a shape obtained by combining a rectangle and a circle when viewed along a direction parallel to the central axis Ax. Specifically, on the radially inner side, there is a rectangular hole whose short side is approximately parallel to the circumferential direction and whose long side is approximately parallel to the radial direction, and a semicircular hole exists on the radially outer side of this rectangle, thereby forming the radial refrigerant passage 15. The radial refrigerant passage 15 is a hole that penetrates the first core 10 in the axial direction.

[0025] The radially inner portion 15a of the radial refrigerant passage 15 is located between the first circumferential refrigerant passages 11 in the circumferential direction. This portion between the first circumferential refrigerant passages 11 is the portion where the second circumferential refrigerant passage 21, formed in the second core 20 (described later), exists. Therefore, when the first core 10 and the second core 20 are in contact, portion 15a of the radial refrigerant passage 15 is connected to the second circumferential refrigerant passage 21. In other words, the radial refrigerant passage 15 is connected to the circumferential refrigerant passage formed in the stator core 100.

[0026] The radially outer portion 15b of the radial refrigerant passage 15 is formed at a position corresponding to the stator-side refrigerant passage 36, which will be described later. Therefore, when the first core 10 and the third core 30 are in contact, the radial refrigerant passage 15 on its radially outer side is connected to the stator-side refrigerant passage 36 formed in the third core 30 that constitutes the stator core 100.

[0027] In this embodiment, a radial refrigerant passage 15 is formed in one of the three protrusions 10a, but not in the other two protrusions 10a. In the other two protrusions 10a, a circular hole 16 is formed at a position corresponding to the stator-side refrigerant passage 36. The hole 16 does not extend radially inward and does not reach the portion between the first circumferential refrigerant passages 11 in the circumferential direction. Therefore, the hole 16 is not connected to the second circumferential refrigerant passage 21.

[0028] As described above, in the first core 10 according to this embodiment, of the radial refrigerant passages 15 and two holes 16 formed in the three protrusions 10a, only the radial refrigerant passage 15 is connected to the stator-side refrigerant passage 36 and the second circumferential refrigerant passage 21. The two holes 16 are connected to the stator-side refrigerant passage 36 but not to the second circumferential refrigerant passage 21. The second core 20 and third core 30, which will be described later, do not have a structure like the radial refrigerant passage 15. Therefore, in this embodiment, the radial refrigerant passage 15 is connected to the stator-side refrigerant passage 36 and the second circumferential refrigerant passage 21 at one location in the stator core 100.

[0029] (1-2) Configuration of the second core: Next, the configuration of the second core 20 will be described. In this embodiment, the second core 20 is constructed by laminating electrical steel sheets of a certain thickness. Figure 4 is a diagram showing the electrical steel sheets constituting the second core 20 as viewed along a direction parallel to the central axis Ax. The second core 20 has a refrigerant passage for flowing the refrigerant in the axial direction and a refrigerant passage for flowing in the circumferential direction. In this embodiment, the second core 20 has a plurality of second circumferential refrigerant passages 21 formed at intervals of a certain distance in the circumferential direction. The second circumferential refrigerant passages 21 are refrigerant flow paths that extend in the circumferential direction with a radial length that is substantially constant.

[0030] Furthermore, in the second core 20, a plurality of second circumferential refrigerant passages 21 are formed at positions radially outward from the teeth 40. As shown in Figure 4, the second circumferential refrigerant passages 21 are formed at six locations in the second core 20. In this embodiment, the sum of the lengths of the plurality of second circumferential refrigerant passages 21 in the circumferential direction is longer than half of the total circumferential length. In addition, the second circumferential refrigerant passages 21 penetrate the second core 20 in the axial direction.

[0031] In this embodiment, the circumferential length of the first circumferential refrigerant passage 11 and the circumferential length of the second circumferential refrigerant passage 21 are the same. Furthermore, the circumferential position of the first circumferential refrigerant passage 11 is set such that when the first core 10 and the second core 20 are in contact, each end of the first circumferential refrigerant passage 11 overlaps in the circumferential direction with each of the adjacent second circumferential refrigerant passages 21.

[0032] Figure 5 shows a state in which the first circumferential refrigerant path 11 and the second circumferential refrigerant path 21 overlap, with the solid line representing the second core 20. Furthermore, in Figure 5, the position of the first circumferential refrigerant path 11 is shown by a dashed line. That is, the position of the first circumferential refrigerant path 11 when the first core 10 and the second core 20 are in contact is shown by a dashed line. As shown in Figure 5, at one end in the circumferential direction, the first circumferential refrigerant path 11 overlaps with the second circumferential refrigerant path 21 in region OL1. At the other end in the circumferential direction, the first circumferential refrigerant path 11 overlaps with the second circumferential refrigerant path 21 in region OL2. With the above configuration, the first circumferential refrigerant path 11 and the second circumferential refrigerant path are alternately continuous in the circumferential direction, forming a series of refrigerant paths connected over the entire circumference in the circumferential direction.

