JP7764428B2 - rotating electrical machines - Google Patents

Description

The present invention relates to a rotating electric machine.

Conventionally, a method of cooling the stator core of a rotating electrical machine involves dripping refrigerant 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 staggered around the stator circumferentially. As a result, the refrigerant that drips onto the outer peripheral surface of the stator core and flows down the outer peripheral surface is guided in the axial direction of the stator by the multiple refrigerant guide vanes, and ultimately to the coil end portions.

JP 2015-115994 A

The cross-sectional shape of the stator core is annular, and the outer peripheral surface of the stator core has multiple stator fastening portions that gently protrude from the outer peripheral surface and extend from one end of the stator core to the other. Most of the refrigerant that drips near the vertical apex of the stator core outer peripheral surface is guided to the coil end portion by the refrigerant guide vanes. Some also flows vertically between the refrigerant guide vanes and reaches the stator fastening portions.

When the refrigerant reaches the stator fastening section, it attempts to flow over the stator fastening section and continue downward. 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, there is a problem in that the vertically lower portion of the stator core is not sufficiently cooled by the refrigerant.

A rotating electric machine according to one aspect of the present invention is a rotating electric machine comprising a stator formed by laminating a plurality of first electromagnetic steel plates 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 plates have a plurality of first fastening portions and a plurality of arc-shaped outer peripheries provided between the first fastening portions and other first fastening portions adjacent to the 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, and a pair of adjacent first fastening portions sandwiching the small diameter portion have a communicating portion, and the communicating portion and the small diameter portion each have a slit opening. the first electromagnetic steel plate is laminated such that the small diameter portion faces the large diameter portion of the adjacent first electromagnetic steel plate and the communicating portion faces the communicating portion of the adjacent first electromagnetic steel plate ; 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 plate where the communicating portion is formed and the area in the first electromagnetic steel plate where the fastening hole is formed are spaced apart in the circumferential direction of the stator, and the distance from the axis of the stator of the inner peripheral end of the area where the fastening hole is formed is set to be smaller than the distance from the axis of the stator of the outer peripheral end of the area where the communicating portion is formed .

This invention improves the cooling performance of the stator using refrigerant.

FIG. 1 is a diagram showing the main parts of a rotating electrical machine. FIG. 2 is a diagram showing the first electromagnetic steel sheet. FIG. 3 is a diagram showing the second electromagnetic steel sheet. FIG. 4 is a diagram showing the arrangement of the magnetic steel sheets to be rotated. FIG. 5 is a schematic diagram illustrating the flow of refrigerant in each laminate block of the stator core. FIG. 6 is a diagram showing the flow of the refrigerant when the stator core is viewed along the axial direction. FIG. 7 is a diagram illustrating the relationship between the radius of the large diameter portion and the flow of the refrigerant. FIG. 8 is a diagram illustrating the positional relationship between the communication portion and the fastening hole. 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. FIG. 10 is a diagram showing an electromagnetic steel sheet according to the first modification. FIG. 11 is a schematic diagram illustrating a stacking pattern of the main stacked body block in the first modification. FIG. 12 is a diagram showing a first electromagnetic steel sheet in Modification 2. FIG. 13 is a diagram illustrating a groove flow path in the second modification.

The following describes an embodiment of the present invention with reference to the drawings. The following description and drawings are examples for explaining the present invention, and have been omitted or simplified as appropriate for clarity of explanation. Furthermore, in the following description, identical or similar elements and processes are given the same reference numerals, and duplicate explanations may be omitted. Note that the content described below is merely 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.

Figure 1 shows the stator 2 and 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 comprises an annular stator 2 and a rotor 3 arranged on the inner periphery of the stator 2. The stator 2 comprises 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.

A number of slots 22 are formed on the inner periphery of the stator core 20. Each slot 22 houses a number of coil conductors that form the coil sides of the stator coil 21. Note that, below, the core region of the stator core 20 that is on the outer periphery of the region in which the slots 22 are provided may be referred to as the back yoke portion.

