Rotating electrical machine and method of manufacturing same

Abstract

This rotating electrical machine (100) comprises a cylindrical frame (40) into the inner circumferential surface of which a stator core (31) is fitted and held, wherein the frame (40) has a cylindrical part (41) into the inner circumferential surface of which the stator core (31) is fitted, and a fastening flange (42) that protrudes from an end part in the axial direction of the cylindrical part (41) outward in the radial direction of the cylindrical part (41) and is fastened to a support member (50), and the fastening flange (42) is formed to slope in the radial direction of the cylindrical part (41) going away from the outer circumferential surface of the cylindrical part (41), and the fastening flange (42) is configured such that in the state with the fastening flange (42) fastened to the support member (50), stress in the compressive direction is generated at a root portion of the fastening flange (42) on the side of the outer circumferential surface of the cylindrical part (41).

Description

Rotating electric machine and manufacturing method thereof

[0001] The present application relates to a rotating electric machine and a manufacturing method thereof.

[0002] Rotating electric machines having a frame that holds a stator core therein are well known. The rotating electric machine is fixed to a support member via the frame. For example, a conventional rotating electric machine disclosed in Patent Document 1 includes a cylindrical stator outer cylinder as a frame, and is fixed to a bracket as a support member via the stator outer casing. The stator core of the rotating electric machine is fixed to the inner peripheral surface of the stator outer casing by shrink fitting.

[0003] The stator mantle of the conventional rotating electric machine disclosed in Patent Document 1 has a fastening flange at at least one of its axial ends that protrudes radially outward from the outer circumferential surface of the stator mantle, and the fastening flange is formed in advance so as to be inclined in a direction approaching the outer circumferential surface of the stator mantle.

[0004] In the rotating electric machine disclosed in Patent Document 1, when the stator core is shrink-fitted onto the inner surface of the stator outer jacket, the fastening flange of the stator outer jacket deforms to become approximately parallel to the radial direction of the stator outer jacket, and a good fastening surface is formed between the stator outer jacket and the housing, thereby ensuring the fastening force between the stator outer jacket and the housing.

[0005] Furthermore, a conventional rotating electric machine disclosed in Patent Document 2 includes a housing as a frame that holds a stator core by shrink fitting, and is fixed to a support member via the housing. The housing includes a first tab having a first through hole through which a first screw passes, and a second tab having a second through hole through which a second screw passes and a fitting portion that fits with the position adjustment member, and the first surface of the first tab that faces the support member is formed farther from the support member than the second surface of the second tab that faces the support member.

[0006] In the rotating electric machine disclosed in Patent Document 2, the first opposing surface of the first tab in the housing is formed farther from the support member than the second opposing surface of the second tab, so that the second opposing surface of the second tab can be made approximately parallel to the support member, thereby improving the positioning accuracy of the housing relative to the support member.

[0007] Patent No. 5607591 Patent No. 6731112

[0008] In the case of the conventional rotating electric machine disclosed in Patent Document 1, if the tightening margin of the stator mantle to the stator core is inappropriate, the fastening flange remains tilted, and an adequate fastening force may not be generated between the stator mantle and the housing. Furthermore, if the fastening flange is forcibly deformed by tightening the bolts while remaining tilted, tensile stress may be generated in the curved portion at the base of the fastening flange, causing breakage, and the stator mantle, which serves as a frame for holding the stator core, may be damaged.

[0009] Furthermore, in the conventional rotating electric machine disclosed in Patent Document 2, the first tab is forcibly deformed by tightening the screws, which generates tensile stress at the base of the first tab, causing breakage and potentially damaging the housing, which serves as a frame that holds the stator core.

[0010] The present application discloses a technique for solving the above-mentioned problems, and aims to provide a highly reliable rotating electric machine that prevents damage to a frame that holds a stator core.

[0011] The present application also discloses technology for solving the above-mentioned problems, and aims to provide a method for manufacturing a highly reliable rotating electric machine that prevents damage to the frame that holds the stator core.

[0012] The rotating electric machine disclosed in the present application is a rotating electric machine comprising: a stator core formed in a circular ring shape; a cylindrical frame that holds the stator core by fitting the stator core onto its inner peripheral surface; a rotor that is arranged in the internal space of the stator core and has an outer peripheral surface that faces the inner peripheral surface of the stator core via a gap; and a rotor shaft that is fixed to the rotor and supported so as to be able to rotate freely, wherein the frame has: a cylindrical portion that fits the stator core onto its inner peripheral surface; and a fastening flange that is provided at the axial end of the cylindrical portion, protrudes radially outward from the axial end of the cylindrical portion, and is fastened to a support member that supports the rotating electric machine, wherein the fastening flange is formed so as to be inclined in a direction away from the outer peripheral surface of the cylindrical portion with respect to the radial direction of the cylindrical portion, and is configured so that when the fastening flange is fastened to the support member, a compressive stress is generated at the base portion of the fastening flange on the outer peripheral surface side of the cylindrical portion.