[0033] In this embodiment, the second core 20 has a plurality of axial refrigerant passages 23 formed on the radially outer side of the teeth 40 (see Figure 4). Specifically, a substantially rectangular hole is formed on the radially outer side of the teeth 40, radially inward from the second circumferential refrigerant passage 21, with the longer side in the radial direction and the shorter side in the circumferential direction, constituting the axial refrigerant passage 23. The axial refrigerant passage 23 is a substantially rectangular hole and has the same shape at any position in the axial direction. That is, the axial refrigerant passage 23 is a refrigerant passage with the same cross-sectional shape extending in the axial direction. The axial refrigerant passage 23 is connected to the axial refrigerant passage 31 of the third core 30, which will be described later.

[0034] In this embodiment, a plurality of connecting portions 22 are formed on the radially inner wall surface of the second circumferential refrigerant passage 21. The connecting portions 22 are radially extending holes, and four are formed for each of the second circumferential refrigerant passages 21. In this embodiment, the connecting portions 22 are portions that narrow in stages toward the radially inward direction, with the radially outer portion connected to the second circumferential refrigerant passage 21 and the radially inner portion connected to the axial refrigerant passage 31 of the third core 30, which will be described later. That is, the radially inner portion of the connecting portion 22 has a shape that overlaps with the axial refrigerant passage 31 when viewed along the axial direction.

[0035] A bolt insertion hole 24 is formed in the protruding portion 20a. This bolt insertion hole 24 constitutes a part of the bolt insertion hole that penetrates the stator 1 in the axial direction. The bolt insertion hole 24 is a circular hole that penetrates the second core 20. Screw threads may or may not be formed in the bolt insertion hole 24. In the protruding portion 20a of the second core 20, there is no radial refrigerant flow path like the radial refrigerant passage 15 formed in the first core 10. That is, in the clockwise direction of the circumferential direction in Figure 4, there is no radial refrigerant passage formed in the part adjacent to the bolt insertion hole 24, and therefore no hole is formed there.

[0036] (1-3) Configuration of the third core: Next, the configuration of the third core 30 will be described. In this embodiment, the third core 30 is constructed by laminating electromagnetic steel sheets of a certain thickness. Figure 6 is a diagram showing the electromagnetic steel sheets constituting the third core 30 as viewed along a direction parallel to the central axis Ax. A bolt insertion hole 34 is formed in the protruding portion 30a. This bolt insertion hole 34 constitutes a part of the bolt insertion hole that penetrates the stator 1 in the axial direction. The bolt insertion hole 34 is a circular hole that penetrates the third core 30. Screw threads may or may not be formed in the bolt insertion hole 34.

[0037] Each of the protruding portions 30a has a stator-side refrigerant passage 36 formed therein, which is a refrigerant flow path extending in the axial direction. In this embodiment, the stator-side refrigerant passage 36 is formed in all three protruding portions 30a, and the opening that opens at the end opposite the first core 10 in the axial direction becomes a refrigerant supply port. The stator-side refrigerant passage 36 has a supply port that is connected to the fixed-part-side refrigerant passage of the fixed part, which will be described later, and the refrigerant is supplied from the fixed-part-side refrigerant passage to form a refrigerant flow path.

[0038] Of the stator-side refrigerant passages 36 formed in the three protrusions 30a, the stator-side refrigerant passages 36 to which the fixed-part-side refrigerant passage is not connected do not become refrigerant flow paths. In this embodiment, a radial refrigerant passage 15 is formed in one of the protrusions 10a of the first core 10, while the other two do not have radial refrigerant passages 15 and instead have holes 16. Furthermore, in the protrusions 20a of the second core 20, no holes are formed at positions corresponding to the stator-side refrigerant passages 36 and holes 16. Therefore, among the stator-side refrigerant passages 36, the stator-side refrigerant passage 36a (see Figure 2) corresponding to the position where the radial refrigerant passage 15 is formed is connected to the second circumferential refrigerant passage 21 via the radial refrigerant passage 15. On the other hand, the stator-side refrigerant passage 36b corresponding to the position where the radial refrigerant passage 15 is not formed is not connected to the second circumferential refrigerant passage 21 or the first circumferential refrigerant passage 11.

[0039] Because the above configuration is adopted, in this embodiment, the supply port of the stator-side refrigerant passage 36a corresponding to the position where the radial refrigerant passage 15 is formed among the stator-side refrigerant passages 36 is connected to the fixed-part-side refrigerant passage of the fixed part. Thus, in this embodiment, the stator-side refrigerant passage 36 is formed in all three protrusions 30a, and only one of them is used. However, if it is formed in all three protrusions 30a, the third core 30 can be used at any of the rotational positions obtained by rotating the third core 30 by 120° around the central axis Ax.

