Power transmission devices and motor devices

Abstract

To provide a power transmission device and motor device that can facilitate heat dissipation. [Solution] A power transmission device according to one embodiment of the present disclosure comprises 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 and having a second winding wound in the circumferential direction of the shaft, a rotating body connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is provided, rotatable in the circumferential direction of the shaft and having a rectifier element connected to the second winding, and a blowing mechanism provided on the shaft or rotating body that can blow air as the shaft rotates and can dissipate heat from one or more of the stator, rotor, and rotating body.

Description

Technical Field

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[0001] The present invention relates to a power transmission device that transmits power without contact, and a motor device provided with such a power transmission device.

Background Art

[0002] For example, a motor includes an electrically excited synchronous motor (EESM). This motor has a stator wound with windings and a rotor wound with windings. In this motor, the efficiency of the motor can be improved by changing the current flowing through the windings wound around the rotor according to the rotation speed of the motor.

[0003] By the way, there is a device capable of transmitting power between the stator and the rotor. For example, Patent Document 1 discloses a power transmission device capable of supplying power to the rotor from the stator without contact.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] It is desirable to provide a power transmission device and a motor device that can be easily cooled.

Means for Solving the Problems

[0007] A power transmission device according to one embodiment of the present invention comprises a shaft, a stator, a rotor, a rotating body, and a blower mechanism. The shaft is rotatable about a rotation axis. The stator is provided 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 in the circumferential direction of the shaft. The rotating body is connected to the shaft at a position different from the position where the rotor is provided in the axial direction of the shaft, is rotatable in the circumferential direction of the shaft, and has a rectifier element connected to the second winding. The blower mechanism is provided on the shaft or the rotating body and is capable of blowing air as the shaft rotates, and is capable of dissipating heat from one or more of the stator, rotor, and rotating body.

[0008] A motor device according to one embodiment of the present invention comprises a motor, a shaft, a stator, a rotor, a rotating body, and a blower mechanism. The motor has a motor stator including a first motor magnetic core and a first motor winding, and a motor rotor including a second motor magnetic core and a second motor winding. The shaft is connected to the motor rotor and is rotatable about a rotation axis. The stator is provided 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 in the circumferential direction of the shaft. The rotating body is connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is provided, is rotatable in the circumferential direction of the shaft, and has a rectifier element connected to the second winding. The blower mechanism is provided on the shaft or the rotating body and is capable of blowing air as the shaft rotates, and is capable of dissipating heat from one or more of the stator, rotor, and rotating body. [Effects of the Invention]

[0009] According to one embodiment of the present invention, the power transmission device and motor device make it easier to dissipate heat. [Brief explanation of the drawing]

[0010] [Figure 1] 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] Figure 2 is a circuit diagram showing one example configuration of the inverter and power transmission device shown in Figure 1. [Figure 3] Figure 3 is a perspective view showing one example configuration of the power transmission device shown in Figure 1. [Figure 4] Figure 4 is a plan view showing one example configuration of the power transmission device shown in Figure 3. [Figure 5] Figure 5 is a plan view showing one example configuration of the stator and rotor shown in Figure 3. [Figure 6] Figure 6 is a cross-sectional view showing one example configuration of the power transmission device shown in Figure 3. [Figure 7] Figure 7 is another cross-sectional view showing an example configuration of the power transmission device shown in Figure 3. [Figure 8] Figure 8 is a perspective view showing one example configuration of the air blowing mechanism shown in Figure 3. [Figure 9] Figure 9 is an explanatory diagram illustrating an example of power transmission operation in the power transmission device shown in Figure 3. [Figure 10] Figure 10 is an explanatory diagram illustrating an example of heat dissipation operation in the power transmission device shown in Figure 3. [Figure 11] Figure 11 is a plan view showing an example configuration of a modified power transmission device. [Figure 12] Figure 12 is a plan view showing an example configuration of a power transmission device relating to other modifications. [Figure 13] Figure 13 is a perspective view showing one example configuration of a power transmission device related to other modifications. [Figure 14] Figure 14 is a perspective view showing one example configuration of the air blowing mechanism shown in Figure 13. [Figure 15] Figure 15 is a perspective view showing one example configuration of a power transmission device related to other modifications. [Figure 16]FIG. 16 is a perspective view showing a configuration example of the blower mechanism shown in FIG. 15. [Figure 17] FIG. 17 is a perspective view showing a configuration example of a power transmission device according to another modification. [Figure 18] FIG. 18 is an explanatory view showing an example of a heat dissipation operation in the power transmission device shown in FIG. 17. [Figure 19] FIG. 19 is a block diagram showing a configuration example of a motor device according to the second embodiment. [Figure 20] FIG. 20 is a perspective view showing a configuration example of the power transmission device shown in FIG. 19. [Figure 21] FIG. 21 is a plan view showing a configuration example of the power transmission device shown in FIG. 20. [Figure 22] FIG. 22 is a plan view showing a configuration example of the stator and the rotor shown in FIG. 20. [Figure 23] FIG. 23 is a cross-sectional view showing a configuration example of the power transmission device shown in FIG. 20. [Figure 24] FIG. 24 is an explanatory view showing an example of a power transmission operation in the power transmission device shown in FIG. 20. [Figure 25] FIG. 25 is an explanatory view showing an example of a heat dissipation operation in the power transmission device shown in FIG. 20. MODE FOR CARRYING OUT THE INVENTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. The description will be made in the following order. 1. First Embodiment 2. Second Embodiment

[0012] <1. First Embodiment> [Configuration Example] Figure 1 shows an example configuration of a motor device 1 equipped with a power transmission device according to an 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.

