EP4668300A1 - Power transmission device and motor device - Google Patents

Power transmission device and motor device

Info

Publication number
EP4668300A1
EP4668300A1 EP23922638.4A EP23922638A EP4668300A1 EP 4668300 A1 EP4668300 A1 EP 4668300A1 EP 23922638 A EP23922638 A EP 23922638A EP 4668300 A1 EP4668300 A1 EP 4668300A1
Authority
EP
European Patent Office
Prior art keywords
magnetic core
opening
winding
motor
electric power
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
EP23922638.4A
Other languages
German (de)
French (fr)
Inventor
Kazuyoshi Hanabusa
Yuki CHAI
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
TDK Corp
Original Assignee
TDK Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by TDK Corp filed Critical TDK Corp
Publication of EP4668300A1 publication Critical patent/EP4668300A1/en
Pending legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01F—MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
    • H01F38/00—Adaptations of transformers or inductances for specific applications or functions
    • H01F38/18—Rotary transformers

Definitions

  • Examples of a motor include an electrically excited synchronous motor (EESM).
  • EESM electrically excited synchronous motor
  • Such a motor includes a stator on which a winding is wound and a rotor on which a winding is wound.
  • a current to be fed through the winding wound on the rotor may be varied in accordance with a rotation speed of the motor. This makes it possible to achieve improved efficiency of the motor.
  • Patent Literature 1 Japanese Unexamined Patent Application Publication No. 2002-75760
  • What is desired of a motor apparatus is to be high in efficiency of a motor, and expectations are placed on further improvement in efficiency of the motor.
  • An electric power transmission device includes a magnetic core, a first winding, a rotary member, a second winding, and a first magnetic body.
  • the magnetic core has a ring shape including a through hole through which a shaft extends.
  • the magnetic core includes therein a cavity along a circumferential direction about an axis of rotation of the shaft, and has a first opening provided along the circumferential direction in a first surface in contact with the through hole. The first opening couples the through hole and the cavity to each other.
  • the first winding is provided in the cavity and wound along the circumferential direction.
  • the rotary member is provided at a position corresponding to the first opening in an axial direction of the axis of rotation, and is rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft.
  • the second winding is provided on the rotary member and wound along the circumferential direction.
  • the first magnetic body is provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core.
  • a motor apparatus includes a motor, a shaft, an inverter, a magnetic core, a first winding, a rotary member, a second winding, a first magnetic body, and a rectifying circuit.
  • the motor includes a motor stator and a motor rotor.
  • the motor stator includes a first motor magnetic core and a first motor winding.
  • the motor rotor includes a second motor magnetic core and a second motor winding.
  • the shaft is coupled to the motor rotor.
  • the magnetic core has a ring shape including a through hole through which the shaft extends.
  • the magnetic core includes therein a cavity along a circumferential direction about an axis of rotation of the shaft, and has a first opening provided along the circumferential direction in a first surface in contact with the through hole.
  • the first opening couples the through hole and the cavity to each other.
  • the first winding is coupled to the inverter, provided in the cavity, and wound along the circumferential direction.
  • the rotary member is provided at a position corresponding to the first opening in an axial direction of the axis of rotation, and is rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft.
  • the second winding is provided on the rotary member and wound along the circumferential direction.
  • the first magnetic body is provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core.
  • the rectifying circuit is provided in a path coupling the second winding and the second motor winding to each other.
  • the magnetic core 21A includes a magnetic material, such as ferrite. Magnetic cores 21A1 and 21A2 are disposed at a predetermined distance from each other in a Z direction, with the rotor 22 interposed therebetween.
  • the Z direction is a direction in which the axis of rotation AZ extends, and is from the motor 30 toward the electric power transmission device 20.
  • the magnetic core 21A includes the magnetic core 21A1 and the magnetic core 21A2.
  • the magnetic core 21A1 is a ring-shaped magnetic member having a through hole 120 through which the shaft 24 extends.
  • the magnetic core 21A1 has the form of a flat plate.
  • the magnetic core 21A2 is a ring-shaped magnetic member having the through hole 120 through which the shaft 24 extends.
