Rotor
The rotor design with non-magnetic and magnetic end plates and balance correction holes addresses unbalance-induced vibrations and costs, achieving cost-effective balance correction and stability.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOYOTA JIDOSHA KK
- Filing Date
- 2023-03-06
- Publication Date
- 2026-07-22
AI Technical Summary
Vibrations and unbalance in rotors due to unbalanced design lead to increased costs due to the need for correction portions, which enlarge the end plates, thereby increasing material costs.
A rotor design with a first end plate made of non-magnetic material and a second end plate made of magnetic material, featuring a balance correction portion, where the second plate is thicker and has holes to correct balance, reducing the size and cost of the non-magnetic plate.
The design achieves cost reduction while maintaining balance correction and stability, suppressing magnetic flux leakage and creep phenomena, and ensuring stable rotor operation.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention relates to a rotor.
Background Art
[0002] A motor, which is a rotating electrical machine, includes a stator and a rotor. The rotor is a rotating part and has a rotor core and end plates (for example, see Patent Document 1).
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] Vibrations and the like may occur due to unbalance in the rotor. To correct the unbalance, a correction portion such as a hole is provided in the end plate. Providing the correction portion makes the end plate large. As a result, the cost increases. Therefore, an object is to provide a rotor capable of suppressing the cost.
Means for Solving the Problems
[0005] The above object can be achieved by Having a magnet a rotor core and end plates, the end plates having a first plate and a second plate, the first plate being formed of a non-magnetic material and provided at an end portion of the rotor core in the axial direction, the second plate being formed of a magnetic material and provided on a surface of the first plate opposite to the rotor core, and having a balance correction portion for correcting the balance of the rotor The rotor core and the first plate have an oil passage extending in the axial direction inside the magnet in the radial direction of the rotor, the second plate has a first portion and a second portion adjacent to each other in the axial direction, the first portion is located closer to the first plate than the second portion, the end of the second portion is located outside the passage and the end of the first portion and inside the magnet in the radial direction of the rotor, and the step between the end of the first portion and the end of the second portion in the radial direction of the rotor is connected to the end of the passage in the axial direction and forms the outer edge of the gap through which the oil flows. a rotor.
[0006] The second plate may be thicker than the first plate. [Effects of the Invention]
[0010] We can provide rotors that allow for cost reduction. [Brief explanation of the drawing]
[0011] [Figure 1] Figure 1 is a cross-sectional view illustrating a motor according to the first embodiment. [Figure 2] Figure 2(a) is a cross-sectional view illustrating a motor according to the second embodiment. Figure 2(b) is a cross-sectional view illustrating a motor according to the third embodiment. [Figure 3] Figure 3(a) is a cross-sectional view illustrating a motor according to the fourth embodiment. Figure 3(b) is a cross-sectional view illustrating a motor according to the fifth embodiment. [Modes for carrying out the invention]
[0012] The rotor of this embodiment will be described below with reference to the drawings. However, the dimensions and proportions of each part in the drawings may not perfectly match those of the actual parts. Also, some details may be omitted in the drawings.
[0013] <First Embodiment> Figure 1 is a cross-sectional view illustrating a motor 100 according to the first embodiment, showing one side from the center of the shaft. The motor 100 is, for example, a motor generator mounted in a hybrid vehicle, and is used as a driving force source and generator. The motor 100 is, for example, a three-phase AC synchronous transmission generator. In Figure 1, the X-axis represents the direction of the shaft of the motor 100. The Y-axis represents the radial direction and is perpendicular to the X-axis.
[0014] The motor 100 has a stator 10 and a rotor 20. The stator 10 has a stator core 12 and a coil 14. The stator core 12 includes a plurality of electrical steel sheets. The plurality of electrical steel sheets are stacked, for example, along the X-axis. The coil 14 is wound around the stator core 12. The coil 14 is electrically connected to a power supply (not shown). When current flows through the coil 14, a magnetic field is generated in the stator 10.
[0015] The rotor 20 includes a shaft 21, a rotor core 22, an end plate 24, and a fixing member 26. The shaft 21 extends parallel to the X-axis. Line L represents the center of the shaft 21. The rotor core 22 protrudes radially from both sides of the shaft 21. The rotor core 22 has multiple electrical steel sheets. The multiple electrical steel sheets are stacked along the X-axis direction. The rotor core 22 has magnets 23 inside. The magnets 23 are permanent magnets.
[0016] End plates 24 are provided at both ends of the rotor core 22 in the X-axis direction. The end plates 24 are fixed by fixing members 26. The end plates 24 and fixing members 26 hold and fix the rotor core 22. The magnets 23 are protected by the end plates 24 covering them.
[0017] The end plate 24 includes a plate 30 (first plate) and a plate 32 (second plate). One surface of plate 30 is in contact with the side surface of the rotor core 22. One surface of plate 32 is in contact with the surface of plate 30 opposite to the rotor core 22. A fixing member 26 is attached to the other surface of plate 32 and is located on the outer circumferential surface of the shaft 21. The diameter of the fixing member 26 is smaller than the diameter of plate 32. The surface of plate 32 opposite to plate 30 is exposed.
