Rotor for rotating electric machine

Abstract

To provide a rotor of a rotating electric machine capable of suppressing induced voltage during rotation without increasing manufacturing cost and reducing strength.SOLUTION: A rotor 12 of a rotating electric machine has a rotor core 18, a rotating shaft, a magnet insertion hole, and a permanent magnet inserted into the magnet insertion hole. A stress adjustment unit is provided at a position corresponding to a main magnetic flux region between the end surfaces of the rotor core 18, the stress adjustment unit including: an inclined portion provided on the end surface and inclined in a direction away from the end surface as it moves from the inner side to the outer side in the radial direction of the rotor core 18; a covering portion extending from the inclined portion to the inner side in the radial direction and covering the inclined portion; and a movable portion capable of moving in the radial direction of the rotor core 18 at the end surface, in which the distance from a base portion of the inclined portion to the covering portion 35 is set to be larger than the length of the movable portion in the axial direction of the rotor core 18, and the distance in the axial direction between the covering portion 35 and the inclined portion is set to be less than the length of the movable portion in the axial direction as it moves from the inner side to the outer side in the radial direction.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a rotor for a rotating electrical machine. [Background technology]

[0002] As a conventional technique related to the rotor of a rotating electric machine, for example, a permanent magnet type rotating electric machine disclosed in Patent Document 1 is known. The permanent magnet type rotating electric machine disclosed in Patent Document 1 includes a stator wound with an excitation coil, and a rotor arranged to rotate freely relative to the stator with a predetermined gap, and provided with a permanent magnet. The rotor is provided with a magnetic characteristic variable element (super magnetostrictive element) whose magnetic characteristics change when stress is applied due to the rotation of the rotor, thereby reducing the magnetic flux of the permanent magnet. According to the permanent magnet type rotating electric machine of Patent Document 1, when the rotation speed of the rotor increases, the rotational centrifugal force of the rotor is applied as stress to the magnetic characteristic variable element, which changes the magnetic characteristics of the magnetic characteristic variable element and reduces the magnetic flux of the permanent magnet, thereby suppressing the induced voltage of the permanent magnet type rotating electric machine and preventing the destruction or failure of electronic components. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2012-228077 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, although the rotor of the permanent magnet type rotating electric machine disclosed in Patent Document 1 can suppress the induced voltage of the permanent magnet type rotating electric machine, there is a problem that the manufacturing cost increases due to the use of expensive magnetic property variable elements. In addition, if the magnetic property variable element deforms during the rotation of the rotor, a gap may occur between the permanent magnet inserted in the rotor and the rotor, which may reduce the strength of the rotor. An example is also disclosed in which a stress adjustment block is provided radially inside the magnetic property variable element, but the need for the stress adjustment block further increases the manufacturing cost.

[0005] The present invention has been made in consideration of the above problems, and an object of the present invention is to provide a rotor for a rotating electric machine that makes it possible to suppress induced voltage during rotation without increasing manufacturing costs or reducing strength. [Means for solving the problem]

[0006] In order to solve the above problems, the present invention provides a rotor for a rotating electric machine having a rotor core formed by laminating electromagnetic steel sheets, a rotating shaft inserted through the center of the rotor core and integrated with the rotor core, magnet insertion holes formed for each magnetic pole of the rotor core and extending along the axial direction of the rotating shaft, and permanent magnets inserted into the magnet insertion holes, the rotor core having a stress adjustment portion provided at a position on an end face of the rotor core that corresponds to a main magnetic flux region, the stress adjustment portion being provided on the end face and gradually decreasing in size from the inside to the outside in the radial direction of the rotor core. the rotor core has an inclined portion inclined in a direction away from the rotor core, a covering portion extending radially inward from the inclined portion and covering the inclined portion, and a movable portion that can move radially of the rotor core at the end face, wherein when the point where the inclined portion contacts the end face is defined as a base of the inclined portion, the distance from the base to the covering portion is set to be greater than or equal to the length of the movable portion in the axial direction of the rotor core, and the axial distance between the covering portion and the inclined portion decreases to less than the length of the movable part in the axial direction as it moves from the radial inside to the radial outside.

[0007] In the present invention, when the rotation of the rotor increases, the movable part is supported between the inclined part and the covering part by moving radially outward from the end face of the rotor core under the centrifugal force, and a load along the axial direction of the rotating shaft is applied to the stress adjustment part by trying to expand the gap between the inclined part and the covering part. As the rotation of the rotor increases, the load along the axial direction of the rotating shaft on the stress adjustment part increases due to the increase in centrifugal force, so that the stress along the axial direction of the rotating shaft in the rotor core increases, and the main magnetic flux in the rotor core is reduced. Since the main magnetic flux in the rotor core is reduced, the induced voltage at high rotation can be suppressed. Since the centrifugal force is smaller at low rotation of the rotor than at high rotation, the movable part is separated from the inclined part and the covering part, there is no load along the axial direction of the rotating shaft via the stress adjustment part, and the main magnetic flux in the rotor core is not reduced. Since the main magnetic flux in the rotor core is not reduced, a high torque of the rotor can be obtained.