  • a recess 121 having a groove shape is provided along a circumferential direction A ( FIG. 4 ) about the axis of rotation AZ in a surface S21 ( FIGs. 3 and 4 ) facing the rotor 22.
  • the magnetic core 21A including the magnetic cores 21A1 and 21A2 is provided with a cavity 122 along the circumferential direction A, and with openings 123 and 124.
  • the opening 123 couples the cavity 122 and a space on an inner side of the magnetic core 21A in a radial direction (i.e., a horizontal direction in FIG. 3 ) to the axis of rotation AZ to each other.
  • the opening 124 couples the cavity 122 and a space on an outer side of the magnetic core 21A in the radial direction to each other.
  • the winding 21B is wound multiple times along the recess 121 of the magnetic core 21A2.
  • the winding 21B is coupled to the inverter 12 through a hole (not illustrated) provided in the magnetic core 21A2, for example.
  • the rotor 22 is what is called a rotor, and is configured to rotationally move about the axis of rotation AZ.
  • the rotor 22 is so disposed as to be interposed between the magnetic core 21A1 and the magnetic core 21A2 of the stator 21 in the Z direction, and is fixed to the shaft 24.
  • the rotor 22 includes a substrate 22A, a winding 22B, a magnetic body 22C, and a magnetic body 22E.
  • the substrate 22A is a printed circuit board (PCB), for example.
  • the substrate 22A is coupled to the shaft 24 and rotationally moves in the circumferential direction A about the axis of rotation AZ with a rotation of the shaft 24.
  • the winding 22B includes a patterned wiring provided on the substrate 22A, and is wound multiple times along the circumferential direction A ( FIG. 5 ) about the axis of rotation AZ.
  • the winding 22B includes a metal material, such as copper.
  • the winding 22B is provided on both surfaces of the substrate 22A. Note that this is non-limiting, and the winding 22B may be provided on one of both surfaces of the substrate 22A.
  • the winding 22B may include a patterned wiring within the substrate 22A.
  • One end and another end of the winding 22B are coupled to the rectifying circuit 14 via a part 22D of the substrate 22A and an unillustrated wiring provided on the shaft 24. The part 22D will be described later.
  • the magnetic body 22C includes a magnetic material, such as ferrite, and is provided at a position in the rotor 22 corresponding to the opening 123 of the stator 21, as illustrated in FIG. 3 . As illustrated in FIG. 5 , the magnetic body 22C is so provided as to extend along the circumferential direction A about the axis of rotation AZ. In this example, the magnetic body 22C has a shape of "C" of the alphabet. Specifically, the substrate 22A is provided with a cutout in the shape of "C" of the alphabet, and the magnetic body 22C is placed in this cutout of the substrate 22A.
  • a part located on an inner side relative to the magnetic body 22C and a part located on an outer side relative to the magnetic body 22C are coupled to each other by the part 22D of the substrate 22A.
  • the magnetic body 22C may have a ring shape.
  • an insulating film may be provided on a surface of a part of the magnetic body 22C, and a wiring that couples the one end and the other end of the winding 22B to the rectifying circuit 14 may be provided on the insulating film.
  • a width in the radial direction (i.e., the horizontal direction in FIG. 3 ) of the magnetic body 22C is equal to a width in the radial direction of one projection, of two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123.
  • the magnetic body 22E includes a magnetic material, such as ferrite, and is provided at a position in the rotor 22 corresponding to the opening 124 of the stator 21, as illustrated in FIG. 3 . As illustrated in FIG. 5 , the magnetic body 22E is so provided as to extend along the circumferential direction A about the axis of rotation AZ. In this example, the magnetic body 22E has a ring shape. Specifically, the substrate 22A is provided with a ring-shaped cutout, and the magnetic body 22E is placed in this cutout of the substrate 22A. In this example, a width in the radial direction (i.e., the horizontal direction in FIG. 3 ) of the magnetic body 22E is equal to a width in the radial direction of another projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
  • a width in the radial direction i.e., the horizontal direction in FIG. 3
  • the rectifying circuit 14 ( FIG. 1 ) is configured to rectify alternating-current electric power supplied from the winding 22B of the rotor 22 and to supply the rectified electric power to a winding 32B of the rotor 32 of the motor 30.