[0013] Furthermore, the manufacturing method of a rotating electric machine disclosed in the present application is a manufacturing method of the above-mentioned rotating electric machine, in which the inner surface of the frame is formed by machining through cutting, and a portion of the fastening flange located radially inward of the circumference of a pitch circle passing through the radially innermost point of a boss that receives the fastening flange and is provided on the support member is used as a machining surface during the machining.

[0014] Furthermore, the manufacturing method of a rotating electric machine disclosed in the present application is a manufacturing method for manufacturing a rotating electric machine comprising a water jacket that is fitted onto the outer peripheral surface of the cylindrical portion of the frame of the rotating electric machine and forms a cooling flow path inside, the water jacket being welded to the frame to seal the cooling flow path, wherein the outer peripheral surface of the cylindrical portion of the frame that fits into the water jacket is formed by press processing, and the inner peripheral surface of the cylindrical portion of the frame that fits into the stator core is formed by machining using cutting.

[0015] Furthermore, the manufacturing method of a rotating electric machine disclosed in the present application is a manufacturing method for manufacturing a rotating electric machine that includes a water jacket that is fitted onto the outer peripheral surface of the cylindrical portion of the frame of the rotating electric machine and forms a cooling flow path inside, and the water jacket is welded to the frame to seal the cooling flow path, the manufacturing method comprising: a first step of fitting the water jacket onto the frame; a second step of sealing the frame and the water jacket by welding on the anti-flange side of the cylindrical portion of the frame; and a third step of sealing the frame and the water jacket by welding on the flange side of the cylindrical portion of the frame, wherein the second step is performed before the third step.

[0016] Furthermore, the manufacturing method of a rotating electric machine disclosed in the present application is a manufacturing method of a rotating electric machine comprising a water jacket fitted to the outer peripheral surface of the cylindrical portion of the frame of the rotating electric machine and forming a cooling flow path therein, the water jacket being welded to the frame to seal the cooling flow path, the manufacturing method comprising: a first step of fitting the water jacket to the frame; a second step of sealing the frame and the water jacket by welding; a third step of machining the inner peripheral surface of the cylindrical portion of the frame by cutting; and a fourth step of fitting the stator core to the inner peripheral surface of the cylindrical portion of the frame, wherein the first step to the fourth step are carried out sequentially.

[0017] According to the rotating electric machine disclosed in the present application, a highly reliable rotating electric machine can be obtained that prevents damage to the frame that holds the stator core.

[0018] Furthermore, according to the method for manufacturing a rotating electric machine disclosed in the present application, a highly reliable rotating electric machine can be obtained that prevents damage to the frame that holds the stator core.

[0019] Fig. 1 is a schematic cross-sectional view of a rotating electric machine according to embodiment 1. Fig. 2 is an explanatory diagram of a frame in the rotating electric machine according to embodiment 1. Fig. 3 is a schematic cross-sectional view of a rotating electric machine according to embodiment 2. Fig. 4 is an explanatory diagram that explains deformation of a fastening flange in the rotating electric machines according to embodiment 1 and embodiment 2. Fig. 5 is an explanatory diagram that explains the dimensional relationship between the frame and a water jacket in the rotating electric machine according to embodiment 2. Fig. 6 is an explanatory diagram of a fastening flange of a frame in the rotating electric machines according to embodiment 1 and embodiment 2.

[0020] Embodiment 1. Figure 1 is a schematic cross-sectional view of a rotating electric machine according to embodiment 1. In Figure 1, the rotating electric machine 100 includes a rotor 10, a rotor shaft 20, and a stator 30. The rotor 10 has a rotor core and field poles made up of a plurality of permanent magnets embedded in the rotor core, and is fixed to the rotor shaft 20. The rotor shaft 20 is rotatably supported via bearings in a housing (not shown) that holds the rotating electric machine 100.

[0021] The stator 30 includes a stator core 31 in which a plurality of split cores are arranged in an annular shape, a stator coil 32 attached to the stator core 31, and a cylindrical frame 40. The rotor 10 is inserted into the inner space of the stator 30, and the outer peripheral surface of the rotor core faces the inner peripheral surface of the stator core 31 across a predetermined air gap. The frame 40 fits the stator core 31 onto the inner peripheral surface and holds the stator core 31.

[0022] The stator coil 32 is, for example, a star-connected three-phase coil, and generates a rotating magnetic field when supplied with three-phase power from a power conversion device (not shown) consisting of multiple semiconductor switching elements. The rotor 10 generates a rotational force due to the interaction between the rotating magnetic field generated by the stator 30 and the field magnetic poles formed by permanent magnets provided on the rotor 10, causing the rotor 10 to rotate and drive a load such as a vehicle.

[0023] The frame 40 includes a cylindrical portion 41 that fits the stator core 31 onto its inner peripheral surface, and a fastening flange 42 provided at one axial end 411 of the cylindrical portion 41. The other axial end 412 of the cylindrical portion 41 is an open end. The fastening flange 42 protrudes from the one axial end 411 of the cylindrical portion 41 radially outward from the cylindrical portion 41 and is formed in an annular shape.

