Power transmission device and motor device

Abstract

The power transmission device of one embodiment of the present application includes a rotating member, a first winding, a second winding, and a magnetic core. The rotating member is connected to a shaft and can rotate in the circumferential direction of the shaft. The first winding is provided on the rotating member and is wound in the circumferential direction. The second winding is provided at a position different from the position where the rotating member is provided in the axial direction of the shaft and is wound in the circumferential direction. The magnetic core is provided so as to surround the rotating member and the second winding and has a first opening portion provided on a surface in a first direction intersecting the axial direction and facing away from the shaft.

Description

Technical Field

[0001] The present invention relates to a power transmission device for transmitting electricity in a non-contact manner and an electric motor device equipped with such a power transmission device. Background Technology

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

[0003] However, there are devices that can transmit electricity between the stator and the rotor. For example, Patent Document 1 discloses an electricity transmission device that can supply electricity from the stator to the rotor in a non-contact manner. [Existing technical documents] [Patent Literature]

[0004] Patent Document 1: US Patent No. 5,637,973 Summary of the Invention

[0005] In such power transmission devices, for example, the greater the amount of power transmitted, the greater the heat generated. Therefore, easier heat dissipation is desirable in power transmission devices.

[0006] The aim is to provide a power transmission device and motor device that can more easily dissipate heat.

[0007] An embodiment of the power transmission device of the present invention includes a rotating member, a first winding, a second winding, and a magnetic core. The rotating member is connected to a shaft and can rotate circumferentially around the shaft. The first winding is disposed on the rotating member and wound circumferentially. The second winding is disposed circumferentially along the axial direction of the shaft at a position different from the position where the rotating member is disposed. The magnetic core is disposed around the rotating member and the second winding, and has a first opening disposed on a surface in a first direction intersecting the axial direction and in a direction away from the axial direction.

[0008] An embodiment of the present invention provides an electric motor device comprising an electric motor, a shaft, an inverter, a rotating member, a first winding, a second winding, a magnetic core, and a rectifier circuit. The electric motor has a stator and a rotor. The stator includes a first motor magnetic core and a first motor winding, and the rotor includes a second motor magnetic core and a second motor winding. The shaft is connected to the rotor. The rotating member is connected to the shaft and is rotatable in the circumferential direction of the shaft. The first winding is disposed on the rotating member and wound circumferentially. The second winding is disposed axially on the shaft at a position different from the position where the rotating member is disposed, wound circumferentially, and connected to the inverter. The magnetic core is disposed around the rotating member and the second winding and has a first opening on a surface in a first direction intersecting the axial direction, away from the shaft. The rectifier circuit is disposed on a path connecting the first winding and the second motor winding.

[0009] According to one embodiment of the present invention, the power transmission device and motor device can be cooled more easily. Attached Figure Description

[0010] [ Figure 1 ] Figure 1 This is a block diagram illustrating a structural example of an electric motor device according to one embodiment of the present invention. [ Figure 2 ] Figure 2 It means Figure 1 A perspective view of a structural example of a power transmission device. [ Figure 3 ] Figure 3 It means Figure 2 An explanatory diagram of a structural example of a power transmission device is shown. [ Figure 4 ] Figure 4 It means Figure 2 A cross-sectional view of a structural example of a power transmission device shown. [ Figure 5 ] Figure 5 It means Figure 2 An explanatory diagram of a structural example of the two substrates shown. [ Figure 6 ] Figure 6 It means Figure 2 An explanatory diagram of a structural example of the stator shown. [ Figure 7 ] Figure 7 It means Figure 4 An explanatory diagram illustrating an example of magnetic flux in a power transmission device. [ Figure 8 ] Figure 8 This is a perspective view of a structural example of a modified power transmission device. [ Figure 9 ] Figure 9 It means Figure 8 An explanatory diagram of a structural example of a power transmission device is shown. [ Figure 10 ] Figure 10 This is an explanatory diagram illustrating a structural example of an electric power transmission device, representing other variations. [ Figure 11 ] Figure 11 This is a cross-sectional view of a structural example of an electric transmission device, representing other variations. [ Figure 12 ] Figure 12 It means Figure 11 An explanatory diagram illustrating an example of magnetic flux in a power transmission device. [ Figure 13 ] Figure 13 This is a cross-sectional view of a structural example of an electric transmission device, representing other variations. [ Figure 14 ] Figure 14 This is an explanatory diagram illustrating a structural example of an electric power transmission device, representing other variations. [ Figure 15 ] Figure 15 This is a perspective view of a structural example of an electric transmission device, representing other variations. [ Figure 16 ] Figure 16 It means Figure 15 An explanatory diagram of a structural example of a power transmission device is shown. Detailed Implementation