  • the winding 32B will be described later.
  • the rectifying circuit 14 is coupled to the shaft 24. More specifically, because the winding 22B and the rotor 32 of the motor 30 are coupled to the shaft 24, the rectifying circuit 14 is also coupled to the shaft 24. Note that although the electric power rectified by the rectifying circuit 14 is directly supplied to the winding 32B in this example, this is non-limiting. Alternatively, for example, the electric power rectified by the rectifying circuit 14 may be supplied to the winding 32B via a stabilizing circuit including a capacitor.
  • the rectifying circuit 14 rectifies the alternating-current electric power supplied from the winding 22B of the rotor 22, and supplies the rectified electric power to the winding 32B of the rotor 32 of the motor 30.
  • a magnetic field is thus generated at the rotor 32 of the motor 30.
  • the control circuit 19 intensifies the magnetic field to be generated by the rotor 32 of the motor 30, and when the rotation speed of the motor 30 is high, the control circuit 19 weakens the magnetic field to be generated by the rotor 32 of the motor 30. This makes it possible for the motor apparatus 1 to increase efficiency of the motor 30 over a wide rotation speed range.
  • the rotor 22 includes the substrate 22A on which the winding 22B is provided. This makes it possible for the rotor 22 to be lightweight as compared with a rotor including a rotor iron core as described in Patent Literature 1, for example. Accordingly, it is possible to reduce a moment of rotation and to reduce an inertial force.
  • the provision of the magnetic body 22C makes it possible to suppress spreading of the leakage fluxes in the vicinity of the opening 123, and thus makes it possible to reduce a possibility that any of the leakage fluxes enter the shaft 24 or the winding 22B.
  • the provision of the magnetic body 22E makes it possible to suppress spreading of the leakage fluxes in the vicinity of the opening 124, and thus makes it possible to reduce the possibility that any of the leakage fluxes enter the winding 22B. As a result, it is possible for the electric power transmission device 20 to reduce energy loss and to increase efficiency of the motor.
  • the gap G in the vicinity of the opening 123 is to be provided between the magnetic core 21A1 and the projection of the magnetic core 21A2 in the vicinity of the opening 123.
  • the leakage fluxes can spread over a larger area in the radial direction (i.e., the horizontal direction in FIG. 8 ). If any of the leakage fluxes enter the shaft 24, an eddy current would occur in the shaft 24 to result in energy loss. Further, if any of the leakage fluxes enter the winding 22B, an eddy current would occur in the winding 22B to result in energy loss.
  • the gap G in the vicinity of the opening 124 is to be provided between the magnetic core 21A1 and the projection of the magnetic core 21A2 in the vicinity of the opening 124.
  • the leakage fluxes can spread over a larger area in the radial direction (i.e., the horizontal direction in FIG. 8 ). If any of the leakage fluxes enter the winding 22B, an eddy current would occur in the winding 22B to result in energy loss.
  • the electric power transmission device 20 is provided with the magnetic bodies 22C and 22E, which makes it possible for the gaps G to be shorter, and thus makes it possible to suppress spreading of the leakage fluxes in the radial direction (i.e., the horizontal direction in FIG. 7 ). Accordingly, it is possible to reduce the possibility that any of the leakage fluxes enter the shaft 24 or the winding 22B. This makes it possible to reduce energy loss and to increase efficiency of the motor.
  • the electric power transmission device 20 includes the magnetic core 21A, the first winding (the winging 21B), the substrate 22A, the second winding (the winding 22B), and the first magnetic body (the magnetic body 22C).
  • the magnetic core 21A has a ring shape including the through hole 120 through which the shaft 24 extends.
  • the magnetic core 21A includes therein the cavity 122 along the circumferential direction A about the axis of rotation AZ of the shaft 24, and has the first opening (the opening 123) provided along the circumferential direction A in a first surface in contact with the through hole 120.
  • the first opening (the opening 123) couples the through hole 120 and the cavity 122 to each other.
  • the first winding (the winding 21B) is provided in the cavity 122 and wound along the circumferential direction A.
  • the substrate 22A is provided at a position corresponding to the first opening (the opening 123) in an axial direction of the axis of rotation AZ, and is rotationally movable, inside the cavity 122, in the circumferential direction A with the rotation of the shaft 24.
  • the second winding (the winding 22B) is provided on the substrate 22A and wound along the circumferential direction A.
  • the first magnetic body (the magnetic body 22C) is provided along the circumferential direction A in a part of the substrate 22A corresponding to the first opening (the opening 123) of the magnetic core 21A.
  • the electric power transmission device 20 further includes the second magnetic body (the magnetic body 22E).
  • the magnetic core 21A has the second opening (the opening 124) provided in a second surface at a position corresponding to the first opening (the opening 123) in the axial direction.
  • the second surface is opposite to the first surface in the radial direction to the axis of rotation AZ.
  • the second magnetic body (the magnetic body 22E) is provided along the circumferential direction A in a part of the substrate 22A corresponding to the second opening (the opening 124) of the magnetic core 21A. This makes it possible to suppress spreading of the leakage fluxes in the vicinity of the opening 124, and to reduce the possibility that any of the leakage fluxes enter the winding 22B. As a result, it is possible for the electric power transmission device 20 to reduce energy loss and to increase efficiency of the motor.
  • a magnetic core, a first winding, a substrate, a second winding, and a first magnetic body are provided in the present embodiment.
  • the magnetic core has a ring shape including a through hole through which a shaft extends.
  • the magnetic core includes therein a cavity along a circumferential direction about an axis of rotation of the shaft, and has a first opening provided along the circumferential direction in a first surface in contact with the through hole. The first opening couples the through hole and the cavity to each other.
  • the first winding is provided in the cavity and wound along the circumferential direction.
  • the substrate is provided at a position corresponding to the first opening in an axial direction of the axis of rotation, and is rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft.
  • the second winding is provided on the substrate and wound along the circumferential direction.
  • the first magnetic body is provided along the circumferential direction in a part of the substrate corresponding to the first opening of the magnetic core. This makes it possible to increase efficiency of the motor.
  • a second magnetic body is further provided.
  • the magnetic core has a second opening provided in a second surface at a position corresponding to the first opening in the axial direction.
  • the second surface is opposite to the first surface in a radial direction to the axis of rotation.
  • the second magnetic body is provided along the circumferential direction in a part of the substrate corresponding to the second opening of the magnetic core. This makes it possible to increase efficiency of the motor.
  • the magnetic body 22C is configured of a single magnetic body; however, this is non-limiting.
  • the magnetic body 22C may include a plurality of magnetic bodies.
  • the magnetic body 22C includes two magnetic bodies.
  • the magnetic body 22E is provided; however, this is non-limiting.
  • no magnetic body 22E may be provided.
  • the width in the radial direction (i.e., the horizontal direction in FIG. 3 ) of the magnetic body 22C is equal to the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123; however, this is non-limiting.
  • the width in the radial direction (i.e., the horizontal direction in FIG. 11 ) of the magnetic body 22C may be greater than the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123.
  • the width in the radial direction (i.e., the horizontal direction in FIG. 3 ) of the magnetic body 22E is equal to the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124, this is non-limiting.
  • the width in the radial direction (i.e., the horizontal direction in FIG. 11 ) of the magnetic body 22E may be greater than the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
  • the magnetic core 21A has the opening 123 and the opening 124; however, this is non-limiting.
  • the magnetic core 21A may have the single opening 123 alone.
  • a part of the magnetic core 21A1 on an outer side in the radial direction bends in the Z direction and is coupled to the magnetic core 21A2 at a coupling part 125.
  • this electric power transmission device 20 In a process of manufacturing this electric power transmission device 20, the magnetic core 21A1, the rotor 22, and the magnetic core 21A2 are arranged in this order in the Z direction, and the magnetic core 21A1, the rotor 22, and the magnetic core 21A2 are brought close to each other to cause the magnetic core 21A1 and the magnetic core 21A2 to be bonded to each other, for example, at the coupling part 125.
  • the electric power transmission device 20 is provided with no opening 124, and is thus free from any leakage flux at the opening 124. This makes it possible to reduce energy loss, and to increase efficiency of the motor.