[0008] Furthermore, in the rotor of the above-mentioned rotating electric machine, the stress adjustment portion may have a cover member that defines a space in which the movable portion is movable, and the inclined portion may be located radially outward of the cover member. In this case, the stress adjusting portion forms a cover member that defines a space in which the movable portion can move, and the inclined portion is located radially outward of the cover member. Therefore, the cover member can define the space in which the movable portion can move, and providing the cover member makes it easier to protect the movable portion.

[0009] In the rotor for the rotating electric machine described above, the inclined portion and the covering portion may be integrally formed on the radially outer side of an electromagnetic steel plate forming the end face. In this case, since the inclined portion and the covering portion are integrally formed on the radially outer side of the electromagnetic steel plate forming the end face of the rotor core, when the movable portion is supported by the inclined portion and the covering portion due to centrifugal force, the movable portion tries to expand between the inclined portion and the covering portion, and a load along the axial direction of the rotating shaft is applied to the stress adjustment portion. The inclined portion and the covering portion can be provided on the electromagnetic steel plate forming the end face of the rotor core. Also, since the electromagnetic steel plate forming the end face of the rotor core is used as the stress adjustment portion, the number of parts can be reduced.

[0010] In the rotor of the rotating electric machine described above, the movable portion may be a rollable cylindrical body. In this case, since the movable part is a rolling cylindrical body, it is easy to realize the movable part. Also, since the movable part is a cylindrical body, the rolling direction is one direction along the radial direction of the rotor core, and the movable part does not roll in any direction other than the radial direction of the rotor core, so that the rolling of the movable part is easy to control.

[0011] In the rotor of the rotating electric machine described above, the movable portion may be a rollable sphere. In this case, since the movable part is a rolling sphere, it is easy to realize the movable part. Also, since the movable part is a sphere, the movable part can roll more easily. Effect of the Invention

[0012] According to the present invention, it is possible to provide a rotor for a rotating electric machine that is capable of suppressing induced voltage during rotation without increasing manufacturing costs or decreasing strength. [Brief description of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view of a rotating electric machine according to a first embodiment. [Diagram 2] 1 is a perspective view of a rotor of a rotating electric machine according to a first embodiment. [Diagram 3] 1 is a plan view of a main portion of a rotor of a rotating electric machine according to a first embodiment. [Figure 4] FIG. 4 is a view taken along line AA in FIG. [Diagram 5] FIG. 1 is a perspective view of a stress adjusting portion provided in a rotor of a rotating electric machine; [Figure 6] 1A is a cross-sectional view of a main portion showing the state of the stress adjusting portion at high rotation speed, and FIG. 1B is a cross-sectional view of a main portion showing the state of the stress adjusting portion at low rotation speed. [Figure 7] 1A is a cross-sectional view of a main part of a rotor for a rotating electric machine according to a second embodiment, and FIG. 1B is a perspective view of the rotor for a rotating electric machine according to the second embodiment. [Figure 8] 10A is a plan view of a main portion of a rotor for a rotating electric machine according to a third embodiment, and FIG. 10B is a cross-sectional view of a main portion of the rotor for a rotating electric machine according to the third embodiment. [Figure 9] FIG. 11 is a cross-sectional view of a main part of a rotating electric machine according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] (First embodiment) Hereinafter, a rotor of a rotating electric machine according to a first embodiment will be described with reference to the drawings. The rotating electric machine of this embodiment is a permanent magnet embedded synchronous motor, and is mounted on a vehicle. The rotating electric machine and the rotor of the rotating electric machine shown in the drawings are both schematic diagrams, and the shapes are exaggerated.

[0015] As shown in FIG. 1, a permanent magnet type rotating electric machine (hereinafter simply referred to as a "rotating electric machine") 10 includes a stator 11 and a rotor 12. The stator 11 has a cylindrical stator core 13. A plurality of slots 14 are formed on the inner periphery of the stator core 13. Each slot 14 opens to the inner periphery of the stator core 13. Teeth 15 are formed between each slot 14. Coils 16 are wound around the teeth 15. The rotor 12 is provided such that a gap is formed between the rotor 12 and the inner periphery of the stator core 13.

[0016] The rotor 12 is disposed inside the stator 11. As shown in FIG. 2, the rotor 12 has a rotor core 18 formed by laminating a plurality of (e.g., several tens of) disk-shaped electromagnetic steel plates 17. A shaft hole 19 is formed penetrating the center of the rotor core 18. A rotating shaft 20 is inserted into the shaft hole 19, and the rotating shaft 20 is fixed to the rotor core 18. The rotor core 18 can rotate integrally with the rotating shaft 20. The rotating shaft 20 is rotatably supported by a motor housing (not shown) via a bearing (not shown). For ease of explanation, the rotating shaft 20 is not shown in FIG. 2.

[0017] As shown in Fig. 3, rotor core 18 is formed with a plurality of pairs of magnet insertion holes 21 adjacent to each other in the circumferential direction of rotor core 18. The magnet insertion holes 21 are formed for each magnetic pole of rotor core 18 and pass through rotor core 18 along the penetrating direction of shaft hole 19. A pair of permanent magnets 22 of the same polarity are inserted into each pair of magnet insertion holes 21. The multiple pairs of permanent magnets 22 are embedded in rotor core 18 such that each pair has alternate magnetic polarities in the circumferential direction of rotor core 18.

