Power transmission device and motor apparatus

Abstract

A power transmission device according to one embodiment of the present disclosure comprises: a shaft; a stator having a first winding wound in a circumferential direction of the shaft; a rotor connected to the shaft, rotatable in the circumferential direction of the shaft, and having a second winding wound an integer number of times in the circumferential direction of the shaft, the second winding including a first terminal provided at one end and a second terminal provided at the other end; and a rotating body connected to the shaft and rotatable in the circumferential direction of the shaft. The rotating body has: a substrate that extends in a plane intersecting the shaft; a first connection terminal and a second connection terminal that are respectively led to the first terminal and the second terminal, and that are provided on the substrate at positions opposite to each other across the shaft; a rectifier circuit that is provided on the substrate, and that is capable of performing a rectification operation on the basis of AC power supplied to the first connection terminal and the second connection terminal; and a conductor member that is provided in a path connecting the first terminal and the first connection terminal, and that extends in a direction intersecting an axial direction of the shaft.

Description

Power transmission device and motor apparatus

[0001] The present invention relates to a power transmission device that transmits power in a contactless manner, and to a motor apparatus provided with such a power transmission device.

[0002] For example, there is a wound-field synchronous motor (EESM: Electrically Excited Synchronous Motor) among motors. This motor comprises a stator having a winding wound therearound and a rotor having a winding wound therearound. In this motor, efficiency of the motor can be improved by changing a current supplied to the winding wound on the rotor in accordance with the rotation speed of the motor. For example, Patent Document 1 discloses a technique related to such a wound-field synchronous motor.

[0003] Japanese Unexamined Patent Publication No. 2020-124100

[0004] Incidentally, there are devices capable of transmitting power to the rotor of such a motor. Such a power transmission device is provided on a shaft connected to the rotor of the motor and can rotate in accordance with rotation of the shaft. Therefore, it is desirable to have less weight unbalance.

[0005] It is desirable to provide a power transmission device and a motor apparatus that can reduce weight unbalance.

[0006] A power transmission device according to one embodiment of the present invention comprises a shaft, a stator, a rotor, and a rotating body. The shaft is rotatable about a rotation axis. The stator is spaced apart from the shaft and has a first winding wound in the circumferential direction of the shaft. The rotor is connected to the shaft, is rotatable in the circumferential direction of the shaft, and has a second winding wound an integer number of times in the circumferential direction of the shaft, including a first terminal provided at one end and a second terminal provided at the other end. The rotating body is connected to the shaft and is rotatable in the circumferential direction of the shaft. The rotating body includes a substrate extending on a surface intersecting the shaft, a first terminal and a second terminal respectively, and a first and second connection terminal provided on the substrate at opposite positions on either side of the shaft, a rectifier circuit provided on the substrate and capable of performing a rectification operation based on the AC power supplied to the first and second connection terminals, and a conductor member provided in the path connecting the first terminal and the first connection terminal, extending in a direction intersecting the axial direction of the shaft.

[0007] A motor device according to one embodiment of the present invention comprises a motor, a shaft, a stator, a rotor, and a rotating body. The motor has a motor stator including a first motor winding and a motor rotor including a second motor winding. The shaft is connected to the motor rotor and is rotatable about a rotation axis. The stator is spaced apart from the shaft and has a first winding wound in the circumferential direction of the shaft. The rotor is connected to the shaft and is rotatable in the circumferential direction of the shaft and has a second winding wound an integer number of times in the circumferential direction of the shaft, including a first terminal provided at one end and a second terminal provided at the other end. The rotating body is connected to the shaft and is rotatable in the circumferential direction of the shaft. The rotating body includes a substrate extending on a surface intersecting the shaft, a first terminal and a second terminal respectively, and a first and second connection terminal provided on the substrate at opposite positions on either side of the shaft, a rectifier circuit provided on the substrate that can perform a rectification operation based on the AC power supplied to the first and second connection terminals and can supply the rectified power to a second motor winding, and a conductor member provided in the path connecting the first terminal and the first connection terminal, extending in a direction intersecting the axial direction of the shaft.

[0008] According to one embodiment of the present invention, the power transmission device and motor device can reduce weight imbalance.

[0009] Figure 1 is a block diagram showing an example configuration of a motor device according to the first embodiment of the present invention. Figure 2 is a circuit diagram showing an example configuration of the inverter and power transmission device shown in Figure 1. Figure 3 is a perspective view showing an example configuration of the power transmission device shown in Figure 1. Figure 4 is an exploded perspective view showing an example configuration of the power transmission device shown in Figure 3. Figure 5 is a cross-sectional view showing an example configuration of the power transmission device shown in Figure 3. Figure 6 is an explanatory diagram showing an example configuration of the stator windings shown in Figure 5. Figure 7 is an explanatory diagram showing an example configuration of the rotor windings shown in Figure 5. Figure 8 is an explanatory diagram showing an example configuration of the shaft and conductor member shown in Figure 5. Figure 9 is an explanatory diagram showing an example of power transmission operation in the power transmission device shown in Figure 3. Figure 10 is a perspective view showing an example configuration of a power transmission device according to a modification of the first embodiment. Figure 11 is an exploded perspective view showing an example configuration of the power transmission device shown in Figure 10. Figure 12 is a cross-sectional view showing an example configuration of the power transmission device shown in Figure 10. Figure 13 is an explanatory diagram showing an example configuration of the shaft and conductor member shown in Figure 12. Figure 14 is a block diagram showing an example configuration of a motor device according to the second embodiment. Figure 15 is a perspective view showing an example configuration of the power transmission device shown in Figure 14. Figure 16 is an exploded perspective view showing an example configuration of the power transmission device shown in Figure 15. Figure 17 is a cross-sectional view showing an example configuration of the power transmission device shown in Figure 15. Figure 18 is a perspective view showing an example configuration of the rotor shown in Figure 16. Figure 19 is a plan view showing an example configuration of the rotating body shown in Figure 16. Figure 20 is an explanatory diagram showing an example of power transmission operation in the power transmission device shown in Figure 15. Figure 21 is a perspective view showing an example configuration of a power transmission device according to a modified example of the second embodiment. Figure 22 is an exploded perspective view showing an example configuration of the power transmission device shown in Figure 21. Figure 23 is a cross-sectional view showing an example configuration of the power transmission device shown in Figure 21. Figure 24 is a plan view showing an example configuration of the rotating body shown in Figure 22.

[0010] The embodiments of the present invention will be described in detail below with reference to the drawings. The description will be in the following order: 1. First Embodiment 2. Second Embodiment

[0011] <1. First Embodiment> [Configuration Example] Figure 1 shows an example configuration of a motor device 1 equipped with a power transmission device according to the first embodiment of the present invention. The motor device 1 is connected to an external control device 8 and a DC power supply 9. The external control device 8 is configured to instruct the motor device 1 on the rotational speed. The DC power supply 9 is configured to supply DC power to the motor device 1. The motor device 1 is configured to generate driving force, which is mechanical energy, using the DC power supplied from the DC power supply 9, based on instructions from the external control device 8. The motor device 1 comprises a drive unit 10 and a motor 70.

