rotating electrical machines

Abstract

To provide a rotary electric machine which can improve cooling performance of stator cooling by coolant.SOLUTION: A plurality of electromagnetic steel sheets 200A comprises: a plurality of fastening parts 201a to 201c; and a plurality of circular arc-shaped outer peripheral parts provided between other fastening part adjacent to the fastening parts, at least one of the plurality of circular arc-shaped outer peripheral parts forms a small diameter part 206a having a radius R0, the other forms a large diameter part 206b having a radius R2 larger than the radius R0, a communication part 203 and a slit 204 are formed in a pair of fastening parts 201a, 201b adjacent to each other on both sides of the small diameter part 206a and laminated so that the small diameter part 206a faces the large diameter part 206b of the adjacent electromagnetic steel sheet 200A, and the communication part 203 faces the communication part 203 of the adjacent electromagnetic steel plate 200A.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] Conventionally, a method of cooling the stator core of a rotating electrical machine is known in which a refrigerant is dripped from above the stator core (see Patent Document 1). In Patent Document 1, multiple refrigerant guide vanes extending in the axial direction are provided on the outer peripheral surface of the stator core. These multiple refrigerant guide vanes are arranged with their positions shifted sequentially around the circumferential direction of the stator. Therefore, the refrigerant dripping onto the outer peripheral surface of the stator core and flowing down the outer peripheral surface is guided sequentially in the axial direction of the stator by the multiple refrigerant guide vanes, and ultimately to the coil end portions. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-115994 Summary of the Invention [Problem to be solved by the invention]

[0004] The stator core has a circular cross section, and its outer circumferential surface is provided with a plurality of stator fastening portions that gently protrude from the outer circumferential surface and extend from one end of the stator core to the other. Most of the refrigerant that drips onto the vertical apex of the outer circumferential surface of the stator core is guided to the coil end by the refrigerant guide vanes. Some of the refrigerant flows vertically between the refrigerant guide vanes and reaches the stator fastening portions.

[0005] The refrigerant that reaches the stator fastening section attempts to flow downward over the stator fastening section. However, because the vertically lower surface of the annular stator outer periphery faces downward, most of the refrigerant flows down from the stator outer periphery due to gravity. As a result, the vertically lower portion of the stator core is not sufficiently cooled by the refrigerant. [Means for solving the problem]

[0006] A rotating electric machine according to one aspect of the present invention is a rotating electric machine comprising: a stator formed by stacking a plurality of first electromagnetic steel sheets in a substantially annular shape; and a rotor rotatably provided on the inner circumferential side of the stator, wherein the plurality of first electromagnetic steel sheets have a plurality of first fastening portions and a plurality of arc-shaped outer peripheries provided between a first fastening portion and another first fastening portion adjacent to the first fastening portion, at least one of the plurality of arc-shaped outer peripheries forms a small diameter portion having a first radius, and the others form large diameter portions having a second radius larger than the first radius, a pair of the first fastening portions adjacent to each other with the small diameter portion therebetween are formed with a communicating portion, and a slit portion having slit openings in each of the communicating portion and the small diameter portion, and the first electromagnetic steel sheets are stacked so that the small diameter portion faces the large diameter portion of an adjacent first electromagnetic steel sheet, and the communicating portion faces the communicating portion of an adjacent first electromagnetic steel sheet. The first fastening portion is formed with a fastening hole for inserting a fixing bolt, the communicating portion is provided in the vicinity of the fastening hole, the area in the first electromagnetic steel sheet where the communicating portion is formed and the area where the fastening hole is formed are separated in the circumferential direction of the stator, and the distance from the axial center of the stator of the inner circumferential end of the area where the fastening hole is formed is set to be smaller than the distance from the axial center of the stator of the outer circumferential end of the area where the communicating portion is formed. It is characterized by: [Effects of the Invention]

[0007] According to the present invention, the cooling performance of the stator cooled by the refrigerant can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a diagram showing a main part of a rotating electrical machine. [Figure 2] FIG. 2 is a diagram showing the first electromagnetic steel sheet. [Figure 3] FIG. 3 is a diagram showing the second electromagnetic steel sheet. [Figure 4] FIG. 4 is a diagram showing the arrangement of the magnetic steel sheets to be rotated. [Figure 5]FIG. 5 is a schematic diagram illustrating the flow of refrigerant in each laminate block of the stator core. [Figure 6] FIG. 6 is a diagram showing the flow of the refrigerant when the stator core is viewed along the axial direction. [Figure 7] FIG. 7 is a diagram illustrating the relationship between the radius of the large diameter portion and the flow of the refrigerant. [Figure 8] FIG. 8 is a diagram illustrating the positional relationship between the communication portion and the fastening hole. [Figure 9] FIG. 9 is a diagram showing an example of a case where the refrigerant is dripped onto the outer peripheral surface of the stator core. [Figure 10] FIG. 10 is a diagram showing an electromagnetic steel sheet according to the first modification. [Figure 11] FIG. 11 is a schematic diagram illustrating the stacking pattern of the main stacked body block in the first modification. [Figure 12] FIG. 12 is a diagram showing a first electromagnetic steel sheet in Modification 2. As shown in FIG. [Figure 13] FIG. 13 is a diagram illustrating a groove flow path in the second modification. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The following description and drawings are examples for explaining the present invention, and appropriate omissions and simplifications have been made for clarity of explanation. Furthermore, in the following description, identical or similar elements and processes are designated by the same reference numerals, and redundant explanations may be omitted. Note that the content described below merely shows an example of an embodiment of the present invention, and the present invention is not limited to the following embodiment, and can be implemented in various other forms.

[0010] 1 is a view of a stator 2 and a rotor 3, which are essential parts of a rotating electric machine 1, viewed from the positive direction of the z-axis along the axial direction of the rotor 3. The rotating electric machine 1 includes an annular stator 2 and a rotor 3 arranged on the inner periphery of the stator 2. The stator 2 includes a stator core 20 and a stator coil 21. Although not shown in the figure, the stator 2 is housed in a motor casing, for example, and fixed to a cover provided at the axial end of the motor casing.