[0040] Furthermore, in the third core 30, a plurality of axial refrigerant passages 31 are formed at positions radially outward of the teeth 40. Specifically, a substantially rectangular hole is formed radially outward of the teeth 40, radially inward of the first circumferential refrigerant passage 11 and the second circumferential refrigerant passage 21, with the longer side being radial and the shorter side being circumferential, thus constituting the axial refrigerant passage 31.

[0041] The axial refrigerant passages 31 are substantially rectangular holes and have the same shape at any position in the axial direction. That is, the axial refrigerant passages 31 are refrigerant passages with the same cross-sectional shape extending in the axial direction. Furthermore, in this embodiment, the axial refrigerant passages 31 are formed at positions corresponding to each tooth 40. Therefore, the number of axial refrigerant passages 31 present in the circumferential direction is the same as the number of teeth 40. With this configuration, each of the teeth 40 can be cooled by the refrigerant flowing inside each of the axial refrigerant passages 31.

[0042] A portion of the axial refrigerant passage 31 is located radially and circumferentially at the same position as the axial refrigerant passage 13 formed in the first core 10 and the axial refrigerant passage 23 formed in the second core 20. Another portion of the axial refrigerant passage 31 is located radially and circumferentially at the same position as the radially inner portion of the connecting portion 12 formed in the first core 10 and the radially inner portion of the connecting portion 22 formed in the second core 20. Therefore, the extension of the axial refrigerant passage 31 forms a hole that penetrates the stator core 100 in the axial direction.

[0043] Figure 7 shows the state in which the first circumferential refrigerant passage 11 is superimposed on the third core 30 shown in Figure 6. As shown in Figure 7, the axial refrigerant passage 31 is connected in the axial direction to the connecting portion 12 of the first core 10. Therefore, the refrigerant flowing through the first circumferential refrigerant passage 11 flows in the axial direction through the axial refrigerant passage 31. As shown in Figure 1, the axial refrigerant passage 31 has an opening at its axial end. Therefore, the refrigerant that reaches the opening through the axial refrigerant passage 31 is discharged from the opening. Similarly, the axial refrigerant passage 31 is connected in the axial direction to the connecting portion 22 of the second core 20.

[0044] With the above configuration, a refrigerant passage is formed that reaches from the supply port to the discharge port. Figure 8 shows the shape of the space that forms the refrigerant passage. Specifically, in the stator-side refrigerant passage 36a corresponding to the position where the radial refrigerant passage 15 is formed, the opening on the opposite side of the radial refrigerant passage 15 becomes the refrigerant supply port, and the radial refrigerant passage 15 is connected to the stator-side refrigerant passage 36a connected to the supply port at the axial center of the stator core 100. A second circumferential refrigerant passage 21 is connected to the radial refrigerant passage 15, and the first circumferential refrigerant passages 11 are connected to both circumferential ends of the second circumferential refrigerant passage 21. In addition, a second circumferential refrigerant passage 21 is connected to both circumferential ends of each first circumferential refrigerant passage 11, and a first circumferential refrigerant passage 11 is connected to both circumferential ends of each second circumferential refrigerant passage 21. Furthermore, multiple axial refrigerant passages 31 are connected to each of the first circumferential refrigerant passage 11 and the second circumferential refrigerant passage 21.

[0045] With the above configuration, it can be seen that the refrigerant supplied from the supply port flows axially through the stator-side refrigerant passage 36a, flows radially through the radial refrigerant passage 15, flows further through the circumferentially extending refrigerant passages formed by the first circumferential refrigerant passage 11 and the second circumferential refrigerant passage 21, flows toward both ends in the axial direction through the axial refrigerant passage 31, and is discharged from the axial refrigerant passage 31 at the axial ends. In Figure 8, it is shown that at the axial center, the radial refrigerant passage 15 does not exist at the end of the stator-side refrigerant passage 36b, and is closed by the protrusion 20a of the second core 20.

[0046] (1-4) Connection to the fixed part: In this embodiment, the first core 10, second core 20, and third core 30, as described above, are connected and fastened to the fixing part in a state that constitutes the stator core 100. That is, the fixing part is located on the lower left side of Figures 1 and 2, and the stator core 100 and the fixing part are fastened together with bolts.

[0047] Specifically, the bolt insertion holes 14 of the first core 10, 24 of the second core 20, and 34 of the third core 30 are holes of the same diameter and are formed at the same positions on the protrusions 10a, 20a, and 30a, respectively. Therefore, when the first core 10 and the second core 20 are in contact and sandwiched between the third core 30 from both axial sides, the bolt insertion holes 14, 24, and 34 become holes that penetrate the stator core 100 in the axial direction.

[0048] The fixing part is then fastened by inserting a bolt 50 from the upper right side in Figures 1 and 2 into the bolt insertion hole formed by bolt insertion hole 14, bolt insertion hole 24, and bolt insertion hole 34. In other words, the axial length of the bolt 50 is longer than the axial length of the stator core 100, and a threaded portion is formed at the axial end of the bolt 50.