[0013] 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.

[0014] 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 winding 71B (described later) of the stator 71 of the motor 70.

[0015] 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.

[0016] 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, a blower mechanism 60, and a shaft 24.

[0017] 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 winding 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.

[0018] 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 constructed 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 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.

[0019] The power transmission device 20 includes a winding 33, a winding 43, and a rectifier circuit 59. Winding 33 is provided on the stator 30, with one end connected to node N1 of the inverter 12 and the other end connected to node N2 of the inverter 12. Winding 43 is provided on the rotor 40, with one end connected to node N3 of the rectifier circuit 59 and the other end connected to node N4 of the rectifier circuit 59. 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 59 is provided on the rotating body 50 and is configured to rectify the AC power supplied from winding 41 of the rotor 40. The rectifier circuit 59 includes diodes D1 to D4. The cathode of diode D1 is connected to voltage line L21, and its anode is connected to node N3. The cathode of diode D2 is connected to node N3, and its anode is connected to 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 reference voltage line L22. Voltage line L21 and reference voltage line L22 are connected to winding 72B (described later) of the rotor 72 of motor 70.

[0020] 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 59 is supplied directly to the winding 72B, but this is not the only option. Alternatively, for example, the power rectified by the rectifier circuit 59 may be supplied to the winding 72B via a stabilization circuit including a capacitor.

[0021] The control circuit 19 is configured to control the operation of inverters 11 and 12 based on instructions from the external control device 8 and control signals indicating the rotational speed supplied from the motor 70. Specifically, the control circuit 19 controls the rotational speed of the 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 the motor 70. In addition, the control circuit 19 controls the strength of the magnetic field generated by the rotor 72 of the motor 70 by controlling the operation of inverter 12 based on control signals indicating the rotational speed supplied from the motor 70.

[0022] Motor 70 (Figure 1) is a wound-field synchronous motor. Motor 70 includes a stator 71, a rotor 72, and a sensor 73.

[0023] 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 magnetic 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.

[0024] The rotor 72 is a so-called rotor and is configured to rotate the rotation axis AZ. The rotor 72 has a magnetic core 72A and a winding 72B. The winding 72B is supplied with a signal rectified by a rectifier circuit 59.

[0025] 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.

[0026] In this configuration, the motor device 1 controls the rotational speed 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 magnetic field generated by the rotor 72 of the motor 70 based on the single-phase AC power generated by the inverter 12. In the motor device 1, for example, 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.

[0027] (Power transmission device 20) Figures 3 and 4 show an example configuration of the power transmission device 20. Figure 5 shows an example configuration of the stator 30 and rotor 40. Figures 6 and 7 show an example of the cross-sectional structure of the power transmission device 20 in a plane including the rotation axis AZ, with Figure 6 showing the cross-sectional structure in the XZ plane and Figure 7 showing the cross-sectional structure in the YZ plane. Figure 8 shows an example configuration of the blower mechanism 60. Note that in Figures 6 and 7, the blower mechanism 60 is depicted as a flat plate for the sake of orientation, but in reality, it has the shape shown in Figure 8.

[0028] The stator 30 is fixed to a housing (not shown) of the motor device 1. As shown in Figures 3 to 7, the stator 30 has a magnetic core 31, a substrate 32, and windings 33.

[0029] The magnetic core 31 is constructed using a magnetic material such as ferrite. The magnetic core 31 is configured to surround the substrate 32 and the rotor 40, as shown in Figures 3 to 5. 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 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. The magnetic core 31 is provided with an opening 38 for passing the shaft 24, as shown in Figures 5 to 7.

[0030] As shown in Figure 5, the magnetic core 31A has a shape in which both ends in the Y direction and the opposite direction of a circle have been cut off in the XY plane intersecting the axial direction of the rotation axis AZ. As shown in Figures 5 and 6, the magnetic core 31A has protrusions 31C at each end in the X direction and the opposite direction that project in the direction in which the magnetic core 31B is provided. Each of the two protrusions 31C of the magnetic core 31A has an arc shape in the XY plane. Furthermore, as shown in Figures 5 to 7, the magnetic core 31A has a protrusion 31D at the end near the shaft 24 that projects in the direction in which the magnetic core 31B is provided. This protrusion 31D has a ring shape in the XY plane.

[0031] Similar to magnetic core 31A, magnetic core 31B has a shape in which both ends in the Y direction and the opposite direction of a circle have been cut off in the XY plane intersecting the axial direction of the rotation axis AZ. Also, similar to magnetic core 31A, magnetic core 31B has protrusions 31C at both ends in the X direction and the opposite direction that project in the direction from which magnetic core 31A is provided.