[0011] A plurality of slots 22 are formed on the inner circumferential side of the stator core 20. Each slot 22 houses a plurality of coil conductors that form the coil sides of the stator coil 21. Note that, in the region of the stator core 20, the core region on the outer circumferential side of the region where the slots 22 are provided may hereinafter be referred to as a back yoke portion.

[0012] The stator core 20 is made by laminating electromagnetic steel sheets. A plurality of fastening portions 201a to 201c for fixing to a motor casing are provided on the outer periphery of the stator core 20 so as to protrude from the outer periphery. In the example shown in Fig. 1, three fastening portions 201a to 201c are provided at equal intervals in the circumferential direction. Each of the fastening portions 201a to 201c is formed with a fastening hole 202 for fixing with a bolt.

[0013] Groove passages 210a to 210c for guiding refrigerant are formed between adjacent fastening portions in the outer peripheral region of stator core 20. As will be described in detail later, groove passage 210a communicates with adjacent groove passage 210b via communication portion 203, and groove passage 210b further communicates with adjacent groove passage 210c via communication portion 203.

[0014] 2 and 3 are diagrams showing electromagnetic steel sheets 200A and 200B used in the stator core 20. Two types of electromagnetic steel sheets with different outer peripheral shapes are used in the stator core 20, which is formed by laminating electromagnetic steel sheets. The first electromagnetic steel sheet 200A, which has a substantially annular shape, shown in FIG. 2 is an electromagnetic steel sheet used in a main laminate block excluding both axial end regions of the stator core 20. The second electromagnetic steel sheet 200B, which has a substantially annular shape, shown in FIG. 3 is an electromagnetic steel sheet used in a laminate block arranged on one end side of the main laminate block. The main laminate block and the laminate block will be described later.

[0015] 2 and 3, the same names and symbols are used for the portions of the electromagnetic steel sheets 200A and 200B corresponding to the portions of the stator core 20.

[0016] As shown in Fig. 2, fastening holes 202, communication portions 203, and slits 204 are formed in two fastening portions 201a and 201b provided on electromagnetic steel sheet 200A. On the other hand, fastening hole 202 and hole 205 are formed in fastening portion 201c. In the example shown in Fig. 2, the diameter of circular communication portion 203 is set to be the same as that of hole 205 and is set to be larger than the slit width of slit 204. The two communication portions 203 and holes 205 are arranged at equal intervals (120° intervals) on the same circumference centered on stator axis C.

[0017] The arc-shaped outer peripheral region between fastening portion 201a and fastening portion 201c is constituted by the outer peripheral surface of small diameter portion 206a having a radius R0 centered on stator axis C. On the other hand, the outer peripheral region between fastening portion 201a and fastening portion 201c and the outer peripheral region between fastening portion 201b and fastening portion 201c are each constituted by the outer peripheral surface of large diameter portion 206b having a radius R2 centered on stator axis C. In this way, in the case of first electromagnetic steel sheet 200A, the outer peripheral region between the fastening portions is constituted by small diameter portion 206a and large diameter portion 206b. The distance from stator axis C to the outer peripheral edge of arc-shaped slit 4 is set to R1.

[0018] Each slit 204 in the fastening portions 201a, 201b is formed on the small diameter portion 206a side of the fastening portion region. In each slit 204, a slit opening 204a at one end is connected to the communicating portion 203, and a slit opening 204b at the other end is connected to the small diameter portion 206a. The edge of the slit 204 on the stator axis C side forms an arc of radius R0 that continues to the small diameter portion 206a. Furthermore, the communicating portion 203, which is a circular hole, is formed so as to contact the edge of the slit 204 on the stator axis C side. In other words, the communicating portion 203 is formed in a region of the electromagnetic steel sheet 200A whose distance from the stator axis C is greater than radius R0.

[0019] 3 is a diagram showing the shape of the second electromagnetic steel sheet 200B. In the second electromagnetic steel sheet 200B, the outer periphery 206c between the fastening portions 201a to 201c is in the shape of an arc with a radius R3. R3 is set so that R2≦R3≦R1. As will be described later, the second electromagnetic steel sheet 200B constitutes laminate blocks that are arranged on both ends of the main laminate block constituted by the first electromagnetic steel sheet 200A.

[0020] The electromagnetic steel sheet 200B shown in FIG. 3 is used in the laminate block on one end of the main laminate block, and has a supply hole 207 for supplying a coolant from outside into the stator core. Note that in FIG. 1, the electromagnetic steel sheet 200B is omitted and only the main laminate block is shown. The position of the supply hole 207 with respect to the stator axis C is set to the same position as the communication portion 203 of the electromagnetic steel sheet 200A shown in FIG. 2. As in the case of the electromagnetic steel sheet 200A, fastening holes 202 are formed in each of the fastening portions 201a to 201c. Note that, although not shown, an electromagnetic steel sheet 200B1 without a supply hole 207 is used for the laminate arranged on the other end of the main laminate block.

[0021] Fig. 4 is a diagram illustrating the arrangement of the electromagnetic steel sheets 200A in each layer in the main laminate block. When the electromagnetic steel sheets 200A are stacked in the main laminate block, they are rotated in the negative z-axis direction while repeating three arrangements D1, D2, and D3 in order, as shown in Fig. 4. If the clockwise phase (angle) of arrangement D1 is 0°, the phase of arrangement D2 is 120°, and the phase of arrangement D3 is 240°.

[0022] The communicating portion 203 provided in the fastening portion 201a of the electromagnetic steel sheet 200A in arrangement D1 overlaps and communicates with the hole 205 provided in the fastening portion 201c of the electromagnetic steel sheet 200A in arrangement D2. Furthermore, the communicating portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D1 overlaps and communicates with the communicating portion 203 provided in the fastening portion 201a of the electromagnetic steel sheet 200A in arrangement D2. Furthermore, the hole 205 provided in the fastening portion 201c of the electromagnetic steel sheet 200A in arrangement D1 overlaps and communicates with the communicating portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D2.

