Rotating electric machine

Abstract

This invention relates to a rotating electric machine in which the housing and stator are fixed to each other by radial clamping, and contributes to improving operating efficiency. [Solution] The rotating electric machine M comprises a cylindrical housing 1 (housing body 11), a stator 2 (stator core 21), and a rotor 3 disposed inside the stator 2 and configured to rotate freely relative to the stator 2. The housing body 11 has a plurality of cooling water passages 111 formed at intervals in the circumferential direction of the housing body 11 for the flow of cooling water. Between the housing body 11 and the stator core 21, a gap (recess n) is formed where the inner circumferential surface of the housing body 11 and the outer circumferential surface of the stator core 21 are spaced radially apart, and at least a portion of the area R sandwiched between adjacent cooling water passages 111 in the circumferential direction overlaps radially.

Description

Technical Field

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

Background Art

[0002] There exists a rotating electric machine including a cylindrical stator and a rotor disposed rotatably with respect to the stator inside the stator, and the housing and the stator are fixed to each other by shrink fitting.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The housing is provided with a cooling water passage for cooling during the operation of the rotating electric machine. For example, a plurality of cooling water passages extending in the axial direction of the housing are formed at intervals in the circumferential direction. When shrink fitting is applied to the fixing of such a housing and stator, the following problems occur.

[0005] Due to the arrangement of the cooling water passages spaced in the circumferential direction, a non-uniform surface pressure is applied in the circumferential direction from the inner circumferential surface of the housing to the outer circumferential surface of the stator after fixing by shrink fitting. Specifically, the surface pressure relatively increases in the region between adjacent cooling water passages, and relatively decreases in other regions.

[0006] As a result, a large compressive stress occurs in the part of the inner peripheral portion of the stator located between the outer peripheral portions receiving a high surface pressure, and due to this, the magnetic characteristics of the stator deteriorate, and the operating efficiency of the rotating electric machine decreases.

[0007] In view of these circumstances, the present invention relates to a rotating electric machine in which a housing and a stator are fixed to each other by radial tightening, and aims to provide a technology that contributes to improving the operating efficiency. [Means for solving the problem]

[0008] To solve the aforementioned problems, a rotating electric machine according to one embodiment of the present invention comprises a cylindrical housing, a stator, and a rotor disposed inside the stator and configured to be rotatable relative to the stator, wherein the housing and the stator are fixed to each other by radial clamping, with the stator positioned concentrically and the stator positioned inside the housing. The housing has a plurality of cooling water passages formed at intervals in the circumferential direction for the flow of cooling water. A gap is formed between the housing and the stator, such that the inner circumferential surface of the housing and the outer circumferential surface of the stator are spaced apart in the radial direction of the housing, and at least a portion of the area sandwiched between adjacent cooling water passages in the circumferential direction overlaps in the radial direction.

[0009] Another embodiment of the present invention is a rotating electric machine comprising a cylindrical housing, a stator, and a rotor disposed inside the stator and configured to be rotatable relative to the stator. The housing has a plurality of cooling water passages formed at intervals in the circumferential direction of the housing for the flow of cooling water. The housing and the stator are fixed to each other by radial clamping, with radially recessed recesses on the inner circumferential surface of the housing or the outer circumferential surface of the stator, concentrically positioned with the stator inside the housing, and at least a portion of the recesses overlapping radially with respect to the area sandwiched in the circumferential direction by adjacent cooling water passages. [Effects of the Invention]

[0010] According to one embodiment of the present invention, it is possible to suppress the occurrence of large compressive stress in the inner circumferential portion of the stator, which is located between the outer circumferential portion that receives high surface pressure from the housing. As a result, it is possible to create a strong bonding force between the housing and the stator due to radial tightening, while suppressing the deterioration of the magnetic properties of the stator caused by compressive stress, thereby improving the operating efficiency of the rotating electric machine. [Brief explanation of the drawing]