[0024] The fastening flange 42 provided on the frame 40 is provided with a plurality of bolt holes 421 through which the bolts 61 pass. While Fig. 1 shows a case where two bolt holes 421 are provided at positions facing each other across the central axis C of the frame 40, other arrangements are also possible. Furthermore, the bolt holes 421 may be provided at two or more positions on the fastening flange, spaced apart from each other, as necessary.

[0025] The stator 30 held by the frame 40 is fixed to a support member 50 provided on the housing via bosses 52 by a plurality of bolts 61 (only one of which is shown in FIG. 1 ) that pass through bolt holes 421 via the fastening flange 42 of the frame 40.

[0026] Fig. 2 is an explanatory diagram of a frame in a rotating electric machine according to embodiment 1, and is a schematic diagram of the frame 40 shown in Fig. 1. As shown in Fig. 2, the fastening flange 42 protrudes from one axial end 411 of the cylindrical portion 41 of the frame 40 to the outside of the cylindrical portion 41 in the radial direction of the cylindrical portion 41, and is formed so as to be inclined at an inclination angle θ in a direction away from the outer circumferential surface of the cylindrical portion 41 with respect to an imaginary line A perpendicular to the central axis C of the cylindrical portion 41.

[0027] 1 and 2 , as described above, fastening flange 42 is inclined in a direction away from the outer peripheral surface of cylindrical portion 41, but when fastening flange 42 abuts against the mounting surface, which is the upper surface of boss 52 fixed to support member 50, and is fastened to support member 50 by bolts 61, it deforms to become parallel to the mounting surface of boss 52 and is fixed to support member 50. Because the mounting surface, which is the upper surface of boss 52, is formed parallel to the plane of support member 50, fastening flange 42 deforms to become parallel to the plane serving as the mounting surface of support member 50 and is fixed to support member 50.

[0028] As described above, when the fastening flange 42 is fastened and fixed to the support member 50 with the bolts 61, the inclination angle θ of the fastening flange 42 is substantially 0°. As a result, as shown in Fig. 1, compressive stress indicated by arrow F occurs on the outer peripheral surface side of the base portion 422 of the fastening flange 42. Therefore, damage to the fastening flange 42 due to the tensile stress T on the base portion 422 can be prevented.

[0029] Since the curvature due to bending of the root portion 422 on the outer surface side of the fastening flange 42 is smaller than the curvature due to bending of the root portion 423 on the inner surface side, the stress concentration coefficient of the root portion 422 on the outer surface side is higher than the stress concentration coefficient of the root portion 423 on the inner surface side.

[0030] By making the root portion 423 on the inner peripheral surface side, which has a smaller stress concentration coefficient than the root portion 422 on the outer peripheral surface side, the portion to which the tensile stress indicated by the arrow T is applied, the tensile stress T that causes damage to the fastening flange 42 becomes smaller than the compressive stress F, thereby preventing damage to the fastening flange 42. Therefore, the curvature due to bending of the root portion 422 on the outer peripheral surface side can be reduced, thereby improving the layout flexibility of the rotating electric machine 100.

[0031] Second Embodiment Next, a rotating electric machine according to a second embodiment will be described. Fig. 3 is a schematic cross-sectional view of a rotating electric machine according to the second embodiment, in which parts that are the same as or equivalent to those in the rotating electric machine according to the first embodiment shown in Fig. 1 are given the same reference numerals. In Fig. 3, a rotating electric machine 100 includes an annular water jacket 70 fitted onto the outer peripheral surface of a cylindrical portion 41 of a frame 40. The other configurations are the same as those of the rotating electric machine according to the first embodiment described above.

[0032] The water jacket 70 is welded to the outer peripheral surface of the cylindrical portion 41 of the frame 40 near one axial end 411, which is the end on the fastening flange side of the cylindrical portion 41, thereby sealing one side of the internal cooling flow path 71, and is also welded to the outer peripheral surface of the cylindrical portion 41 near the other axial end 412, which is the end on the opposite fastening flange side of the cylindrical portion 41, thereby sealing the other side of the internal cooling flow path 71. The stator core 31 of the rotating electric machine 100 is cooled by cooling water flowing through the cooling flow path 71 of the water jacket 70.

[0033] The water jacket 70 is fitted to the frame 40 by press fitting or shrink fitting, and then welded to the cylindrical portion 41 of the frame 40 as described above to form the cooling flow path 71. However, the fastening flange 42, which has been formed at an angle away from the outer circumferential surface of the cylindrical portion 41, is deformed toward the outer circumferential surface of the cylindrical portion 41 of the frame 40 due to the press fitting and welding of the water jacket 70 to the cylindrical portion 41 of the frame 40. As a result, the angle of inclination θ of the fastening flange 42 shown in FIG. 2 becomes smaller than its initial value.