  • the magnetic bodies 22C and 22E are placed in the cutouts of the substrate 22A; however, this is non-limiting.
  • the magnetic bodies 22C and 22E may be provided on the surfaces of the substrate 22A.
  • the rotor 22 includes the magnetic bodies 22C (magnetic bodies 22C1 and 22C2) and the magnetic bodies 22E (magnetic bodies 22E1 and 22E2). As illustrated in FIG.
  • the magnetic body 22C1 is provided on one surface, of the substrate 22A, on a side where the magnetic core 21A1 is provided, and the magnetic body 22C2 is provided on another surface, of the substrate 22A, on a side where the magnetic core 21A2 is provided.
  • the magnetic body 22C1 and the magnetic body 22C2 each have a ring shape.
  • the one end and the other end of the winding 22B are coupled to the rectifying circuit 14 at a part 22D1, for example, via the patterned wiring within the substrate 22A.
  • the magnetic body 22E1 is provided on the one surface, of the substrate 22A, on the side where the magnetic core 21A1 is provided, and the magnetic body 22E2 is provided on the other surface, of the substrate 22A, on the side where the magnetic core 21A2 is provided.
  • FIG. 16 illustrates an example of the magnetic flux in each of the openings 123 and 124 of the electric power transmission device 20 according to the present modification example.
  • the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic bodies 22C1 and 22C2.
  • the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic bodies 22E1 and 22E2.
  • the electric power transmission device 20 according to the present modification example is provided with the magnetic bodies 22C (the magnetic bodies 22C1 and 22C2) and the magnetic bodies 22E (the magnetic bodies 22E1 and 22E2).
  • the width in the radial direction (i.e., the horizontal direction in FIG. 14 ) of each of the magnetic bodies 22C1 and 22C2 is equal to the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123; however, this is non-limiting.
  • each of the magnetic bodies 22C1 and 22C2 may be greater than the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123.
  • each of the magnetic bodies 22E1 and 22E2 is equal to the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124, this is non-limiting.
  • the width in the radial direction i.e., the horizontal direction in FIG.
  • each of the magnetic bodies 22E1 and 22E2 may be greater than the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
  • the magnetic bodies 22C and 22E are placed in the cutouts of the substrate 22A; however, this is non-limiting.
  • the magnetic bodies 22C and 22E may be buried within the substrate 22A.
  • the magnetic bodies 22C and 22E each have a ring shape.
  • the magnetic body 22C is provided within the substrate 22A in a part of the substrate 22A corresponding to the opening 123.
  • the one end and the other end of the winding 22B are coupled to the rectifying circuit 14 at a part 22D2, for example, via a patterned wiring on the surface of the substrate 22A in which the magnetic body 22C is buried.
  • the magnetic body 22E is provided within the substrate 22A in a part of the substrate 22A corresponding to the opening 124.
  • the width in the radial direction (i.e., the horizontal direction in FIG. 18 ) of the magnetic body 22C is equal to the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123; however, this is non-limiting.
  • the width of the magnetic body 22C in the radial direction i.e., the horizontal direction in FIG. 20
  • the width in the radial direction (i.e., the horizontal direction in FIG. 18 ) of the magnetic body 22E is equal to the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124, this is non-limiting.
  • the width in the radial direction (i.e., the horizontal direction in FIG. 20 ) of the magnetic body 22E may be greater than the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
  • the magnetic body 22C is provided only at the position corresponding to the opening 123; however, this is non-limiting.
  • the magnetic body 22C may be provided within the substrate 22A in a region, of the substrate 22A in an XY plane, that includes the part corresponding to the opening 123 of the magnetic core 21A and a part on an outer side thereof.
  • the present modification example is applied to the electric power transmission device 20 according to Modification Example 4 ( FIGs. 12 and 13 ).
  • the magnetic body 22C is buried within the substrate 22A.
  • a gap G is provided between the magnetic core 21A1 and the magnetic body 22C, and a gap G is provided between the magnetic body 22C and the projection of the magnetic core 21A2 in the vicinity of the opening 123. Further, a gap G is provided between an outer end of the magnetic body 22C in the radial direction (i.e., the horizontal direction in FIG. 21 ) and the magnetic core 21A2.