[0049] Figure 9 shows the stator core 100 on the side where the bolt 50 is inserted, viewed along the axial direction. As shown in Figure 9, the bolt 50 is inserted into each of the bolt insertion holes formed in each of the protrusions 100a of the stator core 100. Figure 10 is a cross-sectional view along line AA shown in Figure 9. The cross-sectional view is shown in a continuous manner for each of the ranges (1), (2), and (3) shown in Figure 9.

[0050] A fixing portion 60 is fastened to the tip of the bolt 50 in the axial direction. The fixing portion 60 is an annular member, and at least the portion in contact with the protruding portion 30a is flat. However, the fixing portion 60 only needs to be able to fasten the stator core 100, and its shape is not limited. The fixing portion 60 has a screw hole 61 and a fixing portion side coolant passage 62 formed therein. The fixing portion 60 is part of the housing to which the stator 1 of the rotating electric machine is fixed. The shape of the housing is not limited, and it may be a case that houses the rotating electric machine, or a housing that covers at least a part of the rotating electric machine, and various configurations can be adopted. The housing may be part or all of the component to which the rotating electric machine is fixed.

[0051] The screw hole 61 is formed at a position corresponding to the bolt insertion hole 34 of the protruding portion 30a. That is, the screw hole 61 is located on the extension of the bolt insertion hole formed in the protruding portion 100a of the stator core 100. A screw groove is also formed in the screw hole 61. The threaded tip of the bolt 50 can be inserted into the screw hole 61. With this configuration, as shown in Figure 9, the stator core 100 can be fastened to the fixing portion 60 by inserting three bolts 50 into the three bolt insertion holes and inserting the tip of each bolt 50 into the screw hole 61 of the fixing portion 60.

[0052] The fixed-part side refrigerant passage 62 is a circular hole extending in the axial direction, and its cross-sectional shape perpendicular to the axial direction is the same at each position in the axial direction. That is, the fixed-part side refrigerant passage 62 is a hole that extends in the axial direction while maintaining the same hole shape. Furthermore, the shape of this circle is the same as the shape of the circle that constitutes the opening of the stator-side refrigerant passage 36. The fixed-part side refrigerant passage 62 is formed at a position corresponding to the stator-side refrigerant passage 36. That is, the fixed-part side refrigerant passage 62 is formed in the protruding portion 30a of the third core 30 and is located on the extension line of the stator-side refrigerant passage 36. Refrigerant is supplied to the fixed-part side refrigerant passage 62 from a supply source not shown. Therefore, the refrigerant supplied to the fixed-part side refrigerant passage 62 passes through the stator-side refrigerant passage 36a to the central part of the stator core 100, and further passes through the radial refrigerant passage 15, through the inside of the first circumferential refrigerant passage 11 and the second circumferential refrigerant passage 21, and through the inside of the axial refrigerant passage 31 to cool the stator core 100.

[0053] In this embodiment, the portion where the protruding portion 30a and the fixed portion 60 come into contact is a flat surface, and the two are in surface contact. Here, the surface where the protruding portion 30a and the fixed portion 60 come into contact is called the contact portion 37. In this embodiment, the entire surface of the protruding portion 30a at the axial end, that is, all portions of the part that protrudes radially from the outer circumference of the stator core 100, becomes the contact portion 37 and comes into contact with the fixed portion 60. Therefore, in this embodiment, both the opening of the bolt insertion hole on the fixed portion 60 side and the opening (supply port) of the stator-side refrigerant passage 36 on the fixed portion 60 side are included in the contact portion 37.

[0054] As described above, in this embodiment, the refrigerant supply port, which is the opening on the fixing portion 60 side of the stator-side refrigerant passage 36, is formed in the protruding portion 30a. Furthermore, the stator core 100 is fixed to the fixing portion 60 by bolts 50 that are inserted through bolt insertion holes formed in the protruding portion 30a. With this configuration, in this embodiment, the possibility of refrigerant leakage from between the fixing portion 60 and the stator core 100 can be reduced. Since refrigerant leakage is prevented or reduced, the decrease in the amount of refrigerant used to cool the stator core 100 is prevented or reduced, and thus cooling can be performed efficiently.

[0055] In other words, when the stator core 100 is fastened to the fixing part 60 by the bolt 50, the surface pressure from the bolt acts on the contact area 37 between the stator core 100 and the fixing part 60, allowing them to make firm contact. This reduces the possibility of refrigerant leakage from between the fixing part 60 and the stator core 100. Furthermore, since the contact at the contact area 37 is surface contact, it is possible to prevent refrigerant leakage across the entire contact area 37 compared to when it is supported by multiple point contacts.

[0056] Furthermore, in this embodiment, the contact portion 37 has a supply port corresponding to the opening of the fixed portion side refrigerant passage 62, which is within the distribution range of the surface pressure caused by the fastening of the bolt 50. That is, in the contact portion 37, the supply port, which is the opening of the stator side refrigerant passage 36, is located within the distribution range of the surface pressure caused by the fastening of the bolt 50.