[0032] The magnetic cores 31A and 31B are connected such that the two protrusions 31C of magnetic core 31A and the two protrusions 31C of magnetic core 31B are in contact with each other. In this way, the magnetic core 31 has a cavity inside, and as shown in Figures 3 to 5 and 7, openings 39 are provided at both ends in the Y direction and the opposite direction, connecting the internal cavity of the magnetic core 31 to the outside.

[0033] The substrate 32 is, for example, a printed circuit board (PCB). In this example, as shown in Figures 4 to 7, 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 5. The substrate 32 is fitted onto the outside of the ring-shaped protrusion 31D of the magnetic core 31, as shown in Figures 6 and 7.

[0034] As shown in Figures 6 and 7, the winding 33 is constructed using pattern wiring provided on the substrate 32 and is wound multiple times along the circumferential direction of the rotation axis AZ. In Figures 6 and 7, the cross-sectional area of ​​the substrate 32 where the winding 33 is provided is shown in shaded areas. The winding 33 may be provided on one of the two surfaces of the substrate 32, or on both surfaces. Furthermore, if the substrate 32 is a multilayer substrate, the winding 33 may be constructed using pattern wiring inside the substrate 32. As shown in Figure 7, both ends of the area where the winding 33 is provided, in the Y direction and the opposite direction, protrude from the magnetic core 31. The winding 33 is connected to the inverter 12.

[0035] The rotor 40 is connected to the shaft 24 and configured to rotate about the rotation axis AZ. As shown in Figure 4, the rotor 40 is positioned so as to be sandwiched in the Z direction by the magnetic cores 31A and 31B of the stator 30. As shown in Figures 6 and 7, 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 in the Z direction from the position where the substrate 32 of the stator 30 is provided. The substrate 42 has a circular shape. In this example, the size of the substrate 42 is approximately the same as the size of the substrate 32 of the stator 30.

[0037] The winding 43 is constructed using pattern wiring provided on the substrate 42 and is wound multiple times along the circumferential direction of the rotation axis AZ. In Figures 6 and 7, the area on the substrate 42 where the winding 43 is provided is shown in shaded areas. The winding 43 may be provided on one of the two surfaces of the substrate 42, or on both surfaces. Also, if the substrate 42 is a multilayer substrate, the winding 43 may be constructed using pattern wiring inside the substrate 42. As shown in Figures 6 and 7, in this example, the area on the substrate 42 where the winding 43 is provided is approximately the same as the area on the substrate 32 of the stator 30 where the winding 33 is provided. As shown in Figure 7, both ends of the area where the winding 43 is provided, in the Y direction and the opposite direction, protrude from the magnetic core 31. The winding 43 is connected to the rectifier circuit 59.

[0038] The rotating body 50 is connected to the shaft 24 and configured to rotate about the rotation axis AZ. As shown in Figures 3, 4, 6, and 7, the rotating body 50 has a support portion 51, a substrate 52, and four diodes D.

[0039] The support portion 51 is connected to the shaft 24 and is configured to support the substrate 52. The support portion 51 has a circular plate shape. The support portion 51 may be configured integrally with the shaft 24, or it may be configured using a separate component from the shaft 24.

[0040] The substrate 52 is, for example, a printed circuit board. In this example, as shown in Figures 3, 4, 6, and 7, the substrate 52 is mounted on the side of the support portion 51 opposite to the side in which the stator 30 and rotor 40 are mounted.

[0041] The four diodes D correspond to diodes D1 to D4 shown in Figure 2 and are mounted on the substrate 52. The four diodes D are arranged at equal intervals around the shaft 24 on the substrate 52 in the circumferential direction of the rotation axis AZ. Note that in Figures 3 and 4, only three of the four diodes D are depicted because one of the diodes D is on the other side of the shaft 24.

[0042] The blower mechanism 60 is connected to the shaft 24 and configured to rotate around the rotation axis AZ. As shown in Figures 4 and 8, the blower mechanism 60 in this example has four blades 61. The number of blades 61 is not limited to four; it may be three or fewer, or five or more. The four blades 61 are arranged at equal intervals on the surface of the shaft 24 in the circumferential direction of the rotation axis AZ. The blades 61 have surfaces that are inclined in the circumferential direction with respect to the XY plane (plane W1 in Figure 4). As a result, the four blades 61 can blow air onto the rotating body 50 as the shaft 24 rotates in the circumferential direction A around the rotation axis AZ.

[0043] The shaft 24 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. The shaft 24 may be directly connected to the rotor 72 of the motor 70, or it may be indirectly connected via other components. Alternatively, the shaft 24 may be formed integrally with the rotor 72 of the motor 70.

[0044] In this configuration, the power transmission device 20 transmits AC power supplied from the inverter 12 to the rotor 40 from the stator 30 via contactless transmission, and rectifies the transmitted AC power. The power transmission device 20 then supplies the rectified power to the rotor 72 of the motor 70.

