Rotor

Abstract

To downsize a rotor comprising a plurality of rotary rotor cores.SOLUTION: A rotor comprises: a shaft; a plurality of stationary rotor cores fixed to the shaft; a plurality of rotary rotor cores attached to the shaft and rotatable around the shaft in relative to the shaft; a coupling pin; and a rotation mechanism. The plurality of stationary rotor cores and the plurality of rotary rotor cores are disposed alternately in an axial direction of the shaft. In each stationary rotor core, there is provided a slit hole which penetrates the stationary rotor core in the axial direction and extends in a circumferential direction of the shaft. The coupling pin couples the plurality of rotary rotor cores while being inserted through the slit hole of each stationary rotor core. The rotation mechanism rotates the plurality of rotary rotor cores in relative to the shaft.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The technology disclosed in this specification relates to a rotor.

[0002] The rotor disclosed in Patent Document 1 has a fixed rotor core and a rotating rotor core. The fixed rotor core is fixed to a shaft, and the rotating rotor core is rotatable relative to the shaft. This rotor also has a rotation mechanism that rotates the rotating rotor core. By rotating the rotating rotor core with the rotation mechanism, the magnetic flux generated by the rotor (i.e., the magnetic flux that reaches the stator from the rotor) can be changed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-154699 Summary of the Invention [Problem to be solved by the invention]

[0004] In the case where a plurality of rotating rotor cores are provided on a shaft, providing a rotating mechanism for each rotating rotor core results in an increase in the size of the rotor. This specification proposes a technique for miniaturizing a rotor having a plurality of rotating rotor cores. [Means for solving the problem]

[0005] The rotor disclosed in this specification includes a shaft, a plurality of fixed rotor cores fixed to the shaft, a plurality of rotating rotor cores attached to the shaft and rotatable relative to the shaft around the shaft, a connecting pin, and a rotating mechanism. The plurality of fixed rotor cores and the plurality of rotating rotor cores are alternately arranged in the axial direction of the shaft. Each of the fixed rotor cores has a slit hole that penetrates the fixed rotor core in the axial direction and extends along the circumferential direction of the shaft. The connecting pin connects the plurality of rotating rotor cores while being inserted into the slit hole of each of the fixed rotor cores. The rotating mechanism rotates the plurality of rotating rotor cores relative to the shaft.

[0006] In this rotor, multiple rotating rotor cores are connected by connecting pins. The connecting pins are inserted through slit holes in each fixed rotor core, allowing the connecting pins to move circumferentially along the slit holes. This allows the multiple rotating rotor cores and the connecting pins to rotate together relative to the shaft. This allows the multiple rotating rotor cores to rotate together relative to the shaft using a rotating mechanism. This eliminates the need to provide a rotating mechanism for each rotating rotor core, allowing for a more compact rotor. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a cross-sectional view taken along the rotation axis AX of an electric motor. [Figure 2] FIG. 4 is a plan view of the fixed rotor core 44 as viewed along the axial direction. [Figure 3] FIG. 4 is a plan view of the rotating rotor core 46 as viewed along the axial direction. DETAILED DESCRIPTION OF THE INVENTION

[0008] The electric motor shown in Fig. 1 is mounted on an electric vehicle. The electric motor drives the wheels of the electric vehicle. The electric motor includes a rotor 20 and a stator 60. The stator 60 has a cylindrical shape. The rotor 20 is disposed radially inside the stator 60. The rotor 20 is disposed rotatably about a rotation axis AX.

[0009] The rotor 20 has a shaft 22. The shaft 22 is arranged so that its central axis coincides with the rotation axis AX. A rotor core is attached concentrically to the shaft 22. The rotor core is composed of a plurality of fixed rotor cores 44 and a plurality of rotating rotor cores 46. Each of the fixed rotor cores 44 and the rotating rotor cores 46 is made of a material with high magnetic permeability. Each of the fixed rotor cores 44 and the rotating rotor cores 46 has a disk shape with a through hole in the center. The shaft 22 is inserted through the center holes of the fixed rotor cores 44 and the rotating rotor cores 46. Each fixed rotor core 44 is fixed to the shaft 22. Each rotating rotor core 46 is rotatable relative to the shaft 22 around the rotation axis AX. The fixed rotor cores 44 and the rotating rotor cores 46 are arranged alternately in a direction parallel to the rotation axis AX of the shaft 22 (hereinafter referred to as the axial direction).

[0010] As shown in Fig. 2, a plurality of magnetic poles 48a are arranged inside each fixed rotor core 44. Each magnetic pole 48a is, for example, a permanent magnet. In each fixed rotor core 44, the plurality of magnetic poles 48a are arranged rotationally symmetrically with respect to the rotation axis AX. As shown in Fig. 3, a plurality of magnetic poles 48b are arranged inside each rotating rotor core 46. Each magnetic pole 48b is, for example, a permanent magnet. In each rotating rotor core 46, the plurality of magnetic poles 48b are arranged rotationally symmetrically with respect to the rotation axis AX.