[0023] The communicating portion 203 provided in the fastening portion 201a of the electromagnetic steel sheet 200A in arrangement D2 overlaps and communicates with the hole 205 provided in the fastening portion 201c of the electromagnetic steel sheet 200A in arrangement D3. Furthermore, the communicating portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D2 overlaps and communicates with the communicating portion 203 provided in the fastening portion 201a of the electromagnetic steel sheet 200A in arrangement D3. Furthermore, the hole 205 provided in the fastening portion 201c of the electromagnetic steel sheet 200A in arrangement D2 overlaps and communicates with the communicating portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D3.

[0024] Furthermore, the small diameter portion 206a of the electromagnetic steel sheet 200A in arrangement D1 is sandwiched between the electromagnetic steel sheet 200A in arrangement D2 and the large diameter portion 206b of an electromagnetic steel sheet 200A (arrangement D3) (not shown) arranged in the positive direction of the z-axis. As a result, a groove is formed between the outer peripheral surface of the small diameter portion 206a and the side surfaces of the adjacent large diameter portions 206b. Similarly, the small diameter portion 206a of the electromagnetic steel sheet 200A in arrangement D2 is sandwiched between the electromagnetic steel sheet 200A in arrangement D1 and the large diameter portion 206b of the electromagnetic steel sheet 200A in arrangement D3, forming a groove. The small diameter portion 206a of the electromagnetic steel sheet 200A in arrangement D3 is sandwiched between the electromagnetic steel sheet 200A in arrangement D2 and the large diameter portion 206b of an electromagnetic steel sheet 200A (arrangement D1) (not shown) arranged in the negative direction of the z-axis, forming a groove. The width dimension of each formed groove is the same as the thickness dimension of the electromagnetic steel sheet 200A.

[0025] A pair of slits 204 in the electromagnetic steel sheet 200A in arrangement D1 communicates with a groove formed by a small diameter portion 206a and adjacent large diameter portions 206b, and the groove and the pair of slits 204 form the groove flow path 210a in FIG. 1 . Similarly, a pair of slits 204 in the electromagnetic steel sheet 200A in arrangement D2 and a groove formed in the small diameter portion 206a between the slits 204 form the groove flow path 210b in FIG. 1 . Similarly, a pair of slits 204 in the electromagnetic steel sheet 200A in arrangement D3 and a groove formed in the small diameter portion 206a between the slits 204 form the groove flow path 210c in FIG. 1 . The groove flow path 210a and the groove flow path 210b are communicated by a communicating portion 203. The groove flow path 210b and the groove flow path 210c are communicated by a communicating portion 203.

[0026] FIG. 5 is a schematic diagram illustrating the flow of refrigerant in each laminate block E0, E1, and E2 of the stator core 20. FIG. 5 is a development view of the stator core 20, cross-sectioned in the axial direction along the dashed-dotted line A in FIG. 1, and the cross-section viewed from the outer circumferential direction. In FIG. 5, the center of the fastening portion 201a (the center of the communicating portion 203) in FIG. 1 is set to an angle of 0°, the center of the fastening portion 201b is set to an angle of 120°, and the center of the fastening portion 201c is set to an angle of 240°. The position of the angle of 0° corresponds to the top (uppermost end) of the stator core 20, and the position of the angle of 180° corresponds to the bottom (lowermost end) of the stator core 20. The vertical direction in the figure is the stator axial direction, and the electromagnetic steel sheets 200A, 200B, and 200B1 are stacked from bottom to top in the order of laminate block E1, main laminate block E0, and laminate block E2. The layer structure of the electromagnetic steel sheets 200B, 200B1 in the laminate blocks E1, E2 is not shown in the drawings.

[0027] The main laminate block E0 at the center in the stacking direction is made by stacking the first electromagnetic steel sheets 200A shown in FIG. 2. The main laminate block E0 has 12 layers of electromagnetic steel sheets 200A stacked in the following order from the bottom in the figure: D1, D2, D3, D1, D2, D3, D1, D2, D3, D1, D2, D3, D3. The lower laminate block E1 in the figure is made by stacking multiple second electromagnetic steel sheets 200B shown in FIG. 3. The supply holes 207 of each electromagnetic steel sheet 200B are arranged at an angle of 0°.

[0028] The laminated block E2 on the upper side of the figure is made by stacking a plurality of electromagnetic steel sheets 200B1 that do not have the supply holes 207 in Fig. 3. The shape of the electromagnetic steel sheets 200B1 that make up the laminated block E2 is not shown, but the supply holes 207 of the electromagnetic steel sheets 200B in Fig. 3 have been removed. In Fig. 5, arrows indicate the flow of the refrigerant.

[0029] The first layer of the main laminate block E0 is provided with an electromagnetic steel sheet 200A in arrangement D1, and the communication portion 203 communicating with the groove 210a communicates with the supply hole 207 of the laminate block E1. The communication portion 203 on the right side of the groove 210a faces the communication portion 203 on the left side of the groove 210b of the electromagnetic steel sheet 200A in arrangement D2 of the second layer. The groove 210a and the groove 210b communicate with each other via these two opposing communication portions 203. The groove 210b communicates with the groove 210c of the electromagnetic steel sheet 200A in arrangement D3 of the third layer at an angle of 240° via the communication portion 203. The groove 210c communicates with the groove 210a of the electromagnetic steel sheet 200A in the arrangement D1 of the fourth layer via the communication portion 203 at an angle of 360° (angle 0°).

[0030] Furthermore, at each of the angle positions of 0°, 120°, and 240°, the communicating portions 203 and the holes 205 are arranged in the stator axial direction (the up-down direction in the figure) in the following arrangement: communicating portion 203-hole 205-communicating portion 203-communicating portion 203-hole 205-communicating portion 203-communicating portion 203-... Therefore, at each of the angle positions of 0°, 120°, and 240°, cylindrical hole spaces extending in the stator axial direction are formed. Hereinafter, these cylindrical hole spaces will be referred to as refrigerant reservoirs 300a, 300b, and 300c.

