Rotor for a rotating electric machine

Abstract

The rotor (34) of the rotary electric machine includes a magnet (81) that is an annular member arranged coaxially with the rotor core (38) and assembled to an axial end portion of the rotor core (38). The magnet (81) is used to sense a rotation angle of the rotor (34). The rotor core (38) includes only one pair of core-side positioning portions (71) arranged point-symmetrically about the rotation axis (AX1). The magnet (81) includes only one pair of magnet-side positioning portions (91) arranged point-symmetrically about the rotation axis (AX1). The magnet-side positioning portions (91) respectively engage with the core-side positioning portions (71) to position the magnet (81) relative to the rotor core (38) in the first direction (D1), the second direction (D2), and the circumferential direction (D3), and the magnet-side positioning portions (91) serve as both a magnetization reference and an assembly reference.

Description

Technical Field

[0001] This disclosure relates to a rotor for a rotating electric motor. Background Technology

[0002] Conventionally, it is known that a magnet is fixed to the rotor of a rotating electric machine, and a magnetic sensor is placed near the magnet to sense the rotation angle of the rotor based on the output value of the magnetic sensor. In the rotation angle sensing device disclosed in JP2009-97924A, a ring-shaped magnet is magnetized, and a protrusion provided on the inner periphery of the magnet is used as a reference for magnetization. The magnet is assembled into the rotor (more specifically, the rotor core) when four cylindrical pins protruding axially from the magnet are fitted into the mounting holes of the rotor.

[0003] The accuracy of sensing the rotor's rotation angle affects the control of the rotating electric motor. Therefore, it is desirable to improve the accuracy of rotor rotation angle sensing. Summary of the Invention

[0004] In view of the above, this disclosure is made, and one object of this disclosure is to provide a rotor for a rotary electric motor that can improve the accuracy of sensing rotation angle.

[0005] According to this disclosure, a rotor for a rotary electric motor is provided, the rotor comprising: a rotor core configured to rotate about a rotation axis; and a magnet, which is an annular member and coaxial with the rotor core. The magnet has a plurality of S poles and a plurality of N poles arranged alternately in a circumferential direction. The magnet is assembled to an axial end of the rotor core and is used to sense the rotation angle of the rotor.

[0006] In a relative coordinate system in which the rotor core rotates integrally, a predetermined direction perpendicular to the axis of rotation is defined as a first direction, and a direction perpendicular to both the axis of rotation and the first direction is defined as a second direction. A direction along the circumference of the axis of rotation is defined as a circumferential direction. The rotor core includes only one pair of core-side positioning portions arranged symmetrically about the axis of rotation. The magnet includes only one pair of magnet-side positioning portions arranged symmetrically about the axis of rotation and engaging with the core-side positioning portions respectively to position the magnet relative to the rotor core in the first direction, the second direction, and the circumferential direction. The magnet-side positioning portions serve as both a magnetization reference and an assembly reference.

[0007] By providing only a pair of magnet-side positioning portions to serve not only as assembly references but also as magnetization references, the deviation of the corresponding magnetic poles of the magnets from the ideal position of the rotor core becomes smaller than in previously proposed techniques where the assembly reference and magnetization reference were provided separately. Specifically, in this disclosure, the amount of misalignment is reduced compared to previously proposed techniques because there is no misalignment between the assembly reference and the magnetization reference. Therefore, the accuracy of sensing the rotation angle using magnets is improved, and the performance of the rotating motor is improved. Attached Figure Description

[0008] The accompanying drawings described herein are for illustrative purposes only and not for all possible implementations, and are not intended to limit the scope of this disclosure.

[0009] Figure 1 This is a schematic diagram of a shift-by-wire system, including a rotary actuator of an electric motor of the first embodiment applied to the shift-by-wire system.

[0010] Figure 2 yes Figure 1 A cross-sectional view of the rotary actuator.

[0011] Figure 3 yes Figure 2 A magnified view of part III in the image.

[0012] Figure 4 Is Figure 2 View of the rotor and motor-side bearings as seen in the direction of the middle arrow IV.

[0013] Figure 5 It is along Figure 4 The cross-sectional view of the rotor and motor side bearings taken from line VV.