[0011] [Figure 1] This is a cross-sectional view showing the overall configuration of a rotating electric machine (electric motor) according to one embodiment of the present invention. [Figure 2] Figure 1 is a cross-sectional view along line XX, showing the internal structure of the rotating electric machine according to the above embodiment. [Figure 3] This is a plan view of the motor housing according to the same embodiment. [Figure 4] This is a plan view of the stator (stator core) according to the same embodiment. [Figure 5] This is a schematic diagram showing the positional relationship between the motor housing and the stator in the rotating electric machine according to the same embodiment. [Figure 6] This is a schematic diagram illustrating the distribution of surface pressure from the inner circumference of the motor housing to the outer circumference of the stator. [Figure 7] This is a schematic diagram showing the change in tooth pitch in the comparative example. [Modes for carrying out the invention]

[0012] Embodiments of the present invention will be described below with reference to the drawings.

[0013] (Overall configuration of a rotating electric machine) Figure 1 is a cross-sectional view showing the overall configuration of a rotating electric machine M according to one embodiment of the present invention.

[0014] The rotating electrical machine M according to the present embodiment (hereinafter sometimes referred to as "electric motor" or simply "motor") is a permanent magnet synchronous motor. As the rotating electrical machine M, an electric motor with a driving method different from that of a permanent magnet synchronous motor, such as a wound field synchronous motor or an induction motor, can be adopted.

[0015] The rotating electrical machine M according to the present embodiment is a so-called motor generator that can operate as both a prime mover and a generator. Not limited to this, the rotating electrical machine M may be an electric motor that can only operate as a prime mover.

[0016] In the present embodiment, the rotating electrical machine M constitutes a drive source for an electric vehicle or a hybrid vehicle. It is possible to transmit the output torque of the rotating electrical machine M to the drive wheels of the vehicle and propel the vehicle forward or backward. Not limited to this, the rotating electrical machine M can be applied as an in-vehicle actuator other than the drive source, and can also be applied to uses other than in-vehicle.

[0017] In the following description, the axial direction, radial direction, and circumferential direction are defined based on the rotation center axis A of the rotating electrical machine M. Specifically, the direction along the rotation center axis A is the "axial direction", the direction perpendicular to the rotation center axis A is the "radial direction", and the direction along the circle centered on the rotation center axis A is the "circumferential direction".

[0018] The electric motor M mainly includes a motor housing 1, a stator 2, a rotor 3, and a motor shaft 4.

[0019] The motor housing 1 is generally cylindrical as a whole and is divided into a housing body 11, a first cover 12, and a second cover 13. The housing body 11 has both ends in the axial direction open, and a space penetrating in the axial direction is formed inside. The stator 2 and the rotor 3 are accommodated in this space. The first cover 12 is attached to one end of the housing body 11, and the second cover 13 is attached to the other end, respectively, to form the motor housing 1. The first and second covers 12 and 13 may be configured as brackets used for installing the electric motor M.

[0020] The stator 2 is arranged concentrically with the housing body 11 inside the housing body 11 in the radial direction (that is, on the inner diameter side). The stator 2 is fixed to the housing body 11 and is in a non-rotatable state with respect to the housing body 11. The stator 2 is fixed to the housing body 11 by, for example, shrink fitting. Specifically, the housing body 11 is expanded by heating, fitted onto the outer circumference of the stator 2, and then cooled.

[0021] The rotor 3 is arranged concentrically with the stator 2 inside the stator 2 in the radial direction (that is, on the inner diameter side).

[0022] The motor shaft 4 is press-fitted into a shaft insertion hole that axially penetrates the inner diameter portion of the rotor 3 and is fixed to the rotor 3. As a result, the motor shaft 4 can rotate integrally with the rotor 3.

[0023] The motor shaft 4 is arranged coaxially with the rotation center axis A and is supported by bearings (the first bearing 61 and the second bearing 62) on each side of the rotor 3 in the axial direction with respect to the motor housing 1. The first and second bearings 61 and 62 are supported by the first cover 12 and the second cover 13 of the motor housing 1, respectively, and the motor shaft 4 supports the rotor 3 in a rotatable state about the rotation center axis A with respect to the stator 2.