[0011] As shown in FIG. 1, each fixed rotor core 44 has a slit hole 44a penetrating the fixed rotor core 44 in the axial direction. When viewed in the axial direction as shown in FIG. 2, the slit hole 44a extends in the circumferential direction of the shaft 22 (hereinafter simply referred to as the circumferential direction). As shown in FIG. 1, each rotating rotor core 46 has a through hole 46a penetrating the rotating rotor core 46 in the axial direction. The rotor 20 has a connecting pin 50. The connecting pin 50 extends in the axial direction and is inserted into the slit hole 44a of each fixed rotor core 44 and the through hole 46a of each rotating rotor core 46. The outer circumferential surface of the connecting pin 50 contacts the inner circumferential surface of each through hole 46a. Note that the connecting pin 50 may be fixed to the rotating rotor core 46 within each through hole 46a, or the connecting pin 50 may be slidable relative to the rotating rotor core 46 within each through hole 46a. The connecting pins 50 connect the multiple rotating rotor cores 46 to each other. As described above, the connecting pin 50 is inserted into the slit hole 44a that extends in the circumferential direction. Therefore, the connecting pin 50 can move in the circumferential direction. When the connecting pin 50 moves in the circumferential direction, the connecting pin 50 and the multiple rotating rotor cores 46 rotate together relative to the shaft 22.

[0012] As shown in FIG. 1, a rotation mechanism 52 is provided at the end of the rotor core. The rotation mechanism 52 is connected to a connecting pin 50. The rotation mechanism 52 rotates each rotating rotor core 46 relative to the shaft 22 by moving the connecting pin 50 in the circumferential direction. The rotation mechanism 52 rotates each rotating rotor core 46 in response to the centrifugal force or torque applied to the rotor 20. The rotation mechanism 52 may be operated by the elastic force of a spring or the like, or may be electrically controlled. FIG. 2 shows three positions of the connecting pin 50: a first position 50a, a second position 50b, and a third position 50c. The rotation mechanism 52 can move the connecting pin 50 between the first position 50a, the second position 50b, and the third position 50c. The first position 50a is the frontmost position within the slit 44a (i.e., the front side in the rotation direction of the rotor 20), the second position 50b is the middle position within the slit 44a, and the third position 50c is the rearmost position within the slit 44a. When the rotation mechanism 52 moves the connecting pin 50 in the circumferential direction, each rotating rotor core 46 rotates, changing the relative angle of each rotating rotor core 46 with respect to each fixed rotor core 44. When the connecting pin 50 is in the first position 50a or the third position 50c, the magnetic pole 48b of each rotating rotor core 46 is in a position of the same polarity as the magnetic pole 48a of each fixed rotor core 44 in the axial direction. When the connecting pin 50 moves to the second position 50b, the magnetic pole 48b of each rotating rotor core 46 is in a position of opposite polarity to the magnetic pole 48a of each fixed rotor core 44 in the axial direction. In this state, a short circuit of magnetic flux occurs between magnetic pole 48a and magnetic pole 48b, and less magnetic flux reaches stator 60 from rotor 20. In this way, by rotating each rotating rotor core 46 using rotating mechanism 52, the magnetic flux generated from rotor 20 can be changed.

[0013] The rotor 20 of the embodiment has multiple rotating rotor cores 46, which allows for significant variation in the magnetic flux generated by the rotor 20 (i.e., the magnetic flux reaching the stator 60 from the rotor 20). This effectively reduces drag loss in the electric motor. Furthermore, in the rotor 20 of the embodiment, the multiple rotating rotor cores 46 are connected by connecting pins 50, allowing the multiple rotating rotor cores 46 to rotate as a unit relative to the shaft 22. This allows the multiple rotating rotor cores 46 to be rotated by a single rotating mechanism 52. Since there is no need to provide a rotating mechanism for each rotating rotor core 46, the axial length of the rotor 20 can be shortened. This allows for a more compact electric motor. Furthermore, with this configuration, each rotating rotor core 46 is rotated at the same time, reducing operational variation among the individual rotating rotor cores 46 and stabilizing the operation of each rotating rotor core 46.

[0014] Although the embodiments have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and variations of the specific examples exemplified above. The technical elements described in this specification or drawings exhibit technical utility alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. Furthermore, the technology exemplified in this specification or drawings simultaneously achieves multiple objectives, and achieving one of these objectives itself has technical utility. [Explanation of symbols]

[0015] 20: Rotor 22: Shaft 44: Fixed rotor core 46: Rotating rotor core 50: Connecting pin 52: Rotating mechanism

Claims

[Claim 1] A rotor, A shaft, A plurality of fixed rotor cores fixed to the shaft; A plurality of rotating rotor cores attached to the shaft and rotatable around the shaft relative to the shaft; A connecting pin; Rotation mechanism, having A plurality of the fixed rotor cores and a plurality of the rotating rotor cores are alternately arranged in an axial direction of the shaft, Each of the fixed rotor cores has a slit hole penetrating the fixed rotor core in the axial direction and extending along a circumferential direction of the shaft, the connecting pins connect the plurality of rotating rotor cores together in a state where they are inserted into the slit holes of the respective fixed rotor cores, The rotating mechanism rotates the plurality of rotating rotor cores relative to the shaft. Rotor.

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