Rotating electric machine
The rotating electric machine design with narrower radial backlash connections between the stator and housing effectively reduces vibration and noise by restricting radial movement and maintaining the air gap, addressing the issue of vibration transmission.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- SUBARU CORP
- Filing Date
- 2022-09-09
- Publication Date
- 2026-07-09
Smart Images
Figure 0007887323000001 
Figure 0007887323000002 
Figure 0007887323000003
Abstract
Description
Technical Field
[0001] The present invention relates to a rotating electric machine.
Background Art
[0002] Vehicles such as hybrid vehicles and electric vehicles are equipped with a motor generator which is a rotating electric machine. The motor generator has a stator attached to a housing and a rotor accommodated inside the stator (see Patent Documents 1-4).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Patent Document 2
Patent Document 3
Patent Document 4
Summary of the Invention
Problems to be Solved by the Invention
[0004] By the way, when the stator coil is energized, vibration due to magnetic distortion is generated in the stator, and the vibration is transmitted from the stator to the housing. Thus, since the vibration transmission from the stator to the housing is a factor increasing the vibration and noise of the motor generator, it is required to reduce the vibration transmission from the stator to the housing.
[0005] An object of the present invention is to reduce the vibration transmission from the stator to the housing.
Means for Solving the Problems
[0006] A rotating electric machine according to one embodiment includes a rotor having a shaft, a stator surrounding the rotor, a housing housing the stator, a first annular member provided on the stator with a plurality of first recesses formed in the circumferential direction, a second annular member provided on the housing with a plurality of second recesses formed in the circumferential direction, and a plurality of spheres provided between the first annular member and the second annular member, which fit into both the first and second recesses, and the first annular member, the second annular member and the spheres constitute a connecting mechanism that connects the housing and the stator, wherein the radial backlash of the connecting mechanism is narrower than the circumferential backlash of the connecting mechanism and is narrower than the axial backlash of the connecting mechanism. [Effects of the Invention]
[0007] According to one aspect of the present invention, the radial backlash of the coupling mechanism is narrower than the circumferential backlash of the coupling mechanism, and also narrower than the axial backlash of the coupling mechanism. This reduces the transmission of vibrations from the stator to the housing. [Brief explanation of the drawing]
[0008] [Figure 1] This diagram shows the vehicles in which the power unit is installed. [Figure 2] This diagram shows an example of the internal structure of a power unit. [Figure 3] This is a cross-sectional view showing a motor generator as a rotating electric machine, which is one embodiment of the present invention. [Figure 4] This is a cross-sectional view showing a motor generator with the rotor removed. [Figure 5] This is a cross-sectional view showing the first coupling mechanism along line AA in Figure 4. [Figure 6] This diagram shows the disassembled and assembled states of the first connecting mechanism. [Figure 7] Figure 7 is a cross-sectional view showing a motor generator, which is another embodiment 1 of the present invention. [Figure 8]This is a cross-sectional view showing a motor generator, which is another embodiment 2 of the present invention. [Modes for carrying out the invention]
[0009] Embodiments of the present invention will be described in detail below with reference to the drawings. In the following description, identical or substantially identical components and elements will be denoted by the same reference numerals, and repeated descriptions will be omitted.
[0010] [Power Unit] Figure 1 shows a vehicle 11 on which a power unit 10 is mounted. As shown in Figure 1, the vehicle 11 is equipped with a power unit 10 comprising an engine 12 and motor generators MG1 and MG2. The rear wheels 16 are connected to the rear wheel output shaft 13 of the power unit 10 via a propeller shaft 14 and a rear differential mechanism 15. The power unit 10 also incorporates a front differential mechanism 17, to which the front wheels 18 are connected. The power unit 10 shown is a power unit for all-wheel drive, but is not limited to this, and may also be a power unit for front-wheel drive or rear-wheel drive.
[0011] Figure 2 shows an example of the internal structure of the power unit 10. As shown in Figure 2, the power unit 10 is provided with a main output shaft 20 that passes through the center of the motor generator MG2 in order to output engine torque and motor torque to the front and rear wheels. The front wheel output shaft 22 is connected to the main output shaft 20 via a gear train 21, and the rear wheel output shaft 13 is connected via a transfer clutch 23. In addition, a power split mechanism 25 consisting of a planetary gear train is connected to the main output shaft 20 via a gear train 24. The motor generator MG1 is connected to this power split mechanism 25, and the engine 12 is connected via a damper mechanism 26 and a gear train 27. Furthermore, the motor generator MG2 is connected to the main output shaft 20 via a planetary gear train 28. The front differential mechanism 17 mentioned above is connected to the front wheel output shaft 22.