[0031] The refrigerant supplied from the outside is supplied to the supply holes 207 of the laminate block E1. The refrigerant supplied to the supply holes 207 flows into a refrigerant reservoir (cylindrical hole space) 300a extending in the axial direction of the stator, and fills the refrigerant reservoir 300a. The refrigerant in the refrigerant reservoir 300a flows through the communication portions 203 into the groove channels 210a and 210c. In this way, the supplied refrigerant fills the refrigerant reservoir 300a extending in the axial direction, and the refrigerant is uniformly distributed to the multiple groove channels 210a, 210c arranged in the axial direction.

[0032] 5, the refrigerant in groove flow channel 210a moves in a direction at an angle of 120° due to gravity. The refrigerant that has moved in groove flow channel 210a in the direction at an angle of 120° flows into refrigerant reservoir 300b. The refrigerant that has flowed into refrigerant reservoir 300b moves in the axial direction within refrigerant reservoir 300b and flows into each groove flow channel 210b via communication portion 203. The refrigerant in each groove flow channel 210b moves in a direction at an angle of 180° as shown by the arrow.

[0033] Meanwhile, the refrigerant in groove flow passage 210c moves in a direction at an angle of 240° and flows into refrigerant reservoir 300c. The refrigerant that has flowed into refrigerant reservoir 300c moves in the axial direction within refrigerant reservoir 300c and flows into each groove flow passage 210b via communication portion 203. The refrigerant in each groove flow passage 210b moves in a direction at an angle of 180° as shown by the arrow.

[0034] FIG. 6 is a diagram showing the flow of refrigerant when the stator core 20 is viewed from the positive direction of the z-axis. The refrigerant supplied to the supply hole 207 flows into the groove flow passages 210a and 210c via the refrigerant reservoir 300a (see FIG. 5). The refrigerant moves clockwise through the groove flow passage 210a at an angle of 120° and then flows into the refrigerant reservoir 300b. The refrigerant in the refrigerant reservoir 300b flows into the groove flow passage 210b and then moves clockwise through the groove flow passage 210b at an angle of 180° (toward the bottom). Meanwhile, the refrigerant moves counterclockwise through the groove flow passage 210c at an angle of 240° and then flows into the refrigerant reservoir 300c. The refrigerant in the refrigerant reservoir 300c flows into the groove flow passage 210b and then moves counterclockwise through the groove flow passage 210b at an angle of 180° (toward the bottom). The refrigerant that has collected at the 180° angle position (bottom) of stator core 20 drips downward from the bottom of stator core 20 due to its own weight, as indicated by the downward arrow.

[0035] The thickness of the electromagnetic steel sheets 200A, 200B, and 200B1 used in the stator core 20 is generally 1 mm or less, so the groove width of the grooved passages 210a to 210c is also 1 mm or less. Therefore, the angle of the downward groove 120Even in the range of 100° to 240°, the refrigerant is held in groove passages 210a to 210c due to the effect of surface tension, and is less likely to fall. Ultimately, the refrigerant falls from groove passage 210b in the region at the bottom of stator core 20 where the refrigerant collects.

[0036] As described above, in this embodiment, the grooves 210a-210c that run around the stator core 20 are formed by rotating the electromagnetic steel sheet 200A, which includes the small-diameter portion 206a and the large-diameter portion 206b. The groove width of the grooves 210a-210c is the same as the thickness of the electromagnetic steel sheet 200A, allowing for the formation of grooves with very narrow widths. Therefore, due to the action of surface tension, the refrigerant in the grooves 210a-210c can move vertically downward in the stator core 20 without falling from the grooves 210a-210c. As a result, the refrigerant can be supplied to almost the entire outer peripheral surface of the stator core, improving the cooling performance of the refrigerant. Furthermore, the formation of the grooves 210a-210b increases the contact area of ​​the refrigerant, thereby improving the cooling performance.

[0037] In the above-described embodiment, the electromagnetic steel sheets 200A are transferred one by one, but multiple sheets may be transferred at a time within a range where the effect of surface tension can be expected.

[0038] 7 is a diagram illustrating the relationship between the radius R2 of the large diameter portion 206b and the flow of the refrigerant. The refrigerant that moves inside the groove flow channel 210a toward the fastening portion 201b flows into the slit 204 of the fastening portion 201b. Here, as shown by the dashed-dotted line L1, consider a case where the radius R2 of the large diameter portion 206b is smaller than the radius R1 of the outer peripheral edge of the arc-shaped slit 204. In this case, the groove flow channel 210a sandwiched between the two large diameter portions 206b enters the slit 204 without overlapping with the outer peripheral edge of the slit 204.

[0039] On the other hand, as indicated by dashed line L2, if the radius R2 of the large-diameter portion 206b is greater than the radius R1 of the outer circumferential edge of the arc-shaped slit 204, the magnetic steel sheet near the slit entrance protrudes into the groove flow passage 210a. As a result, the refrigerant moving through the groove flow passage 210a toward the fastening portion 201b is partially branched by the protruding portion and flows out onto the outer circumferential surface of the fastening portion 201b as indicated by arrow F. The refrigerant that flows out onto the outer circumferential surface of the fastening portion 201b falls downward from the fastening portion 201b. In other words, the cooling performance of the refrigerant decreases for the portion of the stator core 20 below the fastening portion 201b in the figure. Therefore, it is preferable to set the radius R2 of the large-diameter portion 206b so that R2≦R1. This setting allows the refrigerant to be guided to the bottom side of the stator core 20 without part of the refrigerant falling off the outer circumferential surface of the stator core.