[0057] Figure 11 schematically shows the simulated surface pressure (MPa) acting on the contact area 37 and its surroundings when the stator core 100 is fastened to the fixing part 60 by bolts 50. In Figure 11, the intensity of the gray indicates the magnitude of the surface pressure. The white areas are where the surface pressure can be considered to be zero. As shown in Figure 11, the contact area 37 includes the maximum surface pressure portion due to the bolts 50 in the bolt insertion hole 34 and the opening of the stator-side refrigerant passage 36, and the maximum surface pressure obtained by the bolts 50 is acting there. Therefore, the possibility of refrigerant leakage from between the fixing part 60 and the stator core 100 can be reduced.

[0058] Furthermore, Figure 11 shows that the contact pressure acting on the contact portion 37 is not zero due to fastening with bolts 50. When the range in which the contact pressure is not zero is defined as the range of contact pressure distribution, locating the supply port, which is the opening of the stator-side refrigerant passage 36, within the range of contact pressure distribution reduces the possibility of refrigerant leakage from between the fixed portion 60 and the stator core 100. In other words, as long as the contact portion 37 is within the range of the protruding portion 30a, which is the part of the stator core 100 that protrudes from the circular outer surface in the radial direction, the possibility of refrigerant leakage from between the fixed portion 60 and the stator core 100 can be reduced.

[0059] Furthermore, in this embodiment, each of the first core 10, second core 20, and third core 30 constituting the stator core 100 is formed by laminating electromagnetic steel sheets in the axial direction. In the third core 30, the bolt insertion hole 34, the stator-side refrigerant passage 36, and the protruding portion 30a have rotational symmetry with respect to the central axis Ax.

[0060] In the example shown in Figure 6, three protrusions 30a are formed, and each protrusion 30a is formed at a position 120° apart in the circumferential direction in the rotational direction around the central axis Ax. Furthermore, the shape of each protrusion 30a is the same, and the positions of the bolt insertion holes 34 and stator-side refrigerant passages 36 formed in each protrusion 30a are also the same. For example, the relative positional relationship between each position of the line constituting the outer circumference of the protrusion 30a and the bolt insertion holes 34 and stator-side refrigerant passages 36 is the same for all protrusions 30a. Therefore, in the example shown in Figure 6, there is 3-fold rotational symmetry with respect to the central axis Ax. Consequently, in the example shown in Figure 6, when the third core 30 is rotated by 120° increments with respect to the central axis Ax, the third core 30 before rotation and the third core after rotation coincide. With this configuration, the third core 30 can be used in any of the orientations shown in Figure 6, or in orientations rotated by 120° or 240° from the orientation shown in Figure 6.

[0061] Each electrical steel sheet constituting the third core 30 is manufactured, for example, by punching out a roll of electrical steel sheet with a die. In a roll of electrical steel sheet, microscopically, the thickness may vary at different positions along the width of the roll, and there may be biases in the direction of magnetization. However, by performing a roll stacking process while rotating each electrical steel sheet, the third core 30 can be manufactured with reduced thickness and magnetization biases. Similarly, the second core 20 can also be manufactured using the same roll stacking process.

[0062] (2) Other embodiments, etc.: The embodiments described above are merely examples for carrying out the present invention, and various other embodiments can be adopted. For example, the axial refrigerant passage 31 is not limited to a configuration in which it is formed inside the stator core 100, but may also be configured in which the refrigerant flows through a slot, that is, a configuration in which the slot also serves as the axial refrigerant passage 31.

[0063] Furthermore, the number, size, and shape of the radial refrigerant passages 15, stator-side refrigerant passages 36, and protrusions 100a may differ from those of the embodiments described above. For example, the stator-side refrigerant passage 36 may be formed in one of the three protrusions 30a. Moreover, the radial refrigerant passages 15 may be formed in two or more locations.

[0064] Figure 12 shows an example configuration in which radial refrigerant passages 15 are formed in all of the multiple protrusions 10a of the first core 10. In Figure 12, components similar to those shown in Figure 3 are denoted by the same reference numerals. In the first core 10 shown in Figure 12, radial refrigerant passages 15 are formed in all of the multiple protrusions 10a, and the relative positional relationship between the protrusions 10a and the radial refrigerant passages 15 is the same in all of the radial refrigerant passages 15. Therefore, with this configuration, the first core 10 can be manufactured while rolling electrical steel sheets.

[0065] In this configuration, each radial refrigerant passage 15 is located at a position where it is connected to the stator-side refrigerant passage 36 of the third core 30. In the example shown in Figure 12, one of the radial refrigerant passages 15 is connected to the fixed-part-side refrigerant passage 62 via the stator-side refrigerant passage 36, and in the other radial refrigerant passage 15, at least one of the radial refrigerant passage 15 and the stator-side refrigerant passage 36 is blocked.