[0045] Here, shaft 24 corresponds to a specific example of the "shaft" in one embodiment of the present disclosure. Stator 30 corresponds to a specific example of the "stator" in one embodiment of the present disclosure. Winding 33 corresponds to a specific example of the "first winding" in one embodiment of the present disclosure. Rotor 40 corresponds to a specific example of the "rotor" in one embodiment of the present disclosure. Winding 43 corresponds to a specific example of the "second winding" in one embodiment of the present disclosure. Magnetic core 31 corresponds to a specific example of the "magnetic core" in one embodiment of the present disclosure. Opening 38 corresponds to a specific example of the "first opening" in one embodiment of the present disclosure. Opening 39 corresponds to a specific example of the "second opening" in one embodiment of the present disclosure. Rotating body 50 corresponds to a specific example of the "rotating body" in one embodiment of the present disclosure. Diode D corresponds to a specific example of the "rectifier element" in one embodiment of the present disclosure. Blower mechanism 60 corresponds to a specific example of the "blower mechanism" in one embodiment of the present disclosure. The blade 61 corresponds to a specific example of the "first blade" in one embodiment of the present disclosure. The motor 70 corresponds to a specific example of the "motor" in one embodiment of the present disclosure. The stator 71 corresponds to a specific example of the "motor stator" in one embodiment of the present disclosure. The rotor 72 corresponds to a specific example of the "motor rotor" in one embodiment of the present disclosure.

[0046] [Action and function] Next, the operation and function of the motor device 1 of this embodiment will be described.

[0047] (Overview of overall operation) The control circuit 19 controls the operation of inverters 11 and 12 based on instructions from the external control device 8 and control signals indicating the rotational speed supplied from the motor 70. Based on instructions from the control circuit 19, inverter 11 converts the DC power supplied from the DC power supply 9 into three-phase (U-phase, V-phase, W-phase) AC power and supplies this three-phase AC power to the winding 71B of the stator 71 of the motor 70. Based on instructions from the control circuit 19, inverter 12 converts the DC power supplied from the DC power supply 9 into single-phase AC power and supplies this AC power to the winding 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 winding 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. This causes the shaft 24 to rotate 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.

[0048] [Action and function] Next, the operation and function of the power transmission device 20 of this embodiment will be described.

[0049] The power transmission device 20 can transmit power via contactless transmission. The power transmission operation is described below.

[0050] 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 shaft 24 and the portion of the magnetic core 31B closest to the shaft are 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 59. In this way, the power transmission device 20 can supply AC power to the rectifier circuit 59 by contactless transmission.

[0051] 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.

[0052] The rectifier circuit 59 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.

[0053] Furthermore, in the power transmission device 20, such power transmission operations can cause heat to be generated in the windings 33 of the stator 30, the windings 43 of the rotor 40, and the diode D of the rotating body 50. The blowing mechanism 60 can dissipate this heat by circulating air through the power transmission device 20. The heat dissipation operation will be described below.

[0054] Figure 10 illustrates the airflow in the power transmission device 20. As the shaft 24 rotates in the circumferential direction A, the four blades 61 of the blower mechanism 60 rotate in the circumferential direction A around the rotation axis AZ. As a result, air flows from outside the magnetic core 31, through the gap between the substrates 32 and 42 at the opening 39 of the magnetic core 31, into the cavity inside the magnetic core 31, and then through the opening 38 of the magnetic core 31A towards the rotating body 50, as indicated by the arrows in Figure 10. Additionally, as indicated by the arrows in Figure 10, air is guided from between the magnetic core 31A and the blower mechanism 60 to near the shaft 24 and flows towards the rotating body 50. Near the rotating body 50, the air flows away from the shaft 24. Consequently, in the power transmission device 20, air heated by the heat generation flows near the substrate 32 of the stator 30, near the substrate 42 of the rotor 40, and near the rotating body 50. As a result, the power transmission device 20 can dissipate heat.

[0055] The power transmission device 20 includes a shaft 24 rotatable around a rotation axis AZ, a stator 30 spaced apart from the shaft 24 and having a first winding (winding 33) wound around the shaft 24, a rotor 40 connected to the shaft 24 and rotatable around the shaft 24 and having a second winding (winding 43) wound around the shaft 24, a rotating body 50 connected to the shaft 24 at a position different from the position where the rotor 40 is installed in the axial direction of the shaft 24, rotatable around the shaft 24 and having a rectifier element (diode D) connected to the second winding (winding 43), and a blowing mechanism 60 provided on the shaft 24 or the rotating body 50, capable of blowing air as the shaft 24 rotates and dissipating heat from one or more of the stator 30, rotor 40, and rotating body 50. As a result, the power transmission device 20 allows the blowing mechanism 60 to blow air in accordance with the rotation of the shaft 24. As a result, the power transmission device 20 can dissipate heat more easily.

[0056] Furthermore, in the power transmission device 20, the blower mechanism 60 is provided between the stator 30 and rotor 40 and the rotating body 50 on the shaft 24, and has a first blade (blade 61) having a surface that is inclined in the circumferential direction with respect to a plane intersecting the shaft 24 (e.g., the XY plane). As a result, in the power transmission device 20, the blower mechanism 60 can blow air in the axial direction of the rotation axis AZ in accordance with the rotation of the shaft 24, so that, for example, air can be blown toward the rotating body 50. Consequently, the power transmission device 20 can dissipate heat more easily.