[0034] That is, when the water jacket 70 is press-fitted onto the outer peripheral surface of the cylindrical portion 41 of the frame 40, the cylindrical portion 41 of the frame 40 deforms radially inward, which in turn deforms the fastening flange 42 toward the outer peripheral surface of the cylindrical portion 41. Furthermore, when the water jacket 70 and the cylindrical portion 41 are welded together, one end 411 and the other end 412 in the axial direction of the cylindrical portion 41 are heated and expand, and then they contract upon cooling. Meanwhile, the outer peripheral surface of the cylindrical portion 41 other than the one end 411 and the other end 412 in the axial direction of the cylindrical portion 41 is not heated by the welding, and deformation thereof is suppressed. As a result, the fastening flange 42 deforms in a direction inclined toward the outer peripheral surface of the cylindrical portion 41.

[0035] However, since the fastening flange 42 is formed so as to be inclined in a direction away from the outer peripheral surface of the eastern part of the circle relative to the cylindrical portion 41 by an amount greater than the amount of deformation caused by the press-fitting and welding described above, it is possible to absorb the variation in assembly caused by the press-fitting and welding described above and maintain the inclination of the fastening flange in a direction away from the outer peripheral surface of the cylindrical portion 41. Therefore, as described in the first embodiment, it is possible to prevent damage to the root portion 422 on the outer peripheral surface side of the fastening flange 42 due to fastening to the support member 50.

[0036] FIG. 4 is an explanatory diagram illustrating deformation of the fastening flange in the rotating electric machines according to the first and second embodiments, in which "A" indicates the initial state of the frame 40, and "B" indicates the state of the frame 40 after the water jacket 70 is pressed in and the above-mentioned welding is performed.

[0037] The amount of inclination of the fastening flange 42 due to deformation of the frame 40 depends on the setting of the interference δ of the fit between the frame 40 and the water jacket 70, the welding conditions, the interference of the fit between the frame 40 and the stator core 31, etc. Here, in Fig. 4, if the inclination toward the outer peripheral surface of the cylindrical portion 41 indicated by arrow SF is the "+" direction and the inclination toward the side away from the outer peripheral surface of the cylindrical portion 41 indicated by arrow SB is the "-" direction, by setting the interference δ of the fit between the frame 40 and the water jacket 70 in the range of "0" [mm] to "0.5" [mm], the inclination angle θ of the fastening flange 42 due to the fit of the water jacket 70 to the cylindrical portion 41 of the frame 40 will be approximately "+0" [°] to "+0.25" [°], and the inclination angle θ of the fastening flange 42 due to the above-mentioned welding will be "+0" [°] to "+0.5" [°].

[0038] Therefore, if the inclination angle θ of the fastening flange 42 in the initial state, before the water jacket 70 is fitted and welded, is set to "-1" [°], the inclination away from the outer peripheral surface of the cylindrical portion 41 can be maintained even after the water jacket 70 has been fitted and welded.

[0039] The deformation of the frame 40 due to the fitting of the stator core 31 is caused by the cylindrical portion 41 of the frame 40 deforming radially outward of the frame 40. This deformation causes the fastening flange 42 to tilt away from the outer peripheral surface of the cylindrical portion 41, i.e., in the direction away from the outer peripheral surface of the cylindrical portion 41. Therefore, the deformation of the frame 40 due to the fitting of the stator core 31 can cancel or suppress the influence of deformation due to the press-fitting and welding of the water jacket 70.

[0040] The inclination angle θ of the fastening flange 42 is preferably 1° or less with respect to the radial direction perpendicular to the central axis C of the cylindrical portion 41. If the inclination angle θ exceeds 1°, the stress generated in the fastening flange 42 after fastening to the support member 50 by the bolts 61 will exceed the material strength of the frame 40. Here, the frame 40 is formed, for example, from SPHC (Steel Plate Hot Commercial) or SPCC (Steel Plate Cold Commercial).

[0041] As described above, by setting the inclination angle θ of the fastening flange 42 to 1° or less relative to the radial direction perpendicular to the central axis C of the cylindrical portion 41, the compressive stress F generated at the root portion 422 on the outer surface side of the fastening flange 42 and the tensile stress T generated at the root portion 423 on the inner surface side can be kept below the material strength of the frame 40.

[0042] The thickness of the water jacket 70 is set smaller than the thickness of the frame 40. The frame 40, which must fit the stator core 31, requires high rigidity and dimensional accuracy, and the frame 40 is configured to meet these requirements, so the water jacket 70 can be fitted and welded for assembly without any problems. Therefore, deformation of the frame 40 can be suppressed.

[0043] Next, a detailed description will be given of a method for setting the relationship between the press-fit interference that provides a desirable strength for the water jacket 70 and the diameter of the frame 40 after the water jacket 70 is fitted to the frame 40. Figure 5 is an explanatory diagram that explains the dimensional relationship between the frame and the water jacket in a rotating electric machine according to a second embodiment.

[0044] 5, the inner diameter of the frame 40 is r1 [mm], the outer diameter of the frame 40 after the water jacket 70 is press-fitted into the frame 40 is r2 [mm], and the outer diameter of the water jacket 70 is r3 [mm] (hereinafter, the units of r1, r2, and r3 will be omitted.) Also, the interference of the fitting is δ, and the frame 40 and the water jacket 70 are made of the same material, with their Young's moduli being E.