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

[0012] <Implementation Method> [Structure Example] Figure 1 This section illustrates a structural example of an electric motor device 1 equipped with a power transmission device according to an embodiment of the present invention. The electric 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 rotational speed of the electric motor device 1. The DC power supply 9 is configured to supply DC power to the electric motor device 1. The electric motor device 1 is configured to generate a driving force as mechanical energy using the DC power supplied by the DC power supply 9, based on the instruction from the external control device 8. The electric motor device 1 includes a drive unit 10 and an electric motor 50.

[0013] The drive unit 10 is configured as a drive motor 50. The drive unit 10 includes inverters 11 and 12, a power transmission device 20, a blower 13, 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, W-phase) AC power according to the instruction from the control circuit 19. In addition, the inverter 11 supplies the three-phase AC power to the winding 51B of the stator 51 of the motor 50 (described later).

[0015] The inverter 12 is configured to convert the DC power supplied by the DC power supply 9 into single-phase AC power according to the instruction from the control circuit 19. In addition, the inverter 12 supplies the AC power to the winding 36 of the stator 30 of the power transmission device 20 (described later).

[0016] The power transmission device 20 is configured to supply AC power to the rectifier circuit 14 via contactless transmission. The power transmission device 20 has a stator 30, a rotor 40, and a shaft 24.

[0017] Figure 2 , Figure 3 This represents a structural example of a power transmission device 20. Figure 3 A cross-sectional structure of the power transmission device 20 along the III-III arrow view direction is also shown. Figure 4 This is an example of a cross-sectional structure of a power transmission device 20 within a plane containing the rotation axis AZ. Figure 5 An example of a structure showing the substrate 34 (described later) of the stator 30 and the substrate 41 (described later) of the rotor 40.

[0018] The stator 30 is fixed to a housing (not shown) of the motor assembly 1. The stator 30 is as follows... Figures 2-5 As shown, it has a magnetic core 31, a substrate 34 and a winding 36.

[0019] The magnetic core 31 is made of magnetic materials such as ferrite. The magnetic core 31, for example... Figures 2-4 As shown, the configuration surrounds the substrate 34 and the rotor 40. The magnetic core 31 has magnetic core 31A and magnetic core 31B. Magnetic cores 31A and 31B are arranged in this order in the Z direction. Here, the Z direction is as follows: Figure 1 As shown, the axis of rotation AZ is the direction from the motor 50 toward the power transmission device 20. The magnetic core 31 is provided with a through hole 33 for the shaft 24 to pass through.

[0020] Magnetic core 31A, for example Figure 3As shown, in the XY plane intersecting the rotation axis AZ, there is a shape similar to cutting off the two ends of a circle in the Y direction and its opposite direction. Magnetic core 31A has protrusions 31C at both ends in the X direction and its opposite direction, which protrude towards the direction where magnetic core 31B is disposed. Each of the two protrusions 31C of magnetic core 31A has an arc shape in the XY plane. Magnetic core 31B has the same shape as magnetic core 31A. Like magnetic core 31A, magnetic core 31B also has protrusions 31C at both ends in the X direction and its opposite direction, which protrude towards the direction where magnetic core 31A is disposed. Magnetic cores 31A and 31B are connected by connecting the two protrusions 31C of magnetic core 31A to the two protrusions 31C of magnetic core 31B. Thus, a cavity is formed inside the magnetic core 31, and openings 120 are provided at both ends in the Y direction and its opposite direction, communicating between the cavity inside the magnetic core 31 and the outside.

[0021] Substrate 34 is, for example, a printed circuit board (PCB). In this example, as... Figure 4 As shown, substrate 34 is disposed on the surface of magnetic core 31A opposite to magnetic core 31B. Substrate 34 as... Figure 3 As shown in Figure 5, it is ring-shaped. On the substrate 34, as... Figure 5 As shown, a winding 36 is provided. The substrate 34 has a wiring lead-out portion 34A located at an end of the substrate 34 in the opposite direction to the Y direction. On this wiring lead-out portion 34A, two patterned wirings are provided to lead both ends of the winding 36 to the outside. Figure 5 In the diagram, these two patterned wirings are represented by thick lines. The winding 36 is connected to the inverter 12 through the two patterned wirings on the wiring lead-out section 34A.