The stator core 20 is made of laminated electromagnetic steel sheets. The outer periphery of the stator core 20 is provided with multiple fastening portions 201a-201c that protrude from the outer periphery for securing it to the motor casing. In the example shown in Figure 1, three fastening portions 201a-201c are provided at equal intervals around the circumference. Each fastening portion 201a-201c is formed with a fastening hole 202 for bolt fastening.

Groove flow paths 210a-210c for guiding refrigerant are formed between adjacent fastening portions in the outer peripheral region of the stator core 20. As will be described in detail below, groove flow path 210a communicates with adjacent groove flow path 210b via communication portion 203, and groove flow path 210b further communicates with adjacent groove flow path 210c via communication portion 203.

Figures 2 and 3 are diagrams showing electromagnetic steel sheets 200A and 200B used in the stator core 20. The stator core 20 is formed by laminating electromagnetic steel sheets, and two types of electromagnetic steel sheets with different outer peripheral shapes are used. The first electromagnetic steel sheet 200A, which has a substantially annular shape, shown in Figure 2 is an electromagnetic steel sheet used in the 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 Figure 3 is an electromagnetic steel sheet used in the laminate block located on one end side of the main laminate block. The main laminate block and laminate block will be described later.

Note that the electromagnetic steel sheets used in the laminate block located on the other end of the main laminate block are not shown. Furthermore, in the description of each part of the electromagnetic steel sheets 200A, 200B shown in Figures 2 and 3, parts corresponding to each part of the stator core 20 are given the same names and symbols as in the stator core 20.

As shown in Figure 2, two fastening portions 201a and 201b on electromagnetic steel sheet 200A have fastening holes 202, communication portions 203, and slits 204 formed therein. Meanwhile, fastening portion 201c has fastening holes 202 and holes 205 formed therein. In the example shown in Figure 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-degree intervals) on the same circumference centered on stator axis C.

The arc-shaped outer peripheral region between fastening portion 201a and fastening portion 201c is formed by the outer peripheral surface of small diameter portion 206a with 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 formed by the outer peripheral surface of large diameter portion 206b with 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 formed 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.

Each slit 204 in the fastening portions 201a and 201b is formed on the small diameter portion 206a side of the fastening portion region. For each slit 204, the slit opening 204a at one end connects to the communicating portion 203, and the slit opening 204b at the other end connects 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 an area of the electromagnetic steel sheet 200A whose distance from the stator axis C is greater than radius R0.

Figure 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-201c is an arc shape 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 arranged at both ends of the main laminate block constituted by the first electromagnetic steel sheet 200A.

The electromagnetic steel sheet 200B shown in Figure 3 is used in the laminate block on one end of the main laminate block, and has a supply hole 207 for supplying refrigerant from the outside into the stator core. Note that in Figure 1, electromagnetic steel sheet 200B is omitted and only the main laminate block is shown. The position of the supply hole 207 relative to the stator axis C is set to the same position as the communication portion 203 of electromagnetic steel sheet 200A shown in Figure 2. As with electromagnetic steel sheet 200A, fastening holes 202 are formed in each fastening portion 201a to 201c. Note that, although not shown, electromagnetic steel sheet 200B1, which does not have a supply hole 207, is used for the laminate located on the other end of the main laminate block.

Figure 4 is a diagram explaining 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 the three arrangements D1, D2, and D3 in order, as shown in Figure 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°.

The communication 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 communication portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D1 overlaps and communicates with the communication 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 communication portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D2.

The communication 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 communication portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D2 overlaps and communicates with the communication 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 communication portion 203 provided in the fastening portion 201b of the electromagnetic steel sheet 200A in arrangement D3.

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 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 of each formed groove is the same as the thickness of the electromagnetic steel sheet 200A.