[0045] The surface pressure P when the water jacket 70 is press-fitted onto the outer peripheral surface of the frame 40 is expressed by the following equation (1): P = E δ (r3 ２ -r2 ２ ) (r2 ２ -r1 ２ ) / 2r2 ３ (r3 ２ -r1 ２ ) ...Formula (1)

[0046] The stress σ generated in the water jacket 70 is expressed by the following equation (2): σ=P·r2 / 2(r3−r2) (2)

[0047] From the above formulas (1) and (2), it can be seen that the smaller the inner diameter r1 of the cylindrical portion 41, the outer diameter r2 of the frame 40 after press-fitting of the water jacket 70, and the outer diameter r3 of the water jacket 70, the higher the surface pressure P and the greater the generated stress σ, which is disadvantageous in terms of material strength. Therefore, the smaller the outer diameter r2 of the frame 40 after press-fitting of the water jacket 70, the more the generated stress σ is suppressed, and it is also desirable to set the interference δ of the fitting to be smaller as the outer diameter r2 of the frame 40 after press-fitting becomes smaller.

[0048] That is, since there is a positive correlation between the "fitting interference δ" and the "relationship between the inner diameter r1 of the frame 40 after fitting the water jacket 70, the outer diameter r2 of the frame 40 after fitting, and the outer diameter r3 of the water jacket 70," within a somewhat limited range, the above correlation can be roughly approximated by a linear correlation.

[0049] Therefore, the relationship between the outer diameter D (= r2) of the frame 40 after fitting the frame 40 to the water jacket 70 and the interference δ of the fitting can be expressed by the following equation (3) using a coefficient α, and can be used as a guide for setting the interference δ of the fitting and the outer diameter D (= r2) of the frame 40 after fitting. α × δ = D Equation (3)

[0050] The inventors estimated the coefficient α in equation (3) as follows: First, the water jacket 70 is made of SPHC, and the thickness is assumed to be in the range of 1.0 mm to 3.5 mm. The tensile strength is set so as not to exceed 270 MPa, which is the limit value of the tensile strength of a typical SP (Steel Plate) material.

[0051] Therefore, using the above-mentioned formula (1) for the surface pressure P during press-fitting, an investigation was conducted under the condition of [σ≦270 MPa]. When the plate thickness dimension of the water jacket 70 was set to the lower limit of the expected range of "1.0" [mm], the surface pressure P was maximized. In this case, the fitting interference δ was further selected to be "0.3" [mm], "0.4" [mm], and "0.5" [mm] as representative values ​​from the range of "0" [mm] to "0.5" [mm], and the outer diameter D (= r2) of the frame 40 after fitting the frame 40 and the water jacket 70 was roughly calculated, where the stress σ generated at each fitting interference δ satisfies [σ≦270 MPa].

[0052] As a result of the above rough calculations, it was confirmed that when the fitting interference δ is "0.3" [mm], the outer diameter D (= r2) of the frame 40 is "190" [mm], when the fitting interference δ is "0.4" [mm], the outer diameter D (= r2) of the frame 40 is "250" [mm], and when the fitting interference δ is "0.5" [mm], the outer diameter D (= r2) of the frame 40 is "320" [mm].

[0053] Based on the results of the above rough calculations, the fitting interference δ and the outer diameter D of the frame 40 are set, and the setting range of the coefficient α is calculated from the representative value at which the surface pressure P is approximately maximum when the water jacket 70 is press-fitted onto the outer peripheral surface of the frame 40. This gives [α = D / δ], so it can be roughly calculated that the desirable range of the coefficient α is between 633.3 and 640.

[0054] To summarize the above calculation results, by setting the outer diameter D (= r2) of the frame 40 after the frame 40 and the water jacket 70 are fitted together and the fitting interference δ, and the coefficient α so that the coefficient α is in the range of 633.3 to 640 and the relationship between the water jacket 70 and the frame 40 is satisfied: [α × δ = D], it is possible to set a relationship between the water jacket 70 and the frame 40 that is desirable in terms of strength.

[0055] As described above, the stress σ generated by the fitting can be suppressed to below the tensile strength of 270 MPa of the SP material used in the water jacket 70, thereby providing the water jacket 70 with sufficient strength to prevent breakage.

[0056] Furthermore, in view of the strength requirement, it is desirable to use SPHC for the frame 40, which has a lineup of thicknesses of 4.0 mm or more. Furthermore, since the strength requirement of the water jacket 70 is not higher than that of the frame 40, there is no need to increase the thickness. Therefore, SPCC is generally used. The thickness is selected so that the above-mentioned relationship holds true within the range of 1.0 mm to 3.5 mm, and the thickness is made smaller than that of the frame 40, which requires strength. This allows the water jacket 70 to be assembled to the frame 40 while following the frame 40. This minimizes deformation of the frame 40.

[0057] 6 is an explanatory diagram of the fastening flange of the frame in the rotating electric machines according to Embodiments 1 and 2. In Fig. 6, when an imaginary line X connecting the center O of frame 40 and bolt hole 421 is denoted by X, and an intersection point Y is denoted by Y between an outer peripheral edge 4201 of fastening flange 42 and imaginary line X, the entire periphery of annular fastening flange 42 has at least one outer edge 4202 that passes through intersection Y and is connected at an angle of 45° or more to imaginary line X from the flange outer peripheral arc or outer peripheral line centered on bolt hole 421.