[0057] Furthermore, in the power transmission device 20, the rotor 40, the first winding (winding 33), and the rotating body 50 are arranged in this order in the axial direction of the shaft 24, and the stator 30 further includes a magnetic core 31 that surrounds the first winding (winding 33) and the rotor 40. The magnetic core 31 has a first opening (opening 38) provided in the portion through which the shaft 24 passes between the first winding (winding 33) and the rotating body 50, and a second opening (opening 39) provided on a part of its outer circumferential surface. As a result, for example, air flows from outside the magnetic core 31, through the space between the substrate 32 and the substrate 42 at the opening 39 of the magnetic core 31, into the cavity inside the magnetic core 31, and then flows towards the rotating body 50 through the opening 38 of the magnetic core 31A, as shown in Figure 10. As a result, air heated by the heat generated flows near the substrate 32 of the stator 30 and near the substrate 42 of the rotor 40. Consequently, the power transmission device 20 can dissipate heat more easily.

[0058] [effect] 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 and having a second winding wound in the circumferential direction of the shaft, a rotating body connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is installed, rotatable in the circumferential direction of the shaft and having a rectifier element connected to the second winding, and a blowing mechanism provided on the shaft or rotating body that can blow air as the shaft rotates and can dissipate heat from one or more of the stator, rotor, and rotating body, thus making heat dissipation easier.

[0059] In this embodiment, the blower mechanism is provided between the stator and rotor on the shaft and the rotating body, and has a first blade having a surface that is inclined in the circumferential direction with respect to the surface that intersects the shaft, thereby facilitating heat dissipation.

[0060] In this embodiment, the rotor, the first winding, and the rotating body are arranged in this order in the axial direction of the shaft, and the stator further includes a magnetic core that surrounds the first winding and the rotor. The magnetic core has a first opening provided in the portion through which the shaft passes between the first winding and the rotating body, and a second opening provided on a part of its outer circumferential surface, thereby facilitating heat dissipation.

[0061] [Variation 1-1] In the above embodiment, the blower mechanism 60 is configured to blow air from the stator 30 and rotor 40 toward the rotating body 50, but it is not limited to this. Alternatively, the blower mechanism 60 may blow air from the rotating body 50 toward the stator 30 and rotor 40. Specifically, for example, the direction of airflow can be set by changing the inclination of the blades 61. Even in this case, since air heated by heat generation can be blown, heat dissipation can be made easier.

[0062] [Variation 1-2] In the above embodiment, the blades 61 of the blower mechanism 60 have the shape shown in Figures 4 and 8, but are not limited to this, and may have any shape as long as they can blow air. For example, as shown in Figure 11, the blower mechanism 60 may have blades 62 that have a helical shape centered on the shaft 24. These blades 62 have surfaces that are inclined in the circumferential direction with respect to the XY plane (plane W2 in Figure 11). As a result, the blower mechanism 60 according to this modified example can blow air onto the rotating body 50 by rotating the shaft 24 in the circumferential direction A around the rotation axis AZ.

[0063] [Modifications 1-3] In the above embodiment, the blower mechanism 60 has blades 61, but it is not limited to this. Alternatively, for example, as shown in Figure 12, the blower mechanism 60 may have grooves 63 provided on the shaft 24, which are helically provided on the surface of the shaft 24. The cross-sectional shape of the grooves 63 may be, for example, rectangular, trapezoidal, or triangular. As a result, the blower mechanism 60 according to this modified example can blow air onto the rotating body 50 by rotating the shaft 24 in the circumferential direction A about the rotation axis AZ.

[0064] [Modifications 1-4] In the above embodiment, the blower mechanism 60 is provided on the shaft 24, but it is not limited to this. Alternatively, for example, as shown in Figures 13 and 14, the blower mechanism 60 may be provided on the support portion 51 of the rotating body 50. In this example, the blower mechanism 60 has eight blades 64. The eight blades 64 are provided on the surface of the support portion 51 facing the magnetic core 31, and are arranged at equal intervals in the circumferential direction of the rotation axis AZ on this surface. The blades 64 have an arc shape on the surface intersecting the rotation axis AZ. Here, the blades 64 correspond to one specific example of the "second blade" in one embodiment of the present disclosure. In this modified example, the blower mechanism 60 can blow air near the shaft 24 away from the shaft 24 by rotating the shaft 24 in the circumferential direction A about the rotation axis AZ.

[0065] Furthermore, as shown in Figures 15 and 16, for example, instead of providing blades, an uneven surface may be provided on the surface of the support portion 51. In this example, the blower mechanism 60 has convex portions 65 and concave portions 66 that are alternately provided in the circumferential direction of the rotation axis AZ. The convex portions 65 have surfaces that are inclined in the circumferential direction with respect to the XY plane. Here, the convex portions 65 and concave portions 66 correspond to a specific example of the "uneven structure" in one embodiment of the present disclosure. In this modified blower mechanism 60, the shaft 24 rotates in the circumferential direction A about the rotation axis AZ, thereby allowing air to flow from the rotating body 50 toward the stator 30 and rotor 40.