[0024] (Internal structure of the rotating electrical machine) FIG. 2 is a cross-sectional view taken along the X-X line shown in FIG. 1 and shows the internal structure of the electric motor M. FIG. 3 is a plan view of the housing body 11, and FIG. 4 is a plan view of the stator 2 (stator core 21).

[0025] The internal structure of the electric motor M will be described with reference to FIG. 2 while appropriately referring to FIGS. 3 and 4.

[0026] The housing body 11 has an annular shape with a constant width dimension in the radial direction in a plan view as shown in Figures 2 and 3. In this embodiment, the inner circumferential surface 11i is perfectly circular in a plan view, and the overall shape is cylindrical.

[0027] The housing body 11 has multiple passages (hereinafter referred to as "water jackets") 111 through which cooling water flows for cooling when the electric motor M is in operation. The water jackets 111 penetrate the housing body 11 in the axial direction and have equal width dimensions in the circumferential direction, and are arranged at equal intervals in the circumferential direction.

[0028] In this embodiment, connecting passages 121 and 131 are formed in the first and second covers 12 and 13, respectively, connecting adjacent water jackets 111, and the direction of the cooling water flow is reversed via the connecting passages 121 and 131. Specifically, in the connecting passage 121 of the first cover 12, the flow of cooling water toward the first cover 12 is reversed to a direction away from the first cover 12, and in the connecting passage 131 of the second cover 13, the flow of cooling water toward the second cover 13 is reversed to a direction away from the second cover 13. As a result, the water jackets 111 formed in the housing body 11 form a series passage in all or part of their area.

[0029] The stator 2 has a stator core 21 and coil windings 22.

[0030] The stator core 21 consists of an iron core formed by laminating multiple thin electromagnetic steel sheets in the axial direction and joining them together, and has a yoke portion 211 and multiple teeth 212.

[0031] The yoke portion 211 is annular in shape and includes the outer circumferential surface 21p of the stator core 21. In other words, the outer circumferential surface of the stator 2 is formed by the outer circumferential surface of the yoke portion 211.

[0032] The teeth 212 are formed circumferentially on the inside (i.e., inner diameter side) of the yoke portion 211 in the radial direction. Each of the multiple teeth 212 protrudes radially inward from the inner circumferential surface of the yoke portion 211 toward the rotational axis A.

[0033] Here, the yoke portion 211 of the stator core 21 corresponds to the "outer ring portion" according to this embodiment, and each of the multiple teeth 212 corresponds to the "protruding portion" according to this embodiment.

[0034] The coil winding 22 is formed by winding a conductor around a plurality of teeth 212. In this embodiment, the coil winding 22 is formed, for example, by concentrated winding. The conductor wound around the teeth 212 is housed in the gap (hereinafter referred to as "slot") s formed between adjacent teeth 212. The teeth 212 and the coil winding 22 provided thereon form an electromagnetic coil. The coil winding 22 is not limited to concentrated winding; it can also be formed by distributed winding.

[0035] As shown in Figure 4, in this embodiment, a plurality of recesses n are formed on the outer circumferential surface 21p of the stator core 21, recessing radially inward. In these plurality of recesses n, the dimensions defined in the circumferential direction (i.e., width) and the dimensions defined in the radial direction (i.e., depth) are equal to each other. Furthermore, the recesses n are arranged at equal intervals in the circumferential direction.

[0036] As shown in Figure 2, by forming the recess n, a radial gap is created between the housing body 11 and the stator 21 after fixing by shrink fitting, and the inner circumferential surface 11i of the housing body 11 and the outer circumferential surface 21p of the stator 21 are spaced radially apart across this gap.

[0037] The rotor 3 has a rotor core 31 and a plurality of permanent magnets 32.

[0038] The rotor core 31 is cylindrical and fixed to the outer circumference of the motor shaft 4. As mentioned earlier, the rotor core 31 has a shaft insertion hole that penetrates its inner diameter in the axial direction, and the motor shaft 4 is inserted into and fixed to this shaft insertion hole.