[0018] Specifically, the stator 11 side is equipped with an N-pole permanent magnet (hereinafter referred to as "N-pole magnet") 22, and the stator 11 side is equipped with an S-pole permanent magnet (hereinafter referred to as "S-pole magnet") 22, and a first set of two S-pole magnets 22 arranged adjacent to each other and a second set of two N-pole magnets 22 arranged adjacent to each other are fixed to the rotor core 18 so as to be arranged alternately in the circumferential direction of the rotor core 18.

[0019] More specifically, rotor core 18 is circumferentially equally divided into a plurality of imaginary regions (six in this embodiment), and each of these imaginary regions has two magnet insertion holes 21 into which two S-pole magnets 22 making up a first set are inserted, and two magnet insertion holes 21 into which two N-pole magnets 22 making up a second set are inserted, which are alternately formed. Therefore, rotating electric machine 10 of this embodiment is a six-pole rotating electric machine. Note that when there is no distinction between N-pole magnets and S-pole magnets, the permanent magnets 22 will be referred to as permanent magnets 22.

[0020] As shown in Fig. 3, the magnet insertion hole 21 has a gap 23 formed by the permanent magnet 22 and the rotor core 18 and located on the outer periphery side of the rotor core 18, and a gap 24 formed by the permanent magnet 22 and the rotor core 18 and located on the inner periphery side of the rotor core 18. Each gap 23 acts as a flux barrier to effectively cause the magnetic flux to act on torque. Between adjacent gaps 23, an outer bridge 25 is formed as a bridge on the radial outside of the rotor core 18. An outer edge 26 is formed between the gap 23 and the outer periphery surface of the rotor core 18.

[0021] The gaps 24 form non-magnetic regions in the magnet insertion holes 21. Between adjacent gaps 24, inner bridges 27 are formed as bridges on the radially inner side of the rotor core 18.

[0022] The rotor core 18 has an outer core portion 28, which is between the pair of magnet insertion holes 21 and the outer peripheral surface of the rotor core 18 and is located on the outer peripheral side of the magnet insertion holes 21, and an inner core portion 29, which is located on the inner peripheral side of the magnet insertion holes 21 in the rotor core 18. The outer bridge 25 extends linearly from the inner core portion 29 toward the outer peripheral surface of the rotor core 18. The outer core portion 28 is supported by the inner bridge 27 and the outer edge portion 26. The inner bridge 27 extends linearly from the inner core portion 29 toward the outer peripheral surface of the rotor core 18. The pair of permanent magnets 22 are arranged in a V-shape with respect to the extension direction of the inner bridge 27. The rotor core 18 has a main magnetic flux region where the main magnetic flux component generated by the permanent magnets 22 flows, and a leakage magnetic flux region where leakage magnetic flux occurs. The regions of the outer core portion 28 and the inner core portion 29 that are sandwiched between adjacent permanent magnets 22 correspond to the main magnetic flux region where the main magnetic flux component flows. Moreover, the outer bridge 25 and the inner bridge 27 correspond to a leakage flux region where leakage flux occurs.

[0023] In this embodiment, the stress adjustment portion 30 is provided at a position close to the outer periphery on one end face of the outer core portion 28 of the rotor core 18, and no stress adjustment portion is provided on the other end face. The stress adjustment portion 30 has a function of adjusting the stress along the axial direction of the rotating shaft 20 on the outer core portion 28. It is preferable that the stress adjustment portion 30 is disposed on the outer radial side of the outer core portion 28, as close to the outer periphery surface as possible. In this embodiment, the stress adjustment portion 30 is provided at a position on the end face of the rotor core 18 that corresponds to the main magnetic flux region, and all of the outer core portions 28 are provided with the stress adjustment portion 30.

[0024] The stress adjusting section 30 has a cover member 31. The cover member 31 is formed of a non-magnetic metal material. Examples of the non-magnetic metal material include aluminum-based alloys and zinc-based alloys, which are elastically deformable metal materials. As shown in FIG. 4 and FIG. 5, the cover member 31 is provided at a position on the end face of the rotor core 18 that corresponds to the main magnetic flux region, and defines a space in which the cylindrical member 32 can move. The cover member 31 has an inclined portion 33 and a covering portion 35 that covers the inclined portion 33. The covering portion 35 has a covering gradient portion 35A, a covering parallel portion 35B, and a covering auxiliary portion 35C.

[0025] The inclined portion 33 is located on the radially outer side of the cover member 31, and inclines in a direction away from the end face of the rotor core 18 as it moves from the radially inner side to the radially outer side of the end face of the rotor core 18. As shown in Fig. 5, the base 33A of the inclined portion 33 is bonded to the end face of the rotor core 18 so that the longitudinal direction of the cover member 31 is aligned with the tangent direction of the outer periphery. The plate thickness of the inclined portion 33 and the inclination angle with respect to the end face of the rotor core 18 are set in accordance with various conditions of the rotating electric machine 10.