[0066] [Variations 1-5] In the above embodiment, the blower mechanism 60 is provided between the rotating body 50 and the stator 30 and rotor 40, but it is not limited to this. Alternatively, for example, as shown in Figure 17, the blower mechanism 60 may be provided in the opposite direction to the direction in which the stator 30 and rotor 40 are provided, with respect to the rotating body 50. The blower mechanism 60 according to this modified example has four blades 67, as shown in Figure 17. The four blades 67 are arranged at equal intervals on the surface of the shaft 24 in the circumferential direction of the rotation axis AZ. The blades 67 have surfaces that are inclined in the circumferential direction with respect to the XY plane. Here, the blades 67 correspond to one specific example of the "third blade" in one embodiment of the present disclosure. The blower mechanism 60 according to this modified example can blow air from the rotating body 50 in the direction opposite to the Z direction by rotating the shaft 24 in the circumferential direction A about the rotation axis AZ, as shown by the arrow in Figure 18. In this example, the air is flowed from the rotating body 50 in the opposite direction to the Z direction, but this is not the only option. Alternatively, for example, the air may be flowed from the opposite direction to the Z direction towards the rotating body 50.

[0067] [Other variations] Furthermore, two or more of these variations may be combined.

[0068] <2. Second Embodiment> Next, a motor device 2 according to a second embodiment will be described. In this embodiment, the stator and rotor differ from those of the first embodiment described above. The other configurations are the same as those of the first embodiment described above. Components that are substantially the same as those of the motor device 1 according to the first embodiment are denoted by the same reference numerals, and their descriptions are omitted as appropriate.

[0069] Figure 19 shows an example configuration of the motor device 2 according to this embodiment. The motor device 1 comprises a drive unit 110 and a motor 70. The drive unit 110 has a power transmission device 120. The power transmission device 120 has a stator 130 and a rotor 140.

[0070] Figures 20 and 21 show an example configuration of the power transmission device 120. Figure 22 shows an example configuration of the stator 130 and rotor 140. Figure 23 shows an example of the cross-sectional structure of the power transmission device 120 in the plane including the rotation axis AZ.

[0071] The stator 130 is fixed to a housing (not shown) of the motor device 2. As shown in Figures 20-23, the stator 130 has a magnetic core 131 and windings 133.

[0072] As shown in Figures 20 and 22, the magnetic core 131 has a ring shape and is provided in a plane intersecting the rotation axis AZ, surrounding the rotation axis AZ. The magnetic core 131 has groove-shaped recesses 131A along the circumferential direction on the plane S131 (Figures 22 and 23) facing the rotation axis AZ.

[0073] As shown in Figure 23, the winding 133 is wound multiple times along the recess 131A of the magnetic core 131. The winding 133 is connected to the inverter 12.

[0074] The rotor 140 is connected to the shaft 24 and configured to rotate about the rotation axis AZ. The rotor 140 is located radially on the shaft 24, between the stator 130 and the shaft 24. The rotor 140 has a magnetic core 141 and windings 143.

[0075] As shown in Figure 22, the magnetic core 141 has a ring shape and is provided in a plane intersecting the rotation axis AZ, surrounding the rotation axis AZ. On the plane S141 (Figures 22, 23) away from the rotation axis AZ, the magnetic core 141 is provided with groove-shaped recesses 141A along the circumferential direction.

[0076] As shown in Figure 23, the winding 143 is wound multiple times along the recess 141A of the magnetic core 141. The winding 143 is connected to the rectifier circuit 59.

[0077] The surface S131 of the magnetic core 131 of the stator 130 faces the surface S141 of the magnetic core 141 of the rotor 140. As shown in Figure 23, a gap G is provided between the tips of the two protrusions on both sides of the recess 131A of the magnetic core 131 and the tips of the two protrusions on both sides of the recess 141A of the magnetic core 141. The magnetic cores 131 and 141 are magnetically coupled through this gap G.

[0078] Here, the stator 130 corresponds to a specific example of the "stator" in one embodiment of the present disclosure. The winding 133 corresponds to a specific example of the "first winding" in one embodiment of the present disclosure. The rotor 140 corresponds to a specific example of the "rotor" in one embodiment of the present disclosure. The winding 143 corresponds to a specific example of the "second winding" in one embodiment of the present disclosure. The magnetic core 141 corresponds to a specific example of the "first magnetic core" in one embodiment of the present disclosure. The magnetic core 131 corresponds to a specific example of the "second magnetic core" in one embodiment of the present disclosure.

[0079] Figure 24 illustrates the power transmission operation in the power transmission device 120. The windings 133 of the stator 130 generate a magnetic field based on the AC power supplied from the inverter 12. The magnetic cores 131 and 141 are magnetically coupled to each other via a gap G. As a result, the power transmission device 20 generates a magnetic path MP through the magnetic cores 131 and 141, as shown in Figure 24. The windings 143 of the rotor 140 then generate AC power based on the magnetic field in this magnetic path MP and supply the generated AC power to the rectifier circuit 59. In this way, the power transmission device 120 can supply AC power to the rectifier circuit 59 by contactless transmission.