[0012] The drive unit 10 is configured to drive the motor 70. The drive unit 10 includes inverters 11 and 12, a power transmission device 20, and a control circuit 19.

[0013] The inverter 11 is configured to convert the DC power supplied from the DC power supply 9 into three-phase (U-phase, V-phase, W-phase) AC power based on instructions from the control circuit 19. The inverter 11 then supplies this three-phase AC power to the windings 71B (described later) of the stator 71 of the motor 70.

[0014] The inverter 12 is configured to convert the DC power supplied from the DC power supply 9 into single-phase AC power based on instructions from the control circuit 19. The inverter 12 then supplies this AC power to the winding 33 (described later) of the stator 30 of the power transmission device 20.

[0015] The power transmission device 20 is configured to supply power supplied from the inverter 12 to the windings 72B (described later) of the rotor 72 of the motor 70. The power transmission device 20 includes a stator 30, a rotor 40, a rotating body 50, and a shaft 24.

[0016] Figure 2 shows an example configuration of the inverter 12 and the power transmission device 20. Figure 2 also shows the DC power supply 9 and the windings 72B of the rotor 72 of the motor 70. The inverter 12 is connected to the DC power supply 9 via the voltage line L11 and the reference voltage line L12.

[0017] In this example, the inverter 12 is a full-bridge type circuit. The inverter 12 has switching elements SW1 to SW4 and a switching control circuit 18. Each of the switching elements SW1 to SW4 is configured using, for example, a field-effect transistor or an insulated-gate bipolar transistor. Switching element SW1 is provided in the path connecting the voltage line L11 and node N1 and is configured to perform switching operations based on a control signal supplied from the switching control circuit 18. Switching element SW2 is provided in the path connecting node N1 and reference voltage line L12 and is configured to perform switching operations based on a control signal supplied from the switching control circuit 18. Switching element SW3 is provided in the path connecting the voltage line L11 and node N2 and is configured to perform switching operations based on a control signal supplied from the switching control circuit 18. Switching element SW4 is provided in the path connecting node N2 and reference voltage line L12 and is configured to perform switching operations based on a control signal supplied from the switching control circuit 18. The switching control circuit 18 is configured to control the switching operation of the switching elements SW1 to SW4 by supplying control signals to each of the switching elements SW1 to SW4 based on instructions from the control circuit 19.

[0018] The power transmission device 20 includes a winding 33, a winding 43, and a rectifier circuit REC. Winding 33 is provided on the stator 30, one end of which is connected to node N1 of the inverter 12, and the other end of which is connected to node N2 of the inverter 12. Winding 43 is provided on the rotor 40, one end of which is connected to node N3 of the rectifier circuit REC, and the other end of which is connected to node N4 of the rectifier circuit REC. Windings 33 and 43 constitute a so-called rotary transformer, and winding 43 is configured to receive AC power supplied from winding 33. The rectifier circuit REC is provided on the rotating body 50 and is configured to rectify the AC power supplied from winding 43 of the rotor 40. The rectifier circuit REC has four diodes D (diodes D1 to D4). The cathode of diode D1 is connected to voltage line L21, and the anode is connected to node N3. The cathode of diode D2 is connected to node N3, and its anode is connected to the reference voltage line L22. The cathode of diode D3 is connected to voltage line L21, and its anode is connected to node N4. The cathode of diode D4 is connected to node N4, and its anode is connected to the reference voltage line L22. Note that the rectifier circuit REC is not limited to this configuration; instead, for example, four transistors may be used instead of four diodes to perform synchronous rectification. Voltage line L21 and reference voltage line L22 are connected to the winding 72B (described later) of the rotor 72 of the motor 70.

[0019] In this configuration, the inverter 12 converts the DC power supplied from the DC power supply 9 into AC power. The power transmission device 20 then transmits the AC power supplied from the inverter 12 from its stator 30 to its rotor 40, and rectifies the transmitted AC power. The power transmission device 20 then supplies the rectified power to the winding 72B (described later) of the rotor 72 of the motor 70. In this example, the power rectified by the rectifier circuit REC is supplied directly to the winding 72B, but this is not the only option. Alternatively, for example, the power rectified by the rectifier circuit REC may be supplied to the winding 72B via a stabilization circuit including a capacitor.

[0020] The control circuit 19 (Figure 1) is configured to control the operation of inverters 11 and 12 based on instructions from the external control device 8, control signals indicating the output current supplied from inverters 11 and 12, and control signals indicating the rotational speed supplied from motor 70. Specifically, the control circuit 19 controls the rotational speed and torque of motor 70 by controlling the operation of inverter 11 based on instructions from the external control device 8 and control signals indicating the rotational speed of motor 70. Furthermore, the control circuit 19 controls the strength of the magnetic field generated by the rotor 72 of motor 70 by controlling the operation of inverter 12 based on control signals indicating the rotational speed supplied from motor 70.

[0021] Motor 70 (Figure 1) is a wound-field synchronous motor. Motor 70 includes a stator 71, a rotor 72, and a sensor 73.

[0022] The stator 71 is a so-called stator and is fixed to a housing (not shown) of the motor 70. The stator 71 has a stator core 71A and windings 71B. Three-phase (U-phase, V-phase, W-phase) AC power generated by the inverter 11 is supplied to the windings 71B.

[0023] The rotor 72 is a so-called rotor and is configured to rotate the rotation axis AZ. The rotor 72 has a rotor core 72A and windings 72B. Power rectified by a rectifier circuit REC is supplied to the windings 72B.

[0024] The sensor 73 is configured to detect the rotational speed of the rotor 72. The sensor 73 then supplies a control signal indicating the rotational speed of the rotor 72 to the control circuit 19.

[0025] In this configuration, the motor device 1 controls the rotational speed and torque of the motor 70 based on the three-phase (U-phase, V-phase, W-phase) AC power generated by the inverter 11, and controls the torque of the motor 70 based on the single-phase AC power generated by the inverter 12. The motor device 1 also controls the magnetic field generated by the rotor 72 of the motor 70 based on the single-phase AC power generated by the inverter 12. For example, in the motor device 1, when the rotational speed of the motor 70 is slow, the magnetic field generated by the rotor 72 of the motor 70 is strengthened, and when the rotational speed of the motor 70 is fast, the magnetic field generated by the rotor 72 of the motor 70 is weakened. As a result, the motor device 1 can increase the efficiency of the motor 70 over a wide range of rotational speeds.

[0026] (Power transmission device 20) Figures 3 to 5 show an example configuration of the power transmission device 20. Figure 3 shows an external view of the power transmission device 20. Figure 4 shows an exploded perspective view of the power transmission device 20. Figure 5 shows a cross-sectional view of the power transmission device 20 in a plane including the rotation axis AZ.

[0027] The stator 30 is fixed to a housing (not shown) of the motor device 1. As shown in Figures 3 to 5, the stator 30 has a magnetic core 31, a substrate 32, and windings 33.

[0028] The magnetic core 31 is constructed using a magnetic material such as ferrite. As shown in Figure 5, the magnetic core 31 is configured to surround the windings 33 of the stator 30 and the windings 43 of the rotor 40. The magnetic core 31 has a magnetic core 31A and a magnetic core 31B. The magnetic cores 31A and 31B are arranged in this order in the direction opposite to the Z direction. Here, the Z direction is the axial direction of the rotation axis AZ, as shown in Figure 1, and is the direction from the motor 70 toward the power transmission device 20.