[0026] As shown in FIG. 4, the gradient covering portion 35A is located on the radial outside of the cover member 31, is a portion bent from the tip of the inclined portion 33, and is inclined so as to move away from the inclined portion 33 as it moves from the radial outside to the radial inside. The parallel covering portion 35B extends from the tip of the gradient covering portion 35A toward the radial inside and is approximately parallel to the end face of the rotor core 18. The inclined portion 33 and the covering portion 35 form the radial outside portion of the cover member 31 in a wedge shape in side view. The auxiliary covering portion 35C is a portion extending from the radial inside end of the parallel covering portion 35B, and approaches the end face of the rotor core 18 as it moves from the radial outside to the radial inside. A gap 37 is provided between the tip of the auxiliary covering portion 35C and the rotor core 18. To prevent the cylindrical member 32 from coming off the cover member 31, restricting pieces 38 extending toward the end faces of the rotor core 18 are provided on both ends of the longitudinal direction (direction perpendicular to the radial direction) of the covering parallel portion 35B. The restricting pieces 38 do not come into contact with the end faces of the rotor core 18.

[0027] The cylindrical member 32 is a cylindrical member made of a non-magnetic metal such as an aluminum alloy or a zinc alloy. The cylindrical member 32 can roll on the end face of the rotor core 18 in the space formed by the cover member 31. The longitudinal direction of the cylindrical member 32 is approximately parallel to the longitudinal direction of the cover member 31. The diameter R of the cylindrical member 32 is larger than the gap 37 and smaller than the distance H between the coating parallel part 35B and the end face of the rotor core 18. That is, as shown in FIG. 4, the distance H from the base 33A of the inclined part 33 to the coating parallel part 35B is set to be equal to or larger than the diameter R, which is equal to the height of the cylindrical member 32. In addition, the distance L between the coating parallel part 35B and the inclined part 33 decreases from the radial inner side to the radial outer side, and becomes smaller than the height of the cylindrical member 32. The maximum value of the distance L is equal to or larger than the diameter R and smaller than the distance H, and the minimum value of the distance L is smaller than the diameter R. Therefore, when the cylindrical member 32 receives centrifugal force and rides on the inclined surface of the inclined portion 33 radially outward, the cylindrical member 32 comes into contact with the coated parallel portion 35B while moving along the inclined surface of the inclined portion 33.

[0028] Next, the operation of the rotating electric machine 10 of this embodiment will be described. When the rotating electric machine 10 is driven under a load, a current is supplied to the coil 16 of the rotor 12, generating a rotating magnetic field in the stator 11, and the rotating magnetic field acts on the rotor 12. Then, the rotor 12 rotates in synchronization with the rotating magnetic field due to the magnetic attraction and repulsion between the rotating magnetic field and the permanent magnets 22.

[0029] As the rotation speed of the rotor 12 increases and the rotor 12 rotates at a higher speed, the centrifugal force acting on the rotor 12 increases. As the centrifugal force increases, the cylindrical member 32 in the stress adjustment section 30 of the rotor core 18 moves radially outward from the rotor core 18 in the space of the cover member 31 due to the centrifugal force. As shown in FIG. 6(a), when the rotation speed of the rotor 12 reaches or exceeds a predetermined rotation speed, the cylindrical member 32 rides on the inclined portion 33 against its own weight due to the centrifugal force, moves radially outward, and comes into contact with the covering parallel portion 35B and stops at the inclined portion 33. In other words, the cylindrical member 32 moves to the outermost position in the radial direction of the rotor core 18 in the space inside the cover member 31 and is supported between the inclined portion 33 and the covering parallel portion 35B.

[0030] The cylindrical member 32, which comes into contact with the gradient covering portion 35A and stops at the inclined portion 33, continues to receive the centrifugal force caused by the rotation of the rotor 12. At this time, the cylindrical member 32 receiving the centrifugal force tries to move further outward in the radial direction of the rotor core 18, and therefore tries to expand the gap between the inclined portion 33 and the parallel covering portion 35B. Therefore, the base portion 33A of the inclined portion 33 receives a load due to a component along the axial direction of the rotating shaft 20, and the rotor core 18 receives a load along the axial direction of the rotating shaft 20 via the base portion 33A of the inclined portion 33. In other words, the cylindrical member 32 applies a load along the axial direction of the rotating shaft 20 to the rotor core 18 via the cover member 31. The stress along the axial direction of the rotating shaft 20 in the core outer circumferential portion 28 increases in accordance with the increase in the centrifugal force received by the cylindrical member 32. In addition, the cylindrical member 32 receiving the centrifugal force expands the space between the inclined portion 33 and the coated parallel portion 35B of the cover member 31, whereby the cover member 31 is elastically deformed in response to the centrifugal force. The elastic deformation of the cover member 31 increases the load on the core outer circumferential portion 28 along the axial direction of the rotating shaft 20.

[0031] The stress in the axial direction of the rotating shaft 20 increases in the core outer circumferential portion 28, thereby reducing the main magnetic flux in the rotor core 18. As a result, the induced voltage during high speed rotation of the rotor 12 is suppressed, and the torque of the rotating electric machine 10 is reduced. In Fig. 6(a), the centrifugal force is indicated by the open arrow F1, and the load in the rotor core 18 in the axial direction of the rotating shaft 20 is indicated by the black arrow F2.