[0014] Figure 6 It is an instruction Figure 4 A diagram of the rotor core, rotatable shaft, and motor-side bearing.

[0015] Figure 7 It is along Figure 6 The cross-sectional view of the rotor core, rotatable shaft, and motor-side bearing taken from line VII-VII.

[0016] Figure 8 It is an instruction Figure 4 A diagram of a magnet.

[0017] Figure 9 It is along Figure 8 The cross-sectional view of the magnet taken by line IX-IX.

[0018] Figure 10This is a view of the rotor and motor-side bearings of the second embodiment, viewed in the axial direction.

[0019] Figure 11 It is along Figure 10 The cross-sectional view of the rotor and motor side bearings taken by line XI-XI.

[0020] Figure 12 It is an instruction Figure 10 A diagram of the rotor core, rotatable shaft, and motor-side bearing.

[0021] Figure 13 It is along Figure 12 The cross-sectional view of the rotor core, rotatable shaft, and motor-side bearing taken from line XIII-XIII in the figure.

[0022] Figure 14 It is an instruction Figure 10 A diagram of a magnet.

[0023] Figure 15 It is along Figure 14 A cross-sectional view of the magnet taken by line XV-XV in the diagram.

[0024] Figure 16 This is a view of the rotor and motor-side bearings of the third embodiment, viewed in the axial direction.

[0025] Figure 17 It is along Figure 16 The cross-sectional view of the rotor and motor side bearings taken from line XVII-XVII.

[0026] Figure 18 It is an instruction Figure 16 A diagram of the rotor core, rotatable shaft, and motor-side bearing.

[0027] Figure 19 It is along Figure 18 The cross-sectional view of the rotor core, rotatable shaft, and motor-side bearing taken by line XIX-XIX in the figure.

[0028] Figure 20 It is an instruction Figure 16 A diagram of a magnet.

[0029] Figure 21 It is along Figure 20 The cross-sectional view of the magnet taken by line XXI-XXI.

[0030] Figure 22 This is a view of the rotor and motor-side bearings of the fourth embodiment, viewed in the axial direction.

[0031] Figure 23 It is along Figure 22The cross-sectional view of the rotor and motor side bearings taken from line XXIII-XXIII.

[0032] Figure 24 This is a view of the rotor and motor-side bearings of the fifth embodiment, viewed in the axial direction.

[0033] Figure 25 It is along Figure 24 The cross-sectional view of the rotor and motor side bearings taken from line XXV-XXV in the figure.

[0034] Figure 26 This is a view of the rotor and motor-side bearings of a first alternative embodiment, viewed in the axial direction.

[0035] Figure 27 This is a view of the rotor and motor-side bearings of a second embodiment, viewed in the axial direction.

[0036] Figure 28 This is a view of the rotor and motor-side bearings of a third, other embodiment, viewed in the axial direction. Detailed Implementation

[0037] Embodiments of an electric motor (used as a rotary motor) will now be described with reference to the accompanying drawings. In each embodiment, the same reference numerals are used for substantially the same parts, and their descriptions will be omitted for simplicity.

[0038] (First Embodiment)

[0039] refer to Figure 1 In the first embodiment, the electric motor 30 is mounted to a rotary actuator (hereinafter referred to as the actuator) 10. The actuator 10 is fixed to the outer wall of the housing 12 of the vehicle transmission 11 and serves as the drive source for the shift-by-wire system 13. In the shift-by-wire system 13, the control device 15 controls the actuator 10 based on a command signal output from the shift operation device 14, thereby driving the gear-changing mechanism 16 of the transmission 11 to change gears.

[0040] (Actuator)

[0041] First, refer to Figure 2 The overall structure of actuator 10 is described. Actuator 10 includes housing 20, electric motor 30, and reducer 40.

[0042] The housing 20 includes a front housing 21 and a rear housing 22, each formed in the shape of a cup. With the openings of the front housing 21 and the rear housing 22 facing each other, the front housing 21 and the rear housing 22 are assembled and secured together using bolts 23. A metal plate 24, formed in the shape of a bottomed tube, is inserted into the front housing 21. The rear housing 22 includes a tubular protrusion 28 projecting away from the front housing 21. A bracket 29 is fixed to the outer wall of the rear housing 22. The actuator 10 is fixed to the housing 12 of the transmission 11 via the bracket 29 (see...). Figure 1 ).