[0040] In this embodiment, as shown in FIG. 2, the holes forming the refrigerant reservoirs 300a to 300c are 205 Furthermore, since the communicating portion 203 is disposed near the fastening hole 202, the sealing performance at the communicating portion 203 is improved by fastening the bolt. The width (radial dimension) of the back yoke portion on the outer circumferential side of the slot 22 affects the torque performance of the rotating electric machine. Therefore, by disposing the communicating portion 203 near the fastening hole 202 and suppressing a decrease in the width of the back yoke portion, it is possible to prevent a decrease in torque performance.

[0041] 8, the communicating portion 203 and the fastening hole 202 are offset in the circumferential direction and then arranged so as to overlap in the radial direction. That is, when considering the radial distance from the stator axis C, the radial distance R11 of the fastening hole 202 on the inner periphery side of the stator is set to be smaller than the radial distance R12 of the communicating portion 203 on the outer periphery side of the stator. By setting them in this way, the outer diameter of the stator core 20 can be reduced while ensuring the width of the back yoke portion.

[0042] In the example shown in FIG. 6, the refrigerant is supplied from supply holes 207 provided in laminate block E1. However, as a method of supplying the refrigerant from the outside, there is also a method of dripping the refrigerant onto the outer peripheral surface of the stator core, as described in Patent Document 1. FIG. 9 is a diagram showing an example of dripping the refrigerant onto the outer peripheral surface of the stator core in this embodiment. The refrigerant is dripped onto the outer peripheral surface between the fastening portions. In the example shown in FIG. 9, the stator core 20 is arranged so that the fastening portion 201a is oriented vertically downward, and the refrigerant is dripped from the refrigerant supply pipe 301 onto the outer peripheral surface between the fastening portions 201b and 201c.

[0043] The refrigerant dripping from refrigerant supply pipe 301 flows along the outer circumferential surface and enters groove flow path 210b. The refrigerant in groove flow path 210b moves toward fastening portions 201b and 201c and flows into refrigerant reservoirs 300b and 300c. The refrigerant in refrigerant reservoir 300b flows into groove flow path 210a and moves toward fastening portion 201a, and flows into refrigerant reservoir 300a in fastening portion 201a. The refrigerant in refrigerant reservoir 300c flows into groove flow path 210c and moves toward fastening portion 201a and flows into refrigerant reservoir 300a. The refrigerant that has accumulated in refrigerant reservoir 300a and in groove flow paths 210a and 210c near fastening portion 201a flows down vertically due to gravity, as shown by the arrows.

[0044] In the case of a method in which the refrigerant is supplied by dripping it onto the outer peripheral surface of the stator core, the refrigerant can be supplied uniformly in the axial direction of the stator core 20 by the refrigerant supply pipe 301. Therefore, the holes 205 in the electromagnetic steel sheet 200A shown in Figures 2 and 5 may be omitted, that is, a configuration may be adopted in which the refrigerant reservoirs 300a to 300c are not formed.

[0045] (Variation 1) 10 and 11 are diagrams illustrating a first modification of the above-described embodiment. In the above-described embodiment, in the main laminate block E0, the electromagnetic steel sheets 200A are stacked in a rotating pattern in which the arrangements D1, D2, and D3 are repeated, as shown in FIGS. 4 and 5. In the first modification, a lamination region of an electromagnetic steel sheet 200B2 that does not have a small diameter portion 206a as shown in FIG. 10 is sandwiched between lamination regions of the electromagnetic steel sheet 200A. The electromagnetic steel sheet 200B2 has holes 205 formed in each of the fastening portions 201a to 201c, similar to those in the electromagnetic steel sheet 200A shown in FIG. 2. The other configurations are the same as those of the electromagnetic steel sheet 200B shown in FIG. 3.

[0046] FIG. 11 is a schematic diagram illustrating the stacking pattern of the main stacked block E0. ,above This is a cross-sectional development similar to that of FIG. 5. From the bottom, a laminate block E1, a main laminate block E0, and a laminate block E2 are provided. The main laminate block E0 is composed of a laminate region E01 of electromagnetic steel sheets 200A and a laminate region E02 of electromagnetic steel sheets 200B2. The laminate regions E01 and E02 are alternately arranged in the stator axial direction (the vertical direction in the figure).

[0047] 11, stacked region E01 is made up of three electromagnetic steel sheets 200A, which are stacked in arrangements D1, D2, and D3 from the bottom in the figure. On the other hand, stacked region E02 is made up of two electromagnetic steel sheets 200B2. Holes 205 are formed in fastening portions 201a to 201c of electromagnetic steel sheets 200B2, thereby forming refrigerant reservoirs 300a to 300c similar to those in FIG. 5. In stacked region E01, refrigerant supplied into refrigerant reservoir 300a is guided clockwise through groove channels 210a and 210b and counterclockwise through groove channels 210c and 210b.

[0048] 11, the stacking region E01 is configured with three electromagnetic steel sheets 200A, but it may be configured with four or more electromagnetic steel sheets 200A. Furthermore, the number of electromagnetic steel sheets 200B2 provided in the stacking region E02 is not limited to two, and may be three or more.

[0049] In the first modification, the grooves 210a-210c are formed around the entire circumference of the stator core 20, so that the stator core 20 can be cooled by the refrigerant almost entirely, improving cooling efficiency. As described above, the width (radial dimension) of the back yoke portion on the outer circumferential side of the slots 22 affects the torque performance of the rotating electric machine. Therefore, if the small diameter portions 206a are provided in the electromagnetic steel sheet 200A to form the grooves 210a-210c, this will result in a decrease in torque performance. In the first modification, the provision of the laminated region E02 formed of the electromagnetic steel sheet 200B2 that does not have the small diameter portions 206a can suppress the decrease in torque performance.

[0050] (Variation 2) 12 and 13 are diagrams illustrating a second modification of the above-described embodiment. In the second modification, the number of fastening portions of the stator core 20 is an even number. FIG. 12 is a diagram showing a first electromagnetic steel sheet 200C constituting the main laminate block E0 of the stator core 20. The electromagnetic steel sheet 200C has four fastening portions 201a to 201d provided at 90° intervals. Small diameter portions 206a with a radius R0 are provided between fastening portions 201a and 201b, and between fastening portions 201c and 201d. Meanwhile, large diameter portions 206b with a radius R2 are provided between fastening portions 201b and 201c, and between fastening portions 201d and 201a.