[0058] If the outer edge portion 4202 is angled at an angle of less than 45° with respect to the imaginary line X, the absolute value of the deformation (warpage) of the fastening flange 42 becomes large when the water jacket 70 is welded to the frame 40 or when the stator 30 is press-fitted. To prevent this, the outer edge portion 4202 is connected at an angle of 45° or more with respect to the imaginary line X. This allows the width of the fastening flange 42 to be increased and the rigidity of the fastening flange 42 to be increased. This reduces the absolute value of the deformation (warpage) of the fastening flange 42 and makes it easier to control the deformation (warpage) of the fastening flange 42.

[0059] The fastening flange 42 may be composed of multiple flange parts spaced apart from one another in the circumferential direction. Each flange part has a bolt hole 421. In this case, the flange parts are manufactured using a press process that allows the inclination angle of each flange part to be individually adjusted. Due to vehicle layout considerations, it may be difficult to provide fastening parts uniformly and at equal intervals around the entire circumference of the fastening flange. If multiple flange parts serving as fastening parts are provided unevenly, the amount of deformation of the flange parts will be uneven after press molding or after the water jacket 70 is fitted. However, because the inclination angle of each flange part can be individually adjusted, damage to the frame can be prevented.

[0060] The outer peripheral surface of the cylindrical portion 41 of the frame 40, which fits with the water jacket 70, is formed by press working using a mold, and the inner peripheral surface of the cylindrical portion 41 of the frame 40, which fits with the stator core 31, is finished by machining by cutting. Since the outer peripheral side of the cylindrical portion 41 of the frame 40 fits with the water jacket 70 and the inner peripheral surface of the cylindrical portion 41 fits with the stator core 31, the outer peripheral surface and the inner peripheral surface of the frame 40 must be formed with high precision, but because there is no dimensional relief when press forming, it is selected to machine the inner peripheral surface of the cylindrical portion 41 by cutting.

[0061] Since high dimensional accuracy is required for the inner peripheral surface of the cylindrical portion 41 of the frame 40, machining by cutting is appropriate. Since the outer peripheral surface of the cylindrical portion 41 does not require the same dimensional accuracy as the inner peripheral surface, it can be formed by press working, which reduces manufacturing costs. Although press working has lower dimensional accuracy than machining, by forming the water jacket 70, which has lower rigidity than the frame 40, into the frame 40, the poor dimensional accuracy of the outer peripheral surface of the frame 40 can be compensated for, and it is possible to achieve both sealing performance of the cooling flow passage 71 of the water jacket 70 and cost efficiency.

[0062] Furthermore, the frame 40, into which the highly rigid stator core 31 is fitted, is the side that follows the shape of the stator core 31 with respect to its inner peripheral surface, and if the precision of the inner peripheral surface is not high, deformation of the frame 40 will occur. However, since the inner peripheral surface is formed using machining by cutting as described above, the inner peripheral surface of the frame 40 is formed with high dimensional precision, and deformation of the frame 40 can be minimized even when the stator core 31 is fitted.

[0063] In the configuration of embodiment 2, in which the water jacket 70 is fitted to the frame 40 and then the fitting portion of the water jacket 70 on the fastening flange 42 side, i.e., on one axial end 411 side of the cylindrical portion 41, and the fitting portion of the water jacket 70 on the other axial end 412 side of the cylindrical portion 41 are sealed by welding, the assembly process is as follows: first, the fitting portion of the water jacket 70 on the other axial end 412 side of the cylindrical portion 41, i.e., the side of the cylindrical portion 41 opposite the fastening flange, is welded, and then the fitting portion of the water jacket 70 on the one axial end 411 side of the cylindrical portion 41, i.e., the side of the fastening flange 42, is welded.

[0064] The manufacturing method of a rotating electric machine according to embodiment 2 includes a manufacturing method that includes a first step of fitting the water jacket 70 to the frame 40, a second step of sealing the frame 40 and the water jacket 70 by welding on the side of the cylindrical portion 41 of the frame 40 opposite the fastening flange, and a third step of sealing the frame 40 and the water jacket 70 by welding on the side of the cylindrical portion 41 of the frame 40 opposite the fastening flange, and that performs the second step before the third step.

[0065] In the cross section of the frame 40, one axial end 411 of the cylindrical portion 41 and the fastening flange 42 are connected in an L-shape, and it is mechanically clear that when pressure is applied to one axial end 411 of the cylindrical portion 41 in the radially inward direction, the fastening flange 42 deforms so as to incline toward the outer peripheral surface of the cylindrical portion 41, and conversely, when pressure is applied to the other axial end 412 of the cylindrical portion 41 in the radially outward direction of the frame 40, the fastening flange 42 tends to deform so as to incline in a direction away from the outer peripheral surface of the cylindrical portion 41. In the case of the rotating electric machine according to the second embodiment, the above-mentioned deformation of the fastening flange 42 must ultimately be the latter deformation, that is, deformation inclining in a direction away from the outer peripheral surface of the cylindrical portion 41.