[0039] The rotor core 31, like the stator core 21, is composed of an iron core formed by laminating multiple thin electromagnetic steel sheets in the axial direction and bonding them together.

[0040] As shown in Figure 1, the motor shaft 4 has end plates made of non-magnetic material (first end plate 51, second end plate 52) attached to each side of the rotor 3 in the axial direction. The first and second end plates 51 and 52 sandwich the multiple electromagnetic steel sheets that make up the rotor core 31 from both sides in the axial direction.

[0041] The permanent magnets 32 are arranged in a circumferential direction on the outer circumference of the rotor core 31. Multiple permanent magnet insertion holes corresponding to each of the multiple permanent magnets 32 are formed on the outer circumference of the rotor core 31, and each permanent magnet 32 ​​is inserted into one of these multiple permanent magnet insertion holes and fixed to the stator core 31. The arrangement of the permanent magnets 32 is not limited to the embedded type shown in Figure 2, but may also be a surface type.

[0042] In this embodiment, two permanent magnets 32 are provided per pole, and the rotor 3 is configured as an 8-pole motor with a total of 16 permanent magnets 32. The permanent magnets 32 form one pole in pairs and are arranged in a V-shape that spreads outward in the radial direction. The total number of permanent magnets 32, the number per pole, and their arrangement in the rotor core 31 are not limited to this, and it is possible to have 4 poles or 1 magnet per pole.

[0043] (Positional relationship between the motor housing and the stator) Here, the positional relationship between the motor housing 1 (housing body 11) and the stator 2 (stator core 21) will be explained with reference to Figure 5.

[0044] The housing body 11 and the stator core 21 are fixed together by shrink fitting such that at least a portion of the recess n overlaps radially with respect to the range Ri that is sandwiched circumferentially by adjacent water jackets 111 (for example, water jackets 111a and 111b shown in Figure 5). In other words, the housing body 11 and the stator core 21 are fixed together such that a straight line extends radially outward from the rotational axis A, passing between adjacent water jackets 111a and 111b, and the recess n lies on this straight line.

[0045] Here, as shown in Figure 5, among adjacent water jackets 111a and 111b, the parts that are closest to each other in the circumferential direction are defined as the proximity parts (first proximity part Pa1, second proximity part Pb1), and the range Ri is defined as the range whose circumferential ends are determined by these proximity parts Pa1 and Pb1. In other words, if the first imaginary boundary line Lv1 is defined as a straight line extending radially outward from the rotational axis A and passing through the first proximity part Pa1, and the second imaginary boundary line Lv2 is defined as a straight line extending radially outward from the rotational axis A and passing through the second proximity part Pb1, then the range Ri corresponds to a sector-shaped range whose circumferential edges are determined by the first and second imaginary boundary lines Lv1 and Lv2, and whose central angle is acute.

[0046] Here, the housing body 11 and the stator core 21 are fixed to each other in such a way that the recess n is located on a straight line that extends radially outward from the rotational axis A and overlaps the range Ri. In this embodiment, on an arc with the first nearest end Pa1 and the second nearest end Pb1 as its ends, the center Pm between the passages is defined as a position at an equal distance from these nearest ends Pa1 and Pb1, and the intermediate virtual line Lv3 is defined as a straight line that extends radially outward from the rotational axis A and passes through the center Pm between the passages. The recess n is fixed to each other in such a way that it is located on the intermediate virtual line Lv3.

[0047] As a result, in the state after fixation by shrink fitting, the gap formed by the recess n is positioned so that at least a portion of it overlaps radially with the range Ri that is sandwiched circumferentially by adjacent water jackets 111 (e.g., water jackets 111a, 111b). Specifically, the gap is located on the intermediate virtual line Lv3, and in this embodiment, the circumferential center of the gap is located on the intermediate virtual line Lv3.

[0048] Furthermore, in this embodiment, the gap has both circumferential ends outside the range Ri, in other words, it is provided so as to straddle the range Ri in the circumferential direction. That is, in this embodiment, the first and second boundary virtual lines Lv1 and Lv2 and the intermediate virtual line Lv3 all pass through the gap.