[0051] Each of the fastening portions 201a to 201d is formed with a fastening hole 201 and a slit 204. One end of the slit 204, designated by reference numeral 204c, on the fastening hole 201 side functions as a communication portion that communicates with the slit 204 of another layer. The other end of the slit 204 is connected to the small diameter portion 206a, as in the case of the electromagnetic steel sheet 200A.

[0052] FIG. 13 is a diagram illustrating grooves 210a-210d formed by electromagnetic steel sheets 200C. When the number of fastening portions is an even number, small diameter portions 206a and large diameter portions 206b are arranged alternately in the circumferential direction as shown in FIG. 12, and therefore, by repeatedly rolling electromagnetic steel sheets 200C with two different arrangements, an even number of grooves arranged around the stator core 20 can be formed. When the number of fastening portions is an even number n, the rotation angle during rolling is 360° / n. Since the number of fastening portions of the electromagnetic steel sheets 200C shown in FIG. 12 is four, the rolling angle is 90°.

[0053] For example, if the arrangement of the electromagnetic steel sheets 200C shown in Fig. 12 is referred to as a first arrangement D11, then a second arrangement D12 is an arrangement in which the electromagnetic steel sheets 200C in Fig. 12 are rotated 90° in the circumferential direction. The electromagnetic steel sheets 200C in the arrangement D11 and the electromagnetic steel sheets 200C in the arrangement D12 are alternately stacked to form a main laminate block E0.

[0054] In FIG. 13 , the electromagnetic steel sheet 200C designated by the reference symbol 200C(D11) is the electromagnetic steel sheet in the arrangement D11, and the electromagnetic steel sheet 200C designated by the reference symbol 200C(D12) is the electromagnetic steel sheet in the arrangement D12. An electromagnetic steel sheet 200C(D12) (not shown) is arranged in front of the electromagnetic steel sheet 200C(D11). The small diameter portion 206a of the electromagnetic steel sheet 200C(D11) is sandwiched between the large diameter portions 206b of the adjacent electromagnetic steel sheets 200C(D12) on both sides, thereby forming grooves 210a and 210c. Meanwhile, the small diameter portion 206a of the electromagnetic steel sheet 200C(D12) is sandwiched between the large diameter portions 206b of the adjacent electromagnetic steel sheets 200C(D11) on both sides, thereby forming grooves 210b and 210d.

[0055] The communicating portions 204c of the slits 204 of the electromagnetic steel sheet 200C(D11) overlap with the communicating portions 204c of the slits 204 of the electromagnetic steel sheet 200C(D12), so that adjacent groove flow paths in the circumferential direction communicate with each other. The communicating portions 204c of the electromagnetic steel sheets 200C(D11), 200C(D12) are arranged in the axial direction of the main laminate block E0, and four refrigerant reservoirs similar to the refrigerant reservoirs shown in Figure 5 are formed in the circumferential direction at 90° intervals.

[0056] The effects of the above-described embodiment and modified examples can be summarized as follows.

[0057] (1) As shown in Figures 1, 2, 4, etc., a rotating electric machine 1 includes a stator 2 formed by laminating a plurality of substantially annular electromagnetic steel sheets 200A (first electromagnetic steel sheets), and a rotor 3 rotatably provided on the inner circumferential side of the stator 2. The plurality of electromagnetic steel sheets 200A have a plurality of fastening portions 201a to 201c (first fastening portions) and a plurality of arc-shaped outer peripheries provided between the fastening portions (201a to 201c) and other adjacent fastening portions (201a to 201c), at least one of the plurality of arc-shaped outer peripheries forming a small diameter portion 206a having a radius R0 (first radius), and the others forming large diameter portions 206b having a radius R2 (second radius) greater than the radius R0. A pair of adjacent fastening portions 201a, 201b sandwiching a small diameter portion 206a therebetween are formed with a communicating portion 203 and a slit (slit portion) 204 having slit openings 204a, 204b in the communicating portion 203 and the small diameter portion 206a, respectively, and the plates are stacked so that the small diameter portion 206a faces the large diameter portion 206b of the adjacent electromagnetic steel plate 200A and the communicating portion 203 faces the communicating portion 203 of the adjacent electromagnetic steel plate 200A.

[0058] As described above, by configuring the small diameter portion 206a to face the large diameter portion 206b of the adjacent electromagnetic steel sheet 200A, it is possible to form groove channels 210a-210c on the outer periphery of the stator 2, with the groove width equal to the sheet thickness of the electromagnetic steel sheet 200A. Therefore, the refrigerant introduced into the groove channels 210a-210c is held within the groove channels 210a-210c by surface tension and can move within the groove channels 210a-210c to the vertically lower side of the stator 2. As a result, the cooling performance of the stator can be improved. Furthermore, by flowing the refrigerant through the groove channels 210a-210c, the contact area of ​​the refrigerant can be increased.

[0059] (2) In (1) above, as shown in Figures 1 and 2, fastening holes (fastening holes) 202 for inserting fixing bolts are formed in the fastening portions 201a to 201c, and the communicating portions 203 are provided near the fastening holes 202. By providing the communicating portions 203 near the fastening holes 202 and fixing the fastening portions 201a to 201c to the motor casing with bolts, the sealing performance in the communicating portions 203 is improved.

[0060] (3) In the above (2), as shown in Fig. 8 etc., the area in electromagnetic steel sheet 200A where communicating portion 203 is formed and the area where fastening hole 202 is formed are spaced apart in the circumferential direction of the stator, and radial distance R11 from stator axis C to the inner peripheral end of fastening hole 202 forming area is set to be smaller than radial distance R12 from stator axis C to the outer peripheral end of communicating portion 203 forming area. By setting them in this manner, the outer diameter of stator core 20 can be reduced while ensuring the width of the back yoke portion.