[0032] On the other hand, when the rotor 12 is rotating at a low speed, the centrifugal force is smaller than that when the rotor 12 is rotating at a high speed. For example, when the rotation speed of the rotor 12 drops from a high speed to below a predetermined rotation speed, as shown in Fig. 6(b), the cylindrical member 32 resting on the inclined portion 33 rolls radially inward from the inclined portion 33 due to its own weight, moves to the end face of the rotor core 18, and separates from the inclined portion 33. The restoring force of the elastic deformation of the cover member 31 tries to roll the cylindrical member 32 radially inward from the rotor core 18. When the cylindrical member 32 separates from the inclined portion 33, the elastic deformation of the cover member 31 is resolved.

[0033] When the cylindrical member 32 moves away from the inclined portion 33, the inclined portion 33 is not subjected to a load due to a component along the axial direction of the rotating shaft 20 generated by the centrifugal force from the cylindrical member 32. Therefore, the stress along the axial direction of the rotating shaft 20 does not increase in the core outer circumferential portion 28. As a result, the main magnetic flux in the rotor core 18 is not reduced, and the torque of the rotating electric machine 10 increases.

[0034] The rotor 12 of the rotating electrical machine 10 according to this embodiment provides the following advantages. (1) When the rotation of the rotor 12 increases, the cylindrical member 32 receives centrifugal force and moves radially outward from the end face of the rotor core 18, thereby being supported between the inclined portion 33 and the coated parallel portion 35B. Then, the cylindrical member 32 attempts to expand between the inclined portion 33 and the coated parallel portion 35B, and a load is applied to the rotor core 18 along the axial direction of the rotating shaft 20 via the cover member 31. As the rotation of the rotor 12 increases, the load on the cover member 31 along the axial direction of the rotating shaft 20 increases due to an increase in centrifugal force, so that the stress in the rotor core 18 along the axial direction of the rotating shaft 20 increases, and the main magnetic flux in the rotor core 18 is reduced. Because the main magnetic flux in the rotor core 18 is reduced, the induced voltage during high rotation can be suppressed. At low rotation speeds of the rotor 12, the centrifugal force is smaller than that at high rotation speeds, so the cylindrical member 32 is separated from the inclined portion 33 and the coated parallel portion 35B, no load is applied along the axial direction of the rotating shaft 20 via the cover member 31, and the main magnetic flux in the rotor core 18 is not reduced. Because the main magnetic flux in the rotor core 18 is not reduced, high torque can be obtained from the rotor 12. In this way, the rotor 12 is a variable field magnet rotor, and it is possible to have a field magnet that is different at high rotation speeds from that at low rotation speeds.

[0035] (2) The stress adjustment portion 30 is provided on the end surface of the rotor core 18 and has a cover member 31 that defines a space in which the cylindrical member 32 can move, and the inclined portion 33 is located radially outward of the cover member 31. Therefore, the cover member 31 can define a space in which the cylindrical member 32 can move, and providing the cover member 31 makes it easier to protect the cylindrical member 32.

[0036] (3) The movable part is easy to realize because it is the rollable cylindrical member 32. In addition, because the cylindrical member 32 is a cylindrical body, the rolling direction is one direction, which is the radial direction of the rotor core 18, and the rolling does not occur in any direction other than the radial direction, so that the rolling of the cylindrical member 32 is easy to control.

[0037] (4) The covering portion 35 is formed integrally with the inclined portion 33 and extends radially inward from the inclined portion 33, with the base 33A of the inclined portion 33 bonded to the end face of the rotor core 18. For this reason, the load acting in the axial direction of the rotating shaft 20 on the rotor core 18 can be effectively applied through the base 33A of the inclined portion 33, which is the radially outer end of the cover member 31. Because only the inclined portion 33 is bonded to the end face of the rotor core 18, the load acting in the axial direction of the rotating shaft 20 on the rotor core 18 at the inclined portion 33 is not dispersed elsewhere.

[0038] (5) Because the cover member 31 and the cylindrical member 32 are made of a non-magnetic material, the magnetic flux distribution in the rotor core 18 is not affected by the cover member 31 and the cylindrical member 32. As a result, stable rotation of the rotor 12 can be achieved.

[0039] (6) The cover member 31 is made of an elastically deformable metal material. Therefore, when the cylindrical member 32 rests on the inclined portion 33 during high speed rotation and is supported between the inclined portion 33 and the coated parallel portion 35B, the cover member 31 elastically deforms in response to centrifugal force. The elastic deformation of the cover member 31 increases the load along the axial direction of the rotating shaft 20, and the load along the axial direction can be effectively applied to the rotor core 18 via the inclined portion 33.

[0040] (7) The inclined portion 33 is inclined so as to move away from the end face of the rotor core 18 as it moves from the radially inner side to the radially outer side of the end face of the rotor core 18. Therefore, when the rotor 12 is rotating at high speed, the cylindrical member 32 receiving centrifugal force rides on the inclined portion 33 and can be supported between the inclined portion 33 and the covering parallel portion 35B. When the rotor 12 changes from high speed to low speed, the cylindrical member 32 moves away from the inclined portion 33, so there is no need to provide a separate means for moving the cylindrical member 32 away from the inclined portion 33 and the covering parallel portion 35B.