[0043] The electric motor 30 includes a stator 31 and a rotor 34, which are received within a housing 20. The stator 31 includes a stator core 32 and a plurality of windings 33. The stator core 32 is fixed to a metal plate 24 by, for example, a press fit, and the windings 33 are wound around the stator core 32. The rotor 34 includes a rotatable shaft 37 and a rotor core 38. The rotatable shaft 37 is supported by a motor-side bearing 35 and a reducer-side bearing 36 and is rotatable about a rotation axis AX1. The rotor core 38 is securely engaged with the outer peripheral surface of the rotatable shaft 37. The motor-side bearing 35 is mounted to the metal plate 24. The reducer-side bearing 36 is mounted to the output member 44, which will be described later.

[0044] The reducer 40 includes an eccentric shaft 41, a ring gear 42, an eccentric gear 43, an output component 44, and a transmission mechanism 45. The eccentric shaft 41 is located on an eccentric axis AX2 that is eccentric to the rotation axis AX1, and the eccentric shaft 41 is integrally formed with the rotatable shaft 37. The ring gear 42 is coaxial with the rotation axis AX1 and fixed to the rear housing 22. The eccentric gear 43 includes external teeth 47 that mesh with the internal teeth 46 of the ring gear 42, and the eccentric gear 43 is supported by bearings 48 mounted to the eccentric shaft 41 so that the eccentric gear 43 can perform planetary motion. Planetary motion refers to motion in which the gear rotates on its own axis AX2 while revolving around the rotation axis AX1. During planetary motion, the rotational speed of the eccentric gear 43 changes relative to the rotational speed of the rotatable shaft 37.

[0045] The output member 44 is coaxial with the rotation axis AX1 and is rotatably supported by a bearing 49 mounted to the rear housing 22. The transmission mechanism 45 includes an engagement protrusion 51 formed on the eccentric gear 43 and an engagement hole 52 formed on the output member 44 and receiving the engagement protrusion 51. The transmission mechanism 45 transmits the rotational motion of the eccentric gear 43 about the eccentric axis AX2 to the output member 44.

[0046] In actuator 10, a rotating magnetic field is generated by changing the phase to be excited among multiple phases of winding 33. Rotor 34 receives the magnetic attraction or repulsion force generated by this rotating magnetic field and rotates therefrom. As eccentric shaft 41 revolves together with rotor 34 about the rotation axis AX1, eccentric gear 43 performs planetary motion. Therefore, the rotation of eccentric gear 43 (whose speed is reduced compared to the rotation of rotor 34) is output from output member 44.

[0047] (rotor)

[0048] Next, we will refer to Figures 2 to 9 This describes the rotor 34 and the sensing of its rotation angle. In the following text, the direction parallel to the rotation axis AX1 will be referred to as the axial direction. Furthermore, the direction along the circumference surrounding the rotation axis AX1 will be referred to as the circumferential direction.

[0049] The rotor 34 includes a rotor core 38 and a magnet (permanent magnet) 81. The rotor core 38 is configured to rotate about a rotation axis AX1. The magnet 81 is assembled to the axial end of the rotor core 38. The magnet 81 is used to sense the rotation angle of the rotor 34.

[0050] Actuator 10 includes a circuit board 56 on which a magnetic sensor 55 is mounted. The magnetic sensor 55 is axially opposed to the magnet 81. The circuit board 56 is fixed to the front housing 21. The magnetic sensor 55 senses the state of the magnetic field, which changes according to the rotation angle of the rotor 34, and converts the sensed magnetic field state into an electrical signal. The magnetic sensor 55 and the magnet 81 form a rotation sensing unit for sensing the rotation angle of the rotor 34.