[0061] (4) In (1) above, Figure 7 As shown in the drawings, the communication portion 203 is formed in an area of ​​the electromagnetic steel sheet 200A where the distance from the stator axis C is greater than the radius R0 (first radius). By configuring the communication portion 203 in this manner, the width of the back yoke portion is ensured, and a decrease in torque performance can be prevented.

[0062] (5) In the above (1), as shown in Fig. 7 etc., the distance (radius R2) from the stator axis C to the large diameter portion 206b is set to be equal to or less than the distance (radius R1) from the stator axis C to the outer peripheral edge of the slit 204 (slit portion). By setting it in this manner, the refrigerant in the groove flow passage 210a is branched at the outer peripheral edge of the slit 204, and it is possible to prevent a portion of the refrigerant from leaking from the groove flow passage 210a and dropping from the stator core 20.

[0063] (6) In the above (1), as shown in Figures 10 and 11, the stator 2 is formed by alternately stacking a lamination region E01 (first laminate) in which electromagnetic steel sheets 200A are stacked and a lamination region E02 (second laminate) in which electromagnetic steel sheets 200B2 (second electromagnetic steel sheets) are stacked, and the electromagnetic steel sheets 200B have a plurality of fastening portions 201a-201c (second fastening portions) and a plurality of outer peripheries 206c (second arc-shaped outer peripheries) provided between the fastening portions (201a-201c) and adjacent other fastening portions (201a-201c), and having a radius R3 (third radius) equal to or greater than the radius R2 (second radius). In this way, by providing the lamination region E02 in which the electromagnetic steel sheets 200B are stacked in the main laminate block E0, it is possible to improve torque performance in a configuration including the grooved channels 201a-201c.

[0064] 10 and 11, holes 205 are provided in electromagnetic steel sheet 200B2 to form refrigerant reservoirs 300a-300c for uniformly distributing the refrigerant in the axial direction. However, in the case of a refrigerant supply method in which the refrigerant drips onto the outer periphery of the stator, holes 205 in electromagnetic steel sheet 200B2 may be omitted, that is, a configuration may be adopted in which refrigerant reservoirs 300a-300c are not formed.

[0065] (7) In the above (6), as shown in Figures 3, 11, etc., a laminate block E1 (second laminate) is provided at least at one end of the stator 2 in the lamination direction, and the electromagnetic steel sheets 200B of the laminate block E1 have supply holes 207 (refrigerant supply holes) that supply a cooling medium from the outside to the communication parts 203 of the electromagnetic steel sheets 200A. By providing the supply holes 207 in the electromagnetic steel sheets 200B of the laminate block E1, the coolant can be supplied to the groove flow paths 201a to 201c from the axial end faces of the stator 2.

[0066] (8) In the above (1), as shown in Figures 3, 11, etc., the stator 2 may include a main laminate block E0 (laminate) formed by stacking electromagnetic steel sheets 200A, and a laminate block E1 of electromagnetic steel sheets 200B provided at one end of the main laminate block E0 in the stacking direction, and the electromagnetic steel sheets 200B may include a plurality of fastening portions 201a to 201c (second fastening portions), a plurality of outer peripheries 206c (second arc-shaped outer peripheries) provided between the fastening portions (201a to 201c) and other fastening portions (201a to 201c) adjacent to each other, and having a radius R3 (third radius) equal to or greater than the radius R2 (second radius), and supply holes 207 (refrigerant supply holes) provided in the fastening portions 201a to 201c to supply a cooling medium from outside to the communication portions 203 of the electromagnetic steel sheets 200A.

[0067] (9) In (1) above, as shown in Figures 1 and 2, the number of fastening portions 201a to 201c is odd, and fastening portions 201c without slits 204 are provided with holes 205 (connecting holes) that connect communicating portions 203 of adjacent electromagnetic steel sheets 200A on one side in the stator axial direction with communicating portions 203 of adjacent electromagnetic steel sheets 200A on the other side in the stator axial direction. By providing holes 205, communicating holes 203 and holes 205 arranged in the stator axial direction form refrigerant reservoirs 300a to 300c extending in the stator axial direction as shown in Figure 5. By providing refrigerant reservoirs 300a to 300c, the refrigerant can be distributed uniformly in the stator axial direction.

[0068] (10) In any of the above (6) to (8), as shown in Figures 2, 3, 7, etc., radius R3 (third radius) is set to be equal to or greater than radius R2 (second radius) and equal to or less than the distance (radius R1) from the stator axis C to the outer peripheral edge of slit 204 (slit portion). By setting radius R3 of the outer periphery of electromagnetic steel sheets 200B, 200B1, 200B2 so that R2 ≤ R3 ≤ R1, groove channels 210a to 210c can be formed that can prevent refrigerant from dropping in the fastening portion region while suppressing deterioration in torque performance.

[0069] The various embodiments and modifications described above are merely examples, and the present invention is not limited to these unless the features of the invention are impaired. Other embodiments that are conceivable within the scope of the technical idea of ​​the present invention are also included within the scope of the present invention. [Explanation of symbols]

[0070] 1... rotating electric machine, 2... stator, 3... rotor, 20... stator core, 21... stator coil, 22... slot, 200A, 200B, 200B1, 200B2, 200C... electromagnetic steel plates, 201a to 201d... fastening portion, 202... fastening hole, 203, 204c... communication portion, 204... slit, 204a, 204b... slit opening, 205... hole, 206a... small diameter portion, 206b... large diameter portion, 206c... outer periphery, 207... supply hole, 210a to 210d... groove flow path, 300a, 300b, 300c... refrigerant reservoir, C... stator axis, D1 to D3, D11, D12... arrangement, E0... main laminate block, E1, E2... laminate block