[0018] Plate 30 is made of a non-magnetic material, such as stainless steel, copper, brass, aluminum, or an aluminum alloy. Plate 32 is made of a magnetic material, such as rolled steel.
[0019] The thickness of the plate 30 may be equal to the thickness of the plate 32, may be greater than the thickness of the plate 32, or may be less than the thickness of the plate 32. The diameter of the plate 30 is the distance from the center L of the shaft 21 to the end of the plate 30 in the Y-axis direction. The diameter of the plate 30 may be equal to the diameter of the plate 32, may be greater than the diameter of the plate 32, or may be less than the diameter of the plate 32. The diameter of the plate 30 may be equal to the diameter of the rotor core 22, or may be less than the diameter of the rotor core 22.
[0020] A balance correction portion is provided on the plate 32. The hole 34 is an example of the balance correction portion. The hole 34 extends from the surface of the plate 32 opposite to the plate 30 to the middle in the thickness direction of the plate 32.
[0021] According to the first embodiment, the end plate 24 has the plate 30 and the plate 32. The plate 30 is formed of a non-magnetic material. The plate 32 is formed of a magnetic material. The cost of the non-magnetic material is higher than the cost of the magnetic material. Therefore, the cost of the plate 30 is higher than the cost of the plate 32. The plate 32 has a hole 34 which is a balance correction portion. The plate 30 is not provided with a hole. For this reason, it is not necessary to make the plate 30 large. The plate 30 may be, for example, of the same size as the plate 32, or may be smaller than the plate 32. Since it is not necessary to increase the size of the high-cost plate 30, the cost can be suppressed.
[0022] By providing a balance correction portion on the low-cost plate 32, it is possible to achieve both balance correction and cost reduction. By correcting the balance, the balance of the rotor 20 is improved and the rotor 20 rotates stably. The hole 34 is an example of the balance correction portion. As the balance correction portion, for example, a groove or the like may be provided on the plate 32.
[0023] One end plate 24 is provided at one end of the rotor core 22, and another end plate 24 is provided at the other end. In each of the two end plates 24 , magneticHoles 34 are provided in the plate 32 of the magnetic body. The cost can be effectively suppressed. With the low-cost end plate 24, it is possible to protect the magnet 23 and suppress the scattering of the rotor core 22. That is, balance correction, cost reduction, and holding of the rotor core 22 are possible.
[0024] <Second Embodiment> FIG. 2(a) is a cross-sectional view illustrating the motor 200 according to the second embodiment, in which the stator 10 is omitted and the rotor 20 is illustrated. The description of the same configuration as that of the first embodiment is omitted. As shown in FIG. 2(a), the thickness of the plate 30 is T1, and the thickness of the plate 32 is T2. The thickness T2 is greater than the thickness T1. The thickness T2 of the plate 32 may be 1.5 times or more, 2 times or more, 3 times or more, etc. of the thickness T1 of the plate 30. Holes 34 are provided in the plate 32.
[0025] According to the second embodiment, the plate 32 formed of a magnetic material is thicker than the plate 30 formed of a non-magnetic material. Since the high-cost plate 30 is thin, it is possible to suppress the cost of the end plate 24. By thickening the low-cost plate 32 and providing the holes 34, balance correction is possible.
[0026] Creep phenomenon may occur in the motor. Due to load and temperature changes, etc., the end plate 24 may become thinner, and the axial force acting on the rotor core 22 may decrease. The creep amount (change amount of thickness) of the non-magnetic material is large. According to the second embodiment, since the non-magnetic plate 30 is thin, the change amount of thickness becomes small. The magnetic plate 32 is less likely to change in thickness compared to the plate 30. Therefore, the creep phenomenon can be suppressed. The force in the X-axis direction applied to the rotor core 22 is less likely to decrease, and the rotor core 22 can be stably fixed by the end plate 24. In addition to balance correction, cost reduction, and holding of the rotor core 22, suppression of the creep phenomenon is possible.
[0027] <Third Embodiment> Figure 2(b) is a cross-sectional view illustrating a motor 300 according to the third embodiment. Descriptions of the same configuration as in the first or second embodiment are omitted.
[0028] As shown in Figure 2(b), let R1 be the radius of plate 30. Let R2 be the radius of plate 32. Let R3 be the distance from the center L of shaft 21 to the end of magnet 23. Radius R1 is greater than radius R2 and distance R3. Radius R2 is less than distance R3. In the radial direction (Y-axis direction), plate 30 extends beyond the magnet 23 of rotor core 22. In the radial direction, the end of plate 32 is located inside the end of plate 30 and the magnet 23. Holes 34 are provided in plate 32.