[0066] When welding the water jacket 70 to the cylindrical portion 41 of the frame 40, when the fitting portion of the water jacket 70 on the side of the fastening flange 42 of the cylindrical portion 41 of the frame 40 is welded, the heat input by the welding expands the outer diameter of the cylindrical portion 41 on the side of the fastening flange 42, and the other axial end 412 of the cylindrical portion 41 deforms toward the inner diameter side. As a result, the fastening flange 42 tilts toward the outer peripheral surface of the cylindrical portion 41.

[0067] Conversely, when welding is performed on the side of the other axial end 412 of the cylindrical portion 41, i.e., the side opposite the fastening flange, the outer diameter of the other axial end 412 of the cylindrical portion 41 expands, and the fastening flange 42 tilts in the opposite direction to the outer peripheral surface of the cylindrical portion 41, i.e., in the direction away from the outer peripheral surface of the cylindrical portion 41.

[0068] Therefore, regardless of which end side of the cylindrical portion 41 in the axial direction, 411 or the other end side, 412, is welded first, it is impossible to prevent the fastening flange 42 from deforming so that it is inclined toward the outer peripheral surface of the cylindrical portion 41. However, by welding the side of the cylindrical portion 41 opposite the fastening flange first, the welding process can be carried out with the fastening flange 42 warped toward the opposite side to the outer peripheral surface of the cylindrical portion 41, and the amount of deformation itself toward the outer peripheral surface of the cylindrical portion 41 can be reduced.

[0069] When the inner surface of the cylindrical portion 41 of the frame 40 is formed by machining through cutting, in the fastening portion having the bolt holes 421 of the fastening flange 42, the surface of the fastening flange 42 that is radially inward of the pitch circumference passing through the radially innermost point Z of the cylindrical portion 41 of the boss 52 that is integral with or fixed to the support member 50 shown in Figures 1 and 3 is used as the machining surface.

[0070] A plurality of bosses 52 are provided corresponding to a plurality of bolt holes 421 provided at intervals in the circumferential direction of the fastening flange 42. Points Z on the radially innermost side of the plurality of bosses 52 are located at or near the starting points of the bent portions of the fastening flange 42, and further, the points Z also serve as measurement points for the flatness of the planar portion of the fastening flange 42. Therefore, point Z on each boss 52 is also a reference portion (a portion pressed against a bending machine) for forming the fastening flange 42 on the frame 40. Therefore, by using a surface of the fastening flange 42 radially inward of a pitch circumference passing through point Z on the radially innermost side of the cylindrical portion 41 of the plurality of bosses 52 integral with or fixed to the support member 50 as a machining receiving surface, the accuracy of the cutting of the inner peripheral surface of the cylindrical portion 41 and the accuracy of the assembly work can be improved.

[0071] If the radially outer side of the fastening flange 42 were used as the receiving surface, it would be farther from the center line C of the frame 40, and therefore a force would act during cutting, making it more susceptible to the influence of a moment and increasing the risk of deformation of the frame 40. In order to suppress deformation of the frame 40 during cutting, the shape of the inner circumference of the cylindrical portion 41 is finished by machining through cutting, receiving a portion close to the base portion, which is the starting point of the inclination of the fastening flange 42, and which will be the starting point of bending when the inclination of the fastening flange 42 is corrected to a horizontal state by bolt tightening. This makes it possible to suppress deformation of the frame 40 after it is fixed to the support member 50. This improves the reliability of the strength of the frame 40.

[0072] The manufacturing method of the rotating electric machine according to the second embodiment includes a first step of fitting the water jacket 70 to the frame 40, a second step of sealing the frame 40 and the water jacket 70 by welding, a third step of machining the inner circumferential surface of the cylindrical portion 41 of the frame 40 by cutting, and a fourth step of fitting the stator core 31 to the inner circumferential surface of the cylindrical portion 41 of the frame 40, and is a manufacturing method in which the first step to the fourth step are performed sequentially. Note that the second step in this manufacturing method includes the second step and the third step in the manufacturing method described above.

[0073] The frame 40 may be made of iron or aluminum, but since the stator core 31 is made of an iron material, it is desirable to use an iron material for the frame 40. By using the same material as the stator core 31 for the frame 40, it is possible to eliminate problems caused by an increase or decrease in the holding force of the frame 40 against the stator core 31 due to the difference in the linear expansion coefficients of the two.

[0074] On the other hand, if an aluminum-based material is used for the frame 40, the difference in linear expansion coefficient between the stator core 31 and the frame 40 can be utilized, and an assembly method using shrink fitting of the stator core 31 and the frame 40 can be selected, thereby preventing problems such as wear caused by pressing different materials together and contamination (incorporation of impurities).

[0075] Although various exemplary embodiments and examples are described in this application, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless modifications not illustrated are contemplated within the scope of the technology disclosed in this application. For example, this includes cases where at least one component is modified, added, or omitted, and even cases where at least one component is extracted and combined with components of another embodiment.