[0049] In this embodiment, in addition to the above, the positional relationship between the motor housing 1 and the stator 2 is also defined from the viewpoint of the position of the teeth 212 relative to the water jacket 111.

[0050] Specifically, for each of the multiple water jackets 111, the center of the water jacket 111 in the circumferential direction is defined as the cooling water passage center Pc, and the straight line extending radially outward from the rotational axis A and passing through the cooling water passage center Pc is defined as the virtual center line Lv4.

[0051] Here, if we define the first virtual end line (which in this embodiment coincides with the second virtual boundary line Lv2) and the second virtual end line Lv5 as straight lines extending radially outward from the rotational axis A and passing through the respective ends Pb1 and Pb2 of the water jacket 111 (111b) in the circumferential direction, then the central virtual line Lv4 coincides with a straight line that bisects the central angle formed between the first and second virtual end lines Lv2 and Lv5.

[0052] In this case, the housing body 11 and the stator core 21 are positioned such that the teeth 212 are located on the central virtual line Lv4 defined for each water jacket 111, and are fixed to each other.

[0053] In other words, in this embodiment, the recesses n are arranged in the stator core 21 such that the teeth 212 are located midway between adjacent recesses n or gaps in the circumferential direction.

[0054] (Explanation of action and effects) Firstly, a gap (recess n) is formed between the motor housing 1 and the stator 2, separating the inner circumferential surface 11i of the housing body 11 and the outer circumferential surface 21p of the stator core 21 in the radial direction of the motor housing 1. This gap is positioned such that at least a portion of it overlaps radially with respect to the range Ri that adjacent water jackets 111 sandwich the motor housing 1 in the circumferential direction.

[0055] In other words, as shown in Figure 5, the relative positional relationship between the housing body 11 and the stator core 21 is such that at least a portion of the gap formed by the recess n on the outer circumference of the stator core 21 overlaps radially with respect to the range Ri between the water jackets 111.

[0056] This makes it possible to suppress the occurrence of large localized compressive stresses in the inner circumference of the stator 2, specifically the stator core 21, and to suppress the deterioration of the magnetic properties of the stator 2 (i.e., increased iron loss) caused by compressive stress.

[0057] Figure 6 is a schematic diagram illustrating the distribution of surface pressure from the inner circumference of the housing body 11 to the outer circumference of the stator core 21, in a comparative example where there is no recess n on the outer surface 21p of the stator core 21. For convenience, the same reference numerals are used to indicate parts of the housing body 11 and stator core 21 of the comparative example that are common to or correspond to the electric motor M according to this embodiment.

[0058] In the comparative example shown in Figure 6, a high surface pressure is applied from the housing body 11 to the outer periphery of the stator core 21 between adjacent water jackets 111 in the circumferential direction.

[0059] Figure 6(a) shows the housing body 11 and stator core 21 viewed in the axial direction, with the surface pressure applied to the outer circumference of the stator core 21 between the water jackets 111 indicated by the white arrow F. Furthermore, Figure 6(b) shows the inner circumference of the housing body 11 viewed radially from the rotational axis A, with the portion of the inner circumference of the housing body 11 where the surface pressure applied to the outer circumference of the stator core 21 increases indicated by a dashed-dot frame W1 with diagonal lines.

[0060] In this way, the surface pressure applied from the housing body 11 to the outer periphery of the stator core 21 has a circumferential distribution, which causes a localized increase in compressive stress in the inner periphery of the stator core 21, resulting in a relatively large compressive stress in the inner periphery of the stator core 21 located between the outer periphery parts.

[0061] Here, Figure 6(a) shows the portion of the inner circumference of the stator core 21 that is subjected to large compressive stress, indicated by the dashed circle W2. In this embodiment, it has been found that large compressive stress occurs particularly on the inscribed surfaces that connect adjacent teeth 212 in the circumferential direction.