A pair of slits 204 in the electromagnetic steel sheet 200A in arrangement D1 communicate with a groove formed by the small diameter portion 206a and the adjacent large diameter portions 206b, and this 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 the groove formed in the small diameter portion 206a between those 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 the groove formed in the small diameter portion 206a between those slits 204 form the groove flow path 210c in FIG. 1. Groove flow path 210a and groove flow path 210b are connected by a connecting portion 203. Groove flow path 210b and groove flow path 210c are connected by a connecting portion 203.

Figure 5 is a schematic diagram illustrating the flow of refrigerant in each laminate block E0, E1, and E2 of the stator core 20. Figure 5 is an axial cross-section of the stator core 20 taken along dashed line A in Figure 1, with the cross-section viewed from the outer periphery. In Figure 5, the center of fastening portion 201a (center of communicating portion 203) in Figure 1 is set to an angle of 0°, the center of fastening portion 201b to an angle of 120°, and the center of fastening portion 201c to an angle of 240°. The 0° angle position corresponds to the top (uppermost end) of the stator core 20, and the 180° angle position corresponds to the bottom (lowermost end) of the stator core 20. The vertical direction in the figure is the stator axial direction, and 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 and 200B1 in the laminate blocks E1 and E2 is not shown in the illustration.

The main laminate block E0 at the center in the stacking direction is made by stacking the first electromagnetic steel sheets 200A shown in Figure 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. The lower laminate block E1 in the figure is made by stacking multiple second electromagnetic steel sheets 200B shown in Figure 3. The supply holes 207 of each electromagnetic steel sheet 200B are located at an angle of 0°.

The upper laminate block E2 shown in the figure is made by stacking multiple electromagnetic steel sheets 200B1 that do not have the supply holes 207 shown in Figure 3. The shape of the electromagnetic steel sheets 200B1 that make up the laminate block E2 is not shown, but the supply holes 207 of the electromagnetic steel sheets 200B in Figure 3 have been removed. In Figure 5, arrows indicate the flow of refrigerant.

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 connecting to its groove flow passage 210a communicates with the supply hole 207 of the laminate block E1. The communication portion 203 on the right side of groove flow passage 210a faces the communication portion 203 on the left side of groove flow passage 210b of electromagnetic steel sheet 200A in arrangement D2 of the second layer. Groove flow passage 210a and groove flow passage 210b communicate via these two opposing communication portions 203. Groove flow passage 210b communicates with groove flow passage 210c of electromagnetic steel sheet 200A in arrangement D3 of the third layer at an angle of 240° via communication portion 203. Groove flow path 210c communicates with groove flow path 210a of electromagnetic steel sheet 200A in arrangement D1 on the fourth layer via communication portion 203 at an angle of 360° (angle 0°).

Furthermore, at angles of 0°, 120°, and 240°, the communicating portions 203 and holes 205 are aligned in the stator axial direction (the up-and-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 angles 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.

The refrigerant supplied from outside is supplied to the supply holes 207 of the laminate block E1. The refrigerant supplied to the supply holes 207 flows into the refrigerant reservoir (cylindrical hole space) 300a extending in the axial direction of the stator, filling the refrigerant reservoir 300a. The refrigerant in the refrigerant reservoir 300a flows through the communication portions 203 into each groove flow path 210a and each groove flow path 210c. In this way, the supplied refrigerant fills the refrigerant reservoir 300a extending in the axial direction, thereby evenly distributing the refrigerant to the multiple groove flow paths 210a, 210c arranged in the axial direction.

As shown by the arrows in Figure 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 a 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 arrows.

Meanwhile, the refrigerant in groove flow channel 210c moves in a direction at an angle of 240° and flows into refrigerant reservoir 300c. The refrigerant that flows into refrigerant reservoir 300c moves axially within refrigerant reservoir 300c 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 arrows.

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

Since the thickness of the electromagnetic steel sheets 200A, 200B, and 200B1 used in the stator core 20 is generally 1 mm or less, the groove width of the grooves 210a to 210c is also 1 mm or less. Therefore, even in the downward groove angle range of 120 ° to 240°, the refrigerant is held in the grooves 210a to 210c due to the influence of surface tension, making it difficult for the refrigerant to fall. Ultimately, the refrigerant falls from the grooves 210b in the bottom region of the stator core 20 where the refrigerant collects.