[0041] Second embodiment Next, a rotor for a rotating electric machine according to a second embodiment will be described. This embodiment differs from the first embodiment in that the covering portion and the inclined portion are integrally formed from electromagnetic steel sheets. In this embodiment, the same configuration as in the first embodiment will be described with reference to the first embodiment, and common reference numerals will be used.

[0042] 7(a), a rotor 41 of a rotating electric machine 40 of this embodiment has a rotor core 42. The rotor core 42 has a plurality of laminated electromagnetic steel sheets 43 and an electromagnetic steel sheet 44 that forms one end face of the rotor core 42. The electromagnetic steel sheet 43 has the same configuration as the electromagnetic steel sheet 17 of the first embodiment.

[0043] The electromagnetic steel sheet 44 is fixed to the electromagnetic steel sheet 43 on the end face side of the electromagnetic steel sheet 43. The electromagnetic steel sheet 44 forms a stress adjustment portion 45 together with the cylindrical member 32. The electromagnetic steel sheet 44 has a main body portion 46, a mountain-shaped portion 47, a flat portion 48, an inclined portion 49, a covering portion 50 that covers the inclined portion 49, and a restricting piece 52. The main body portion 46, the mountain-shaped portion 47, the flat portion 48, the inclined portion 49, the covering portion 50, and the restricting piece 52 are integrally formed.

[0044] The main body portion 46 is a flat plate-like portion, and the angled portion 47 is a portion formed by bending the main body portion 46 radially outward. The flat portion 48 is located radially outward of the angled portion 47, and has a flat surface on which the cylindrical member 32 rolls. The inclined portion 49 is a portion located radially outward of the angled portion 47. The inclined portion 49 inclines so as to move away from the electromagnetic steel sheet 43 as it moves from the radially inner side to the radially outer side.

[0045] 7(b), base 49A of inclined portion 49 extends such that its longitudinal direction is tangent to the outer periphery. Inclined portion 49 corresponds to an inclined portion provided on the radially outer side of electromagnetic steel sheet 44. The plate thickness of inclined portion 49 and the inclination angle with respect to the end face of rotor core 18 are set according to various conditions of rotating electric machine 10.

[0046] As shown in FIG. 7(a), the covering portion 50 has a covering gradient portion 50A and a covering parallel portion 50B. The covering gradient portion 50A is a portion bent from the tip of the inclined portion 49, and is inclined so as to move away from the inclined portion 49 as it moves from the radial outside to the radial inside. The covering parallel portion 50B extends from the tip of the covering gradient portion 50A toward the radial inside and is approximately parallel to the end face of the rotor core 42. In order to prevent the cylindrical member 32 from coming off, a restricting piece 52 extending toward the end face of the rotor core 42 is provided at both ends of the longitudinal direction (direction perpendicular to the radial direction) of the covering parallel portion 50B. The restricting piece 52 does not abut against the end face of the rotor core 42. In this embodiment, the mountain-shaped portion 47, the flat portion 48, the inclined portion 49, the covering gradient portion 50A, the covering parallel portion 50B, and the restricting piece 52 constitute the stress adjustment portion 45.

[0047] In this embodiment, the inclined portion 49 and the covering portion 50 are the electromagnetic steel sheets 44 that form the end faces of the rotor core 42 among the laminated electromagnetic steel sheets that form the rotor core 42. Since the inclined portion 49 is provided on the radial outside of the electromagnetic steel sheets 44 that form the end faces of the rotor core 42, when the cylindrical member 32 is supported by the inclined portion 49 and the covering parallel portion 50B under centrifugal force, a load along the axial direction of the rotating shaft 20 is applied to the core outer periphery 28 by trying to expand between the inclined portion 49 and the covering parallel portion 50B. By providing the inclined portion 49 on the electromagnetic steel sheets 44 that form the end faces of the rotor core 18, it is possible to suppress the induced voltage at high rotation speeds and obtain high torque of the rotor 41 at low rotation speeds. In this way, the rotor 41 is a variable field magnet rotor, as in the first embodiment, and it is possible to make the field magnet at high rotation speeds different from the field magnet at low rotation speeds. In addition, since the inclined portion 49 and the covering portion 50 are integrally formed with a part of the electromagnetic steel sheets 44 that form the end faces of the rotor core 42, the number of parts can be suppressed.

[0048] (Third embodiment) Next, a rotor of a rotating electric machine according to a third embodiment will be described. This embodiment differs from the first embodiment in the configuration of the pressure regulator. In this embodiment, the same configuration as in the first embodiment will be described with reference to the first embodiment, and common reference numerals will be used.

[0049] As shown in Figures 8(a) and 8(b), a rotor 61 of a rotating electric machine 60 of this embodiment has a rotor core 18, and each core outer periphery 28 of the rotor core 18 is provided with a plurality of stress adjustment portions 63.

[0050] The stress adjustment portion 63 has a cover member 64 and a spherical member 65 as a movable portion. The cover member 64 is formed of a non-magnetic metal material. Examples of the non-magnetic metal material include aluminum-based alloys and zinc-based alloys, which are elastically deformable metal materials. The cover member 64 is provided on the end surface of the rotor core 18 and forms a space in which the spherical member 65 moves. The cover member 64 has an inclined portion 66 and a covering portion 67 that covers the inclined portion 66. The covering portion 67 has a covering inclined portion 67A, a covering parallel portion 67B, a covering auxiliary portion 67C, and a restricting piece 71.