[0062] In this embodiment, a gap is formed between the motor housing 1 and the stator 2, and at least a portion of this gap is positioned to overlap radially with the range Ri between the water jackets 111. This makes it possible to suppress the situation in which the surface pressure applied to the outer circumference of the stator core 21 between the water jackets 111 increases relatively, causing a large localized compressive stress to occur on the inner circumference of the stator core 21.

[0063] This makes it possible to create a strong bonding force between the housing body 11 and the stator core 21 through shrink-fitting, while suppressing the deterioration of the magnetic properties of the stator 2 caused by compressive stress, thereby improving the operating efficiency of the electric motor M. In other words, it is possible to achieve both the advantages of using shrink-fitting and improved operating efficiency of the electric motor M. Here, by suppressing the generation of compressive stress in the inner circumference of the stator core 21 where the magnetic flux density is high, it is possible to effectively suppress the deterioration of magnetic properties.

[0064] Furthermore, by suppressing compressive stress, it is possible to prevent variations in the spacing between the teeth 212 of the stator core 21 (tooth pitch), thereby ensuring the roundness of the inner diameter of the stator core 21 and stator 2, and improving the operational stability of the electric motor M.

[0065] Secondly, the gap formed by the recess n is positioned on a straight line (intermediate imaginary line) Lv3 connecting the center (center between passages) Pm between the adjacent ends Pa1 and Pb1 of the water jackets 111 and the rotation center A of the electric motor M.

[0066] This effectively suppresses the increase in compressive stress in the inner circumference of the stator core 21, thereby more reliably suppressing the deterioration of magnetic properties.

[0067] Thirdly, a straight line (first boundary imaginary line) Lv1 connecting one adjacent water jacket 111's adjacent end Pa1 to the rotation center A, and a straight line (second boundary imaginary line) Lv2 connecting the other adjacent end Pb1 to the rotation center A were virtually set, and the gap was formed so as to span the range Ri defined by these lines Lv1 and Lv2 in the circumferential direction. In other words, the dimension of the gap in the circumferential direction, that is, the width of the gap, was set to be wider than the distance defined in the circumferential direction by the first boundary imaginary line Lv1 and the second boundary imaginary line Lv2 at the same radial position.

[0068] This makes it possible to more reliably suppress the increase in compressive stress in the inner circumference of the stator core 21.

[0069] Fourth, the stator core 21 is configured to include an annular yoke portion 211 and a plurality of teeth 212 protruding inward from the yoke portion 211. A coil winding 22 is formed by winding a wire around these multiple teeth 212, and the teeth 212 are arranged on a straight line (imaginary center line) Lv4 connecting the center of the water jacket 111 (center of the cooling water passage) Pc in the circumferential direction and the rotation center A of the electric motor M.

[0070] This makes it possible to suppress deformation of the stator core 21 due to compressive stress generated in the inner circumference of the stator core 21, specifically, the occurrence of variations in the spacing (tooth pitch p) of the teeth 212 located near the central virtual line Lv4.

[0071] Figure 7 is a schematic diagram showing the change in tooth pitch p in the same comparative example as shown in Figure 6.

[0072] In the comparative example shown in Figure 7, there are no teeth 212 on the central virtual line Lv4, and the inner circumference or inscribed surface of the stator core 21, where the compressive stress is significantly increased, is located there. The teeth 212 are located on each side of the central virtual line Lv4 in the circumferential direction.

[0073] In this configuration, the increased compressive stress causes significant deformation of the teeth 212 around the central virtual line Lv4, in other words, inside the cooling water passage center Pc, which is the center of the water jacket 111 in the circumferential direction, and the tooth pitch p expands relatively significantly. This causes a phase shift in the direction of coil rotation, leading to increased torque ripple (i.e., torque pulsation) and noise.

[0074] In contrast, in this embodiment, by arranging the teeth 212 on the central virtual line Lv4, that is, inside the cooling water passage center Pc, it is possible to suppress deformation of the stator core 21 due to compressive stress, specifically, the opening of the teeth 212, and to suppress the occurrence of variations in the tooth pitch p in the circumferential direction.