[0066] For example, when the stator-side refrigerant passage 36a shown in Figure 2 is connected to the fixed-part-side refrigerant passage 62 of the fixed-part 60, the radial refrigerant passage 15 connected to the stator-side refrigerant passage 36a is not blocked. On the other hand, at least one of the stator-side refrigerant passage 36b and the radial refrigerant passage 15 corresponding to the stator-side refrigerant passage 36b is blocked, preventing refrigerant from flowing. Various configurations can be used to block the stator-side refrigerant passage 36b and the radial refrigerant passage 15 corresponding to the stator-side refrigerant passage 36b. For example, the fixed-part 60 may not have a fixed-part-side refrigerant passage 62, thus blocking it, or any structure may be fitted into the refrigerant passage. With this configuration, the refrigerant supplied from the fixed-part-side refrigerant passage 62 to the stator-side refrigerant passage 36a will not leak out through the stator-side refrigerant passage 36b. As a result, refrigerant can be circulated through the circumferential refrigerant passages, which consist of the first circumferential refrigerant passage 11 and the second circumferential refrigerant passage 21, and the axial refrigerant passage 31, thereby cooling the stator core 100.

[0067] Furthermore, the contact portion 37 may have a configuration to prevent refrigerant leakage. For example, a configuration may be adopted in which a sealing material 63 is placed around the supply port, which is the opening of the refrigerant passage 62 on the fixed portion side and the opening of the refrigerant passage 36 on the stator side. Figure 13 shows that in the contact portion 37, a recess is formed in the fixed portion 60 for placing an annular sealing material 63. That is, in the fixed portion 60, the diameter of the opening of the refrigerant passage 62 on the fixed portion side is larger than that of other parts. Also, the part with a larger diameter than other parts has a constant depth in the axial direction.

[0068] The sealing material 63 is placed in the recess. Then, the bolt 50 brings the protruding portion 30a into contact with the fixed portion 60, and the stator core 100 is fastened to the fixed portion 60. As a result, the sealing material 63 is pressed against the contact portion 37 and deforms slightly, sealing the contact portion 37. With this configuration, the possibility of refrigerant supplied from the fixed portion side refrigerant passage 62 to the stator side refrigerant passage 36a leaking through the stator side refrigerant passage 36b can be further reduced.

[0069] The stator is fixed to a fixed part, which has screw holes and a fixed-part side refrigerant passage that serves as a flow path for the refrigerant. That is, the fixed part has screw holes for fixing the stator with bolts and a fixed-part side refrigerant passage for supplying refrigerant to the stator to flow within the stator. The screw holes only need to be on the extension of the bolt insertion holes, and the stator should be fastened to the fixed part by inserting bolts inserted into the bolt insertion holes into the screw holes. The fixed-part side refrigerant passage should be configured so that refrigerant passing through the fixed-part side refrigerant passage is supplied to the stator from the supply port.

[0070] The stator core only needs to have bolt insertion holes formed through it in the axial direction of the stator. The stator core is typically an annular member and has multiple teeth. The teeth can be any part where the coil is wound or arranged, and their number, size, etc., are not limited. Although the stator core is annular, the shape of the ring, such as the outer circumference or inner circumference, is not limited. For example, the outer circumference may be polygonal. The bolt insertion holes only need to be configured so that a bolt can be inserted from one opening and the end of the bolt protruding from the other opening can be inserted into the screw hole of the fixing part.

[0071] Any bolt is a component that is inserted into a bolt insertion hole, and its tip is inserted into a screw hole, thereby fixing the bolt insertion hole, including the opening on the fixing side of the bolt insertion hole, to the fixing part by causing surface contact. In other words, in the stator, a predetermined area including the opening on the fixing side of the bolt insertion hole becomes the contact area, and the stator is fixed in a state where the contact area is in contact with the fixing part. The contact area is an area including the opening on the fixing side of the bolt insertion hole and the supply port, and it is sufficient if it is an area where the stator and the fixing part are in surface contact. In other words, it is sufficient if the surface pressure acting on the contact area causes the stator and the fixing part to be in close surface contact, thereby sealing to prevent refrigerant leakage between the supply port of the stator and the refrigerant passage on the fixing side of the fixing part.

[0072] The surface pressure distribution range is the range that can be sealed to prevent refrigerant leakage between the stator supply port and the refrigerant passage on the fixed side of the fixed part. Such a surface pressure distribution range only needs to be predetermined. That is, the surface pressure distribution range is defined as the range in which the surface pressure is above a predetermined threshold, and if a supply port is located within this distribution range, the distribution range should be defined in such a way that refrigerant leakage between the supply port and the refrigerant passage on the fixed side is prevented.

[0073] The stator-side refrigerant passage formed in the stator core can be any refrigerant flow path extending axially from the supply port. That is, in a state where the supply port is located on the extension of the fixed-part-side refrigerant passage and the stator-side refrigerant passage is formed continuously from the supply port, the stator-side refrigerant passage only needs to extend in the same direction as the bolt insertion hole. At the end of the stator-side refrigerant passage opposite the supply port, it may be connected to a refrigerant passage of any shape and direction. That is, any refrigerant passage may be connected to the stator-side refrigerant passage so that the refrigerant can cool a desired part of the stator core 100 after the stator-side refrigerant passage.