As described above, in this embodiment, groove channels 210a-210c are formed around the stator core 20 by rotating electromagnetic steel sheets 200A having small diameter portions 206a and large diameter portions 206b. The groove width of groove channels 210a-210c is the same as the thickness of electromagnetic steel sheets 200A, allowing for the formation of groove channels with very narrow widths. Therefore, surface tension allows the refrigerant in groove channels 210a-210c to migrate vertically downward on the stator core 20 without falling out of groove channels 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, by forming groove channels 210a-210b, the contact area of the refrigerant can be increased, thereby improving cooling performance.

In the above-described embodiment, the electromagnetic steel sheets 200A are stacked one by one, but multiple sheets may be stacked at a time as long as the effect of surface tension can be expected.

Figure 7 is a diagram illustrating the relationship between the radius R2 of the large diameter portion 206b and the flow of refrigerant. Refrigerant moving within the groove flow path 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 the case where the radius R2 of the large diameter portion 206b is smaller than the radius R1 of the outer edge of the arc-shaped slit 204. In this case, the groove flow path 210a sandwiched between the two large diameter portions 206b enters the slit 204 without overlapping with the outer edge of the slit 204.

On the other hand, as shown by dashed line L2, if the radius R2 of the large-diameter portion 206b is greater than the radius R1 of the outer edge of the arc-shaped slit 204, the electromagnetic steel sheet near the slit entrance will protrude into the groove flow channel 210a. As a result, the refrigerant moving through the groove flow channel 210a toward the fastening portion 201b is partially branched by the protruding portion and flows out onto the outer surface of the fastening portion 201b, as indicated by arrow F. The refrigerant that flows out onto the outer 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 of the stator core 20 without some of the refrigerant falling off the outer surface of the stator core along the way.

2, in this embodiment, holes 205 forming refrigerant reservoirs 300a-300c and communicating portions 203 are disposed near fastening holes 202, thereby improving the sealing performance of communicating portions 203 through bolt fastening. The width (radial dimension) of the back yoke portion on the outer circumferential side of slots 22 affects the torque performance of the rotating electric machine. Therefore, by disposing communicating portions 203 near fastening holes 202 and suppressing a decrease in the width of the back yoke portion, it is possible to prevent a decrease in torque performance.

Also, as shown in Figure 8, the communication portion 203 and the fastening hole 202 are offset in the circumferential direction and then arranged so that they overlap in the radial direction. In other words, when considering the radial distance from the stator axis C, the radial distance R11 of the fastening hole 202 on the inner periphery of the stator is set to be smaller than the radial distance R12 of the communication portion 203 on the outer periphery 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.

In the example shown in Figure 6, the refrigerant is supplied from supply hole 207 provided in laminate block E1. However, another method of supplying refrigerant from the outside is to drip the refrigerant onto the outer peripheral surface of the stator core, as described in Patent Document 1. Figure 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 Figure 9, the stator core 20 is positioned so that fastening portion 201a is oriented vertically downward, and the refrigerant is dripped from refrigerant supply pipe 301 onto the outer peripheral surface between fastening portions 201b and 201c.

The refrigerant dripping from the refrigerant supply pipe 301 flows along the outer periphery and enters groove flow channel 210b. The refrigerant in groove flow channel 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 channel 210a and moves toward fastening portion 201a, flowing into refrigerant reservoir 300a at fastening portion 201a. The refrigerant in refrigerant reservoir 300c flows into groove flow channel 210c and moves toward fastening portion 201a, flowing into refrigerant reservoir 300a. The refrigerant that has accumulated in refrigerant reservoir 300a and in groove flow channels 210a and 210c near fastening portion 201a flows vertically downward due to gravity, as shown by the arrows.

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

(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 rest of the configuration is the same as that of the electromagnetic steel sheet 200B shown in FIG. 3 .