[0029] According to the third embodiment, in the Y-axis direction, the end of the plate 32 is located inward from the magnet 23. The plate 32, which is made of magnetic material, is moved away from the magnet 23 and the stator 10. The magnetic flux generated by the magnet 23 and the stator 10 is less likely to leak into the plate 32. The deterioration of the motor 300's performance is suppressed. In other words, in addition to balance correction, cost reduction, and retention of the rotor core 22, it is possible to suppress magnetic flux leakage.
[0030] Plate 30 is longer than plate 32 and covers the magnet 23. The magnet 23 can be protected by plate 30, which is made of a non-magnetic material.
[0031] <Fourth Embodiment> Figure 3(a) is a cross-sectional view illustrating a motor 400 according to the fourth embodiment, in which the stator 10 is omitted and the rotor 20 is shown. Descriptions of configurations identical to any of the first to third embodiments are omitted.
[0032] As shown in Figure 3(a), the plate 32 has a first portion 40 and a second portion 42. In the X-axis direction, the first portion 40 is located closer to the plate 30 and the magnet 23 than the second portion 42 and is in contact with the plate 30. The second portion 42 is further away from the plate 30 and the magnet 23 and is in contact with the fixing member 26.
[0033] In the radial direction (Y-axis direction), the second portion 42 is longer than the first portion 40. The first portion 40 and the second portion 42 form a step. The radius of the first portion 40 is R4. The radius of the second portion 42 is R5. Radius R5 is larger than radius R4, for example, 1.2 times or more, 1.5 times or more, or 2 times or more than radius R4. Radii R4 and R5 are smaller than the distance R3 from the center L of the shaft 21 to the magnet 23. A gap 44 is formed at the position surrounded by the first portion 40 and the second portion 42 of plate 30 and plate 32. A balance correction portion (hole 34) is provided in the second portion 42 of plate 32.
[0034] According to the fourth embodiment, in the Y-axis direction, the end of the first portion 40 of the plate 32 is located inward from the end of the second portion 42 and farther from the magnet 23. The plate 32, which is made of magnetic material, can be kept away from the magnet 23 and the stator 10 (not shown in Figure 3(a)). Therefore, leakage of magnetic flux can be suppressed.
[0035] The second part 42 is longer than the first part 40. A hole 34 for balance correction can be provided in the second part 42. This allows for both balance correction and magnetic flux leakage to be achieved.
[0036] <Fifth Embodiment> Figure 3(b) is a cross-sectional view illustrating the motor 500 according to the fifth embodiment, in which the stator 10 is omitted and the rotor 20 is shown. Descriptions of configurations identical to any of the first to fourth embodiments are omitted.
[0037] The rotor 20 has passages 46. The passages 46 are provided in the shaft 21, the rotor core 22, and the plate 32. Inside the shaft 21, the passages 46 are parallel to the Y-axis direction. Inside the rotor 20, part of the passages 46 are parallel to the Y-axis direction, and another part is parallel to the X-axis direction.
[0038] Radius R of the first part 40 of plate 32 5The radius R of the second part 42 is smaller than the distance R6 from the center L of the shaft 21 to the passage 46. 4 It is greater than the distance R6. The end of the passage 46 is located on the outer side of the plate 30 and is exposed to the gap 44.
[0039] According to the fifth embodiment, since the end of the passage 46 is exposed to the gap 44, the flow of oil is less likely to be obstructed by the end plate 24. That is, the oil flows inside the passage 46 and is discharged into the gap 44. The supply of oil enables lubrication and cooling of the motor 500.
[0040] Although preferred embodiments of the present invention have been described in detail above, the present invention is not limited to these specific embodiments, and various modifications and changes are possible within the scope of the gist of the invention as described in the claims. [Explanation of Symbols]
[0041] 10 Stator, 12 Stator core, 14 Coil, 20 Rotor, 21 Shaft, 22 Rotor core, 23 Magnet, 24 End plate, 26 Fixing member, 30 Plate (first plate), 32 Plate (second plate), 34 Hole (balance correction part), 40 First part, 42 Second part, 44 Gap, 46 Passage, 100, 200, 300, 400, 500 Motor
Claims
1. A rotor core having a magnet, It comprises an end plate and, The end plate has a first plate and a second plate. The first plate is made of a non-magnetic material and is provided at the end of the rotor core in the axial direction. The second plate is made of a magnetic material, is provided on the side of the first plate opposite to the rotor core, and has a balance correction portion for correcting the balance of the rotor. The rotor core and the first plate have oil passages extending in the axial direction inside the magnets in the radial direction of the rotor. The second plate has a first portion and a second portion that are adjacent to each other in the axial direction, The first part is located closer to the first plate than the second part, In the radial direction of the rotor, the end of the second portion is located outside the passage and the end of the first portion, and inside the magnet. The step between the end of the first portion and the end of the second portion of the rotor in the radial direction is connected to the end of the passage in the axial direction and forms the outer edge of the gap through which the oil flows. Rotor.
2. The rotor according to claim 1, wherein the second plate is thicker than the first plate.