[0051] The rotor core 38 is a laminate formed by stacking multiple metal plates. To avoid complexity, Figure 5 and Figure 7 The rotor core 38 appears to be made of a single component, but it is actually made of stacked metal plates. The rotor core 38 includes a central body 61 and a plurality of salient poles 62. The central body 61 is coaxial with the rotation axis AX1, and the plurality of salient poles 62 project radially outward from the central body 61. The central body 61 has a central protrusion 63, which is formed in an annular shape and protrudes toward one axial side (i.e., toward the circuit board 56).

[0052] The rotor core 38 includes only a pair of core-side positioning portions 71, which are arranged symmetrically about the rotation axis AX1. The core-side positioning portions 71 are formed on the radial outer wall of the central protrusion 63. In a relative coordinate system that will rotate integrally with the rotor core 38, a predetermined direction perpendicular to the rotation axis AX1 is defined as a first direction D1, and a direction perpendicular to both the rotation axis AX1 and the first direction D1 is defined as a second direction D2, and a direction along the circumference of the rotation axis AX1 is defined as a circumferential direction D3. Each core-side positioning portion 71 includes a flat surface 72 parallel to the first direction D1 and a partially cylindrical surface 73 having a center of curvature located on the rotation axis AX1. The flat surface 72 of the core-side positioning portion 71 forms a double-sided segment, which is defined as a segment having two flat surfaces located on two opposite diameter sides of the double-sided segment and parallel to each other. The core-side positioning portions 71 are formed on the radial outer wall of the central protrusion 63 such that the core-side positioning portions 71 extend continuously around the rotation axis AX1.

[0053] The magnet 81 includes only a pair of magnet-side positioning portions 91, which are arranged symmetrically about the rotation axis AX1. The magnet-side positioning portions 91 are formed on the radially inner wall of the magnet 81. Each magnet-side positioning portion 91 includes a flat surface 92 parallel to the first direction D1 and a partially cylindrical surface 93 having a center of curvature located on the rotation axis AX1. The flat surfaces 92 of the magnet-side positioning portions 91 are parallel to each other. The magnet-side positioning portions 91 are formed on the radially inner wall of the magnet 81 such that they extend continuously around the rotation axis AX1, and each magnet-side positioning portion 91 forms a central mounting hole 82 located on the radially inner side of the magnet-side positioning portion 91 and adaptable to the radially outer wall of the central protrusion 63.

[0054] Magnetization of magnet 81 is performed before magnet 81 is assembled into rotor core 38. During this process, magnetization of magnet 81 is performed, and magnet-side positioning portion 91 is used as a reference for magnetization. Specifically, magnet-side positioning portion 91 serves as a magnetization reference. In the following text, the deviation of the position of each magnetic pole of magnet 81 from its ideal position relative to the magnetization reference will be referred to as "magnetization misalignment".

[0055] The magnet 81 is assembled to the end of the rotor core 38 by adapting the central mounting hole 82 to the central protrusion 63 and magnetically coupling the magnet 81 to the rotor core 38 via the magnetic attraction of the magnet 81. Magnet-side positioning portions 91 engage with core-side positioning portions 71 respectively to position the magnet 81 relative to the rotor core 38 in the first direction D1, the second direction D2, and the circumferential direction D3. Specifically, each of the flat surfaces 92 engages with a corresponding one of the flat surfaces 72 to limit relative misalignment of the magnet 81 in the second direction D2 and the circumferential direction D3, and each of the partially cylindrical surfaces 93 engages with a corresponding one of the partially cylindrical surfaces 73 to limit relative misalignment of the magnet 81 in the first direction D1. The magnet-side positioning portions 91 serve as both a magnetization reference and an assembly reference. In the following text, the assembly clearance between the central mounting hole 82 and the central protrusion 63 will be referred to as the "assembly clearance".

[0056] (advantage)

[0057] As described above, in the first embodiment, the rotor 34 of the electric motor (rotary motor) 30 includes a magnet 81, which is an annular member arranged coaxially with the rotor core 38 and assembled to the axial end of the rotor core 38. The magnet 81 is used to sense the rotation angle of the rotor 34. The rotor core 38 includes only a pair of core-side positioning portions 71 arranged symmetrically about the rotation axis AX1. The magnet 81 includes only a pair of magnet-side positioning portions 91 arranged symmetrically about the rotation axis AX1. The magnet-side positioning portions 91 engage with the core-side positioning portions 71 respectively to position the magnet 81 relative to the rotor core 38 in the first direction D1, the second direction D2, and the circumferential direction D3, and the magnet-side positioning portions 91 serve as both a magnetization reference and an assembly reference.