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

In the example shown in Figure 11, stacked region E01 is composed of three electromagnetic steel plates 200A, rotated from the bottom in arrangements D1, D2, and D3. On the other hand, stacked region E02 is composed of two electromagnetic steel plates 200B2 stacked together. Holes 205 are formed in the fastening portions 201a-201c of electromagnetic steel plates 200B2, forming refrigerant reservoirs 300a-300c similar to those in Figure 5. In stacked region E01, refrigerant supplied to refrigerant reservoir 300a is guided clockwise through groove channels 210a and 210b, and counterclockwise through groove channels 210c and 210b.

In the example shown in FIG. 11, the stacking region E01 is made up of three electromagnetic steel sheets 200A, but it may be made up of 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.

In variant 1, groove channels 210a-210c are formed around the entire circumference of the stator core 20, allowing the refrigerant to cool almost the entire circumference of the stator core 20, improving cooling efficiency. As mentioned above, the width (radial dimension) of the back yoke portion outer than the slots 22 affects the torque performance of the rotating electric machine. Therefore, providing small diameter portions 206a in electromagnetic steel sheet 200A to form groove channels 210a-210c results in a decrease in torque performance. In variant 1, the decrease in torque performance can be suppressed by providing laminated region E02 formed from electromagnetic steel sheet 200B2, which does not have small diameter portions 206a.

(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.

A fastening hole 201 and a slit 204 are formed in each fastening portion 201a-201d. One end of the slit 204, labeled 204c, on the fastening hole 201 side functions as a communication portion that communicates with the slit 204 in other layers. 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.

Figure 13 is a diagram illustrating groove channels 210a-210d formed by electromagnetic steel sheets 200C. When the number of fastening portions is an even number, the small diameter portions 206a and large diameter portions 206b are arranged alternately in the circumferential direction as shown in Figure 12. Therefore, by repeatedly rolling two types of arrangement of electromagnetic steel sheets 200C, an even number of groove channels can be formed that are arranged around the stator core 20. 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 sheet 200C shown in Figure 12 is four, the rolling angle is 90°.

For example, if the arrangement of the electromagnetic steel sheets 200C shown in Figure 12 is referred to as the first arrangement D11, the second arrangement D12 is an arrangement in which the electromagnetic steel sheets 200C in Figure 12 are rotated 90 degrees in the circumferential direction. The main laminate block E0 is constructed by alternately stacking the electromagnetic steel sheets 200C in arrangement D11 and the electromagnetic steel sheets 200C in arrangement D12.

In FIG. 13, the electromagnetic steel sheet 200C designated by the reference symbol 200C (D11) is the electromagnetic steel sheet in arrangement D11, and the electromagnetic steel sheet 200C designated by the reference symbol 200C (D12) is the electromagnetic steel sheet in 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, forming groove channels 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, forming groove channels 210b and 210d.

The communicating portions 204c of the slits 204 of the electromagnetic steel plate 200C (D11) overlap with the communicating portions 204c of the slits 204 of the electromagnetic steel plate 200C (D12), thereby communicating with adjacent groove flow paths in the circumferential direction. The communicating portions 204c of each electromagnetic steel plate 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 at 90° intervals in the circumferential direction.

The effects of the above-described embodiment and variations can be summarized as follows:

(1) As shown in Figures 1, 2, 4, etc., a rotating electric machine 1 includes a stator 2 formed by stacking a plurality of substantially annular electromagnetic steel sheets 200A (first electromagnetic steel sheets), and a rotor 3 rotatably provided on the inner periphery of the stator 2. The plurality of electromagnetic steel sheets 200A have a plurality of fastening portions 201a-201c (first fastening portions) and a plurality of arc-shaped outer peripheries provided between a fastening portion (201a-201c) and another adjacent fastening portion (201a-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 the small diameter portion 206a has a communicating portion 203 and a slit (slit portion) 204 with 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.

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 thickness of the electromagnetic steel sheet 200A. As a result, the refrigerant introduced into the groove channels 210a-210c is held within the groove channels 210a-210c by surface tension, and is able to travel 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.