[0051] The inclined portion 66 inclines so as to move away from the end face of the rotor core 18 as it moves from the radially inner side to the radially outer side. The inclined portion 66 corresponds to the radially outer inclined portion of the cover member 64. The plate thickness of the inclined portion 66 and the inclination angle with respect to the end face of the rotor core 18 are set in accordance with various conditions of the rotating electric machine 60. As shown in FIG. 8(b), a base 66A of the inclined portion 66 is bonded to the end face of the rotor core 18.

[0052] As shown in FIG. 8(b), the covering gradient portion 67A is a portion bent from the tip of the inclined portion 66, and is inclined so as to move away from the end face of the rotor core 18 as it moves from the radial outside to the radial inside. The covering parallel portion 67B extends from the tip of the covering gradient portion 67A toward the radial inside and is approximately parallel to the end face of the rotor core 18. The covering auxiliary portion 67C is a portion extending from the inner end of the covering parallel portion 67B, and approaches the end face of the rotor core 18 as it moves from the radial outside to the radial inside. A gap 70 is provided between the tip of the covering auxiliary portion 67C and the rotor core 18.

[0053] The space formed by the cover member 64 extends in the radial direction, and the direction perpendicular to the radial direction of the space, i.e., the width of the cover member 64, is greater than the diameter of the spherical member 65. The cover member 64 allows the spherical member 65 to move in the radial direction. To prevent the spherical member 65 from coming off the cover member 64, restricting pieces 71 extending toward the end faces of the rotor core 18 are provided on both ends of the longitudinal direction (direction perpendicular to the radial direction) of the covering parallel portion 67B. The restricting pieces 71 do not come into contact with the end faces of the rotor core 18.

[0054] The spherical member 65 is a spherical member made of a non-magnetic metal such as an aluminum-based alloy or a zinc-based alloy. The spherical member 65 can roll on the end face of the rotor core 18 in the space formed by the cover member 31, but moves in the radial direction while being restricted by the restricting piece 71. The diameter of the spherical member 65 is larger than the gap 70 and smaller than the distance between the coating parallel portion 67B and the end face of the rotor core 18.

[0055] This embodiment provides the same advantages as the advantages (1), (2), (4) to (7) of the first embodiment. In addition, since the movable portion is a spherical member 65, it is easier to roll under centrifugal force than the cylindrical member 32.

[0056] (Fourth embodiment) Next, a rotor of a rotating electric machine according to a fourth embodiment will be described. This embodiment differs from the first embodiment in the configuration of the pressure regulator. In this embodiment, the same configuration as in the first embodiment will be described with reference to the first embodiment, and common reference numerals will be used.

[0057] As shown in FIG. 9, a rotor 81 of a rotating electric machine 80 of this embodiment has a rotor core 18, and each core outer periphery 28 of the rotor core 18 is provided with a stress adjustment portion 82. The stress adjustment portion 82 has a cover member 31, a wedge-shaped member 83 as a movable portion, a coil spring 84 as a biasing member, and a locking portion 85 that locks the coil spring 84. The longitudinal direction of the wedge-shaped member 83 is approximately parallel to the longitudinal direction of the cover member 31, and is formed of a non-magnetic metal such as an aluminum-based alloy or a zinc-based alloy. The wedge-shaped member 83 has a pentagonal shape in a side view. The wedge-shaped member 83 has a contact surface 86, an inclined surface 87, a front surface 88, a parallel surface 89, and a rear surface 90.

[0058] The abutment surface 86 is slidable against the end face of the rotor core 18 in the space formed by the cover member 31. The inclined surface 87 is slidable against the inclined portion 33 of the cover member 31, and the inclination angle of the inclined surface 87 is substantially the same as the inclination angle of the inclined portion 33. The front surface 88 is a surface connecting the inclined surface 87 to the parallel surface 89. The parallel surface 89 is a surface substantially parallel to the abutment surface 86. The rear surface 90 is a surface substantially parallel to the front surface 88, and one end of the coil spring 84 is connected to the rear surface 90. The other end of the coil spring 84 is connected to a locking portion 85 provided radially inward from the wedge-shaped member 83.

[0059] The coil spring 84 has a biasing force in a direction that pulls the wedge-shaped member 83 radially inward. Therefore, when the rotor 81 changes from a high rotation speed to a low rotation speed, the wedge-shaped member 83 is returned to the end face of the rotor core 18. In this embodiment, when the rotor 81 is rotating at a high rotation speed, the wedge-shaped member 83 receives a centrifugal force and moves radially outward, and rides on the inclined portion 33 against the biasing force of the coil spring 84, and is supported between the inclined portion 33 and the coated parallel portion 35B. When the rotor 81 changes from a high rotation speed to a low rotation speed, the biasing force of the coil spring 84 moves the wedge-shaped member 83 radially inward as the centrifugal force decreases, and moves the wedge-shaped member 83 away from the inclined portion 33.