[0058] By providing only a pair of magnet-side positioning parts 91 that serve as both assembly and magnetization references, the amount of deviation from the ideal position of the corresponding magnetic pole of the magnet 81 relative to the rotor core 38 becomes smaller than the deviation amount in the previously proposed technology, where the assembly reference and magnetization reference were provided separately. In other words, although magnetization misalignment and assembly backlash can exist in this system similar to those in the previously proposed system, the amount of misalignment and assembly backlash can be smaller than the corresponding amounts in the previously proposed system because there is no misalignment between the assembly reference and the magnetization reference. Therefore, the rotation angle sensing accuracy using the magnet 81 is improved, and the performance of the electric motor 30 is improved.

[0059] Furthermore, in the first embodiment, each magnet-side positioning portion 91 includes a flat surface 92 formed on the radial inner wall of the magnet 81 and parallel to the first direction D1. Therefore, when the magnet 81 is positioned by adapting the central mounting hole 82 to the central protrusion 63 concentric with the rotation axis AX1, misalignment between the center of the magnet 81 and the center of the rotor core 38 is virtually impossible compared to the previously proposed technology, in which four pins arranged in the circumferential direction are adapted to holes in the rotor core.

[0060] (Second Embodiment)

[0061] In the second embodiment, as Figures 10 to 15 As shown, the central body 61 has a central mounting hole 642 instead of the central protrusion 63 in the first embodiment. The central mounting hole 642 is recessed toward the side opposite to the circuit board 56.

[0062] Only one pair of core-side positioning portions 712 are formed on the radial inner wall of the central mounting hole 642, such that the core-side positioning portions 712 extend continuously around the rotation axis AX1. Each core-side positioning portion 712 includes a flat surface 722 parallel to the first direction D1 and a partially cylindrical surface 732 having a center of curvature located on the rotation axis AX1. The flat surfaces 722 of the core-side positioning portions 712 are parallel to each other.

[0063] Only one pair of magnet-side positioning portions 912 are formed on the radial outer wall of the magnet 81, such that the magnet-side positioning portions 912 extend continuously around the rotation axis AX1, and the magnet-side positioning portions 912 can be fitted to the central mounting hole 642. Each magnet-side positioning portion 912 includes a flat surface 922 parallel to the first direction D1 and a partially cylindrical surface 932 having a center of curvature located on the rotation axis AX1. The flat surface 922 of the magnet-side positioning portion 912 forms a double-sided segment, and a double-sided segment is defined as a segment having two flat surfaces located on two diameter-opposite sides of the double-sided segment and parallel to each other.

[0064] In the second embodiment, the rotor core 38 includes only one pair of core-side positioning portions 71 arranged symmetrically about the rotation axis AX1. The magnet 81 includes only one pair of magnet-side positioning portions 912 arranged symmetrically about the rotation axis AX1. The magnet-side positioning portions 912 serve as both a magnetization reference and an assembly reference, enabling advantages similar to those of the first embodiment to be achieved. When the magnet 81 is positioned by fitting it into a central mounting hole 642 concentric with the rotation axis AX1, misalignment between the center of the magnet 81 and the center of the rotor core 38 is virtually impossible.

[0065] (Third Embodiment)

[0066] In the third embodiment, as Figures 16 to 21As shown, the central body 61 has a pair of mounting holes 653 instead of the central mounting hole 642 in the second embodiment. The mounting holes 653 are spaced apart from each other in the second direction D2 and the rotation axis AX1 is located between the mounting holes 653.