[0029] As shown in Figures 3 to 5, the magnetic core 31A has a ring shape in a plane intersecting the axial direction (Z direction) of the rotation axis AZ. As shown in Figure 5, the magnetic core 31A has a protrusion 31C on its outer circumference in the plane intersecting the axial direction of the rotation axis AZ that protrudes in the direction in which the magnetic core 31B is provided. Also, as shown in Figure 5, the magnetic core 31A has a protrusion 31D at its end near the rotation axis AZ that protrudes in the direction in which the magnetic core 31B is provided. These protrusions 31C and 31D have a ring shape in a plane intersecting the axial direction of the rotation axis AZ. As shown in Figures 4 and 5, a notch 35 is provided in a part of the protrusion 31D of the magnetic core 31A, so that the wire wiring 34 (described later) passes through this notch 35.

[0030] The magnetic core 31B, like the magnetic core 31A, has a ring shape in a plane intersecting the axial direction (Z direction) of the rotation axis AZ. The magnetic core 31B, like the magnetic core 31A, has a protrusion 31C on its outer circumference in a plane intersecting the axial direction of the rotation axis AZ, projecting in the direction from which the magnetic core 31A is provided. This protrusion 31C has a ring shape in a plane intersecting the axial direction of the rotation axis AZ.

[0031] The magnetic cores 31A and 31B are connected such that the protrusions 31C of magnetic core 31A and magnetic core 31B are in contact with each other. In this way, a cavity is provided inside the magnetic core 31. The substrate 32 of the stator 30 and the substrate 42 of the rotor 40 are provided in this cavity.

[0032] The substrate 32 is, for example, a printed circuit board (PCB). In this example, as shown in Figure 5, the substrate 32 is provided on the surface of the magnetic core 31A that faces the magnetic core 31B. The substrate 32 has a ring shape, as shown in Figure 4. The substrate 32 is positioned outside the ring-shaped protrusion 31D of the magnetic core 31, as shown in Figure 5.

[0033] As shown in Figure 5, the winding 33 is constructed using pattern wiring provided on the substrate 32. The winding 33 is made of, for example, copper.

[0034] Figure 6 shows an example of the configuration of a winding 33 on a substrate 32. In Figure 6, the winding 33 is shown by a dotted shading. In this example, the substrate 32 is a multilayer substrate, and the winding 33 is constructed using the internal pattern wiring of the substrate 32. As shown in Figure 5, the winding 33 is provided in two layers inside the substrate 32 and is wound multiple times along the circumferential direction of the rotation axis AZ, as shown in Figure 6. The winding 33 is connected to a wire wiring 34 as shown in Figures 5 and 6. This wire wiring 34 is led to the outside of the magnetic core 31 through a notch 35 in the magnetic core 31A. The winding 33 is connected to the inverter 12 via this wire wiring 34.

[0035] The rotor 40 is connected to the shaft 24 and configured to rotate about the rotation axis AZ. As shown in Figure 5, the rotor 40 is positioned so as to be sandwiched between the magnetic cores 31A and 31B of the stator 30 in the axial direction (Z direction) of the rotation axis AZ. As shown in Figures 4 and 5, the rotor 40 has a substrate 42 and windings 43.

[0036] The substrate 42 is, for example, a printed circuit board. The substrate 42 is provided at a different position from the position where the substrate 32 of the stator 30 is provided, in the axial direction (Z direction) of the rotation axis AZ. The substrate 42 has a circular outer shape, as shown in Figure 4. The substrate 42 has a hole 42A, which in this example has a roughly rectangular shape, near the center of the substrate 42 in a plane intersecting the Z direction. The substrate 42 also has two through holes 42B provided at opposite positions on either side of the hole 42A. The substrate 42 is fixed to the screw holes 58 (Figure 4) of the shaft 24 by screws through these through holes 42B.

[0037] As shown in Figure 5, the winding 43 is constructed using pattern wiring provided on the substrate 42. The winding 43 is made of, for example, copper.

[0038] Figure 7 shows an example of the configuration of a winding 43 on a substrate 42. In this example, the substrate 42 is a multilayer substrate, and the winding 43 is constructed using the internal pattern wiring of the substrate 42. As shown in Figure 5, the winding 43 is provided in two layers inside the substrate 42, and as shown in Figure 7, it is wound multiple times along the circumferential direction of the rotation axis AZ. The number of turns of the winding 43 is an integer. As shown in Figure 5, a terminal 43A is provided at one end of the winding 43, and a terminal 43B is provided at the other end. Since the number of turns of the winding 43 is an integer, these terminals 43A and 43B are arranged in the same direction when viewed from the rotation axis AZ. These terminals 43A and 43B are located closer to the rotation axis AZ than the winding 43 in the radial direction of the shaft 24. The winding 43 is connected to the rectifier circuit REC via these terminals 43A and 43B.

[0039] The rotating body 50 is connected to the shaft 24 and is configured to rotate about the rotation axis AZ. As shown in Figures 4 and 5, the rotating body 50 has a substrate 52, connection terminals 54A and 54B, connection members 56A and 56B, and a conductor member 57.

[0040] The substrate 52 is, for example, a printed circuit board. The substrate 52 has a ring shape and is fixed to the shaft 24. The rectifier circuit REC shown in Figure 2 is mounted on this substrate 52. Although not shown, the four diodes D1 to D4 of the rectifier circuit REC are arranged at equal intervals along the circumferential direction of the rotation axis AZ on this substrate 52.

[0041] As shown in Figures 4 and 5, the connection terminals 54A and 54B are provided on the substrate 52 at opposite positions on either side of the shaft 24. These connection terminals 54A and 54B are connected to nodes N3 and N4 (Figure 2) of the rectifier circuit REC, respectively.

[0042] The connecting members 56A, 56B and the conductor member 57 are configured to connect the connecting terminals 54A, 54B to the windings 43 of the rotor 40.

[0043] The connecting member 56A is configured to connect the connecting terminal 54A and the conductor member 57 as shown in FIGS. 4 and 5. A spacer 53A, which is an insulator, is provided between the connecting member 56A and the shaft 24. The connecting terminal 54A, the connecting member 56A, and the spacer 53A are fixed to the shaft 24 by a screw 55A.

[0044] The conductor member 57 is configured to connect the connecting member 56A and a terminal 43A of a winding 43 of the rotor 40 as shown in FIG. 5. The conductor member 57 extends in a direction intersecting the axial direction (Z direction) of the rotation axis AZ.

[0045] FIG. 8 illustrates an example of the arrangement of the conductor member 57. The shaft 24 has a through hole 24A extending in a direction intersecting the Z direction. The conductor member 57 is disposed in this through hole 24A. In this through hole 24A, a spacer 59, which is an insulator, is provided between the conductor member 57 and the shaft 24. In this example, the conductor member 57 passes through the position of the rotation axis AZ inside the shaft 24. As shown in FIG. 5, one end of the conductor member 57 is connected to the connecting member 56A, and the other end is connected to the terminal 43A of the winding 43 of the rotor 40.