[0022] The winding 36 is constructed using patterned wiring provided on the substrate 34 and is wound multiple times along the circumferential direction of the rotation axis AZ. Figure 5 In the diagram, the area on the substrate 34 where the winding 36 is located is indicated by a grid pattern. The winding 36 can be located on one side or both sides of the substrate 34. Alternatively, if the substrate 34 is a multilayer board, the winding 36 can be constructed using patterned wiring within the substrate 34. The winding 36 is connected to the inverter 12 via two patterned wirings on the wiring lead-out portion 34A of the substrate 34.

[0023] Figure 6 This indicates the position of winding 36 in the XY plane. Figure 6 In the diagram, the magnetic core 31A and the substrate 34 are superimposed. In the XY plane, the two ends (parts W1) of the region where the winding 36 is located protrude from the region of the magnetic core 31 in the Y direction and in the opposite direction. That is, because the width of the magnetic core 31A in the Y direction is narrower, a portion of the region where the winding 36 is located protrudes from the region of the magnetic core 31.

[0024] The rotor 40 is configured to rotate around the rotation axis AZ. For example... Figure 4 As shown, the rotor 40 is configured in the Z direction to be clamped by the magnetic cores 31A and 31B of the fixing element 30 and fixed to the shaft 24. The rotor 40 is as follows... Figures 2-5 As shown, it has a substrate 41 and a winding 42.

[0025] Substrate 41 is, for example, a printed circuit board. Substrate 41 is positioned in the Z-direction at a location different from that of substrate 34, where the fixing member 30 is located. Substrate 41 is, for example... Figure 5 As shown, it is circular. In this example, the dimensions of the substrate 41 are approximately the same as the dimensions of the substrate 34 of the fixing element 30. On the substrate 41, as... Figure 5 As shown, there is a winding 42.

[0026] The winding 42 is constructed using patterned wiring provided on the substrate 41 and is wound multiple times along the circumferential direction of the rotation axis AZ. Figure 5 In the diagram, the area on the substrate 41 where the winding 42 is located is indicated by a mesh pattern. The winding 42 can be provided on one side or both sides of the substrate 41. Furthermore, if the substrate 41 is a multilayer board, the winding 42 can also be constructed using the internal pattern wiring of the substrate 41. For example... Figure 5 As shown, in this example, the area on substrate 41 where the winding 42 is provided is substantially the same as the area on substrate 34 of the fixing element 30 where the winding 36 is provided. However, it is not limited to this; the area on substrate 41 where the winding 42 is provided may also differ from the area on substrate 34 where the winding 36 is provided. (The text repeats itself here, so the translation will only include the first instance.) Figure 6 Similarly, the two ends of the region where the winding 42 is located, in the Y direction and the opposite direction, protrude from the region of the magnetic core 31. The two ends of the winding 42 are connected to the rectifier circuit 14 via two patterned wirings provided on the substrate 41 and unshown wirings provided on the shaft 24. Figure 5 In the image, the two pattern lines are represented by thick lines.

[0027] Shaft 24 is configured to be connected to the rotor 52 of the motor 50 and rotate around the rotation axis AZ in response to the driving force generated by the motor 50. Shaft 24 can be directly connected to the rotor 52 of the motor 50, or it can be indirectly connected through other components. Alternatively, shaft 24 can be integrally formed with the rotor 52 of the motor 50. Furthermore, although in this example, as... Figure 1 As shown in Figure 2, shaft 24 passes through the power transmission device 20 in the Z direction, but it is not limited to this and may not protrude from the power transmission device 20 in the Z direction.

[0028] Through this structure, in the power transmission device 20, the shaft 24 rotates around the rotating shaft AZ, thereby transmitting the AC power supplied by the inverter 12 from the stator 30 to the rotor 40, and supplying the transmitted AC power to the rectifier circuit 14. The power transmission device 20 is also called a rotary transformer.

[0029] Furthermore, in this example, the power transmission device 20 is arranged in sequence along the Z-direction with magnetic core 31A, substrate 34, substrate 41, and magnetic core 31B, but it is not limited to this. Alternatively, the power transmission device 20 can be arranged in the opposite direction along the Z-direction. In this case, magnetic core 31B, substrate 41, substrate 34, and magnetic core 31A are arranged in sequence along the Z-direction.