[0012] [Motor generator (rotating electrical machine)] FIG. 3 is a cross-sectional view showing a motor generator MG2 as a rotating electrical machine according to an embodiment of the present invention. As shown in FIG. 3, the motor generator MG2 has a cylindrical stator 31 housed in a housing 30 and a rotor 32 housed inside the stator 31 in the radial direction. That is, inside the housing 30 of the motor generator MG2, the stator 31 is provided so as to surround the rotor 32. The housing 30 has a cylindrical housing body 33 surrounding the stator 31 and a housing cover 34 attached to the open end of the housing body 33.
[0013] The stator 31 has a cylindrical stator core 35 made of a plurality of electromagnetic steel sheets and a three-phase stator coil 36 wound around the stator core 35. The rotor 32 has a cylindrical rotor core 37 made of a plurality of electromagnetic steel sheets, a plurality of permanent magnets 38 embedded in the rotor core 37, and a hollow rotor shaft (shaft) 39 fixed to the center of the rotor core 37. Further, one end of the rotor shaft 39 is supported by the housing body 33 via a bearing 40, and the other end of the rotor shaft 39 is supported by the housing cover 34 via a bearing 41.
[0014] One end (first end) 31a of the stator 31 and the housing body 33 are connected via a first coupling mechanism (coupling mechanism) 51. This first coupling mechanism 51 has a first outer ring member (first annular member, outer ring member, first stator-side annular member) 52 attached to the stator 31 and a first inner ring member (second annular member, inner ring member, first housing-side annular member) 53 attached to the housing body 33. The first outer ring member 52 and the first inner ring member 53 are arranged in the radial direction with respect to each other, and a plurality of first spheres (spheres) 54 are provided between the first outer ring member 52 and the first inner ring member 53.
[0015] Similarly, the other end (second end) 31b of the stator 31 and the housing cover 34 are connected via a second coupling mechanism (coupling mechanism) 61. This second coupling mechanism 61 includes a second outer ring member (first annular member, outer ring member, second stator-side annular member) 62 attached to the stator 31 and a second inner ring member (second annular member, inner ring member, second housing-side annular member) 63 attached to the housing cover 34. Further, the second outer ring member 62 and the second inner ring member 63 are arranged radially with respect to each other, and a plurality of second spheres (spheres) 64 are provided between the second outer ring member 62 and the second inner ring member 63.
[0016] Also, the first outer ring member 52 and the second outer ring member 62 are fixed to the stator 31 using fastening bolts 65, and the first inner ring member 53 and the second inner ring member 63 are fixed to the housing 30 by spline fitting. In addition, in order to position the stator 31 in the axial direction, a spacer 66 that regulates the interval is attached between the stator 31 and the first outer ring member 52, and a spacer 67 that regulates the interval is attached between the stator 31 and the second outer ring member 62.
[0017] [Coupling mechanism] Next, the structure of the coupling mechanisms 51 and 61 that connect the housing 30 and the stator 31 will be described. Hereinafter, the structure of the first coupling mechanism 51 will be described. However, since the first coupling mechanism 51 and the second coupling mechanism 61 have the same structure, the description of the structure of the second coupling mechanism 61 will be omitted. Here, FIG. 4 is a cross-sectional view showing the motor generator MG2 with the rotor 32 removed, and FIG. 5 is a cross-sectional view showing the first coupling mechanism 51 along the line A-A in FIG. 4. Further, FIG. 6 is a view showing the disassembled state and the assembled state of the first coupling mechanism 51. In FIG. 6, the cross-section of the first outer ring member 52 and the side surface of the first inner ring member 53 are shown.
[0018] As shown in Figures 4 and 5, the first connecting mechanism 51 has an annular first outer ring member 52 provided on the stator 31. Multiple first recesses 55 are formed on the inner circumferential surface 52a of the first outer ring member 52 at equal intervals in the circumferential direction. The first connecting mechanism 51 also has an annular first inner ring member 53 provided on the housing 30. Multiple second recesses 56 are formed on the outer circumferential surface 53a of the first inner ring member 53 at equal intervals in the circumferential direction. Furthermore, multiple first spheres 54 are provided between the first outer ring member 52 and the first inner ring member 53, and the first spheres 54 are positioned in both the first recesses 55 and the second recesses 56, which are spherical indentations.
[0019] As shown in Figure 6, in order to incorporate the first sphere 54 between the first outer ring member 52 and the first inner ring member 53, the first inner ring member 53 can be divided in its center into two annular bodies (members) 57 and 58. That is, after assembling multiple first spheres 54 into the first recess 55 of the first outer ring member 52, a pair of annular bodies 57 and 58 are assembled to sandwich the multiple first spheres 54. The pair of annular bodies 57 and 58 constituting the first inner ring member 53 are fixed by screw members or the like (not shown). In the illustrated example, the first inner ring member 53 is divided by two annular bodies 57 and 58, but it is not limited to this, and the first inner ring member 53 may be divided into three or more members. Furthermore, although the illustrated example shows the first inner ring member 53 being divided by two annular bodies 57 and 58, the design is not limited to this. The first outer ring member 52 may be divided by two or more members, and both the first outer ring member 52 and the first inner ring member 53 may be divided by two or more members.
[0020] As shown in the enlarged portions of Figures 4 and 5, the curvature of the first recess 55 and the second recess 56 is set to be smaller than the curvature of the first sphere 54. In other words, the radius of curvature of the first recess 55 and the second recess 56 is set to be larger than the radius of curvature of the first sphere 54. By setting the first recess 55 and the second recess 56 in this way, as indicated by the symbol α1, the center of the first recess 55 is in close contact with the first sphere 54, and as indicated by the symbol α2, a gap is provided between the edge of the first recess 55 and the first sphere 54. Similarly, as indicated by the symbol β1, the center of the second recess 56 is in close contact with the first sphere 54, and as indicated by the symbol β2, a gap is provided between the edge of the second recess 56 and the first sphere 54.
[0021] In this way, by making the first sphere 54 tightly attached to the center of the first recess 55 and the first sphere 54 tightly attached to the center of the second recess 56, the radial movement of the first outer ring member 52 is restricted, as shown by the dashed arrow X1 in Figures 4 and 5. Furthermore, by providing a gap between the edge of the first recess 55 and the first sphere 54, and a gap between the edge of the second recess 56 and the first sphere 54, the axial movement of the first outer ring member 52 is permitted, as shown by the arrow X2 in Figure 4. In addition, by providing a gap between the edge of the first recess 55 and the first sphere 54, and a gap between the edge of the second recess 56 and the first sphere 54, the circumferential movement of the first outer ring member 52 is permitted, as shown by the arrow X3 in Figure 5.
[0022] In other words, the radial backlash in the first connecting mechanism 51 is set to be narrower than the circumferential backlash in the first connecting mechanism 51 and narrower than the axial backlash in the first connecting mechanism 51. To put it another way, when the same amount of load is applied to the first outer ring member 52 of the first connecting mechanism 51, the amount of radial movement of the first outer ring member 52 is set to be less than the amount of circumferential movement of the first outer ring member 52 and less than the amount of axial movement of the first outer ring member 52. To put it another way, the radial stiffness of the first connecting mechanism 51 is set to be higher than the circumferential stiffness of the first connecting mechanism 51 and higher than the axial stiffness of the first connecting mechanism 51.
[0023] As a result, even if the stator 31 vibrates due to magnetic strain when the coil is energized, vibration transmission to the housing 30 can be suppressed via the coupling mechanisms 51 and 61, thereby suppressing vibration and noise of the motor generator MG2. Moreover, since the radial movement of the outer ring members 52 and 62 in the coupling mechanisms 51 and 61 is restricted, it is possible to prevent the stator 31 from moving radially, and the air gap, which is the radial gap between the stator 31 and the rotor 32, can be properly maintained.
[0024] [Other Embodiment 1] In the example shown in Figure 3, the housing 30 and the stator 31 are connected by two connecting mechanisms 51 and 61, but this is not the only option; for example, the housing 30 and the stator 31 may be connected by a single connecting mechanism 51. Here, Figure 7 is a cross-sectional view showing a motor generator MG2a, which is another embodiment 1 of the present invention. In Figure 7, parts and components similar to those shown in Figure 3 are denoted by the same reference numerals and their descriptions are omitted.