[0076] REFERENCE SIGNS LIST 100 Rotating electric machine, 10 Rotor, 20 Rotor shaft, 30 Stator, 31 Stator core, 32 Stator coil, 40 Frame, 41 Cylindrical portion, 42 Fastening flange, 421 Bolt hole, 422 Root portion, 50 Support member, 52 Boss, 61 Bolt, 70 Water jacket, 71 Cooling flow path

Claims

1. A stator core configured in an annular shape; a cylindrical frame having an inner circumferential surface into which the stator core is fitted to hold the stator core; a rotor that is disposed in an internal space of the stator core and has an outer circumferential surface that faces an inner circumferential surface of the stator core with a gap therebetween; a rotor shaft fixed to the rotor and rotatably supported; A rotating electric machine comprising: The frame is a cylindrical portion that fits the stator core to the inner circumferential surface; a fastening flange provided at an axial end of the cylindrical portion, protruding from the axial end to a radial outside of the cylindrical portion, and fastened to a support member that supports the rotating electric machine; having The fastening flange is formed so as to be inclined in a direction away from the outer circumferential surface of the cylindrical portion with respect to a radial direction of the cylindrical portion, and is configured so that, in a state in which the fastening flange is fastened to the support member, a compressive stress is generated in a base portion of the fastening flange on the outer circumferential surface side of the cylindrical portion. A rotating electric machine characterized by:

2. a water jacket that is fitted to an outer circumferential surface of the cylindrical portion of the frame and that defines a cooling passage therein; The water jacket is welded to the frame to seal the cooling passage.

2. The rotating electric machine according to claim 1 .

3. The inclination angle of the fastening flange is the inclination angle is set to an angle larger than an angle at which the inclination angle is reduced due to deformation of the frame based on the fitting and welding of the water jacket.

3. The rotating electric machine according to claim 2.

4. The thickness of the water jacket is set smaller than the thickness of the frame.

4. The rotating electric machine according to claim 2 or 3.

5. When the outer diameter of the frame after the water jacket is fitted to the outer periphery of the frame is D [mm], the interference of the fitting is δ [mm], and a coefficient is α, D and δ are set so that the relationship of [α×δ=D] holds when α is in the range of "633.3" to "640".

4. The rotating electric machine according to claim 2 or 3.

6. The fastening flange has a bolt hole and is configured to be fastened to the support member by a bolt inserted into the bolt hole.

3. The rotating electric machine according to claim 1 or 2.

7. The fastening flange is When a virtual line connecting the center of the frame and the center of the bolt hole is defined as X, and an intersection point between the outer periphery of the fastening flange and X is defined as Y, the fastening flange has at least one outer periphery edge portion that passes through Y and is connected to an outer periphery arc portion or an outer periphery straight portion having the bolt hole as a center at an angle of 45° or more with respect to X.

7. The rotating electric machine according to claim 6.

8. The fastening flange has a plurality of flange parts each having the bolt holes, and is configured to be fastened to the support member by bolts inserted into the bolt holes of the plurality of flange parts; The inclination angles of the plurality of flange parts are set individually for each of the plurality of flange parts.

7. The rotating electric machine according to claim 6.

9. The inclination angle of the fastening flange is 1° or less with respect to the radial direction.

3. The rotating electric machine according to claim 1 or 2.

10. A method for manufacturing a rotating electric machine according to claim 1 or 2, comprising the steps of: The inner peripheral surface of the frame is formed by machining through cutting, a portion of the fastening flange located radially inward of a circumference of a pitch circle passing through an innermost point in the radial direction of a boss that receives the fastening flange provided on the support member is set as a machining receiving surface during the machining. A method for manufacturing a rotating electric machine comprising the steps of:

11. A method for manufacturing a rotating electric machine according to claim 2 or 3, comprising the steps of: an outer circumferential surface of the cylindrical portion of the frame that is fitted with the water jacket is formed by pressing; an inner circumferential surface of the cylindrical portion of the frame into which the stator core is fitted is formed by machining using cutting; A method for manufacturing a rotating electric machine comprising the steps of:

12. A method for manufacturing a rotating electric machine according to claim 2 or 3, comprising the steps of: a first step of fitting the water jacket to the frame; a second step of sealing the frame and the water jacket by welding on a side of the cylindrical portion of the frame opposite to the fastening flange; a third step of sealing the frame and the water jacket by welding on a fastening flange side of the cylindrical portion of the frame; having The second step is carried out prior to the third step. A method for manufacturing a rotating electric machine comprising the steps of:

13. A method for manufacturing a rotating electric machine according to claim 2 or 3, comprising the steps of: a first step of fitting the water jacket to the frame; a second step of sealing the frame and the water jacket by welding; a third step of machining an inner circumferential surface of the cylindrical portion of the frame by cutting; a fourth step of fitting the stator core onto an inner circumferential surface of the cylindrical portion of the frame; having The first step to the fourth step are carried out in sequence. A method for manufacturing a rotating electric machine comprising the steps of: