Power transmission device and motor apparatus

Abstract

A power transmission device according to one embodiment of the present invention is provided with a magnetic core, a first winding, a rotating member, and a second winding. The magnetic core has an annular shape including a through hole through which the shaft passes, includes a cavity therein along the circumferential direction of the rotation axis of the shaft, and has an opening portion with respect to the cavity, and the opening portion is provided along the circumferential direction on a surface different from a surface in contact with the through hole. The first winding is disposed in the cavity and wound in a circumferential direction. The rotating member is connected to the shaft through the opening portion, and is rotatable in the circumferential direction inside the cavity in accordance with rotation of the shaft. The second winding is provided on the rotating member and wound in a circumferential direction.

Description

Technical Field

[0001] The present invention relates to a power transmission device for contactlessly transmitting electric power and a motor device provided with such a power transmission device. Background Art

[0002] For example, the electric motor can be an electrically excited synchronous motor (EESM). This type of motor has a stator with windings and a rotor with windings. In such a motor, the efficiency of the motor can be improved by varying the current flowing through the windings wound around the rotor according to the motor's rotational speed.

[0003] However, there are devices that can transmit power between a stator and a rotor. For example, Patent Document 1 discloses a rotary transformer that includes a stator with a winding wound thereon and a rotor with a winding wound thereon, and that can transmit power between the stator and the rotor. [Prior art literature] [Patent Document]

[0004] Patent Document 1: Japanese Patent Application Laid-Open No. 2002-75760 Summary of the Invention

[0005] In electric motor devices, high motor efficiency is desired, and further improvement of the motor efficiency is also desired.

[0006] It is desirable to provide a power transmission device and a motor apparatus capable of improving the efficiency of a motor.

[0007] A power transmission device according to one embodiment of the present invention includes a magnetic core, a first winding, a rotating member, and a second winding. The magnetic core is annular, including a through-hole through which a shaft passes. The core includes a cavity circumferentially extending along the axis of rotation of the shaft. The cavity has an opening, which is circumferentially disposed on a surface different from the surface in contact with the through-hole. The first winding is disposed in the cavity and wound circumferentially. The rotating member is connected to the shaft via the opening and can rotate circumferentially within the cavity in response to the shaft's rotation. The second winding is disposed on the rotating member and wound circumferentially.

[0008] An electric motor device according to one embodiment of the present invention comprises an electric motor, a shaft, an inverter, a magnetic core, a first winding, a rotating member, a second winding, and a rectifier circuit. The electric motor comprises a motor stator and a motor rotor, the motor stator comprising a first motor magnetic core and a first motor winding, and the motor rotor comprising a second motor magnetic core and a second motor winding. The shaft is connected to the motor rotor. The magnetic core is annular and includes a through hole for the shaft to pass through, and includes a cavity in its interior along the circumference of the rotation axis of the shaft, and has an opening relative to the cavity, the opening being circumferentially arranged on a surface different from the surface in contact with the through hole. The first winding is connected to the inverter, arranged in the cavity, and wound circumferentially. The rotating member is connected to the shaft through the opening and can rotate circumferentially inside the cavity in response to the rotation of the shaft. The second winding is arranged on the rotating member and wound circumferentially. The rectifier circuit is arranged on a path connecting the second winding and the second motor winding.

[0009] According to the power transmission device and the motor apparatus according to one embodiment of the present invention, the efficiency of the motor can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] [ Figure 1 ] Figure 1 This is a block diagram showing a configuration example of a motor device according to the first embodiment of the present invention. [ Figure 2 ] Figure 2 Yes Figure 1 A perspective view of a structural example of a power transmission device shown. [ Figure 3 ] Figure 3 Yes Figure 2 1 is an explanatory diagram of a configuration example of a power transmission device shown. [ Figure 4 ] Figure 4 Yes Figure 2 A cross-sectional view of a structural example of a power transmission device shown. [ Figure 5 ] Figure 5 Yes Figure 4 An explanatory diagram of a structural example of a stator shown. [ Figure 6 ] Figure 6 Yes Figure 4 An explanatory diagram of a structural example of a rotor shown. [ Figure 7 ] Figure 7 Yes Figure 4 1 is an explanatory diagram of an operation example of the power transmission device shown. [ Figure 8 ] Figure 8 Yes Figure 4An explanatory diagram of an example of magnetic flux of a power transmission device shown. [ Figure 9 ] Figure 9 This is an explanatory diagram showing an example of magnetic flux of a power transmission device according to a reference example. [ Figure 10 ] Figure 10 This is a cross-sectional view showing a configuration example of a power transmission device according to a modification of the first embodiment. [ Figure 11 ] Figure 11 It is a perspective view showing a configuration example of a power transmission device according to another modified example of the first embodiment. [ Figure 12 ] Figure 12 Yes Figure 11 1 is an explanatory diagram of a configuration example of a power transmission device shown. [ Figure 13 ] Figure 13 Yes Figure 11 A cross-sectional view of a structural example of a power transmission device shown. [ Figure 14 ] Figure 14 Yes Figure 13 An explanatory diagram of a structural example of a stator shown. [ Figure 15 ] Figure 15 Yes Figure 13 An explanatory diagram of a structural example of a rotor shown. [ Figure 16 ] Figure 16 It is a cross-sectional view showing a configuration example of a power transmission device according to another modified example of the first embodiment. [ Figure 17 ] Figure 17 This is a block diagram showing a configuration example of a motor device according to a second embodiment. [ Figure 18 ] Figure 18 Yes Figure 17 A perspective view of a structural example of a power transmission device shown. [ Figure 19 ] Figure 19 Yes Figure 17 A cross-sectional view of a structural example of a power transmission device shown. [ Figure 20 ] Figure 20 Yes Figure 19 An explanatory diagram of a structural example of a stator shown. [ Figure 21 ] Figure 21 Yes Figure 19 An explanatory diagram of a structural example of a rotor shown. [ Figure 22] Figure 22 Yes Figure 19 1 is an explanatory diagram of an example of a manufacturing process of a power transmission device shown in FIG. [ Figure 23 ] Figure 23 It is a cross-sectional view showing a configuration example of a power transmission device according to a modification of the second embodiment. [ Figure 24 ] Figure 24 It is a perspective view showing a configuration example of a power transmission device according to another modified example of the second embodiment. [ Figure 25 ] Figure 25 Yes Figure 24 A cross-sectional view of a structural example of a power transmission device shown. [ Figure 26 ] Figure 26 Yes Figure 25 An explanatory diagram of a structural example of a stator shown. [ Figure 27 ] Figure 27 Yes Figure 25 An explanatory diagram of a structural example of a rotor shown. [ Figure 28 ] Figure 28 It is a cross-sectional view showing a configuration example of a power transmission device according to another modified example of the second embodiment. [ Figure 29 ] Figure 29 It is a cross-sectional view showing a configuration example of a power transmission device according to another modified example of the second embodiment. [ Figure 30 ] Figure 30 It is a cross-sectional view showing a configuration example of a power transmission device according to another modified example of the second embodiment. DETAILED DESCRIPTION