[0046] The connecting member 56B is configured to connect the connecting terminal 54B and a terminal 43B of the winding 43 of the rotor 40 as shown in FIG. 5. A spacer 53B, which is an insulator, is provided between the connecting member 56B and the shaft 24. The connecting terminal 54B, the connecting member 56B, and the spacer 53B are fixed to the shaft 24 by a screw 55B.

[0047] The shaft 24 is connected to a rotor 72 of a motor 70, and is configured to rotate about the rotation axis AZ in accordance with a driving force generated by the motor 70. The shaft 24 may be directly connected to the rotor 72 of the motor 70, or may be indirectly connected via another component. Further, the shaft 24 may be formed integrally with the rotor 72 of the motor 70.

[0048] With this configuration, the power transmission device 20 transmits AC power supplied from the inverter 12 from the stator 30 to the rotor 40 through non-contact transmission, and rectifies the transmitted AC power. Then, the power transmission device 20 is configured to supply the rectified power to the rotor 72 of the motor 70.

[0049] Here, the shaft 24 corresponds to one specific example of "the shaft" in one embodiment of the present disclosure. The stator 30 corresponds to one specific example of "the stator" in one embodiment of the present disclosure. The winding 33 corresponds to one specific example of "the first winding" in one embodiment of the present disclosure. The rotor 40 corresponds to one specific example of "the rotor" in one embodiment of the present disclosure. The winding 43 corresponds to one specific example of "the second winding" in one embodiment of the present disclosure. The terminal 43A corresponds to one specific example of "the first terminal" in one embodiment of the present disclosure. The terminal 43B corresponds to one specific example of "the second terminal" in one embodiment of the present disclosure. The rotating body 50 corresponds to one specific example of "the rotating body" in one embodiment of the present disclosure. The substrate 52 corresponds to one specific example of "the substrate" in one embodiment of the present disclosure. The rectifier circuit REC corresponds to one specific example of "the rectifier circuit" in one embodiment of the present disclosure. The connection terminal 54A corresponds to one specific example of "the first connection terminal" in one embodiment of the present disclosure. The connection terminal 54B corresponds to one specific example of "the second connection terminal" in one embodiment of the present disclosure. The conductor member 57 corresponds to one specific example of "the conductor member" in one embodiment of the present disclosure. The motor 70 corresponds to one specific example of "the motor" in one embodiment of the present disclosure. The stator 71 corresponds to one specific example of "the motor stator" in one embodiment of the present disclosure. The winding 71B corresponds to one specific example of "the first motor winding" in one embodiment of the present disclosure. The rotor 72 corresponds to one specific example of "the motor rotor" in one embodiment of the present disclosure. The winding 72B corresponds to one specific example of "the second motor winding" in one embodiment of the present disclosure.

[0050] [Operation and Action] Next, the operation and action of the motor device 1 according to the present embodiment will be described.

[0051] (Overall Operation Overview) First, the overall operation overview of the motor device 1 will be explained with reference to Figures 1 and 2. The control circuit 19 controls the operation of inverters 11 and 12 based on instructions from the external control device 8, control signals indicating the output current supplied from inverters 11 and 12, and control signals indicating the rotational speed supplied from motor 70. Inverter 11 converts the DC power supplied from the DC power supply 9 into three-phase (U-phase, V-phase, W-phase) AC power based on instructions from the control circuit 19, and supplies this three-phase AC power to the windings 71B of the stator 71 of motor 70. Inverter 12 converts the DC power supplied from the DC power supply 9 into single-phase AC power based on instructions from the control circuit 19, and supplies this AC power to the windings 33 of the stator 30 of the power transmission device 20. The power transmission device 20 transmits the AC power supplied from inverter 12 from the stator 30 to the rotor 40 by contactless transmission, and rectifies the transmitted AC power. The power transmission device 20 then supplies the rectified power to the windings 72B of the rotor 72 of the motor 70. The motor 70 generates driving force, which is mechanical energy, based on the three-phase (U-phase, V-phase, W-phase) AC power supplied from the inverter 11. As a result, the shaft 24 rotates around the rotation axis AZ. The sensor 73 of the motor 70 supplies a control signal indicating the rotational speed of the motor 70 to the control circuit 19.

[0052] (Detailed Operation) Next, the operation and function of the power transmission device 20 of this embodiment will be described.

[0053] The power transmission device 20 can transmit power by contactless transmission. The power transmission operation is described below.

[0054] Figure 9 illustrates the power transmission operation in the power transmission device 20. The windings 33 of the stator 30 generate a magnetic field based on the AC power supplied from the inverter 12. The portion of the magnetic core 31A closest to the rotation axis AZ and the portion of the magnetic core 31B closest to the rotation axis AZ are magnetically coupled to each other. The portion of the magnetic core 31A far from the rotation axis AZ and the portion of the magnetic core 31B far from the rotation axis AZ are also magnetically coupled to each other. As a result, the power transmission device 20 generates a magnetic path MP through the magnetic cores 31A and 31B, as shown in Figure 9. The windings 43 of the rotor 40 then generate AC power based on the magnetic field in this magnetic path MP and supply the generated AC power to the rectifier circuit REC. In this way, the power transmission device 20 can supply AC power to the rectifier circuit REC (Figure 2) by contactless transmission.

[0055] Thus, since power is transmitted by non-contact transmission in the power transmission device 20, reliability can be improved compared to, for example, the case where power is transmitted by contact transmission using slip rings and brushes.

[0056] The rectifier circuit REC rectifies the AC power supplied from the winding 43 of the rotor 40 and supplies the rectified power to the winding 72B of the rotor 72 of the motor 70. This generates a magnetic field in the rotor 72 of the motor 70. The control circuit 19 strengthens the magnetic field generated by the rotor 72 of the motor 70 when the rotational speed of the motor 70 is slow, and weakens the magnetic field generated by the rotor 72 of the motor 70 when the rotational speed of the motor 70 is fast. As a result, the motor device 1 can increase the efficiency of the motor 70 over a wide range of rotational speeds.

[0057] In the power transmission device 20, the winding 43 on the rotor 40 is wound an integer number of times in the circumferential direction of the shaft 24. The terminals 43A and 43B of this winding 43 are provided in the same direction when viewed from the rotation axis AZ, as shown in Figure 5. In the power transmission device 20, since the winding 43 is wound an integer number of times in the circumferential direction of the shaft 24 in this way, the weight imbalance of the winding 43 can be reduced.

[0058] In other words, for example, if the winding 43 is wound around the shaft 24 circumferentially for an integer half of the number of turns, and terminals 43A and 43B are provided in opposite directions when viewed from the rotation axis AZ, these terminals 43A and 43B can be easily connected to the connection terminals 54A and 54B of the rotating body 50. However, the number of turns on one side of the rotor 40 becomes greater than the number of turns on the opposite side. In the power transmission device 20, in order to transmit a large amount of power, copper can be used to construct the winding 43 with thick pattern wiring. Therefore, this half-circle winding 43 causes an imbalance in the weight of the winding 43. Since the rotor 40 rotates around the rotation axis AZ, this weight imbalance may cause malfunctions in the motor device 1. In particular, when the number of turns of the winding 43 is small (for example, 10 turns or less), this weight imbalance becomes relatively large, increasing the likelihood of malfunctions in the motor device 1.