Claims

1. a stator formed by laminating a plurality of first electromagnetic steel plates each having a substantially annular shape; a rotor rotatably provided on an inner circumferential side of the stator, The plurality of first electromagnetic steel sheets are a plurality of first fastening portions and a plurality of arc-shaped outer peripheries provided between the first fastening portions and other adjacent first fastening portions; At least one of the plurality of arc-shaped outer peripheries forms a small diameter portion having a first radius, and the others form large diameter portions having a second radius larger than the first radius, a pair of the first fastening portions adjacent to each other with the small diameter portion interposed therebetween are formed with a communicating portion and a slit portion having a slit opening in each of the communicating portion and the small diameter portion, the first electromagnetic steel sheets are stacked such that the small diameter portion faces the large diameter portion of the adjacent first electromagnetic steel sheet and the communicating portion faces the communicating portion of the adjacent first electromagnetic steel sheet, The first fastening portion is formed with a fastening hole for inserting a fixing bolt therethrough, the communication portion is provided in the vicinity of the fastening hole, a forming area of ​​the communication portion in the first electromagnetic steel plate and a forming area of ​​the fastening hole are spaced apart in the circumferential direction of the stator, A rotating electric machine characterized in that the distance from the stator axis center to the inner end of the stator in the range where the fastening holes are formed is set to be smaller than the distance from the stator axis center to the outer end of the stator in the range where the communicating portions are formed.

2. In the rotating electric machine according to claim 1, The rotating electric machine, wherein the communication portion is formed in a region of the first electromagnetic steel plate at a distance from the stator axis center that is greater than the first radius.

3. A stator formed by stacking a plurality of first electromagnetic steel plates each having a substantially annular shape; a rotor rotatably provided on an inner circumferential side of the stator, The plurality of first electromagnetic steel sheets are a plurality of first fastening portions and a plurality of arc-shaped outer peripheries provided between the first fastening portions and other adjacent first fastening portions; At least one of the plurality of arc-shaped outer peripheries forms a small diameter portion having a first radius, and the others form large diameter portions having a second radius larger than the first radius, a pair of the first fastening portions adjacent to each other with the small diameter portion interposed therebetween are formed with a communicating portion and a slit portion having a slit opening in each of the communicating portion and the small diameter portion, the first electromagnetic steel sheets are stacked such that the small diameter portion faces the large diameter portion of the adjacent first electromagnetic steel sheet and the communicating portion faces the communicating portion of the adjacent first electromagnetic steel sheet, A rotating electric machine, characterized in that the distance from the stator axis to the large diameter portion is set to be equal to or less than the distance from the stator axis to the outer peripheral edge of the slit portion.

4. A stator formed by stacking a plurality of first electromagnetic steel plates each having a substantially annular shape; a rotor rotatably provided on an inner circumferential side of the stator, The plurality of first electromagnetic steel sheets are a plurality of first fastening portions and a plurality of arc-shaped outer peripheries provided between the first fastening portions and other adjacent first fastening portions; At least one of the plurality of arc-shaped outer peripheries forms a small diameter portion having a first radius, and the others form large diameter portions having a second radius larger than the first radius, a pair of the first fastening portions adjacent to each other with the small diameter portion interposed therebetween are formed with a communicating portion and a slit portion having a slit opening in each of the communicating portion and the small diameter portion, the first electromagnetic steel sheets are stacked such that the small diameter portion faces the large diameter portion of the adjacent first electromagnetic steel sheet and the communicating portion faces the communicating portion of the adjacent first electromagnetic steel sheet, the stator is formed by alternately stacking first laminates in which the first electromagnetic steel sheets are stacked and second laminates in which the second electromagnetic steel sheets are stacked, a rotating electric machine, characterized in that the second electromagnetic steel sheet has a plurality of second fastening portions and a plurality of second arc-shaped outer peripheries provided between the second fastening portion and other adjacent second fastening portions and having a third radius greater than or equal to the second radius.

5. In the rotating electric machine according to claim 4, The second laminate is provided at at least one end of the stator in the lamination direction, A rotating electric machine characterized in that the second electromagnetic steel plate of the second laminate provided at one end has a refrigerant supply hole that supplies a cooling medium from outside to the communication portion of the first electromagnetic steel plate.

6. In the rotating electric machine according to claim 1, the stator includes a first laminate formed by laminating the first electromagnetic steel sheets, and a laminate of second electromagnetic steel sheets provided at one end of the first laminate in a lamination direction, The second electromagnetic steel sheet is a plurality of second fastening portions; a plurality of second arc-shaped outer peripheries provided between the second fastening portion and adjacent other second fastening portions, the second arc-shaped outer peripheries having a third radius equal to or greater than the second radius; a coolant supply hole provided in the second fastening portion for supplying a coolant from outside to the communication portion of the first electromagnetic steel plate.

7. A stator formed by stacking a plurality of first electromagnetic steel plates each having a substantially annular shape; a rotor rotatably provided on an inner circumferential side of the stator, The plurality of first electromagnetic steel sheets are a plurality of first fastening portions and a plurality of arc-shaped outer peripheries provided between the first fastening portions and other adjacent first fastening portions; At least one of the plurality of arc-shaped outer peripheries forms a small diameter portion having a first radius, and the others form large diameter portions having a second radius larger than the first radius, a pair of the first fastening portions adjacent to each other with the small diameter portion interposed therebetween are formed with a communicating portion and a slit portion having a slit opening in each of the communicating portion and the small diameter portion, the first electromagnetic steel sheets are stacked such that the small diameter portion faces the large diameter portion of the adjacent first electromagnetic steel sheet and the communicating portion faces the communicating portion of the adjacent first electromagnetic steel sheet, The number of the first fastening portions is odd, a connecting hole is provided in the first fastening portion in which the slit portion is not formed, connecting the communicating portion of the first electromagnetic steel plate adjacent to one side in the stator axial direction with the communicating portion of the first electromagnetic steel plate adjacent to the other side in the stator axial direction.

8. In the rotating electric machine according to claim 4 or 5, The rotating electric machine, wherein the third radius is set to be equal to or larger than the second radius and equal to or smaller than the distance from the axial center of the stator to the outer peripheral edge of the slit portion.

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