[0067] Each of the pair of core-side positioning portions 713 includes a flat surface 723 parallel to the first direction D1 and a partially cylindrical surface 733 having a center of curvature located on the rotation axis AX1. The flat surface 723 of each core-side positioning portion 713 is formed on the radial inner wall of a corresponding mounting hole 653. The flat surface 723 of the core-side positioning portion 713 forms a double-sided segment, and the double-sided segment is defined as a segment having two flat surfaces located on two diameter-opposite sides of the double-sided segment and parallel to each other. The partially cylindrical surface 733 of the core-side positioning portion 713 is formed on the radial outer wall of a corresponding mounting hole 653.

[0068] The magnet 81 includes a body 833 and a pair of protrusions 843, wherein the body 833 is formed in an annular shape, and the pair of protrusions 843 protrude axially from the body 833 toward the rotor core 38. The protrusions 843 are spaced apart from each other in a second direction D2 and the axis of rotation AX1 is located between the protrusions 843.

[0069] Each of the pair of magnet-side positioning portions 913 includes a flat surface 923 parallel to the first direction D1 and a partially cylindrical surface 933 having a center of curvature located on the rotation axis AX1. The flat surface 923 of each magnet-side positioning portion 913 extends continuously from the radial inner wall of the body 833 to the side surface of the corresponding protrusion 843. The flat surfaces 923 of the magnet-side positioning portions 913 are parallel to each other. The partially cylindrical surface 933 of each magnet-side positioning portion 913 extends continuously from the radial outer wall of the body 833 to the other side surface of the corresponding protrusion 843. The protrusion 843 can be fitted into the mounting hole 653.

[0070] In the third embodiment, the rotor core 38 includes only a pair of core-side positioning portions 713 arranged symmetrically about the rotation axis AX1. The magnet 81 includes only a pair of magnet-side positioning portions 913 arranged symmetrically about the rotation axis AX1. The magnet-side positioning portions 913 serve as both magnetization references and assembly references, thereby achieving advantages similar to those of the first embodiment.

[0071] (Fourth Embodiment)

[0072] In the fourth embodiment, as Figures 22 to 23As shown, in each of only one pair of core-side positioning portions 714, the positions of the flat surface 724 and the partially cylindrical surface 734 are opposite to the corresponding positions in the third embodiment. Similarly, in each of only one pair of magnet-side positioning portions 914, the positions of the flat surface 924 and the partially cylindrical surface 934 are opposite to the corresponding positions in the third embodiment. The remaining construction of the fourth embodiment is the same as that of the third embodiment. For example, similar to the third embodiment, the flat surface 724 and the partially cylindrical surface 734 of each core-side positioning portion 714 are formed at a corresponding mounting hole 654, and the flat surface 924 and the partially cylindrical surface 934 of each magnet-side positioning portion 914 extend continuously from the body 834 to a corresponding protrusion 844.

[0073] In the fourth embodiment, the magnet 81 includes only a pair of magnet-side positioning portions 914 arranged symmetrically about the rotation axis AX1, and the magnet-side positioning portions 914 serve as both a magnetization reference and an assembly reference, thereby achieving advantages similar to those of the third embodiment.

[0074] (Fifth Embodiment)

[0075] In the fifth embodiment, as Figures 24 to 25 As shown, each of the pair of core-side positioning portions 715 includes a flat surface 725 parallel to the first direction D1 and a pair of flat surfaces 745 parallel to the second direction D2. The flat surface 725 is formed on the radial inner wall of a corresponding mounting hole 655. The pair of flat surfaces 745 are formed on two sidewalls (side surfaces) of the mounting hole 655 that are opposite to each other in the first direction D1.

[0076] Each of the pair of magnet-side positioning portions 915 includes a flat surface 925 parallel to the first direction D1 and a pair of flat surfaces 935 parallel to the second direction D2. The flat surface 925 of each magnet-side positioning portion 915 is formed only at a corresponding protrusion 845 and does not extend into the body 835. The flat surface 935 of each magnet-side positioning portion 915 is formed only at a corresponding protrusion 845 and does not extend into the body 835. The flat surface 935 of each magnet-side positioning portion 915 is formed at the two sidewalls (side surfaces) of the corresponding protrusion 845 that are opposite each other in the first direction D1.

[0077] In the fifth embodiment, the magnet 81 includes only one pair of magnet-side positioning portions 915 arranged symmetrically about the rotation axis AX1, and the magnet-side positioning portions 915 are used as both magnetization reference and assembly reference, so that advantages similar to those of the third embodiment can be achieved.