[0059] On the other hand, in the power transmission device 20, the winding 43 on the rotor 40 is wound an integer number of times in the circumferential direction of the shaft 24. This reduces the weight imbalance of the winding 43. In particular, the weight imbalance can be effectively suppressed when the number of turns of the winding 43 is small.

[0060] Furthermore, as shown in Figure 5, the terminals 43A and 43B of the winding 43 are provided in the same direction when viewed from the rotation axis AZ. However, these terminals 43A and 43B are provided in a position closer to the rotation axis AZ than the winding 43 in the radial direction of the shaft 24. Therefore, the moment of terminals 43A and 43B is small, which reduces the impact on weight imbalance.

[0061] Thus, the power transmission device 20 includes a shaft 24 that can rotate around a rotation axis AZ, a stator 30 provided spaced apart from the shaft 24 and having a first winding (winding 33) wound in the circumferential direction of the shaft 24, a rotor 40 connected to the shaft 24 and rotatable in the circumferential direction of the shaft 24, and having a second winding (winding 43) wound an integer number of times in the circumferential direction of the shaft 24, including a first terminal (terminal 43A) provided at one end and a second terminal (terminal 43B) provided at the other end, and a rotating body 50 connected to the shaft 24 and rotatable in the circumferential direction of the shaft 24. The rotating body 50 includes a substrate 52 extending on a surface intersecting the shaft 24, a first connection terminal (connection terminal 54A) and a second connection terminal (connection terminal 54B) respectively, which are guided to a first terminal (terminal 43A) and a second terminal (terminal 43B), and which are located on the substrate 52 at opposite positions on either side of the shaft 24, a rectifier circuit REC provided on the substrate 52 that can perform rectification based on the AC power supplied to the first connection terminal (connection terminal 54A) and the second connection terminal (connection terminal 54B), and a conductor member 57 provided in the path connecting the first terminal (terminal 43A) and the first connection terminal (connection terminal 54A), extending in a direction intersecting the axial direction of the shaft 24. In this way, in the power transmission device 20, the winding 43 of the rotor 40 is wound an integer number of times in the circumferential direction of the shaft 24, so that, as described above, the imbalance due to gravity can be reduced.

[0062] Furthermore, in the power transmission device 20, the shaft 24 has a through hole 24A that extends in a direction intersecting the axial direction of the shaft 24, and the conductor member 57 is provided in the through hole 24A. Since the winding 43 is wound an integer number of times in the circumferential direction of the shaft 24, the terminals 43A and 43B of the winding 43 are provided in the same direction when viewed from the rotation axis AZ, as shown in Figure 5. On the other hand, in the rotating body 50, the connection terminals 54A and 54B are provided in different directions when viewed from the rotation axis AZ. Therefore, by using such a conductor member 57, the winding 43 of the rotor 40 and the rectifier circuit REC of the rotating body 50 can be connected.

[0063] Furthermore, in the power transmission device 20, the rotor 40 has a printed circuit board, and the second winding (winding 43) is a patterned wiring provided on the printed circuit board. As a result, the power transmission device 20 can have a simpler configuration compared to, for example, a case where wire wiring wound on a bobbin is used.

[0064] Furthermore, in the power transmission device 20, the first terminal (terminal 43A) and the second terminal (terminal 43B) are positioned closer to the rotation axis AZ than the second winding (winding 43) in the radial direction of the shaft 24. This reduces the moment of terminals 43A and 43B, thereby reducing weight imbalance.

[0065] Furthermore, in the power transmission device 20, the first winding (winding 33) and the second winding (winding 43) are provided at different positions relative to each other in the axial direction of the shaft 24, and the stator 30 further includes a magnetic core 31 provided so as to surround the first winding (winding 33) and the second winding (winding 43) from both sides in the axial direction and both sides in the radial direction. As a result, in the power transmission device 20, as shown in Figure 9, a magnetic path MP is formed in the magnetic core 31, and the winding 43 generates AC power based on the magnetic field in this magnetic path MP. In this way, the power transmission device 20 can transmit AC power to the rotating system by contactless transmission.

[0066] [Effects] As described above, this embodiment includes a shaft rotatable around a rotation axis, a stator spaced apart from the shaft and having a first winding wound in the circumferential direction of the shaft, a rotor connected to the shaft and rotatable in the circumferential direction of the shaft, having a second winding wound an integer number of times in the circumferential direction of the shaft, including a first terminal provided at one end and a second terminal provided at the other end, and a rotating body connected to the shaft and rotatable in the circumferential direction of the shaft. This rotating body includes a substrate extending in a plane intersecting the shaft, a first connection terminal and a second connection terminal respectively, which are guided to the first terminal and the second terminal and are provided on the substrate at opposite positions on either side of the shaft, a rectifier circuit provided on the substrate and capable of performing rectification based on AC power supplied to the first and second connection terminals, and a conductor member provided in the path connecting the first terminal and the first connection terminal and extending in a direction intersecting the axial direction of the shaft. This makes it possible to reduce the imbalance due to gravity.

[0067] [Modification 1] In the above embodiment, a through hole 24A is provided in the shaft 24 and a conductor member 57 is placed in this through hole 24A, but the invention is not limited to this. Alternatively, for example, a groove may be provided at the end of the shaft 24 and the conductor member 57 may be placed in this groove. The power transmission device 120 according to this modification will be described in detail below.

[0068] Figures 10 to 12 show an example configuration of the power transmission device 120. These figures correspond to Figures 3 to 5 of the above embodiment, respectively. The power transmission device 120 includes a stator 30, a rotor 140, a rotating body 150, and a shaft 124.

[0069] The rotor 140 is connected to the shaft 124 and configured to rotate about the rotation axis AZ. As shown in Figure 12, the rotor 140 is positioned so as to be sandwiched between the magnetic cores 31A and 31B of the stator 30 in the axial direction (Z direction) of the rotation axis AZ. As shown in Figures 11 and 12, the rotor 140 has a substrate 42 and a winding 43. As shown in Figure 12, a terminal 143A is provided at one end of the winding 43 and a terminal 143B is provided at the other end. Since the number of turns of the winding 43 is an integer, these terminals 143A and 143B are positioned in the same direction when viewed from the rotation axis AZ. The winding 43 is connected to the rectifier circuit REC via these terminals 143A and 143B.

[0070] The rotating body 150 is connected to the shaft 124 and is configured to rotate about the rotation axis AZ. As shown in Figures 11 and 12, the rotating body 150 has a base plate 52, connection terminals 54A and 54B, connecting members 156A and 156B, and a conductor member 157.

[0071] The connecting members 156A, 156B and the conductor member 157 are configured to connect the connecting terminals 54A, 54B to the windings 43 of the rotor 140.

[0072] As shown in Figure 12, the connecting member 156A is configured to connect the connecting terminal 54A and the conductor member 157. An insulating spacer 153A is provided between the connecting member 156A and the shaft 124. The connecting terminal 54A, the connecting member 156A, and the spacer 153A are fixed to the shaft 124 by screws 55A.