[0011] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. 1. First Implementation 2. Second Implementation

[0012] <First embodiment> [Structure example] Figure 1This figure shows an example configuration of a motor device 1 equipped with a power transmission device according to a 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 a 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 mechanical energy, or driving force, using the DC power supplied by the DC power supply 9 in accordance with instructions from the external control device 8. The motor device 1 includes a drive unit 10 and a motor 30.

[0013] The drive unit 10 is configured to drive the electric motor 30 . The drive unit 10 includes inverters 11 and 12 , a power transmission device 20 , a rectifier circuit 14 , and a control circuit 19 .

[0014] The inverter 11 is configured to convert the DC power supplied by the DC power supply 9 into three-phase (U-phase, V-phase, and W-phase) AC power in accordance with instructions from the control circuit 19. Furthermore, the inverter 11 supplies this three-phase AC power to the windings 31B (described later) of the stator 31 of the motor 30.

[0015] Inverter 12 is configured to convert DC power supplied from DC power source 9 into single-phase AC power according to instructions from control circuit 19. Inverter 12 also supplies this AC power to winding 21B of stator 21 of power transmission device 20 (described later).

[0016] The power transmission device 20 is configured to supply AC power to the rectifier circuit 14 by contactless transmission. The power transmission device 20 includes a stator 21 , a rotor 22 , and a shaft 24 .

[0017] Figure 2 ,3 shows a structural example of the power transmission device 20. Figure 4 An example of a cross-sectional structure of the power transmission device 20 in a plane including the rotation axis AZ is shown. Figure 5 : shows a structural example of the stator 21. Figure 5 , a cross-sectional structure of the stator 21 in a plane including the rotation axis AZ in the VV arrow direction is also depicted. Figure 6 1 shows an example of the structure of the rotor 22. Figure 6 , a cross-sectional structure of the rotor 22 in a plane including the rotation axis AZ in the direction of arrows VI-VI is also depicted.

[0018] The stator 21 is a so-called stator, and is fixed to a housing (not shown) of the motor device 1. Figures 3-5 As shown, there is a magnetic core 21A and a winding 21B.

[0019] The magnetic core 21A is made of a magnetic material such as ferrite. The magnetic core 21A is an annular magnetic component having a through hole 120 for the shaft 24 to pass through. The magnetic core 21A includes a magnetic core 21A1 and a magnetic core 21A2. The magnetic core 21A1 mainly constitutes the outer peripheral portion of the magnetic core 21A, and has a shape bent toward the rotation axis AZ at the end in the direction opposite to the Z direction. Here, the Z direction is the extension direction of the rotation axis AZ, and is the direction from the motor 30 toward the power transmission device 20. The magnetic core 21A2 mainly constitutes the inner peripheral portion of the magnetic core 21A, and has a shape bent away from the rotation axis AZ at the end in the Z direction. The end in the Z direction of the magnetic core 21A1 is connected to the magnetic core 21A2 at the connecting portion 125. With this structure, a cavity 122 ( Figure 5 ), and an opening portion 123 relative to the cavity 122 is provided on a surface in a direction opposite to the Z direction.

[0020] Winding 21B is wound multiple times along circumferential direction A on a surface of core 21A2 that faces core 21A1 and forms the outer periphery of core 21A. Winding 21B is connected to inverter 12 through, for example, a hole (not shown) provided in core 21A1 or core 21A2.

[0021] The rotor 22 is a so-called rotor, and is configured to rotate around the rotation axis AZ. The rotor 22 is arranged in the radial direction of the rotation axis AZ ( Figure 3 The rotor 22 is arranged in the horizontal direction and is fixed on the shaft 24. Figure 3 ,4,6, it has a supporting part 22A and a winding 22B.

[0022] The support member 22A has a generally cylindrical shape, with its end portion in the direction opposite to the Z direction curved toward the shaft 24. The support member 22A is connected to the shaft 24 and rotates about the rotation axis AZ in the circumferential direction A in response to the rotation of the shaft 24. The support member 22A is made of, for example, resin. The surface of the support member 22A facing the magnetic core 21A1 is provided with a convex portion 22C, a convex portion 22D, and a concave portion 22E. The convex portion 22C is provided on the surface of the support member 22A facing the magnetic core 21A1 near the center in the Z direction. The convex portion 22D is provided on the surface facing the magnetic core 21A1 at the end portion in the Z direction. The concave portion 22E is provided on the surface facing the magnetic core 21A1 between the convex portion 22C and the convex portion 22D in the Z direction. During the manufacturing process of the power transmission device 20, the support member 22A serves as a bobbin around which the winding 22B is wound.

[0023] The winding 22B is wound multiple times along the recess 22E of the support member 22A. One end and the other end of the winding 22B are connected to the rectifier circuit 14 via the support member 22A and wiring (not shown) provided on the shaft 24.

[0024] In the manufacturing process of the power transmission device 20, in this example, the magnetic core 21A1, the rotor 22, and the magnetic core 21A2 are arranged in this order in the Z direction so that the magnetic core 21A1, the rotor 22, and the magnetic core 21A2 are close to each other, and the magnetic core 21A1 and the magnetic core 21A2 are bonded to each other at the connecting portion 125, for example.

[0025] In the power transmission device 20, as Figure 3 As shown in FIG. 5 , a gap G is provided between magnetic core 21A1 and magnetic core 21A2 near opening 123. Consequently, in power transmission device 20, magnetic core 21A1 and magnetic core 21A2 are magnetically coupled to each other near opening 123. With this structure, power transmission device 20 converts the AC power supplied from inverter 12 at a ratio corresponding to the number of turns of winding 21B and winding 22B, and supplies the converted AC power to rectifier circuit 14. Power transmission device 20 is also referred to as a rotary transformer.

[0026] The shaft 24 is connected to the rotor 32 of the motor 30 and is configured to rotate about the rotation axis AZ in response to the driving force generated by the motor 30 .

[0027] Rectification circuit 14 ( Figure 1 ) is configured to rectify the AC power supplied from the winding 22B of the rotor 22 and supply the rectified power to the winding 32B of the rotor 32 of the motor 30 (described later). The rectifier circuit 14 is connected to the shaft 24, which is not shown. That is, because the winding 22B and the rotor 32 of the motor 30 are connected to the shaft 24, the rectifier circuit 14 is also connected to the shaft 24. In this example, although the power rectified by the rectifier circuit 14 is directly supplied to the winding 32B, this is not limited to this. As an alternative, for example, the power rectified by the rectifier circuit 14 may be supplied to the winding 32B through a stabilization circuit including a capacitor.

[0028] The control circuit 19 is configured to control the operation of the inverters 11 and 12 based on instructions from the external control device 8 and a control signal indicating the rotational speed supplied from the motor 30. Specifically, the control circuit 19 controls the rotational speed of the motor 30 by controlling the operation of the inverter 11 based on instructions from the external control device 8 and a control signal indicating the rotational speed of the motor 30. Furthermore, the control circuit 19 controls the intensity of the magnetic field generated by the rotor 32 of the motor 30 by controlling the operation of the inverter 12 based on the control signal indicating the rotational speed supplied from the motor 30. Specifically, the control circuit 19 strengthens the magnetic field generated by the rotor 32 of the motor 30 when the rotational speed of the motor 30 is slow, and weakens the magnetic field generated by the rotor 32 of the motor 30 when the rotational speed of the motor 30 is fast.

[0029] The motor 30 is an electrically excited synchronous motor and includes a stator 31 , a rotor 32 , and a sensor 33 .

[0030] Stator 31 is a so-called stator and is fixed to a housing (not shown) of motor 30. Stator 31 includes core 31A and winding 31B. Winding 31B is supplied with three-phase (U-phase, V-phase, W-phase) AC power generated by inverter 11.

[0031] The rotor 32 is a so-called rotor and is configured to rotate about the rotation axis AZ. The rotor 32 includes a core 32A and a winding 32B. A signal rectified by the rectifier circuit 14 is supplied to the winding 32B.

[0032] The sensor 33 is configured to detect the rotation speed of the rotor 32. The sensor 33 also supplies a control signal indicating the rotation speed of the rotor 32 to the control circuit 19.

[0033] With this configuration, in motor device 1, the rotational speed of motor 30 is controlled based on the three-phase (U-phase, V-phase, and W-phase) AC power generated by inverter 11, and the magnetic field generated by rotor 32 of motor 30 is controlled based on the single-phase AC power generated by inverter 12. In motor device 1, for example, when the rotational speed of motor 30 is slow, the magnetic field generated by rotor 32 of motor 30 is strengthened; when the rotational speed of motor 30 is fast, the magnetic field generated by rotor 32 of motor 30 is weakened. Consequently, in motor device 1, the efficiency of motor 30 can be improved over a wide rotational speed range.

[0034] Here, the shaft 24 corresponds to a specific example of the “shaft” of one embodiment of the present disclosure. The rotation axis AZ corresponds to a specific example of the “rotation axis” of one embodiment of the present disclosure. The magnetic core 21A corresponds to a specific example of the “magnetic core” of one embodiment of the present disclosure. The cavity 122 corresponds to a specific example of the “cavity” of one embodiment of the present disclosure. The opening 123 corresponds to a specific example of the “opening” of one embodiment of the present disclosure. The winding 21B corresponds to a specific example of the “first winding” of one embodiment of the present disclosure. The supporting part 22A corresponds to a specific example of the “rotating member” of one embodiment of the present disclosure. The winding 22B corresponds to a specific example of the “second winding” of one embodiment of the present disclosure.

[0035] The stator 31 corresponds to a specific example of a "motor stator" in one embodiment of the present disclosure. The magnetic core 31A corresponds to a specific example of a "first motor magnetic core" in one embodiment of the present disclosure. The winding 31B corresponds to a specific example of a "first motor winding" in one embodiment of the present disclosure. The rotor 32 corresponds to a specific example of a "motor rotor" in one embodiment of the present disclosure. The magnetic core 32A corresponds to a specific example of a "second motor magnetic core" in one embodiment of the present disclosure. The winding 32B corresponds to a specific example of a "second motor winding" in one embodiment of the present disclosure. The inverter 12 corresponds to a specific example of an "inverter" in one embodiment of the present disclosure. The rectifier circuit 14 corresponds to a specific example of a "rectifier circuit" in one embodiment of the present disclosure.

[0036] [Action and Effect] Next, the operation and effect of the motor device 1 according to the present embodiment will be described.

[0037] (Overall action summary) The control circuit 19 controls the operation of the inverters 11 and 12 based on instructions from the external control device 8 and a control signal indicating the rotational speed supplied from the motor 30. In response to instructions from the control circuit 19, the inverter 11 converts the DC power supplied by the DC power supply 9 into three-phase (U-phase, V-phase, and W-phase) AC power and supplies this three-phase AC power to the winding 31B of the stator 31 of the motor 30. In response to instructions from the control circuit 19, the inverter 12 converts the DC power supplied by the DC power supply 9 into single-phase AC power and supplies this AC power to the winding 21B of the stator 21 of the power transmission device 20. The power transmission device 20 supplies the AC power to the rectifier circuit 14 via contactless transmission. The rectifier circuit 14 rectifies the AC power supplied by the winding 22B of the rotor 22 and supplies the rectified power to the winding 32B of the rotor 32 of the motor 30. Motor 30 generates mechanical energy, or driving force, from three-phase (U-phase, V-phase, and W-phase) AC power supplied from inverter 11. This causes shaft 24 to rotate about rotation axis AZ. A sensor 33 of motor 30 provides a control signal indicating the rotational speed of motor 30 to control circuit 19.

[0038] [Action and Effect] Next, the operation and effect of the power transmission device 20 according to this embodiment will be described.

[0039] AC power is supplied from the inverter 12 to the winding 21B of the stator 21 of the power transmission device 20. The rotor 22 rotates about the rotation axis AZ, for example, along Figure 2 The circumferential direction A of rotation is shown.

[0040] Figure 7 1 shows a cross-sectional view of the stator 21 and the rotor 22 of the power transmission device 20. The winding 21B of the stator 21 generates a magnetic field based on the AC power supplied from the inverter 12. Near the opening 123, the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other.

[0041] Figure 8 An example of the magnetic flux of the opening 123 of the power transmission device 20 is shown. Figure 7 In the figure, a portion of the power transmission device 20 is omitted. Leakage magnetic flux is generated near the opening 123. The direction of this leakage magnetic flux changes depending on the polarity of the AC power. In this example, leakage magnetic flux is generated near the opening 123 from the magnetic core 21A2 toward the magnetic core 21A1. Thus, near the opening 123, the magnetic cores 21A1 and 21A2 are magnetically coupled to each other.

[0042] Thus, in the power transmission device 20, as shown in FIG. Figure 7 As shown, a magnetic path MP is generated through the magnetic core 21A1 and the magnetic core 21A2.

[0043] The winding 22B of the rotor 22 generates AC power based on the magnetic field of the magnetic circuit MP and supplies the generated AC power to the rectifier circuit 14. In this way, the power transmission device 20 can supply AC power to the rectifier circuit 14 through contactless transmission.

[0044] As described above, in the power transmission device 20 , since power is transmitted by non-contact transmission, reliability can be improved compared to a case where power is transmitted by contact transmission using, for example, a slip ring and a brush.

[0045] Rectifier circuit 14 rectifies the AC power supplied from winding 22B of rotor 22 and supplies the rectified power to winding 32B of rotor 32 of motor 30. This generates a magnetic field in rotor 32 of motor 30. For example, control circuit 19 strengthens the magnetic field generated by rotor 32 of motor 30 when the rotation speed of motor 30 is slow, and weakens the magnetic field generated by rotor 32 of motor 30 when the rotation speed of motor 30 is fast. Consequently, motor device 1 can improve the efficiency of motor 30 over a wide rotation speed range.

[0046] As described above, in power transmission device 20, rotor 22 is constructed using support member 22A provided with winding 22B. This reduces the weight of rotor 22, compared to, for example, a rotor core as in Patent Document 1, thereby reducing rotational torque and inertia.

[0047] Furthermore, in the power transmission device 20 , since the opening 123 is provided on the surface of the magnetic core 21A opposite to the Z direction, the possibility of leakage magnetic flux entering the shaft 24 when it spreads through the opening 123 can be reduced.

[0048] That is to say, if Figure 9 As shown, when the opening 123 is provided on the surface of the magnetic core 21A that contacts the through hole 120, the leakage magnetic flux may be in the radial direction ( Figure 9 If the leakage magnetic flux enters the shaft 24, eddy currents are generated in the shaft 24, resulting in energy loss.

[0049] On the other hand, in power transmission device 20, because opening 123 is provided on a surface of magnetic core 21A different from the surface in contact with through-hole 120, the possibility of leakage flux entering shaft 24 when it spreads near opening 123 is reduced. Consequently, power transmission device 20 can reduce energy loss and improve motor efficiency.

[0050] As described above, the power transmission device 20 includes a magnetic core 21A, a first winding (winding 21B), a support member 22A, and a second winding (winding 22B). The magnetic core 21A has a ring shape including a through-hole 120 through which the shaft 24 passes. It contains a cavity 122 along the circumferential direction A of the rotation axis AZ of the shaft 24. The cavity 122 has an opening 123, which is located on a surface different from the surface in contact with the through-hole 120. The winding 21B is disposed within the cavity 122 and wound along the circumferential direction A. The support member 22A is connected to the shaft 24 via the opening 123 and can rotate within the cavity 122 along the circumferential direction A in response to the rotation of the shaft 24. The winding 22B is disposed on the support member 22A and wound along the circumferential direction A. This reduces the possibility of leakage magnetic flux from the vicinity of the opening 123 entering the shaft 24. As a result, in the power transmission device 20 , energy loss can be reduced and the efficiency of the electric motor can be improved.

[0051] Furthermore, in the power transmission device 20, the support member 22A has a first recess (recess 22E) provided along the circumferential direction A on the surface opposite to the surface in the direction of the rotation axis AZ. The second winding (winding 22B) is wound in the first recess (recess 22E) of the support member 22A. This simplifies the manufacturing process, for example, by using the support member 22A as a bobbin to wind the winding 22B around it.