[0030] Air supply device 13 ( Figure 1 The power transmission device 20 is configured to be cooled by supplying air to it. The air supply device 13 supplies air, for example, to the opening 120 of the power transmission device 20. As a result, air flows through the cavity inside the power transmission device 20 in the Y direction. Thus, the air supply device 13, through air cooling, can cool, for example, the magnetic core 31, the winding 36 of the substrate 34, and the winding 42 of the substrate 41 within the power transmission device 20.

[0031] The rectifier circuit 14 is configured to rectify the AC power supplied by the winding 42 of the rotor 40 and supply the rectified power to the winding 52B of the rotor 52 of the motor 50 (described later). The rectifier circuit 14 is connected to the shaft 24, which is not shown in the figure. That is, since the winding 42 and the rotor 52 of the motor 50 are connected to the shaft 24, the rectifier circuit 14 is also connected to the shaft 24. Furthermore, although in this example the power rectified by the rectifier circuit 14 is directly supplied to the winding 52B, it is not limited to this. As an alternative, for example, the power rectified by the rectifier circuit 14 can be supplied to the winding 52B through a voltage regulator circuit including a capacitor.

[0032] 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 a control signal indicating the rotational speed supplied by the motor 50. Specifically, the control circuit 19 controls the operation of inverter 11 based on instructions from the external control device 8 and the control signal indicating the rotational speed of the motor 50, thereby controlling the rotational speed of the motor 50. Furthermore, the control circuit 19 controls the operation of inverter 12 based on the control signal indicating the rotational speed supplied by the motor 50, thereby controlling the strength of the magnetic field generated by the rotor 52 of the motor 50. Specifically, for example, the control circuit 19 strengthens the magnetic field generated by the rotor 52 of the motor 50 when the motor 50's rotational speed is low, and weakens the magnetic field generated by the rotor 52 of the motor 50 when the motor 50's rotational speed is high.

[0033] The electric motor 50 is an electrically excited synchronous motor. The electric motor 50 has a stator 51, a rotor 52, and a sensor 53.

[0034] The stator 51, also known as the stationary, is fixed to the housing (not shown) of the motor 50. The stator 51 has a magnetic core 51A and windings 51B. Three-phase (U-phase, V-phase, W-phase) AC power generated by the inverter 11 is supplied to the windings 51B.

[0035] The rotor 52 is a so-called rotor configured to rotate the rotation axis AZ. The rotor 52 has a magnetic core 52A and a winding 52B. A signal rectified by the rectifier circuit 14 is supplied to the winding 52B.

[0036] Sensor 53 is configured to detect the rotational speed of rotor 52. In addition, sensor 53 supplies a control signal indicating the rotational speed of rotor 52 to control circuit 19.

[0037] With this structure, in the motor unit 1, the speed of the motor 50 is controlled based on the three-phase (U-phase, V-phase, W-phase) AC power generated by the inverter 11, and the magnetic field generated by the rotor 52 of the motor 50 is controlled based on the single-phase AC power generated by the inverter 12. In the motor unit 1, for example, when the motor 50 speed is low, the magnetic field generated by the rotor 52 of the motor 50 is enhanced; when the motor 50 speed is high, the magnetic field generated by the rotor 52 of the motor 50 is weakened. Therefore, in the motor unit 1, the efficiency of the motor 50 can be improved over a wider speed range.

[0038] Here, shaft 24 corresponds to a specific example of a "shaft" in one embodiment of this disclosure. Substrate 41 corresponds to a specific example of a "rotating member" in one embodiment of this disclosure. Winding 42 corresponds to a specific example of a "first winding" in one embodiment of this disclosure. Winding 36 corresponds to a specific example of a "second winding" in one embodiment of this disclosure. Magnetic core 31 corresponds to a specific example of a "magnetic core" in one embodiment of this disclosure. Opening 120 corresponds to a specific example of a "first opening" and a "second opening" in one embodiment of this disclosure.