[0073] As shown in Figure 12, the conductor member 157 is configured to connect the connecting member 156A to the terminal 143A of the winding 43 of the rotor 140. The conductor member 157 extends in a direction intersecting the axial direction (Z direction) of the rotation axis AZ.

[0074] Figure 13 shows an example of the arrangement of the conductor member 157. The shaft 124 has a groove 124A at its Z-direction end that extends in a direction intersecting the Z-direction. The conductor member 157 is positioned in this groove 124A. In this groove 124A, an insulating spacer 159 is provided between the conductor member 157 and the shaft 124. In this example, the conductor member 157 passes through the position of the rotation axis AZ. As shown in Figure 12, one end of the conductor member 157 is connected to the connecting member 156A, and the other end is connected to the terminal 143A of the winding 43 of the rotor 140.

[0075] As shown in Figure 12, the connecting member 156B is configured to connect the connecting terminal 54B to the terminal 143B of the winding 43 of the rotor 140. An insulating spacer 153B is provided between the connecting member 156B and the shaft 124. The connecting terminal 54B, the connecting member 156B, and the spacer 153B are fixed to the shaft 124 by screws 55B.

[0076] <2. Second Embodiment> Next, a motor device 2 according to a second embodiment will be described. In this embodiment, the configuration of the power transmission device differs from that of the first embodiment described above. The same reference numerals are used for components that are substantially the same as those in the motor device 1 according to the first embodiment described above, and their descriptions are omitted as appropriate.

[0077] Figure 14 shows an example configuration of the motor device 2. The motor device 2 comprises a drive unit 210 and a motor 70. The drive unit 210 includes inverters 11 and 12, a power transmission device 220, and a control circuit 19. The power transmission device 220 includes a stator 230, a rotor 240, a rotating body 250, and a shaft 224.

[0078] Figures 15-17 show an example configuration of the power transmission device 220. Figure 15 shows an external view of the power transmission device 220. Figure 16 shows an exploded perspective view of the power transmission device 220. Figure 17 shows a cross-sectional view of the power transmission device 220 in a plane including the rotation axis AZ.

[0079] The stator 230 is fixed to a housing (not shown) of the motor device 2. As shown in Figures 15 to 17, the stator 230 has a magnetic core 231, a bobbin 232, and a winding 233.

[0080] The magnetic core 231 is constructed using a magnetic material such as ferrite. As shown in Figure 17, the magnetic core 231 is configured to surround the windings 233 of the stator 230 and the windings 243 of the rotor 240 (described later). The magnetic core 231 has a magnetic core 231A and a magnetic core 231B.

[0081] As shown in Figures 15-17, the magnetic core 231A has a ring shape in a plane intersecting the axial direction (Z direction) of the rotation axis AZ. As shown in Figure 17, the magnetic core 231A surrounds the windings 233 of the stator 230 and the windings 243 of the rotor 240 (described later) from the inside in the radial direction of the shaft 224.

[0082] The magnetic core 231B, like the magnetic core 231A, has a ring shape in a plane intersecting the axial direction (Z direction) of the rotation axis AZ. The magnetic core 231B surrounds the windings 233 of the stator 230 and the windings 243 of the rotor 240 (described later) from the radial outside of the shaft 224. As shown in Figures 16 and 17, a notch 235 is provided in a part of the magnetic core 231B, and the windings 233 pass through this notch 235.

[0083] The magnetic cores 231A and 231B are connected as shown in Figure 17. In this way, a cavity is provided inside the magnetic core 231. The windings 233 of the stator 230 and the windings 243 of the rotor 240 (described later) are provided in this cavity.

[0084] The bobbin 232 is a support member that supports the winding 233. As shown in Figure 17, the bobbin 232 is located on the outside of the rotor 240's bobbin 242 (described later) in the radial direction of the shaft 224.

[0085] The winding 233 is constructed using wire wiring wound on a bobbin 232, as shown in Figures 16 and 17. The winding 233 is made of, for example, copper. The winding 233 is wound multiple times along the circumferential direction of the rotation axis AZ. The winding 233 is led to the outside of the magnetic core 231 through a notch 235 in the magnetic core 231B. The winding 233 is connected to the inverter 12.

[0086] The rotor 240 is connected to the shaft 224 and configured to rotate around the rotation axis AZ.

[0087] Figure 18 shows one example of the configuration of the rotor 240. As shown in Figures 16 to 18, the rotor 240 has a bobbin 242 and a winding 243.

[0088] The bobbin 242 is a support member that supports the winding 243. As shown in Figure 17, the bobbin 242 is located inward of the bobbin 232 of the stator 230 in the radial direction of the shaft 224. As shown in Figure 18, the bobbin 242 has four through holes 242B arranged at equal intervals in the circumferential direction of the rotation axis AZ. The bobbin 242 is fixed to the screw holes 258 (Figure 16) of the shaft 224 by screws through these through holes 242B.

[0089] The winding 243 is constructed using wire wiring wound on a bobbin 242, as shown in Figures 16 and 17. The winding 243 is made of, for example, copper. The winding 243 is wound multiple times along the circumferential direction of the rotation axis AZ. The number of turns of the winding 243 is an integer. As shown in Figure 18, a terminal 243A is provided at one end of the winding 243, and a terminal 243B is provided at the other end. Since the number of turns of the winding 243 is an integer, these terminals 243A and 243B are positioned in the same direction when viewed from the rotation axis AZ. In the direction of the rotation axis AZ, the length of terminal 243A is shorter than the length of terminal 243B. As shown in Figure 17, these terminals 243A and 243B are located closer to the rotation axis AZ than the winding 243 in the radial direction of the shaft 224. Winding 243 is connected to the rectifier circuit REC via terminals 243A and 243B.

[0090] The rotating body 250 is connected to the shaft 224 and is configured to rotate about the rotation axis AZ.

[0091] Figure 19 shows an example configuration of the rotating body 250. As shown in Figures 16, 17, and 19, the rotating body 250 has a substrate 252, connection terminals 254A and 254B, and a conductive member 257.

[0092] The substrate 252 is, for example, a printed circuit board. The substrate 252 has a ring shape and is fixed to the shaft 224 using screws 253. The rectifier circuit REC shown in Figure 2 is mounted on this substrate 252. Although not shown, the four diodes D1 to D4 of the rectifier circuit REC are arranged at equal intervals along the circumferential direction of the rotation axis AZ on this substrate 252.

[0093] As shown in Figures 16, 17, and 19, the connection terminals 254A and 254B are provided on the substrate 252 at opposite positions on either side of the shaft 224. These connection terminals 254A and 254B are connected to nodes N3 and N4 (Figure 2) of the rectifier circuit REC, respectively. Connection terminal 254A is connected to terminal 243A of the winding 243 of the rotor 240 via a conductive member 257. Connection terminal 254B is connected to terminal 243B of the winding 243 of the rotor 240.