[0025] As shown in Figure 7, one end 31a of the stator 31 and the housing body 33 are connected via a first connecting mechanism 51. This first connecting mechanism 51 includes a first outer ring member 52 attached to the stator 31 and a first inner ring member 53 attached to the housing body 33. The first connecting mechanism 51 also includes a plurality of first spheres 54 provided between the first outer ring member 52 and the first inner ring member 53. The first outer ring member 52 is fixed to the stator 31 using fastening bolts 65, and the first inner ring member 53 is fixed to the housing 30 by spline fitting. In order to position the stator 31 in the axial direction, a spacer 66 is installed between the stator 31 and the first outer ring member 52 to regulate the gap. In this way, even when the housing 30 and the stator 31 are connected by a single connecting mechanism 51, vibration and noise of the motor generator MG2a can be suppressed while appropriately maintaining the air gap of the motor generator MG2a, similar to the motor generator MG2 shown in Figure 3.
[0026] [Another Embodiment 2] In the examples shown in Figures 2 and 3, the first and second outer ring members 52 and 62 are attached to the stator 31, and the first and second inner ring members 53 and 63 are attached to the housing 30. However, the invention is not limited to this, and the first and second inner ring members 53 and 63 may be attached to the stator 31, and the first and second outer ring members 52 and 62 may be attached to the housing 30. Here, Figure 8 is a cross-sectional view showing another embodiment 2 of the present invention, a motor generator MG2b. In Figure 8, parts and components similar to those shown in Figure 2 are denoted by the same reference numerals, and their descriptions are omitted.
[0027] As shown in Figure 8, one end (first end) 31a of the stator 31 and the housing 30 are connected via a first connecting mechanism (connecting mechanism) 71. This first connecting mechanism 71 includes a first inner ring member (first annular member, inner ring member, first stator-side annular member) 72 attached to the stator 31 and a first outer ring member (second annular member, outer ring member, first housing-side annular member) 73 attached to the housing 30. The first inner ring member 72 and the first outer ring member 73 are arranged radially relative to each other, and a plurality of first spheres (spheres) 74 are placed in the first recess 75 of the first inner ring member 72 and the second recess 76 of the first outer ring member 73. The curvature of the first recess 75 and the second recess 76 is set to be smaller than the curvature of the first spheres 74.
[0028] Similarly, the other end (second end) 31b of the stator 31 and the housing 30 are connected via a second connecting mechanism (connecting mechanism) 81. This second connecting mechanism 81 includes a second inner ring member (first annular member, inner ring member, second stator-side annular member) 82 attached to the stator 31 and a second outer ring member (second annular member, outer ring member, second housing-side annular member) 83 attached to the housing 30. The second inner ring member 82 and the second outer ring member 83 are arranged radially relative to each other, and a plurality of second spheres (spheres) 84 are provided between the first recess 85 of the second outer ring member 62 and the second recess 86 of the second inner ring member 63. The curvature of the first recess 85 and the second recess 86 is set to be smaller than the curvature of the second spheres 84.
[0029] Thus, even when the housing 30 and the stator 31 are connected by the first connecting mechanism 71 and the second connecting mechanism 81, vibration and noise of the motor generator MG2b can be suppressed while appropriately maintaining the air gap of the motor generator MG2b, similar to the motor generator MG2 shown in Figure 2. In other words, the radial backlash in the first connecting mechanism 51 is set to be narrower than the circumferential backlash in the first connecting mechanism 51, and also narrower than the axial backlash in the first connecting mechanism 51. Furthermore, the radial backlash in the second connecting mechanism 61 is set to be narrower than the circumferential backlash in the second connecting mechanism 61, and also narrower than the axial backlash in the second connecting mechanism 61. As a result, even if the stator 31 vibrates due to magnetic strain when the coil is energized, vibration transmission to the housing 30 can be suppressed via the connecting mechanism, thereby suppressing vibration and noise of the motor generator MG2b. Furthermore, since the radial movement of the outer ring member in the coupling mechanism is restricted, it is possible to prevent the stator 31 from moving radially, and the air gap between the stator 31 and the rotor 32 can be properly maintained.