[0080] Figure 25 illustrates the airflow in the power transmission device 120. As the shaft 24 rotates in the circumferential direction A, the four blades 61 of the blower mechanism 60 rotate in the circumferential direction A around the rotation axis AZ. As a result, air is guided from between the stator 130 and rotor 140 and the blower mechanism 60, as indicated by the arrows in Figure 25, to the vicinity of the shaft 24 and flows towards the rotating body 50. Consequently, in the power transmission device 120, air heated by the heat generated flows near the stator 130, rotor 140, and rotating body 50. As a result, the power transmission device 120 can dissipate heat.

[0081] The power transmission device 120 includes a shaft 24 rotatable around a rotation axis AZ, a stator 130 spaced apart from the shaft 24 and having a first winding (winding 133) wound around the shaft 24, a rotor 140 connected to the shaft 24 and rotatable around the shaft 24 and having a second winding (winding 143) wound around the shaft 24, a rotating body 150 connected to the shaft 24 at a position different from the position where the rotor 140 is installed in the axial direction of the shaft 24, rotatable around the shaft 24 and having a rectifier element (diode D) connected to the second winding (winding 43), and a blowing mechanism 60 provided on the shaft 24 or the rotating body 150, capable of blowing air as the shaft 24 rotates and dissipating heat from one or more of the stator 130, rotor 140, and rotating body 150. As a result, the power transmission device 120 can use the air blowing mechanism 60 to circulate air in accordance with the rotation of the shaft 24. Consequently, the power transmission device 120 can dissipate heat more easily.

[0082] [effect] 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 and having a second winding wound in the circumferential direction of the shaft, a rotating body connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is installed, rotatable in the circumferential direction of the shaft and having a rectifier element connected to the second winding, and a blowing mechanism provided on the shaft or rotating body that can blow air as the shaft rotates and can dissipate heat from one or more of the stator, rotor, and rotating body, thus making heat dissipation easier.

[0083] [Differentiation 2] Modified versions of the first embodiment may be applied to the motor device 2 according to the second embodiment described above.

[0084] Although the present invention has been described above with reference to several embodiments and modifications, the present invention is not limited to these embodiments, and various modifications are possible.

[0085] For example, the arrangement and shape of the stator, rotor, magnetic core, substrate, and windings shown in the above embodiments are examples only and are not limited to the disclosed arrangements and shapes.

[0086] 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.

[0087] Furthermore, this disclosure may take the following forms:

[0088] (1) A shaft that can rotate around a rotation axis, A stator provided spaced apart from the shaft and having a first winding wound in the 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 in the circumferential direction of the shaft, A rotating body having a rectifier element connected to the second winding is connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is provided, and is rotatable in the circumferential direction of the shaft. A blowing mechanism provided on the shaft or the rotating body, capable of blowing air as the shaft rotates, and capable of dissipating heat from one or more of the stator, rotor, and rotating body. A power transmission device equipped with the following features. (2) The blowing mechanism has a first blade provided between the stator and rotor and the rotating body on the shaft, and having a surface that is inclined in the circumferential direction with respect to the surface that intersects the shaft. The power transmission device described in (1) above. (3) The first blade includes a plurality of blades provided in the circumferential direction of the shaft. The power transmission device described in (2) above. (4) The first blade has a helical shape centered on the shaft. The power transmission device described in (2) above. (5) The blowing mechanism is provided between the stator and rotor and the rotating body on the shaft, and has a helical groove provided on the surface of the shaft. A power transmission device as described in any of (1) to (4) above. (6) The blowing mechanism has a second blade provided on the rotating body on the surface in the direction in which the stator and rotor are provided. A power transmission device as described in any of (1) to (5) above. (7) The blowing mechanism has an uneven structure provided on the surface of the rotating body in the direction in which the stator and rotor are provided, and having a surface that is inclined in the circumferential direction with respect to the surface of the shaft that intersects the axial direction. A power transmission device as described in any of (1) to (5) above. (8) The blowing mechanism has a third blade that is provided on the shaft in a direction opposite to the direction in which the stator and rotor are provided, with respect to the rotating body, and has a surface that is inclined in the circumferential direction with respect to the surface that intersects the shaft. A power transmission device as described in any of (1) to (7) above. (9) In the axial direction of the shaft, the rotor, the first winding, and the rotating body are arranged in this order. The stator further comprises a magnetic core provided so as to surround the first winding and the rotor, The aforementioned magnetic core is A first opening is provided in the portion through which the shaft passes between the first winding and the rotating body, A second opening is provided on a part of the outer surface away from the shaft, and has A power transmission device as described in any of (1) to (9) above. (10) The stator and the rotor are provided at the same positions relative to each other in the axial direction of the shaft. The stator is provided on the outer side of the rotor in the radial direction of the shaft. The rotor further comprises a first magnetic core provided such that it surrounds the second winding in the radial direction of the shaft from a direction close to the shaft, The stator further comprises a second magnetic core provided such that it surrounds the first winding in the radial direction of the shaft from a direction away from the shaft. A power transmission device as described in any of (1) to (9) above. (11) A motor having a motor stator including a first motor magnetic core and a first motor winding, and a motor rotor including a second motor magnetic core and a second motor winding, A shaft connected to the motor rotor and capable of rotating around the axis of rotation, A stator provided spaced apart from the shaft and having a first winding wound in the 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 in the circumferential direction of the shaft, A rotating body having a rectifier element connected to the second winding is connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is provided, and is rotatable in the circumferential direction of the shaft. A blowing mechanism provided on the shaft or the rotating body, capable of blowing air as the shaft rotates, and capable of dissipating heat from one or more of the stator, rotor, and rotating body. A motor device equipped with a motor. [Explanation of Symbols]