[0094] As shown in Figure 17, the conductor member 257 is configured to connect the connection terminal 254A to the terminal 243A of the winding 243 of the rotor 240. The conductor member 257 extends in a direction intersecting the axial direction (Z direction) of the rotation axis AZ. As shown in Figure 19, the shaft 224 has a through hole 224A that extends in a direction intersecting the Z direction, similar to the shaft 24 (Figure 8) in the first embodiment. The conductor member 257 is positioned in this through hole 224A. In this through hole 224A, an insulating spacer 259 is provided between the conductor member 257 and the shaft 224. In this example, the conductor member 257 passes through the position of the rotation axis AZ inside the shaft 224. As shown in Figure 17, one end of the conductor member 257 is connected to the connection terminal 254A, and the other end is connected to the terminal 243A of the winding 243 of the rotor 240. Note that, in reality, the connection terminal 254A is located slightly offset from the cross-section including the conductor member 257 shown in Figure 17, as shown in Figure 16, but for the sake of explanation, it is depicted in Figure 17.

[0095] The shaft 224 is connected to the rotor 72 of the motor 70 and is configured to rotate around the rotation axis AZ in accordance with the driving force generated by the motor 70.

[0096] Here, shaft 224 corresponds to a specific example of the "shaft" in one embodiment of the present disclosure. Stator 230 corresponds to a specific example of the "stator" in one embodiment of the present disclosure. Winding 233 corresponds to a specific example of the "first winding" in one embodiment of the present disclosure. Rotor 240 corresponds to a specific example of the "rotor" in one embodiment of the present disclosure. Substrate 252 corresponds to a specific example of the "substrate" in one embodiment of the present disclosure. Winding 243 corresponds to a specific example of the "second winding" in one embodiment of the present disclosure. Terminal 243A corresponds to a specific example of the "first terminal" in one embodiment of the present disclosure. Terminal 243B corresponds to a specific example of the "second terminal" in one embodiment of the present disclosure. Rotating body 250 corresponds to a specific example of the "rotating body" in one embodiment of the present disclosure. Connection terminal 254A corresponds to a specific example of the "first connection terminal" in one embodiment of the present disclosure. Connection terminal 254B corresponds to a specific example of the "second connection terminal" in one embodiment of the present disclosure. The conductor member 257 corresponds to one specific example of the "conductor member" in one embodiment of the present disclosure.

[0097] Figure 20 illustrates the power transmission operation in the power transmission device 220. The windings 233 of the stator 230 generate a magnetic field based on the AC power supplied from the inverter 12. In the power transmission device 220, as shown in Figure 20, a magnetic path MP is generated via the magnetic cores 231A and 231B. The windings 243 of the rotor 240 then generate AC power based on the magnetic field in this magnetic path MP and supply the generated AC power to the rectifier circuit REC. In this way, the power transmission device 220 can supply AC power to the rectifier circuit REC by contactless transmission.

[0098] In the power transmission device 220, the winding 243 on the rotor 240 is wound an integer number of times in the circumferential direction of the shaft 224. The terminals 243A and 243B of this winding 243 are located in approximately the same direction when viewed from the rotation axis AZ, as shown in Figure 18. In the power transmission device 220, since the winding 243 is wound an integer number of times in the circumferential direction of the shaft 24 in this way, the weight imbalance of the winding 243 can be reduced.

[0099] Thus, the power transmission device 220 includes a shaft 224 that can rotate around a rotation axis AZ, a stator 230 spaced apart from the shaft 224 and having a first winding (winding 233) wound in the circumferential direction of the shaft 224, a rotor 240 connected to the shaft 224 and rotatable in the circumferential direction of the shaft 224, and having a second winding (winding 243) wound an integer number of times in the circumferential direction of the shaft 224, including a first terminal (terminal 243A) provided at one end and a second terminal (terminal 243B) provided at the other end, and a rotating body 250 connected to the shaft 224 and rotatable in the circumferential direction of the shaft 224. The rotating body 250 includes a substrate 252 extending on a surface intersecting the shaft 224, a first connection terminal (connection terminal 254A) and a second connection terminal (connection terminal 254B) respectively, which are guided to a first terminal (terminal 243A) and a second terminal (terminal 243B), and which are provided on the substrate 252 at opposite positions on either side of the shaft 224, a rectifier circuit REC provided on the substrate 252 and capable of performing a rectification operation based on the AC power supplied to the first connection terminal (connection terminal 254A) and the second connection terminal (connection terminal 254B), and a conductor member 257 provided in the path connecting the first terminal (terminal 243A) and the first connection terminal (connection terminal 254A), extending in a direction intersecting the axial direction of the shaft 224. Thus, in the power transmission device 220, the windings 243 of the rotor 240 are wound an integer number of times in the circumferential direction of the shaft 224, and as described above, the imbalance due to gravity can be reduced.

[0100] Furthermore, in the power transmission device 220, the first winding (winding 233) and the second winding (winding 243) are provided at the same position relative to each other in the axial direction of the shaft 224, and the second winding (winding 243) is provided inward of the first winding (winding 233) in the radial direction of the shaft 224. The stator 230 further includes a magnetic core 231 provided so as to surround the first winding (winding 233) and the second winding (winding 243) from both sides in the axial direction and both sides in the radial direction. As a result, in the power transmission device 220, a magnetic path MP is formed in the magnetic core 231 as shown in Figure 20, and the winding 243 generates AC power based on the magnetic field in this magnetic path MP. In this way, the power transmission device 220 can transmit AC power to the rotating system by contactless transmission.

[0101] [Modification 2] In the above embodiment, a through hole 224A is provided in the shaft 224 and a conductor member 257 is placed in this through hole 224A, but the invention is not limited to this. Alternatively, for example, a groove may be provided at the end of the shaft 224 and the conductor member 257 may be placed in this groove. The power transmission device 320 according to this modification will be described in detail below.

[0102] Figures 21 to 23 show an example configuration of the power transmission device 320. These figures correspond to Figures 15 to 17, respectively, of the above embodiment. The power transmission device 320 includes a stator 230, a rotor 240, a rotating body 350, and a shaft 324. Figure 24 shows an example configuration of the rotating body 350.

[0103] The rotating body 350 is connected to the shaft 324 and is configured to rotate about the rotation axis AZ. As shown in Figures 22 to 24, the rotating body 350 has a base plate 252, connection terminals 254A and 254B, a conductor member 357, and four column members 358.

[0104] As shown in Figure 23, the conductor member 357 is configured to connect the connection terminal 254A to the terminal 243A of the winding 243 of the rotor 240. The conductor member 357 extends in a direction intersecting the axial direction (Z direction) of the rotation axis AZ. The shaft 324, similar to the shaft 124 in the first embodiment (Figure 13), has a groove 324A at its Z-direction end that extends in a direction intersecting the Z direction. The conductor member 357 is positioned in this groove 324A. In this groove 324A, an insulating spacer 359 is provided between the conductor member 357 and the shaft 324. In this example, the conductor member 357 passes through the position of the rotation axis AZ. As shown in Figure 23, one end of the conductor member 357 is connected to the connection terminal 254A, and the other end is connected to the terminal 243A of the winding 243 of the rotor 240.

[0105] The four column members 358 are positioned at four locations surrounding the rotation axis AZ at the Z-direction end of the shaft 324. Each of the four column members 358 has a screw hole at its tip. The bobbin 242 of the rotor 240 is fixed by screws to the screw holes at the tips of the column members 358 via through holes 242B.