[0074] The protruding portion is a part that protrudes radially outward from the stator, and it should be a part that has a bolt insertion hole that penetrates the stator axially and a stator-side refrigerant passage that is a flow path for refrigerant extending axially from a supply port corresponding to the opening of the fixed-part side refrigerant passage. In other words, the protruding portion is a part that is directly fastened to the fixed part by a bolt inserted into the bolt insertion hole, and the stator-side refrigerant passage is formed in this part. With this configuration, it is sufficient that the protruding portion and the fixed part are fastened together by a bolt, and that the force of this fastening seals the connection between the stator's supply port and the fixed-part side refrigerant passage of the fixed part so as to prevent refrigerant leakage.

[0075] Furthermore, there may be multiple bolt insertion holes formed in a single protrusion. Figure 14 shows an example of a third core 300 in a configuration where two bolt insertion holes are formed in a single protrusion, and the stator-side refrigerant passage is sandwiched between the two bolt insertion holes in the circumferential direction. In Figure 14, components similar to those of the third core 30 shown in Figure 6 are indicated by the same reference numerals. The third core 300 is used together with the first core 10 shown in Figure 3 and the second core 20 shown in Figure 4. However, the first core 10 and the second core 20 may have different configurations to match the shape of the third core 300. For example, the shapes of the protrusions 10a and 20a may be the same as the shape of the protrusion 300a in the third core 300, and the position and number of bolt insertion holes may also be changed to match the position and number in the third core 300.

[0076] Here, the configuration of the third core 300 shown in Figure 14 will be described. The third core 300 is constructed by laminating electrical steel sheets of a certain thickness. Figure 14 is a diagram showing the electrical steel sheets constituting the third core 300 as viewed along a direction parallel to the central axis Ax. Two bolt insertion holes 340 are formed in the protruding portion 300a. These bolt insertion holes 340 constitute a part of the bolt insertion hole that penetrates the stator 1 in the axial direction. The bolt insertion hole 340 is a circular hole that penetrates the third core 300. Screw threads may or may not be formed in the bolt insertion hole 340. Two bolt insertion holes 340 are formed in the protruding portion 300a of the third core 300 shown in Figure 14. In the first core 10 and the second core 20, bolt insertion holes of the same diameter are formed in the axial direction at positions corresponding to the bolt insertion holes 340 and penetrate the stator 1 in the axial direction.

[0077] Each of the protruding portions 300a has a stator-side refrigerant passage 360 ​​formed therein, which is a refrigerant flow path extending in the axial direction. In this embodiment, the stator-side refrigerant passage 360 ​​is formed in all three protruding portions 300a, and the opening that opens in the axial direction at the end opposite the first core 10 becomes a refrigerant supply port. The supply port, which is the opening of the stator-side refrigerant passage 360, is connected to the fixed portion-side refrigerant passage 62 of the fixed portion 60, and the refrigerant is supplied from the fixed portion-side refrigerant passage 62 to form a refrigerant flow path. In this embodiment, the stator-side refrigerant passage 360 ​​is sandwiched between bolt insertion holes 340 in the circumferential direction. That is, in the example shown in Figure 14, two bolt insertion holes 340 are formed in one protruding portion 300a, and the stator-side refrigerant passage 360 ​​is sandwiched between two bolt insertion holes 240 in the circumferential direction.

[0078] In the above configuration, the bolt 50 is inserted into the bolt insertion hole 340 of the third core 300, passes through the first core 10, the second core 20, and the third core 300, and is inserted into the screw hole 61 formed in the fixing part 60. That is, in the fixing part 60, screw holes 61 are formed at two positions corresponding to the bolt insertion hole 340, and the fixing part side refrigerant passage 62 is sandwiched between these two screw holes 61 in the circumferential direction. As a result, the fixing part side refrigerant passage 62 and the stator side refrigerant passage 360 ​​are sandwiched between the two bolts 50. Consequently, at the contact portion 37, which is the surface where the protruding part 300a and the fixing part 60 come into contact, a sufficiently large force is applied between the fixing part side refrigerant passage 62 and the stator side refrigerant passage 360, thereby reducing the possibility of refrigerant leakage from between the fixing part 60 and the stator core 100.