[0030] The present invention is not limited to the embodiments described above, and it goes without saying that various modifications are possible without departing from the spirit of the invention. In the illustrated example, the present invention is applied to a motor generator MG2, but it is not limited to this, and the present invention may also be applied to a motor generator MG1. Furthermore, in the illustrated example, the present invention is applied to a motor generator MG2 incorporated into the power unit 10 of a hybrid vehicle, but it is not limited to this, and for example, the present invention may be applied to an electric axle in which a differential mechanism and a rotating electric machine are incorporated into a housing. It should be noted that the rotating electric machine to which the present invention can be applied is not limited to a rotating electric machine used in a hybrid vehicle or an electric vehicle, and the present invention may also be applied to a rotating electric machine provided in other equipment.
[0031] In the above description, the outer ring members 52 and 62 are attached to the stator 31 using fastening bolts 65, but the method is not limited to this, and the outer ring members 52 and 62 may be attached to the stator 31 by other methods. Also, in the above description, the inner ring members 53 and 63 are attached to the housing 30 by spline fitting, but the method is not limited to this, and the inner ring members 53 and 63 may be attached to the housing 30 by other methods. [Explanation of symbols]
[0032] 30 Housing 31 stata 31a One end (first end) 31b Other end (second end) 32 rotors 39. Rotor shaft (shaft) 51 1st connection mechanism (connection mechanism) 52 First outer ring member (first annular member, outer ring member, first stator-side annular member) 52a Inner surface 53. First inner ring member (second annular member, inner ring member, first housing-side annular member) 53a Outer surface 54. First Sphere (Sphere) 55 First recess 56 Second recess 57, 58 Ring-shaped body (component) 61 Second connection mechanism (connection mechanism) 62. Second outer ring member (first annular member, outer ring member, second stator-side annular member) 63. Second inner ring member (second annular member, inner ring member, second housing-side annular member) 64. Second Sphere (Sphere) 71 1st connection mechanism (connection mechanism) 72 First inner ring member (first annular member, inner ring member, first stator-side annular member) 73. First outer ring member (second annular member, outer ring member, first housing-side annular member) 74. First Sphere (Sphere) 75 First recess 76 Second recess 81 Second connection mechanism (connection mechanism) 82. Second inner ring member (first annular member, inner ring member, second stator-side annular member) 83. Second outer ring member (second annular member, outer ring member, second housing-side annular member) 84. Second Sphere (Sphere) 85 First recess 86 Second recess MG2 Motor Generator (Rotating Electric Machine) MG2a Motor Generator (Rotating Electric Machine) MG2b Motor Generator (Rotating Electric Machine)
Claims
1. A rotor equipped with a shaft, The stator surrounding the rotor, A housing for the stator, A first annular member provided on the stator, having a plurality of first recesses formed in the circumferential direction, A second annular member provided in the housing, having a plurality of second recesses formed in the circumferential direction, A plurality of spheres are provided between the first annular member and the second annular member, and which fit into both the first recess and the second recess, It has, The first annular member, the second annular member, and the sphere constitute a connecting mechanism that connects the housing and the stator. The radial backlash of the coupling mechanism is narrower than the circumferential backlash of the coupling mechanism, and narrower than the axial backlash of the coupling mechanism. Rotating electric machine.
2. In the rotating electric machine described in claim 1, The first annular member is an outer ring member in which the first recess is formed on the inner circumferential surface. The second annular member is an inner ring member in which the second recess is formed on the outer circumferential surface. Rotating electric machine.
3. In the rotating electric machine described in claim 1, The first annular member is an inner ring member in which the first recess is formed on the outer circumferential surface. The second annular member is an outer ring member in which the second recess is formed on the inner circumferential surface. Rotating electric machine.
4. In the rotating electric machine described in claim 1, At least one of the first annular member and the second annular member is divisible into at least two members. Rotating electric machine.
5. In the rotating electric machine according to any one of claims 1 to 4, The first annular member provided on the stator includes a first stator-side annular member provided at the first end of the stator and a second stator-side annular member provided at the second end of the stator. The second annular member provided in the housing includes a first housing-side annular member located radially to the first stator-side annular member, and a second housing-side annular member located radially to the second stator-side annular member. The aforementioned spheres include a plurality of first spheres provided between the first stator-side annular member and the first housing-side annular member, and a plurality of second spheres provided between the second stator-side annular member and the second housing-side annular member. The aforementioned connecting mechanism includes a first connecting mechanism comprising the first stator-side annular member, the first housing-side annular member, and the first sphere, and a second connecting mechanism comprising the second stator-side annular member, the second housing-side annular member, and the second sphere. Rotating electric machine.