[0075] In the above description, a recess n was formed on the outer circumferential surface 21p of the stator core 21 in order to form a radial gap between the motor housing 1 and the stator 2. However, the recess n can also be formed on the inner circumferential surface 11i of the housing body 11, and can be formed alternately in the circumferential direction on both the inner circumferential surface 11i of the housing body 11 and the outer circumferential surface 21p of the stator core 21, for example.

[0076] Furthermore, the fixing of the housing body 11 and the stator core 21 is not limited to shrink-fitting of the housing body 11, but can also be done by press-fitting the stator core 21. For example, the stator core 21 can be shrunk by cooling, inserted into the internal cavity of the housing body 11, and then restored to its original size.

[0077] Furthermore, the gap may be formed so as to span the range Ri between adjacent water jackets 111 in the circumferential direction, in other words, so that the edges of the gap in the circumferential direction are located outside the range Ri, and so as to so that at least one of the edges is located inside the gap Ri. [Explanation of Symbols]

[0078] M...rotating electric machine, 1...motor housing, 11...housing body, 12...first cover, 13...second cover, 111, 121, 131...water jacket (cooling water passage), 2...stator, 21...stator core, 22...coil winding, 211...yoke section, 212...teeth, 3...rotor, 31...rotor core, 32...permanent magnet, 4...motor shaft, 51...first end plate, 52...second end plate, 61...first bearing, 62...second bearing, n...recess, s...slit, Ri...range sandwiched in the circumferential direction by adjacent cooling water passages, Pa1...proximity end, Pb1...proximity end, Lv1...first boundary virtual line, Lv2...second boundary virtual line, first end virtual line, Lv3...intermediate virtual line, Lv4...center virtual line, Lv5...second end virtual line, Pc...center of cooling water passage.

Claims

1. A cylindrical housing and Stator and, A rotor is positioned inside the stator and configured to be rotatable relative to the stator, A rotating electric machine in which the housing and the stator are fixed to each other by radial clamping, with the housing and the stator positioned concentrically and the stator positioned inside the housing, The housing has multiple cooling water passages formed at intervals in the circumferential direction of the housing for the flow of cooling water. A gap is formed between the housing and the stator, separating the inner circumferential surface of the housing and the outer circumferential surface of the stator in the radial direction of the housing. The gap in the rotating electric machine overlaps, at least in part, with the area enclosed by adjacent cooling water passages in the circumferential direction.

2. The rotating electric machine according to claim 1, wherein the portions closest to each other between adjacent cooling water passages are designated as the proximity ends, and the gap is arranged on a straight line connecting the center between the proximity ends of each of the adjacent cooling water passages and the rotation center of the rotating electric machine.

3. The aforementioned range is defined by a straight line connecting one of the adjacent cooling water passages to the rotation center of the rotating electric machine, and a straight line connecting the other adjacent passage to the rotation center of the rotating electric machine, with both ends in the circumferential direction determined by these lines. The rotating electric machine according to claim 2, wherein the gap is formed so as to span the range in the circumferential direction.

4. The aforementioned stator is It forms an annular shape and includes an outer ring portion that includes the outer peripheral surface, It has a plurality of protrusions formed in the circumferential direction and each protruding inward from the outer ring portion, The aforementioned stator is The coil winding formed by the wires wrapped around the plurality of protrusions is held, The rotating electric machine according to any one of claims 1 to 3, wherein the protrusion is arranged on a straight line connecting the center of the cooling water passage in the circumferential direction and the center of rotation of the rotating electric machine.

5. A cylindrical housing and Stator and, A rotating electric machine comprising a rotor disposed inside the stator and configured to be rotatable relative to the stator, The housing has multiple cooling water passages formed at intervals in the circumferential direction of the housing for the flow of cooling water. The housing and the stator are, The inner circumferential surface of the housing or the outer circumferential surface of the stator has a recess that is recessed in the radial direction, A rotating electric machine in which the stator is located concentrically inside the housing, and the adjacent cooling water passages are fixed to each other by radial clamping such that at least a portion of the recesses overlaps radially with respect to the area sandwiched in the circumferential direction.

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