[0052] Furthermore, in the power transmission device 20, the opening 123 is provided on the surface of the magnetic core 21A that intersects the rotation axis AZ. This reduces the likelihood of leakage magnetic flux from the vicinity of the opening 123 entering the shaft 24, thereby improving the efficiency of the motor. Furthermore, compared to, for example, providing the opening 123 on the surface of the magnetic core 21A opposite to the surface where the through-hole 120 is provided, it is easier to connect the support member 22A to the shaft 24.

[0053] [Effect] As described above, in this embodiment, there are provided a magnetic core, a first winding, a supporting member, and a second winding. The magnetic core is in the shape of a ring including a through hole for the shaft to pass through, and contains a cavity in the interior thereof along the circumferential direction of the rotation axis of the shaft, and has an opening relative to the cavity, and the opening is circumferentially arranged on a surface different from the surface in contact with the through hole. The first winding is arranged in the cavity and is wound circumferentially. The supporting member is connected to the shaft through the opening and can rotate circumferentially inside the cavity in response to the rotation of the shaft. The second winding is arranged on the supporting member and is wound circumferentially. Therefore, the efficiency of the motor can be improved.

[0054] In this embodiment, the support member has the first recess provided along the circumferential direction on the surface opposite to the surface in which the rotation axis is provided, and the second winding is wound in the first recess of the support member, so that the manufacturing process can be simplified.

[0055] In this embodiment, since the opening is provided on the surface of the core intersecting the rotating shaft, the efficiency of the motor can be improved and the support member can be easily connected to the shaft.

[0056] [Variation 1-1] In the above embodiment, if Figure 4 5, the winding 21B is wound multiple times along the circumferential direction A on the surface of the core 21A2 that is opposite to the core 21A1 in the portion constituting the outer periphery of the core 21A. Figure 10 As shown, stator 21 is provided with a support member 21C, and winding 21B is wound multiple times around this support member 21C. Like support member 22A, support member 21C has a recess 21E on the surface facing magnetic core 21A1, along which winding 21B is wound multiple times. Support member 21C is made of, for example, resin. During the manufacturing process of power transmission device 20, support member 21C serves as a bobbin around which winding 21B is wound.

[0057] [Variation 1-2] In the above embodiment, although Figure 3 As shown in FIG, the support member 22A itself is connected to the shaft 24, but the present invention is not limited thereto, and instead, the support member 22A may be connected to the shaft 24 via another member. This modification will be described in detail below.

[0058] Figure 11 , 12 shows a structural example of the power transmission device 20 of this modification. Figure 13 An example of a cross-sectional structure of the power transmission device 20 in a plane including the rotation axis AZ is shown. Figure 14 One structural example of the stator 21 is shown. Figure 15 FIG. 2 shows a configuration example of the rotor 22 . The power transmission device 20 includes a stator 21 , a rotor 22 , and a connection member 23 .

[0059] Stator 21 Figure 11 , as shown in FIG12, there is a magnetic core 21A. The magnetic core 21A includes a magnetic core 21A1 and a magnetic core 21A2. The magnetic core 21A1 mainly constitutes the outer peripheral portion of the magnetic core 21A. The magnetic core 21A2 mainly constitutes the inner peripheral portion of the magnetic core 21A. In this embodiment, the magnetic core 21A1 and the magnetic core 21A2 are different from those in the above embodiment ( Figure 3) are different and are not connected to each other. In this case, a cavity 122 ( Figure 12 ) In addition, in the magnetic core 21A, an opening 123 is provided on the surface in the direction opposite to the Z direction, facing the cavity 122; and an opening 124 is provided on the surface in the Z direction, facing the cavity 122.

[0060] The rotor 22 is as follows Figure 12 , 13, and 15 , a support member 22A is provided. The support member 22A has a generally cylindrical shape. The support member 22A is connected to the shaft 24 via a connecting member 23 and rotates along the circumferential direction A about the rotation axis AZ in response to the rotation of the shaft 24. The support member 22A is made of, for example, resin. A recess 22E is provided on the surface of the support member 22A facing the magnetic core 21A1. During the manufacturing process of the power transmission device 20, the support member 22A is used as a bobbin around which the winding 22B is wound.

[0061] The connecting member 23 is, for example, a printed circuit board (PCB). It is connected to the shaft 24 and to the support member 22A of the rotor 22. In this example, the rectifier circuit 14 is provided on a portion of the Z-direction surface of the connecting member 23. This rectifier circuit 14 is connected to the winding 22B of the rotor 22 via the connecting member 23 and the support member 22A of the rotor 22.

[0062] In this example, the power transmission device 20 includes the stator 21, the rotor 22, and the connecting member 23, but the present invention is not limited thereto. Figure 16 As shown, a heat sink 25 is further provided. In this example, the heat sink 25 is provided on the surface of the connecting member 23 in the direction opposite to the Z direction. The heat sink 25 dissipates the heat generated in the winding 22B and the rectifier circuit 14.

[0063] [Other modifications] Furthermore, two or more of these modified examples may be combined.

[0064] <2. Second embodiment> Next, a motor device 2 according to a second embodiment will be described. The configuration of the power transmission device in this embodiment differs from that of the first embodiment. Components substantially identical to 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.

[0065] Figure 17A configuration example of the motor device 2 according to the second embodiment is shown. The motor device 2 includes a drive unit 40 and a motor 30. The drive unit 40 includes a power transmission device 50. The power transmission device 50 includes a stator 51, a rotor 52, a connection member 53, and a shaft 24.

[0066] Figure 18 One configuration example of the power transmission device 50 is shown. Figure 19 An example of a cross-sectional structure of the power transmission device 50 in a plane including the rotation axis AZ is shown. Figure 20 One structural example of the stator 51 is shown. Figure 21 One structural example of the rotor 52 is shown.