[0039] Stator 51 corresponds to a specific example of a "motor stator" according to an embodiment of this disclosure. Magnetic core 51A corresponds to a specific example of a "first motor magnetic core" according to an embodiment of this disclosure. Winding 51B corresponds to a specific example of a "first motor winding" according to an embodiment of this disclosure. Rotor 52 corresponds to a specific example of a "motor rotor" according to an embodiment of this disclosure. Magnetic core 52A corresponds to a specific example of a "second motor magnetic core" according to an embodiment of this disclosure. Winding 52B corresponds to a specific example of a "second motor winding" according to an embodiment of this disclosure. Inverter 12 corresponds to a specific example of an "inverter" according to an embodiment of this disclosure. Rectifier circuit 14 corresponds to a specific example of a "rectifier circuit" according to an embodiment of this disclosure. Air supply device 13 corresponds to a specific example of a "cooling device" according to an embodiment of this disclosure.

[0040] [Action and Function] Next, the operation and function of the electric motor device 1 in this embodiment will be explained.

[0041] (Overall Movement Overview) Control circuit 19 controls the operation of inverters 11 and 12 according to instructions from external control device 8 and control signals indicating rotational speed supplied by motor 50. Inverter 11, according to instructions from control circuit 19, converts DC power supplied by 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 51B of stator 51 of motor 50. Inverter 12, according to instructions from control circuit 19, converts DC power supplied by DC power supply 9 into single-phase AC power and supplies this AC power to the winding 36 of stator 30 of power transmission device 20. Power transmission device 20 supplies AC power to rectifier circuit 14 via contactless transmission. Rectifier circuit 14 rectifies the AC power supplied by winding 42 of rotor 40 and supplies the rectified power to winding 52B of rotor 52 of motor 50. The motor 50 generates a driving force as mechanical energy based on the three-phase (U-phase, V-phase, W-phase) AC power supplied by the inverter 11. As a result, the shaft 24 rotates around the rotation axis AZ. The sensor 53 of the motor 50 supplies a control signal indicating the rotational speed of the motor 50 to the control circuit 19.

[0042] [Actions and Functions] Next, the operation and function of the power transmission device 20 in this embodiment will be explained.

[0043] Alternating current is supplied by inverter 12 to the windings 36 of the stator 30 of power transmission device 20. Rotor 40 rotates about the rotation axis AZ, for example along... Figure 2 Rotate in the circumferential direction A as shown.

[0044] Figure 7 This is a cross-sectional view showing the stator 30 and rotor 40 of the power transmission device 20. The area on the stator 30 where the winding 36 is located is indicated by a grid pattern. Similarly, the area on the rotor 40 where the winding 42 is located is indicated by a grid pattern.

[0045] The windings 36 of the stator 30 generate a magnetic field based on the alternating current supplied by the inverter 12. The portion of magnetic core 31A near the shaft 24 is magnetically coupled to the portion of magnetic core 31B near the shaft 24. Thus, in the power transmission device 20, as... Figure 7 As shown, a magnetic circuit MP is formed via magnetic core 31A and magnetic core 31B.

[0046] Furthermore, the winding 42 of the rotor 40 generates alternating current based on the magnetic field in the magnetic circuit MP, and supplies the generated alternating current to the rectifier circuit 14. In this way, the power transmission device 20 can supply alternating current to the rectifier circuit 14 through contactless transmission.

[0047] Thus, because power is transmitted non-contactly in the power transmission device 20, reliability is improved compared to contact transmission using, for example, slip rings and brushes.

[0048] The rectifier circuit 14 rectifies the AC power supplied by the winding 42 of the rotor 40 and supplies the rectified power to the winding 52B of the rotor 52 of the motor 50. This generates a magnetic field in the rotor 52 of the motor 50. The control circuit 19, for example, strengthens the magnetic field generated by the rotor 52 of the motor 50 when the motor 50's speed is low, and weakens the magnetic field generated by the rotor 52 of the motor 50 when the motor 50's speed is high. Therefore, in the motor assembly 1, the efficiency of the motor 50 can be improved over a wider speed range.

[0049] Thus, the power transmission device 20 includes a rotating member (substrate 41), a first winding (winding 42), a second winding (winding 36), and a magnetic core 31. The substrate 41 is connected to the shaft 24 and can rotate circumferentially around the shaft 24. The winding 42 is disposed on the substrate 41 and wound circumferentially. The winding 36 is disposed circumferentially around the shaft 24 at a position different from where the substrate 41 is disposed. The magnetic core 31 is arranged around the substrate 41 and the winding 36, and has a first opening (an opening 120 in the Y direction), which is located on a surface in a first direction (Y direction) intersecting the axial direction and away from the axial direction. Therefore, in the power transmission device 20, heat can be dissipated from the magnetic core 31, the winding 36 of the substrate 34, and the winding 42 of the substrate 41. In other words, for example, if the magnetic core 31 is constructed without the opening 120, heat will accumulate in the cavity inside the magnetic core 31 due to the heating of the windings 36, 42, resulting in poor heat dissipation. On the other hand, in the power transmission device 20, because the opening 120 is provided on the magnetic core 31, heat is less likely to accumulate in the cavity inside the magnetic core 31. As a result, heat dissipation can be achieved more easily in the power transmission device 20.

[0050] Furthermore, in the power transmission device 20, because the opening 120 is provided, it is easier to configure the wiring connecting the winding 36 located inside the magnetic core 31 to the inverter 12. In other words, for example, if the magnetic core 31 were constructed without the opening 120, it would be difficult to guide the winding 36 located inside the magnetic core 31 to the inverter 12. On the other hand, in the power transmission device 20, because the opening 120 is provided on the magnetic core 31, the winding 36 can be easily led out from inside the magnetic core 31 to the outside and connected to the inverter 12. Therefore, in the power transmission device 20, it is easier to configure the wiring connecting the winding 36 to the inverter 12.

[0051] Furthermore, in the power transmission device 20, the magnetic core 31 has a second opening (an opening 120 provided in the direction opposite to the Y direction), and the opening 120 is provided on a surface in the second direction opposite to the first direction (Y direction) and in a direction away from the axis 24. Therefore, air can more easily flow along the Y direction within the cavity inside the magnetic core 31. As a result, heat dissipation can be more easily achieved in the power transmission device 20.

[0052] Specifically, in the electric motor assembly 1, a cooling device (air supply device 13) is provided that can supply a cooling medium (air in this example) to the first opening (opening 120) of the magnetic core 31. Thus, in the electric motor assembly 1, cooler air, for example, can be supplied into the interior of the power transmission device 20. As a result, in the power transmission device 20, the magnetic core 31, the winding 36 of the substrate 34, and the winding 42 of the substrate 41 can be cooled.

[0053] Furthermore, in the power transmission device 20, the rotating member (substrate 41) includes a printed circuit board. The first winding (winding 42) is a pattern wiring provided on the printed circuit board. As a result, for example, compared to the case where the rotor 40 is constructed using an iron core, the rotor 40 can be made lighter, thus reducing the moment of inertia and the inertial force.

[0054] Furthermore, in the power transmission device 20, a portion of the rotating member (substrate 41) extends from the first opening (opening 120) of the magnetic core 31 in a first direction (Y direction) intersecting the axial direction. This allows for a reduction in the size of the magnetic core 31 in the power transmission device 20. In other words, since the winding 42 is a patterned wiring provided on the substrate 41, increasing the number of turns of the winding 42 would increase the diameter of the substrate 41. Therefore, for example, if a portion of the substrate 41 is not configured to extend from the opening 120 of the magnetic core 31, the size of the magnetic core 31 would increase. In this case, for example, the size of the power transmission device 20 would increase. Additionally, the cost of the magnetic core 31 would increase. On the other hand, in the power transmission device 20, because a portion of the substrate 41 extends from the opening 120 of the magnetic core 31, the size of the magnetic core 31 can be reduced. This, for example, allows for a reduction in the size of the power transmission device 20 and reduces the cost of the magnetic core 31.

[0055] Specifically, in the power transmission device 20, a portion of the first winding (winding 42) disposed on the rotating member (substrate 41) extends from the first opening (opening 120) of the magnetic core 31 in a first direction (Y direction) intersecting the axial direction. As a result, since the size of the magnetic core 31 can be reduced, for example, the size of the power transmission device 20 can be reduced, and the cost of the magnetic core 31 can be suppressed.

[0056] [Effect] As described above, in this embodiment, a rotating member, a first winding, a second winding, and a magnetic core are provided. The rotating member is connected to a shaft and can rotate circumferentially around the shaft. The first winding is disposed on the rotating member and wound circumferentially. The second winding is disposed axially on the shaft at a position different from the location where the rotating member is disposed and wound circumferentially. The magnetic core is disposed around the rotating member and the second winding and has a first opening on a surface in a first direction intersecting the axial direction, away from the axial direction. This facilitates heat dissipation.

[0057] [Variation Example 1] In the above embodiments, although as Figure 3 As shown, openings 120 are provided at both ends of the magnetic core 31 in the Y direction and the opposite direction, but this is not the only possibility. Alternatively, as... Figure 8 , Figure 9 As shown, the opening 120 may also be provided only at one of the two ends of the magnetic core 31 in the Y direction and the opposite direction. In this example, the magnetic core 31A is as follows: Figure 9 As shown, the magnetic core 31A has a shape in the XY plane similar to cutting off the end of a circle in the opposite direction of the Y direction. The magnetic core 31A has a protrusion 31C at its end in the XY plane, excluding the cut-off portion, protruding in the direction in which the magnetic core 31B is located. This protrusion 31C has an arc shape in the XY plane. The magnetic core 31B has the same shape as the magnetic core 31A. Like the magnetic core 31A, the magnetic core 31B has a protrusion 31C at its end, excluding the cut-off portion, protruding in the direction in which the magnetic core 31A is located. The magnetic cores 31A and 31B are connected by the protrusion 31C of the magnetic core 31A and the protrusion 31C of the magnetic core 31B. Therefore, in the magnetic core 31, an opening 120 is provided only at the end in the opposite direction of the Y direction.

[0058] [Variation Example 2] In the above embodiments, although as Figure 4 As shown, the position of the inner side surface of the magnetic core 31A opposite to the shaft 24 is aligned with the position of the inner side surface of the substrate 34 opposite to the shaft 24, but this is not a limitation. As an alternative, such as... Figure 10 , Figure 11 As shown, these positions may also be misaligned. In this example, the magnetic core 31A has a protrusion 31D at its inner end, which protrudes in the direction in which the magnetic core 31B is disposed. This protrusion 31D has a ring shape in the XY plane. Furthermore, a substrate 34 is fitted onto the outer side of the protrusion 31D with the ring shape. In this structure, as... Figure 12 As shown, a magnetic circuit MP is formed through the protrusion 31D.

[0059] [Variation Example 3] In the above embodiment, although the winding 36 of the fixing element 30 is formed using patterned wiring provided on the substrate 34, it is not limited to this. Alternatively, the winding 36 can be formed using wire or copper plate. When using wire, for example, stranded wire can be used. When using wire to form the winding 36, such as... Figure 13 As shown, the winding 36 can also be wound on the bobbin 37. As in the above embodiment, by using the substrate 34, the center of gravity of the substrate 34 can be easily adjusted to be aligned with the rotation axis AZ, thereby suppressing eccentricity.

[0060] [Variation Example 4] In the above embodiments, although as Figure 5 As shown, the winding 36 is wound in a circular shape on the substrate 34, but it is not limited to this. As an alternative, it can also be wound in a polygonal shape, for example. Similarly, although the winding 42 is wound in a circular shape on the substrate 41, it is not limited to this. As an alternative, it can also be wound in a polygonal shape, for example.

[0061] [Variation Example 5] In the above embodiment, although the substrate 34 of the fixing element 30 is made to have a circular ring shape, it is not limited to this, such as... Figure 14 As shown, it can also be a non-circular ring. In this example, it is a rectangular ring.

[0062] [Variation Example 6] In the above embodiments, although as Figure 2 , Figure 3 As shown, the magnetic cores 31A and 31B have a shape in the XY plane similar to the two ends of a circle cut off in the Y direction and its opposite direction, but are not limited to this. As an alternative, such as... Figure 15 , Figure 16 As shown, magnetic cores 31A and 31B can also be rectangular in the XY plane. In this case, each of the two protrusions 31C of magnetic core 31A is rectangular in the XY plane. The same applies to magnetic core 31B. Magnetic cores 31A and 31B are connected by connecting the two protrusions 31C of magnetic core 31A to the two protrusions 31C of magnetic core 31B, respectively. Thus, a cavity is provided inside the magnetic core 31, and openings 120 are provided on both sides in the Y direction to connect the cavity inside the magnetic core 31 to the outside.

[0063] [Variation Example 7] In the above embodiment, although an air supply device 13 is provided and air is used as the cooling medium to cool the power transmission device 20, the cooling medium is not limited to air. As an alternative, oil can be used as the cooling medium to cool the power transmission device 20; water can also be used as the cooling medium to cool the power transmission device 20.

[0064] [Other variations] Alternatively, two or more of these variations can be combined.

[0065] The present invention has been described above with examples of embodiments and modifications, but the present invention is not limited to these embodiments and can be modified in various ways.