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

(3) In (2) above, as shown in FIG. 8 and other figures, the formation area of the communication portion 203 in the electromagnetic steel sheet 200A and the formation area of the fastening hole 202 are spaced apart in the circumferential direction of the stator, and the radial distance R11 from the stator axis C of the inner peripheral end of the formation area of the fastening hole 202 is set to be smaller than the radial distance R12 from the stator axis C of the outer peripheral end of the formation area of the communication portion 203. By setting it in this manner, the outer diameter of the stator core 20 can be reduced while ensuring the width of the back yoke portion.

(4) In (1) above, as shown in Fig. 7 and other figures, 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.

(5) In (1) above, as shown in Figure 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 path 210a is branched at the outer peripheral edge of the slit 204, preventing some of the refrigerant from leaking from the groove flow path 210a and falling from the stator core 20.

(6) In (1) above, as shown in Figures 10 and 11, the stator 2 is formed by alternately stacking a stacking region E01 (first stack) in which electromagnetic steel sheets 200A are stacked and a stacking region E02 (second stack) in which electromagnetic steel sheets 200B2 (second electromagnetic steel sheets) are stacked. 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) that are provided between the fastening portions (201a-201c) and adjacent other fastening portions (201a-201c) and have a radius R3 (third radius) equal to or greater than the radius R2 (second radius). In this way, by providing the stacking region E02 in which electromagnetic steel sheets 200B are stacked in the main stack block E0, torque performance can be improved in a configuration that includes grooved flow paths 201a-201c.

In the configuration shown in Figures 10 and 11, holes 205 are provided in electromagnetic steel plate 200B2 to form refrigerant reservoirs 300a-300c for uniform axial distribution of refrigerant. However, in the case of a refrigerant supply system in which refrigerant drips onto the outer periphery of the stator, holes 205 in electromagnetic steel plate 200B2 may be omitted, i.e., a configuration may be adopted in which refrigerant reservoirs 300a-300c are not formed.

(7) In (6) above, as shown in Figures 3, 11, etc., a laminate block E1 (second laminate) is provided at at least 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 portions 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-201c from the axial end faces of the stator 2.

(8) In (1) above, 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. The electromagnetic steel sheets 200B may include a plurality of fastening portions 201a-201c (second fastening portions), a plurality of outer peripheries 206c (second arc-shaped outer peripheries) provided between the fastening portions (201a-201c) and other fastening portions (201a-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-201c to supply a cooling medium from outside to the communication portions 203 of the electromagnetic steel sheets 200A.

(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 the communicating portions 203 of adjacent electromagnetic steel sheets 200A on one side in the stator axial direction to the communicating portions 203 of adjacent electromagnetic steel sheets 200A on the other side in the stator axial direction. By providing holes 205, the 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.

(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 falling in the fastening portion area while suppressing a decrease in torque performance.

The various embodiments and modifications described above are merely examples, and the present invention is not limited to these details as long as they do not impair the characteristics of the invention. Other embodiments conceivable within the technical spirit of the present invention are also included within the scope of the present invention.

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-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-210d...groove flow path, 300a, 300b, 300c...refrigerant reservoir, C...stator axis, D1-D3, D11, D12...arrangement, E0...main laminate block, E1, E2...laminated block

Claims (8)

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 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 portions face the large diameter portions of the adjacent first electromagnetic steel sheets and the communicating portions face the communicating portions of the adjacent first electromagnetic steel sheets ,
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 portion is formed . 2. 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. 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,
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. 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 portions face the large diameter portions of the adjacent first electromagnetic steel sheets and the communicating portions face the communicating portions of the adjacent first electromagnetic steel sheets,
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. 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. 2. 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. 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 portions face the large diameter portions of the adjacent first electromagnetic steel sheets and the communicating portions face the communicating portions of the adjacent first electromagnetic steel sheets,
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. 6. The rotating electric machine according to claim 4,
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.