[0078] (Other embodiments)

[0079] In another embodiment, such as Figure 26 As shown, each of the pair of magnet-side positioning portions 916 may include a pair of flat surfaces 956, 966 instead of the flat surface 92 and the partially cylindrical surface 93 of the first embodiment. The flat surface 956 of each magnet-side positioning portion 916 is parallel to a direction (fourth direction) intersecting both the first direction D1 and the second direction D2. The flat surface 966 of each magnet-side positioning portion 916 is parallel to another direction (fifth direction) intersecting the first direction D1, the second direction D2, and the flat surface 956 (or the fourth direction) of the magnet-side positioning portion 916. Even with this configuration, when the flat surfaces 956, 966 of each of the magnet-side positioning portions 916 engage with the pair of flat surfaces 756, 766 of the corresponding one of the pair of core-side positioning portions 716, the magnet 81 is positioned relative to the rotor core 38 in the first direction D1, the second direction D2, and the circumferential direction D3. The magnet-side positioning portions 916 serve as both a magnetization reference and an assembly reference, enabling advantages similar to those of the first embodiment to be achieved. Figure 26 In this embodiment, the flat surfaces 956, 966 of each magnet-side positioning portion 916 are formed on the two sidewalls (side surfaces) of a corresponding protrusion among two radially inwardly protruding portions at the magnet 81. Alternatively, in another embodiment, the flat surface of each of the pair of magnet-side positioning portions may be formed on the two sidewalls (side surfaces) of a corresponding recess among a pair of radially outwardly recessed portions at the magnet 81. Furthermore, in another embodiment, each of the pair of magnet-side positioning portions may be formed by a curved convex surface or a curved concave surface (instead of the pair of flat surfaces) to provide the pair of curved convex surfaces or the pair of curved concave surfaces as the pair of magnet-side positioning portions.

[0080] In another embodiment, such as Figure 27 As shown, each of the pair of magnet-side positioning portions 917 may include a pair of flat surfaces 957, 967, like Figure 26 The flat surfaces 956 and 966 replace the flat surface 923 and the partially cylindrical surface 933 of the third embodiment. The flat surfaces 957 and 967 of each magnet-side positioning portion 917 are formed at the two sidewalls (side surfaces) of a corresponding protrusion in a pair of protrusions 847. Even with this configuration, when the flat surfaces 957 and 967 of each of the magnet-side positioning portions 917 engage with the pair of flat surfaces 757 and 767 of only one of the pair of core-side positioning portions 717 corresponding to one of the inner walls of the two mounting holes 657, the magnet 81 is positioned relative to the rotor core 38 in the first direction D1, the second direction D2, and the circumferential direction D3. The magnet-side positioning portions 917 serve as both magnetization references and assembly references, enabling advantages similar to those of the third embodiment to be achieved. Figure 27In this embodiment, the flat surfaces 957 and 967 of each magnet-side positioning portion 917 are formed on the two radially outer sidewalls (side surfaces) of a corresponding protrusion in the pair of protrusions 847. Alternatively, in another embodiment, the two flat surfaces of each of the pair of magnet-side positioning portions may be formed on the two radially inner sidewalls (side surfaces) of a corresponding protrusion in the pair of protrusions. Furthermore, in another embodiment, each of the pair of magnet-side positioning portions may be formed by a curved convex surface instead of the pair of flat surfaces to provide the pair of curved convex surfaces as the pair of magnet-side positioning portions.