[0066] For example, the shapes of the magnetic core 31, substrate 34, and substrate 41 shown in the above embodiments are just examples and are not limited to the disclosed shapes.

[0067] The effects described in this specification are merely illustrative, and the effects of this disclosure are not limited to those described herein. Therefore, other effects can also be obtained with this disclosure.

[0068] Furthermore, this disclosure can be implemented in the following ways. (1) A power transmission device comprising: A rotating component, connected to a shaft, is rotatable in the circumferential direction of the shaft; The first winding is disposed on the rotating member and wound along the circumferential direction; The second winding is located axially on the shaft at a position different from the position where the rotating member is located, and is wound circumferentially; and The magnetic core is arranged around the rotating member and the second winding, and has a first opening on a surface in a first direction intersecting the axis and in a direction away from the axis. (2) The power transmission device described in (1), wherein, The magnetic core has a second opening. The second opening is disposed on a surface in a second direction opposite to the first direction, in a direction away from the axis. (3) The power transmission device described in (1) or (2), wherein, The rotating component includes a printed circuit board. The first winding is a pattern wiring disposed on the printed circuit board. (4) The power transmission device according to any one of (1) to (3), wherein, In the first direction within the plane intersecting the axial direction, a portion of the rotating member extends from the first opening of the magnetic core. (5) The power transmission device described in (4), wherein, In the first direction within the plane intersecting the axial direction, a portion of the first winding disposed on the rotating member extends from the first opening of the magnetic core. (6) An electric motor device comprising: An electric motor has a stator and a rotor, wherein the stator includes a first motor core and a first motor winding, and the rotor includes a second motor core and a second motor winding. A shaft is connected to the rotor of the electric motor; Inverter; A rotating component, connected to the shaft, is rotatable in the circumferential direction of the shaft; The first winding is disposed on the rotating member and wound along the circumferential direction; The second winding is located on the axial direction of the shaft at a position different from the position where the rotating member is located, and is wound around the circumferential direction and connected to the inverter. A magnetic core, arranged around the rotating member and the second winding, and having a first opening disposed on a surface in a first direction intersecting the axial direction and in a direction away from the axial direction; and The rectifier circuit is disposed on the path connecting the first winding and the second motor winding. (7) The electric motor device described in (6), wherein, It is further equipped with a cooling device. The cooling device can supply cooling medium to the first opening of the magnetic core.

Claims

1. A power transmission device, comprising: A rotating component, connected to a shaft, is rotatable in the circumferential direction of the shaft; The first winding is disposed on the rotating member and wound along the circumferential direction; The second winding is located on the axial direction of the shaft, at a position different from the position where the rotating member is located, and is wound along the circumferential direction; as well as The magnetic core is arranged around the rotating member and the second winding, and has a first opening on a surface in a first direction intersecting the axis and in a direction away from the axis.

2. The power transmission device according to claim 1, wherein, The magnetic core has a second opening. The second opening is disposed on a surface in a second direction opposite to the first direction, in a direction away from the axis.

3. The power transmission device according to claim 1, wherein, The rotating component includes a printed circuit board. The first winding is a pattern wiring disposed on the printed circuit board.

4. The power transmission device according to claim 1, wherein, In the first direction within the plane intersecting the axial direction, a portion of the rotating member extends from the first opening of the magnetic core.

5. The power transmission device according to claim 4, wherein, In the first direction within the plane intersecting the axial direction, a portion of the first winding disposed on the rotating member extends from the first opening of the magnetic core.

6. An electric motor device comprising: An electric motor has a stator and a rotor, wherein the stator includes a first motor core and a first motor winding, and the rotor includes a second motor core and a second motor winding. A shaft is connected to the rotor of the electric motor; Inverter; A rotating component, connected to the shaft, is rotatable in the circumferential direction of the shaft; The first winding is disposed on the rotating member and wound along the circumferential direction; The second winding is located on the axial direction of the shaft at a position different from the position where the rotating member is located, and is wound around the circumferential direction and connected to the inverter. A magnetic core, arranged around the rotating member and the second winding, and having a first opening disposed on a surface in a first direction intersecting the axial direction and in a direction away from the axial direction; and The rectifier circuit is disposed on the path connecting the first winding and the second motor winding.

7. The electric motor device according to claim 6, wherein, It is further equipped with a cooling device. The cooling device can supply cooling medium to the first opening of the magnetic core.

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