[0106] Although the present invention has been described above with reference to embodiments, the present invention is not limited to these embodiments and various modifications are possible.

[0107] For example, the arrangement and shape of the stator, rotor, magnetic core, windings, and rotating body shown in the above embodiments are examples only and are not limited to the disclosed arrangements and shapes.

[0108] The effects described herein are illustrative only, and the effects of this disclosure are not limited to those described herein. Therefore, other effects may be obtained with respect to this disclosure.

[0109] Furthermore, this disclosure may take the following forms:

[0110] (1) A power transmission device comprising: a shaft rotatable about a rotation axis; a stator spaced apart from the shaft and having a first winding wound in the circumferential direction of the shaft; a rotor connected to the shaft and rotatable in the circumferential direction of the shaft, having a second winding wound an integer number of times in the circumferential direction of the shaft, including a first terminal provided at one end and a second terminal provided at the other end; and a rotating body connected to the shaft and rotatable in the circumferential direction of the shaft, wherein the rotating body comprises: a substrate extending in a plane intersecting the shaft; a first connection terminal and a second connection terminal, respectively, led to the first terminal and the second terminal and provided on the substrate at opposite positions on either side of the shaft; a rectifier circuit provided on the substrate and capable of performing a rectification operation based on AC power supplied to the first connection terminal and the second connection terminal; and a conductor member provided in a path connecting the first terminal and the first connection terminal and extending in a direction intersecting the axial direction of the shaft. (2) The shaft has a through hole extending in a direction intersecting the axial direction of the shaft, and the conductor member is the power transmission device according to (1) provided in the through hole. (3) The shaft has a groove provided at the end of the shaft in the axial direction and extending in a direction intersecting the axial direction of the shaft, and the conductor member is the power transmission device according to (1) provided in the groove. (4) The power transmission device according to any one of (1) to (3) wherein the first terminal and the second terminal are provided in the radial direction of the shaft at a position closer to the rotation axis than the second winding. (5) The power transmission device according to any one of (1) to (4) wherein the rotor has a printed circuit board, and the second winding is a pattern wiring provided on the printed circuit board. (6) The power transmission device according to any one of (1) to (4) wherein the second winding is a wire wiring.(7) The power transmission device according to any one of (1) to (5), wherein the first winding and the second winding are provided at different positions relative to each other in the axial direction of the shaft, and the stator further comprises a magnetic core provided to surround the first winding and the second winding from both sides in the axial direction and both sides in the radial direction. (8) The power transmission device according to any one of (1) to (4) and (6), wherein the first winding and the second winding are provided at the same positions relative to each other in the axial direction of the shaft, the second winding is provided inward of the first winding in the radial direction of the shaft, and the stator further comprises a magnetic core provided to surround the first winding and the second winding from both sides in the axial direction and both sides in the radial direction. (9) A motor having a motor stator including a first motor winding and a motor rotor including a second motor winding; a shaft connected to the motor rotor and rotatable about a rotation axis; a stator spaced apart from the shaft and having a first winding wound in the circumferential direction of the shaft; a rotor connected to the shaft and rotatable in the circumferential direction of the shaft and having a second winding wound an integer number of times in the circumferential direction of the shaft, including a first terminal provided at one end and a second terminal provided at the other end; and a rotating body connected to the shaft and rotatable in the circumferential direction of the shaft, wherein the rotating body comprises a substrate extending to a plane intersecting the shaft, and a first connection terminal and a second connection terminal provided on the substrate at opposite positions on either side of the shaft, respectively, and guided to the first terminal and the second terminal. A motor device comprising: a rectifier circuit provided on the substrate and capable of performing a rectification operation based on AC power supplied to the first connection terminal and the second connection terminal, and capable of supplying the power rectified by the rectification operation to the second motor winding; and a conductor member provided in the path connecting the first terminal and the first connection terminal and extending in a direction intersecting the axial direction of the shaft.

Claims

1. A power transmission device comprising: a shaft rotatable about a rotation axis; a stator spaced apart from the shaft and having a first winding wound in the circumferential direction of the shaft; a rotor connected to the shaft and rotatable in the circumferential direction of the shaft, having a second winding wound an integer number of times in the circumferential direction of the shaft, including a first terminal provided at one end and a second terminal provided at the other end; and a rotating body connected to the shaft and rotatable in the circumferential direction of the shaft, wherein the rotating body comprises: a substrate extending in a plane intersecting the shaft; a first connection terminal and a second connection terminal, respectively, led to the first terminal and the second terminal and provided on the substrate at opposite positions on either side of the shaft; a rectifier circuit provided on the substrate and capable of performing a rectification operation based on AC power supplied to the first connection terminal and the second connection terminal; and a conductor member provided in a path connecting the first terminal and the first connection terminal and extending in a direction intersecting the axial direction of the shaft.

2. The power transmission device according to claim 1, wherein the shaft has a through hole extending in a direction intersecting the axial direction of the shaft, and the conductor member is provided in the through hole.

3. The power transmission device according to claim 1, wherein the shaft has a groove provided at the end of the shaft in the axial direction and extending in a direction intersecting the axial direction of the shaft, and the conductor member is provided in the groove.

4. The power transmission device according to claim 1, wherein the first terminal and the second terminal are provided in the radial direction of the shaft at a position closer to the rotation axis than the second winding.

5. The power transmission device according to claim 1, wherein the rotor has a printed circuit board, and the second winding is a patterned wiring provided on the printed circuit board.

6. The second winding is a wire wiring. The power transmission device according to claim 1.

7. The power transmission device according to claim 1, wherein the first winding and the second winding are provided at different positions in the axial direction of the shaft, and the stator further comprises a magnetic core provided to surround the first winding and the second winding from both sides in the axial direction and both sides in the radial direction.

8. The power transmission device according to claim 1, wherein the first winding and the second winding are provided at the same positions relative to each other in the axial direction of the shaft, the second winding is provided inward of the first winding in the radial direction of the shaft, and the stator further comprises a magnetic core provided so as to surround the first winding and the second winding from both sides in the axial direction and both sides in the radial direction.

9. A motor comprising a motor stator including a first motor winding and a motor rotor including a second motor winding; a shaft connected to the motor rotor and rotatable about a rotation axis; a stator spaced apart from the shaft and having a first winding wound in the circumferential direction of the shaft; a rotor connected to the shaft and rotatable in the circumferential direction of the shaft, and having a second winding wound an integer number of times in the circumferential direction of the shaft, including a first terminal provided at one end and a second terminal provided at the other end; and a rotating body connected to the shaft and rotatable in the circumferential direction of the shaft, wherein the rotating body comprises a substrate extending in a plane intersecting the shaft, and first and second connection terminals guided to the first and second terminals, respectively, and provided on the substrate at opposite positions on either side of the shaft, A motor device comprising: a rectifier circuit provided on the substrate and capable of performing a rectification operation based on AC power supplied to the first connection terminal and the second connection terminal, and capable of supplying the power rectified by the rectification operation to the second motor winding; and a conductor member provided in the path connecting the first terminal and the first connection terminal and extending in a direction intersecting the axial direction of the shaft.

Images