[0081] In another embodiment, such as Figure 28 As shown, each of the magnet-side positioning portions 918 may include a pair of flat surfaces 958, 968, like Figure 26 The same pair of flat surfaces 956, 966 replace the flat surface 925 and the pair of flat surfaces 935 in the fifth embodiment. The flat surfaces 958, 968 of each magnet-side positioning portion 918 are formed at the two sidewalls (side surfaces) of a corresponding protrusion in a pair of protrusions 848 at the magnet 81. Even with this configuration, when the flat surfaces 958, 968 of each of the magnet-side positioning portions 918 engage with the pair of flat surfaces 758, 768 of a corresponding core-side positioning portion in only one pair of core-side positioning portions 718 formed at the inner wall of a corresponding assembly hole in the two assembly holes 658, the magnet 81 is positioned relative to the rotor core 38 in the first direction D1, the second direction D2, and the circumferential direction D3. The magnet-side positioning portions 918 serve as both a magnetization reference and an assembly reference, enabling advantages similar to those of the fifth embodiment to be achieved. Figure 28 In this embodiment, the flat surfaces 958 and 968 of each magnet-side positioning portion 918 are formed on the two radially outer sidewalls (side surfaces) of a corresponding protrusion in the pair of protrusions 848. Alternatively, in another embodiment, the two flat surfaces of each of the pair of magnet-side positioning portions may be formed on the two radially inner sidewalls (side surfaces) of a corresponding protrusion in the pair of protrusions. Furthermore, in another embodiment, each of the pair of magnet-side positioning portions may be formed by a curved convex surface instead of the pair of flat surfaces to provide the pair of curved convex surfaces as the pair of magnet-side positioning portions.

[0082] This disclosure is not limited to the above embodiments, and may be implemented in various other forms without departing from the spirit of this disclosure.

Claims

1. A rotor for a rotating electric motor (30), comprising: The rotor core (38) is configured to rotate about the axis of rotation (AX1); as well as A magnet (81), which is an annular member and coaxial with the rotor core (38), wherein the magnet (81) is assembled to the axial end of the rotor core (38) and is used to sense the rotation angle of the rotor (34), wherein: In a relative coordinate system that rotates integrally with the rotor core (38), a predetermined direction perpendicular to the rotation axis (AX1) is defined as a first direction, and a direction perpendicular to both the rotation axis (AX1) and the first direction is defined as a second direction, and a direction along the circumference of the rotation axis (AX1) is defined as a circumferential direction. The rotor core (38) includes only one pair of core-side positioning portions (71, 712, 713, 714, 715, 716, 717, 718), which are arranged symmetrically about the axis of rotation (AX1); and The magnet (81) includes only one pair of magnet-side positioning portions (91, 912, 913, 914, 915, 916, 917, 918), which are arranged symmetrically about the axis of rotation (AX1) and respectively engage with the core-side positioning portions (71, 712, 713, 714, 715, 716, 717, 718) to position the magnet (81) relative to the rotor core (38) in the first direction, the second direction, and the circumferential direction, wherein the magnet-side positioning portions (91, 912, 913, 914, 915, 916, 917, 918) serve as both a magnetization reference and an assembly reference; With the magnet (81) assembled to the axial end of the rotor core (38), the magnet-side positioning parts (91, 912, 913, 914, 915, 916, 917, 918) are partially exposed from the rotor core (38); The rotor core (38) includes a plurality of salient poles (62) that project radially outward at the rotor core (38), wherein the plurality of salient poles (62) includes a pair of salient poles (62), each of the pair of salient poles (62) projecting radially outward in the second direction; Each of the core-side positioning portions (71, 712, 713, 714, 715, 716, 717, 718) includes a flat surface (72, 723) parallel to the first direction; Each of the magnet-side positioning portions (91, 913) has a flat surface (92, 923) formed on the radial inner wall of the magnet (81) and parallel to the first direction, wherein the flat surface (92, 923) of the magnet-side positioning portion (91, 913) engages with the flat surface (72, 723) of the core-side positioning portion (71, 712, 713, 714, 715, 716, 717, 718); and The flat surfaces (72, 723) of the core-side positioning portions (71, 712, 713, 714, 715, 716, 717, 718) and the flat surfaces (92, 923) of the magnet-side positioning portions (91, 913) are located between the paired convex poles (62) in the second direction.

2. The rotor according to claim 1, wherein: The magnet (81) includes a body (833, 834) formed in an annular shape and a pair of protrusions (843, 844) axially projecting from the body (833, 834) toward the rotor core (38); and The flat surface (923, 924) of each of the magnet-side positioning portions (913, 914) extends continuously from the body (833, 834) to a corresponding protrusion (843, 844).

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