[0067] Stator 51 Figure 19 , as shown in 20, having a magnetic core 51A and a winding 51B.

[0068] The core 51A is an annular magnetic member having a through hole 150 through which the shaft 24 passes. The core 51A includes a core 51A1 and a core 51A2. The core 51A forms a surface of the core 51A opposite to the Z direction and has a radial direction ( Figure 19 The outer portion of the core 51A1 is bent in the Z direction. Figure 20 As shown, there are magnetic cores 51A11 and 51A12. The magnetic cores 51A11 and 51A12 each have a half-ring shape in a plane intersecting the Z direction, and are connected to the connecting portion 156 ( Figure 20 ) are bonded to each other. The core 51A2 forms the Z-direction surface of the core 51A and has a radial direction ( Figure 19 The outer and inner portions of the core 51A2 are bent in the opposite direction to the Z direction. Figure 19 The portion sandwiched between the outer portion and the inner portion (in the transverse direction) has a recess 151. The core 51A1 and the core 51A2 are bonded to each other at a joint 155 on the outer periphery of the core 51A. With this structure, a cavity 152 ( Figure 20 ), and an opening portion 153 relative to the cavity 152 is provided on a surface in a direction opposite to the Z direction.

[0069] The winding 51B is wound multiple times along the recessed portion 151 of the core 51A2. The winding 51B is connected to the inverter 12 through, for example, a hole (a notch 100 described later) provided in the core 51A2.

[0070] The rotor 52 is arranged in the Z direction so as to be sandwiched between the core 51A1 and the core 51A2 of the stator 51, and is fixed to the shaft 24 via the connecting member 53. Figure 19, as shown in 21, having a substrate 52A and a winding 52B.

[0071] The substrate 52A is, for example, a printed circuit board, and is connected to the shaft 24 via a connecting member 53 , and rotates in the circumferential direction A around the rotation axis AZ in response to the rotation of the shaft 24 .

[0072] The winding 52B is formed by pattern wiring provided on the substrate 52A, and is arranged along the circumferential direction A ( Figure 21 ) is wound multiple times. Winding 52B is made of a metal material such as copper. In this example, winding 52B is provided on both sides of substrate 52A. However, this is not limiting, and winding 52B may be provided on one of the two sides of substrate 52A. Furthermore, if substrate 52A is a multi-layer substrate, winding 52B may be formed using patterned wiring within substrate 52A. One end and the other end of winding 52B are connected to rectifier circuit 14 via substrate 52A and wiring (not shown) provided on shaft 24.

[0073] In the manufacturing process of the power transmission device 50, as shown in FIG. Figure 22 As shown, first, the rotor 52 and the connecting member 53 are connected. Then, the magnetic core 51A11 and the magnetic core 51A12 are brought close to each other in such a manner that the rotor 52 and the connecting member 53 are clamped from both sides. The rotor 52 and the connecting member 53 are clamped. The magnetic core 51A11 and the magnetic core 51A12 are bonded to each other to form the magnetic core 51A1. Then, the magnetic core 51A1 is bonded to the magnetic core 51A2 provided with the winding 51B. Figure 22 In FIG. 5 , the magnetic core 51A2 has a cutout portion 100 . The winding 51B is connected to the inverter 12 through the cutout portion 100 .

[0074] In the power transmission device 50, as Figure 19 As shown in FIG. 20 , a gap G is provided between magnetic core 51A1 and magnetic core 51A2 near opening 153. Consequently, in power transmission device 50, magnetic core 51A1 and magnetic core 51A2 are magnetically coupled to each other near opening 153. With this structure, power transmission device 50 converts the AC power supplied from inverter 12 at a ratio corresponding to the number of turns of winding 51B and the number of turns of winding 52B, and supplies the converted AC power to rectifier circuit 14.

[0075] The connecting member 53 is configured to connect the rotor 52 to the shaft 24. The connecting member 53 includes a connecting member 53A and a connecting member 53B. The connecting member 53A is, for example, a printed circuit board. The connecting member 53A is connected to the shaft 24 and also to the connecting member 53B. In this example, the rectifier circuit 14 is provided on a portion of the Z-direction surface of the connecting member 53A. The rectifier circuit 14 is connected to the winding 52B of the rotor 52 via the connecting member 53A, the connecting member 53B, and the substrate 52A of the rotor 52. The connecting member 53B has a cylindrical shape and is connected to the Z-direction surface of the connecting member 53A. It is also connected to the substrate 52A of the rotor 52 through the opening 153.

[0076] Here, the magnetic core 51A corresponds to a specific example of a "magnetic core" in one embodiment of the present disclosure. The cavity 152 corresponds to a specific example of a "cavity" in one embodiment of the present disclosure. The opening 153 corresponds to a specific example of an "opening" in one embodiment of the present disclosure. The winding 51B corresponds to a specific example of a "first winding" in one embodiment of the present disclosure. The substrate 52A corresponds to a specific example of a "rotating member" in one embodiment of the present disclosure. The winding 52B corresponds to a specific example of a "second winding" in one embodiment of the present disclosure.

[0077] In the power transmission device 50, because the opening 153 is provided on the surface of the magnetic core 51A opposite to the Z direction, the leakage flux in the opening 153 is expanded, thereby reducing the possibility of the leakage flux entering the shaft 24. As a result, the power transmission device 50 can reduce energy loss and improve the efficiency of the motor.

[0078] As described above, the power transmission device 50 includes a magnetic core 51A, a first winding (winding 51B), a substrate 52A, and a second winding (winding 52B). The magnetic core 51A has a ring-shaped shape including a through-hole 150 through which the shaft 24 passes. It contains a cavity 152 extending along the circumferential direction A of the rotation axis AZ of the shaft 24. The cavity 152 has an opening 153 disposed on a surface different from the surface in contact with the through-hole 150. The winding 51B is disposed within the cavity 152 and wound along the circumferential direction A. The substrate 52A is connected to the shaft 24 via the opening 153 and can rotate within the cavity 152 along the circumferential direction A in response to the rotation of the shaft 24. The winding 52B is disposed on the substrate 52A and wound along the circumferential direction A. This reduces the possibility of leakage magnetic flux from the vicinity of the opening 153 entering the shaft 24. As a result, in the power transmission device 50 , energy loss can be reduced and the efficiency of the electric motor can be improved.