[0079] In this embodiment as well, among the stator-side refrigerant passages 360 formed in the three protrusions 300a, the stator-side refrigerant passages 360 to which the fixed-part-side refrigerant passage 62 is not connected do not become refrigerant passages. In this embodiment, a radial refrigerant passage 15 is formed in one of the protrusions 10a of the first core 10, while the other two do not have radial refrigerant passages 15 formed, and holes 16 are formed instead. Furthermore, in the protrusions 20a of the second core 20, no holes are formed at positions corresponding to the stator-side refrigerant passages 360 and holes 16. Therefore, among the stator-side refrigerant passages 360, the stator-side refrigerant passage corresponding to the position where the radial refrigerant passage 15 is formed (36a in Figure 2) is connected to the second circumferential refrigerant passage 21 via the radial refrigerant passage 15. On the other hand, the stator-side refrigerant passage corresponding to the position where the radial refrigerant passage 15 is not formed (36b in Figure 2) is not connected to the second circumferential refrigerant passage 21 or the first circumferential refrigerant passage 11. Of course, the configuration of the protrusions 10a and 20a in the first core 10 and second core 20 is determined in accordance with the configuration of the protrusion 300a of the third core 300. For example, in the first core 10, the radial refrigerant passage 15 and hole 16 are sandwiched between two bolt insertion holes 14 in the circumferential direction. Also, in the second core 20, no hole is formed between the two bolt insertion holes 24. [Explanation of Symbols]

[0080] 10...First core, 10a...Protrusion, 11...First circumferential refrigerant passage, 12...Connecting part, 13...Axial refrigerant passage, 14...Bolt insertion hole, 15...Radial refrigerant passage, 15a...Part, 15b...Part, 16...Hole, 20...Second core, 20a...Protrusion, 21...Second circumferential refrigerant passage, 22...Connecting part, 23...Axial refrigerant passage, 24...Bolt insertion hole, 30...Third core, 30a...Protrusion, 31...Axial refrigerant passage, 34...Bolt insertion hole, 36...Stator side refrigerant passage, 36a...Stator side refrigerant passage, 36b...Stator side refrigerant passage, 37...Contact part, 40...Teeth, 41...Slot, 50...Bolt, 60...Fixing part, 61...Screw hole, 62...Fixing part side refrigerant passage, 63...Sealing material, 100...Stator core, 100a...Protrusion

Claims

1. A housing having a fixed part in which screw holes and a fixed part side refrigerant passage which is a flow path for refrigerant are formed, An annular stator fixed to the aforementioned fixed part, The stator core has bolt insertion holes formed that penetrate in the axial direction of the stator, The stator comprises a bolt which is inserted into the bolt insertion hole and whose tip is inserted into the screw hole, thereby fixing the contact portion of the bolt insertion hole, including the opening on the fixing portion side, to the fixing portion by bringing it into surface contact with the fixing portion, The contact portion has a supply port formed within the distribution range of surface pressure due to the fastening of the bolt, corresponding to the opening of the refrigerant passage on the fixed portion side. The stator core has a stator-side refrigerant passage formed therein, which is a refrigerant flow path extending axially from the supply port. Rotating electric machine.

2. A housing having a fixed part in which screw holes and a fixed part side refrigerant passage which is a flow path for refrigerant are formed, An annular stator fixed to the aforementioned fixed part, A stator core having a protrusion that extends radially outward from the stator, the protrusion having a bolt insertion hole that penetrates the stator in the axial direction, and a stator-side refrigerant passage which is a refrigerant flow path that extends axially from a supply port corresponding to the opening of the fixed-part-side refrigerant passage, The stator has a bolt that is inserted into the bolt insertion hole, and whose tip is inserted into the screw hole, thereby fixing the stator by bringing the contact portion, including the opening on the fixing side of the bolt insertion hole and the supply port, into surface contact with the fixing portion. A rotating electric machine equipped with the following features.

3. The stator core is formed by stacking electrical steel sheets in the axial direction, The aforementioned electrical steel sheet is provided with a plurality of the aforementioned protrusions, The bolt insertion hole and stator-side refrigerant passage formed in the protruding portion and the protruding portion have rotational symmetry with respect to the axis of symmetry of the stator. The rotating electric machine according to claim 2.

4. The stator core is, A circumferential refrigerant path is a flow path for refrigerant that extends in the circumferential direction, A radial refrigerant passage, which is a refrigerant flow path extending radially, is connected to the stator-side refrigerant passage and the circumferential refrigerant passage at one location in the stator core, Equipped with, The rotating electric machine according to claim 1 or claim 2.

5. The stator core is, Multiple of the aforementioned protrusions, A circumferential refrigerant path is a flow path for refrigerant that extends in the circumferential direction, It comprises a plurality of radial refrigerant passages that are connected to the stator-side refrigerant passage and the circumferential refrigerant passage and are radially extending refrigerant passages, One of the radial refrigerant passages is connected to the fixed part side refrigerant passage via the stator side refrigerant passage, In other radial refrigerant passages, at least one of the radial refrigerant passage and the stator-side refrigerant passage is blocked. The rotating electric machine according to claim 2.

6. In the contact area, a sealing material is provided to surround the opening of the refrigerant passage on the fixed part side and the supply port. The rotating electric machine according to claim 1 or claim 2.

7. Two screw holes are formed in the fixing portion, and the refrigerant passage on the fixing portion side is sandwiched between the two screw holes in the circumferential direction. The stator core has two bolt insertion holes, each corresponding to one of the two screw holes. The rotating electric machine according to claim 1 or claim 2.

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