[0060] In this embodiment, even with the wedge-shaped member 83 in which the movable part does not roll, the induced voltage can be suppressed when the rotor 81 is rotating at high speed. When the rotor 81 is rotating at low speed, the centrifugal force is smaller than when it is rotating at high speed, so the main magnetic flux in the rotor core 18 is hardly reduced. Since the main magnetic flux in the rotor core 18 is not reduced, the rotor 81 can obtain high torque. In this way, the rotor 81 is a variable field magnet rotor, and it is possible to make the field magnet at high speed different from the field magnet at low speed.

[0061] The present invention is not limited to the above-described embodiment, and various modifications are possible within the scope of the invention. For example, the following modifications may be made.

[0062] In the above embodiment, the stress adjustment portion is provided on the outer periphery of the core as the main magnetic flux region, but this is not limited to the above. For example, the stress adjustment portion may be provided on the inner periphery of the core as the main magnetic flux region, and the position of the stress adjustment portion is free as long as it is in the main magnetic flux region. However, it is preferable that the position of the stress adjustment portion is closer to the outer periphery of the rotor core. In the above embodiment, the stress adjuster is provided on one end face of the rotor core, and the stress adjuster is not provided on the other end face, but this is not limited to the above. The stress adjuster may be provided on both end faces. In the above embodiment, the inclined portion is in contact with the rotor core at the base and is spaced apart from the rotor core at other locations, but this is not limited to the above. For example, the inclined portion may be in contact with the rotor core entirely without any gaps. In the above embodiment, the stress adjusting portion includes the gradient coating portion, but this is not limited to the above. The stress adjusting portion may have a structure in which the inclined portion and the parallel coating portion are in direct contact with each other without including the gradient coating portion. In the second embodiment, the stress adjustment portion is realized by processing the electromagnetic steel sheets that form the end faces of the rotor core, but this is not limited to the above. A plurality of electromagnetic steel sheets may be cut out to form the inclined portions in the rotor core, or the thickness of the electromagnetic steel sheets may be locally changed to form the inclined portions. In the above embodiment, only the inclined portion of the cover member is adhered to the rotor core, but this is not limited to the above. The cover member and the rotor core may be adhered not only to the inclined portion, but also to the rotor core by extending a covering auxiliary portion of the covering portion of the cover member to the rotor core, or a portion of the cover member other than the inclined portion may be adhered to the rotor core. Furthermore, the cover member may be fixed to the rotor core by a means other than adhesion. In the above embodiment, the stress adjusting portion is made of a metal material, but this is not limiting. The stress adjusting portion may be made of a non-magnetic material, such as a resin material, or a material other than a metal material. In the above embodiment, the rotor is provided with 12 permanent magnets, but this is not limited to this number. The number of permanent magnets may be, for example, 4, 8, or 16, and is not particularly limited. Furthermore, the arrangement of the permanent magnets is not limited to a V-shape. [Explanation of symbols]

[0063] 10, 40, 60, 80 Permanent magnet type rotating electric machine 11 Stator 12, 41, 61, 81 rotors 17, 43, 44 Electrical steel sheet 18, 42 Rotor core 20 Rotational Axis 21 Magnet insertion hole 22 Permanent magnets 28 Core Outer Part 29 Inner circumference of core 30, 45, 63, 82 Stress adjustment section 31, 64 Cover member 32 Cylindrical member (movable part) 33, 49, 66 Slope 35, 50, 67 Covering part 65 Spherical parts (moving parts) 83 Wedge-shaped member (movable part) 84 Coil Spring 85 Locking part

Claims

1. a rotor core formed by laminating electromagnetic steel sheets; A rotating shaft that is inserted through the center of the rotor core and integrated with the rotor core; a magnet insertion hole formed for each magnetic pole of the rotor core and extending along the axial direction of the rotating shaft; a permanent magnet inserted into the magnet insertion hole, A stress adjustment portion is provided at a position on an end surface of the rotor core that corresponds to a main magnetic flux region, The stress adjustment portion is an inclined portion provided on the end surface and inclined in a direction away from the end surface as it moves from an inner side to an outer side in a radial direction of the rotor core; a covering portion extending radially inward from the inclined portion and covering the inclined portion; a movable portion that is movable in a radial direction of the rotor core at the end surface, When the point where the inclined portion contacts the end surface is defined as the base of the inclined portion, A rotor for a rotating electric machine, characterized in that the distance from the base to the covered portion is set to be greater than or equal to the length of the movable portion in the axial direction of the rotor core, and the axial distance between the covered portion and the inclined portion decreases to less than the length of the movable portion in the axial direction as it moves from the inside to the outside in the radial direction.

2. the stress adjustment portion has a cover member that defines a space in which the movable portion can move, 2. The rotor for a rotating electric machine according to claim 1, wherein the inclined portion is positioned radially outward of the cover member.

3. 2. The rotor for a rotating electric machine according to claim 1, wherein the inclined portion and the covering portion are integrally formed on a radially outer side of an electromagnetic steel plate forming the end face.

4. 3. The rotor for a rotating electric machine according to claim 1, wherein the movable portion is a rollable cylindrical body.

5. 3. The rotor for a rotating electric machine according to claim 1, wherein the movable portion is a ball capable of rolling.

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