[0079] Furthermore, in the power transmission device 50, the opening 153 is provided on the surface of the magnetic core 51A intersecting the rotation axis AZ. This reduces the likelihood of leakage magnetic flux from the vicinity of the opening 153 entering the shaft 24, thereby improving the efficiency of the motor. Furthermore, compared to, for example, providing the opening 153 on the surface of the magnetic core 51A opposite to the surface provided with the through-hole 150, it is easier to connect the substrate 52A to the shaft 24.

[0080] [Effect] As described above, in this embodiment, there are provided a magnetic core, a first winding, a substrate, and a second winding. The magnetic core is annular and includes a through hole for the shaft to pass through. Inside, there is a cavity along the circumference of the rotation axis of the shaft, and there is an opening relative to the cavity. The opening is circumferentially arranged on a surface different from the surface in contact with the through hole. The first winding is arranged in the cavity and wound circumferentially. The substrate is connected to the shaft through the opening and can rotate circumferentially inside the cavity in response to the rotation of the shaft. The second winding is arranged on the substrate and wound circumferentially. Therefore, the efficiency of the motor can be improved.

[0081] In this embodiment, since the opening is provided on the surface of the core intersecting the rotating shaft, the efficiency of the motor can be improved and the substrate can be easily connected to the shaft.

[0082] [Variation 2-1] In the above embodiment, the power transmission device 50 includes a stator 51, a rotor 52, and a connecting member 53, but is not limited thereto. Figure 23 As shown, a heat sink 55 is further provided. In this example, the heat sink 55 is provided on the surface of the connecting member 53 in the direction opposite to the Z direction. The heat sink 55 dissipates the heat generated in the winding 52B and the rectifier circuit 14.

[0083] [Variation 2-2] In the above embodiment, although Figure 23 As shown, the opening 153 is provided on the surface of the core 51A opposite to the Z direction, but the present invention is not limited to this. As an alternative, for example, the opening may be provided on the surface of the core 51A radially outward of the rotation axis AZ. This modified example will be described in detail below.

[0084] Figure 24 A configuration example of a power transmission device 50 according to this modification is shown. Figure 25 An example of a cross-sectional structure of the power transmission device 50 in a plane including the rotation axis AZ is shown. Figure 26 One structural example of the stator 51 is shown. Figure 27 One structural example of the rotor 52 is shown.

[0085] Stator 51 Figure 25 , 26, has a magnetic core 51A. The magnetic core 51A has a magnetic core 21A1 and a magnetic core 21A2. The magnetic core 51A1 constitutes the surface of the magnetic core 51A in the direction opposite to the Z direction and has a radial direction ( Figure 25 The inner portion of the core 51A2 is bent in the Z direction. The core 51A2 forms the Z direction surface of the core 51A and has a radial direction ( Figure 25 The outer and inner portions of the core 51A1 and 51A2 are bent in the opposite direction to the Z direction. The core 51A1 and the core 51A2 are bonded to each other at the connecting portion 156 of the inner circumference of the core 51A. With this structure, in the core 51A having the core 51A1 and the core 51A2, the radial direction ( Figure 25 An opening 154 is provided on the outer surface (in the lateral direction) of the cavity 152. Here, the opening 154 corresponds to a specific example of the "opening" in one embodiment of the present disclosure.

[0086] The rotor 52 is as follows Figure 25 , 27, having a substrate 52A. The substrate 52A is as shown Figure 25 As shown, in the radial direction ( Figure 25 It is arranged in a manner that expands toward the outside of the opening portion 154 in the horizontal direction).

[0087] In the power transmission device 50, as Figure 25 As shown in FIG. 26 , a gap G is provided between magnetic core 51A1 and magnetic core 51A2 near opening 154. Consequently, in power transmission device 50, magnetic core 51A1 and magnetic core 51A2 are magnetically coupled to each other near opening 154. With this structure, power transmission device 50 converts the AC power supplied from inverter 12 at a ratio corresponding to the number of turns of winding 51B and the number of turns of winding 52B, and supplies the converted AC power to rectifier circuit 14.

[0088] The connecting member 53 includes a connecting member 53A and a connecting member 53B. The connecting member 53A is, for example, a printed circuit board. The connecting member 53A is connected to the shaft 24 and is also connected to the connecting member 53B. The connecting member 53B has a cylindrical shape and is connected to the Z-direction surface of the connecting member 53A and is radially ( Figure 25 The outer side of the magnetic core 51A (in the horizontal direction) is connected to the substrate 52A of the rotor 52.

[0089] Furthermore, when bonding the magnetic core 51A1 and the magnetic core 51A2, Figure 28 As shown, a gap may be generated between the magnetic core 51A1 and the magnetic core 51A2 at the joint 156. In this case, since the width of the gap is small, the leakage flux does not spread excessively, and the possibility of the leakage flux entering the shaft 24 is low.

[0090] In addition, although the power transmission device 50 includes a stator 51, a rotor 52, and a connecting member 53, it is not limited thereto and may also include a stator 51, a rotor 52, and a connecting member 53. Figure 29 As shown, a heat sink 55 is further provided. In this example, the heat sink 55 is provided on the surface of the connecting member 53 in the direction opposite to the Z direction. The heat sink 55 dissipates the heat generated in the winding 52B and the rectifier circuit 14.

[0091] In addition, although the power transmission device 50 uses the connection member 53A of the printed circuit board as the connection member 53, it is not limited to this. Figure 30 As shown, a heat sink 53C is used as the connecting member 53. The heat sink 53C is connected to the shaft 24 and is also connected to the connecting member 53B.