[0089] 1,2…Motor unit, 8…External control device, 9…DC power supply, 10…Drive unit, 11…Inverter, 12…Inverter, 18…Switching control circuit, 19…Control circuit, 20…Power transmission device, 24…Shaft, 30…Stator, 31,31A,31B…Magnetic core, 31C…Protrusion, 31D…Protrusion, 32…Substrate, 33…Winding, 38,39…Opening, 40…Rotor, 41…Winding, 42…Substrate, 43…Winding, 50…Rotating body, 51…Support part, 52…Substrate, 59…Rectifier circuit, 60…Blower mechanism, 61…Blade, 62…Blade, 63…Groove, 64…Blade, 65…Protrusion, 66…Concave, 67…Blade, 70… Motor, 71...stator, 71A...magnetic core, 71B...winding, 72...rotor, 72A...magnetic core, 72B...winding, 73...sensor, 110...drive unit, 120...power transmission device, 130...stator, 131...magnetic core, 131A...recess, 133...winding, 140...rotor, 141...magnetic core, 141A...recess, 143...winding, 150...rotating body, A...circumferential direction, AZ...rotating axis, D, D1~D4...diode, G...gap, L11...voltage line, L12...reference voltage line, L21...voltage line, L22...reference voltage line, MP...magnetic path, S131...plane, S141...plane, SW1~SW4...switching element.

Claims

1. A shaft that can rotate around a rotation axis, A stator provided spaced apart from the shaft and having a first winding wound in the 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 in the circumferential direction of the shaft, A rotating body is connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is provided, and is rotatable in the circumferential direction of the shaft, and has a rectifier element connected to the second winding, A blowing mechanism provided on the shaft or the rotating body, capable of blowing air as the shaft rotates, and capable of dissipating heat from one or more of the stator, rotor, and rotating body. A power transmission device equipped with the following features.

2. The blowing mechanism is provided between the stator and rotor and the rotating body on the shaft, and has a first blade having a surface that is inclined in the circumferential direction with respect to the surface that intersects the shaft. The power transmission device according to claim 1.

3. The first blade includes a plurality of blades provided in the circumferential direction of the shaft. The power transmission device according to claim 2.

4. The first blade has a helical shape centered on the shaft. The power transmission device according to claim 2.

5. The blowing mechanism is provided between the stator and rotor and the rotating body on the shaft, and has a helical groove provided on the surface of the shaft. The power transmission device according to claim 1.

6. The blowing mechanism has a second blade provided on the rotating body on the surface in the direction in which the stator and rotor are provided. The power transmission device according to claim 1.

7. The blowing mechanism has an uneven structure provided on the surface of the rotating body in the direction in which the stator and rotor are provided, and having a surface that is inclined in the circumferential direction with respect to the surface of the shaft that intersects the axial direction. The power transmission device according to claim 1.

8. The blowing mechanism has a third blade that is provided on the shaft in a direction opposite to the direction in which the stator and rotor are provided, with respect to the rotating body, and has a surface that is inclined in the circumferential direction with respect to the surface that intersects the shaft. The power transmission device according to claim 1.

9. In the axial direction of the shaft, the rotor, the first winding, and the rotating body are arranged in this order. The stator further comprises a magnetic core provided so as to surround the first winding and the rotor, The aforementioned magnetic core is A first opening is provided in the portion through which the shaft passes between the first winding and the rotating body, A second opening is provided on a part of the outer surface away from the shaft, and has The power transmission device according to claim 1.

10. The stator and the rotor are provided at the same positions relative to each other in the axial direction of the shaft. The stator is provided on the outer side of the rotor in the radial direction of the shaft. The rotor further comprises a first magnetic core provided such that it surrounds the second winding in the radial direction of the shaft from a direction close to the shaft, The stator further comprises a second magnetic core provided such that it surrounds the first winding in the radial direction of the shaft from a direction away from the shaft. The power transmission device according to claim 1.

11. A motor having a motor stator including a first motor magnetic core and a first motor winding, and a motor rotor including a second motor magnetic core and a second motor winding, A shaft connected to the motor rotor and capable of rotating around the axis of rotation, A stator provided spaced apart from the shaft and having a first winding wound in the 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 in the circumferential direction of the shaft, A rotating body is connected to the shaft at a position in the axial direction of the shaft different from the position where the rotor is provided, and is rotatable in the circumferential direction of the shaft, and has a rectifier element connected to the second winding, A blowing mechanism provided on the shaft or the rotating body, capable of blowing air as the shaft rotates, and capable of dissipating heat from one or more of the stator, rotor, and rotating body. A motor device equipped with a motor.

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