[0092] [Other modifications] Furthermore, two or more of these modified examples may be combined.

[0093] While the present invention has been described above by way of examples of embodiments and modifications, the present invention is not limited to these embodiments and the like, and various modifications are possible.

[0094] For example, the shapes of the stators 21 and 51 and the rotors 22 and 52 shown in the above-mentioned embodiments are merely examples and are not limited to the disclosed shapes.

[0095] The effects described in this specification are merely examples, and the effects of the present disclosure are not limited to the effects described in this specification. Therefore, the present disclosure can also achieve other effects.

[0096] Furthermore, the present disclosure may have the following aspects. (1) A power transmission device comprising: a magnetic core having an annular shape including a through-hole for the shaft to pass through, a hollow space inside the core along the circumferential direction of the rotation axis of the shaft, and an opening portion relative to the hollow space, the opening portion being provided along the circumferential direction on a surface different from a surface in contact with the through-hole; a first winding, disposed in the cavity and wound along the circumferential direction; a rotating member connected to the shaft through the opening and rotatable in the circumferential direction within the cavity in response to rotation of the shaft; and The second winding is provided on the rotating member and wound along the circumferential direction. (2) The power transmission device described in (1), wherein The rotating member has a first recessed portion provided along the circumferential direction on a surface opposite to a surface in which the rotating axis is provided. The second winding is wound in the first recess of the rotating member. (3) The power transmission device described in (1) or (2), wherein: A support member is further provided inside the cavity, the support member having a second recess provided along the circumferential direction on a surface opposite to a surface in which the rotation axis is provided. The first winding is wound in the second recess of the support member. (4) The power transmission device according to any one of (1) to (3), wherein: further comprising a connecting member connected to the shaft at a position different from the position at which the magnetic core is provided in the axial direction of the rotating shaft, The rotating member is connected to the shaft through the connecting member. (5) The power transmission device described in (4), wherein further comprising a rectifier circuit connected to the second winding, The connection member includes a substrate provided with the rectifier circuit. (6) The power transmission device described in (4), wherein The connecting member includes a heat sink. (7) The power transmission device according to any one of (1) to (6), wherein: The opening is provided on a surface of the magnetic core that intersects the rotation axis. (8) The power transmission device according to any one of (1) to (7), wherein: The opening portion is provided on a surface of the magnetic core opposite to a surface on which the through hole is provided in the radial direction of the rotation axis. (9) An electric motor device comprising: an electric motor having a motor stator and a motor rotor, the motor stator including a first motor core and a first motor winding, the motor rotor including a second motor core and a second motor winding; a shaft connected to the motor rotor; Inverter; A magnetic core having a ring shape including a through hole for a shaft to pass through, a hollow space inside the core along the circumferential direction of the shaft, and an opening portion relative to the hollow space, the opening portion being provided along the circumferential direction on a surface different from a surface in contact with the through hole; a first winding connected to the inverter, disposed in the cavity, and wound along the circumferential direction; a rotating member connected to the shaft through the opening and capable of rotating in the circumferential direction within the cavity in response to the rotation of the shaft; a second winding provided on the rotating member and wound along the circumferential direction; and The rectifier circuit is provided on a path connecting the second winding and the second motor winding.

Claims

1. A power transmission device comprising: a magnetic core having an annular shape including a through-hole for the shaft to pass through, a hollow space inside the core along the circumferential direction of the rotation axis of the shaft, and an opening portion relative to the hollow space, the opening portion being provided along the circumferential direction on a surface different from a surface in contact with the through-hole; a first winding, disposed in the cavity and wound along the circumferential direction; a rotating member connected to the shaft through the opening and capable of rotating in the circumferential direction within the cavity in response to the rotation of the shaft; as well as The second winding is provided on the rotating member and wound along the circumferential direction.

2. The power transmission device according to claim 1, wherein The rotating member has a first recessed portion provided along the circumferential direction on a surface opposite to a surface in which the rotating axis is provided. The second winding is wound in the first recess of the rotating member.

3. The power transmission device according to claim 1, wherein A support member is further provided inside the cavity, the support member having a second recess provided along the circumferential direction on a surface opposite to a surface in which the rotation axis is provided. The first winding is wound in the second recess of the support member.

4. The power transmission device according to claim 1, wherein further comprising a connecting member connected to the shaft at a position different from the position at which the magnetic core is provided in the axial direction of the rotating shaft, The rotating member is connected to the shaft through the connecting member.

5. The power transmission device according to claim 4, wherein: further comprising a rectifier circuit connected to the second winding, The connection member includes a substrate provided with the rectifier circuit.

6. The power transmission device according to claim 4, wherein The connecting member includes a heat sink.

7. The power transmission device according to claim 1, wherein The opening is provided on a surface of the magnetic core that intersects the rotation axis.

8. The power transmission device according to claim 1, wherein The opening portion is provided on a surface of the magnetic core opposite to a surface on which the through hole is provided in the radial direction of the rotation axis.

9. An electric motor device comprising: an electric motor having a motor stator and a motor rotor, the motor stator including a first motor core and a first motor winding, the motor rotor including a second motor core and a second motor winding; a shaft connected to the motor rotor; Inverter; A magnetic core having a ring shape including a through hole for a shaft to pass through, a hollow space inside the core along the circumferential direction of the shaft, and an opening portion relative to the hollow space, the opening portion being provided along the circumferential direction on a surface different from a surface in contact with the through hole; a first winding connected to the inverter, disposed in the cavity, and wound along the circumferential direction; a rotating member connected to the shaft through the opening and capable of rotating in the circumferential direction within the cavity in response to the rotation of the shaft; a second winding, provided on the rotating member and wound along the circumferential direction; as well as The rectifier circuit is provided on a path connecting the second winding and the second motor winding.

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