  • FIG. 23 illustrates a cross-sectional view of the stator 21 and the rotor 22 in the electric power transmission device 20 according to the present modification example.
  • the winding 21B of the stator 21 generates a magnetic field, based on alternating-current electric power supplied from the inverter 12.
  • the magnetic core 21A1 and the magnetic body 22C are magnetically coupled to each other, and the magnetic body 22C and the projection of the magnetic core 21A2 in the vicinity of the opening 123 are magnetically coupled to each other.
  • the outer end of the magnetic body 22C in the radial direction (i.e., the horizontal direction in FIG. 23 ) and the magnetic core 21A2 are magnetically coupled to each other.
  • a magnetic path MP is generated that passes through the magnetic core 21A1, the magnetic body 22C, and the magnetic core 21A2, and a magnetic path MP is generated that passes through the magnetic body 22C and the magnetic core 21A2.
  • the rotor 22 includes the substrate 22A; however, this is non-limiting, and the rotor 22 may include any of various members that are able to support the winding 22B.
  • the present modification example will be described in detail below.
  • FIGs. 24 and 25 illustrate a configuration example of the electric power transmission device 20 according to the present modification example.
  • the present modification example is applied to the electric power transmission device 20 according to Modification Example 4 ( FIGs. 12 and 13 ).
  • the electric power transmission device 20 includes a rotor 42.
  • the rotor 42 includes a support member 42A, a winding 42B, and a magnetic body 42C.
  • the support member 42A includes a resin.
  • the support member 42A is coupled to the shaft 24 and rotationally moves about the axis of rotation AZ with the rotation of the shaft 24.
  • a recess 142 having a groove shape is provided along the circumferential direction A ( FIG. 25 ) about the axis of rotation AZ.
  • the winding 42B is wound multiple times along the recess 142 of the support member 42A. One end and another end of the winding 42B are coupled to the rectifying circuit 14 via a part 42D of the support member 42A and via an unillustrated wiring provided on the shaft 24.
  • the part 42D will be described later.
  • the magnetic body 42C is provided at a position in the rotor 42 corresponding to the opening 123 of the stator 21. As illustrated in FIG. 25 , the magnetic body 42C is so provided as to extend along the circumferential direction A about the axis of rotation AZ. In this example, the magnetic body 42C has a shape of "C" of the alphabet. Specifically, the support member 42A is provided with a cutout in the shape of "C" of the alphabet, and the magnetic body 42C is placed in this cutout of the support member 42A.
  • the support member 42A corresponds to a specific example of the "rotary member” in one embodiment of the disclosure.
  • the winding 42B corresponds to a specific example of the "second winding” in one embodiment of the disclosure.
  • the magnetic body 42C corresponds to a specific example of the "first magnetic body” in one embodiment of the disclosure.
  • the winding 21B is wound directly on the magnetic core 21A2 along the recess 121 of the magnetic core 21A2; however, this is non-limiting.
  • a bobbin 21C on which the winding 21B is wound may be placed in the recess 121 of the magnetic core 21A2.
  • the bobbin 21C includes a resin, for example.
  • stator 21 and the rotors 22 and 42 disclosed in the foregoing embodiment, etc. are mere examples, and their shapes are not limited to the disclosed ones.

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  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Synchronous Machinery (AREA)
  • Iron Core Of Rotating Electric Machines (AREA)

Abstract

An electric power transmission device according to one embodiment of the invention includes a magnetic core, a first winding, a rotary member, a second winding, and a first magnetic body. The magnetic core has a ring shape including a through hole through which a shaft extends. The magnetic core includes therein a cavity along a circumferential direction about an axis of rotation of the shaft, and has a first opening provided along the circumferential direction in a first surface in contact with the through hole, and coupling the through hole and the cavity to each other. The first winding is provided in the cavity and wound along the circumferential direction. The rotary member is provided at a position corresponding to the first opening in an axial direction of the axis of rotation, and is rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft. The second winding is provided on the rotary member and wound along the circumferential direction. The first magnetic body is provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core.

Description

    Technical Field
  • The invention relates to an electric power transmission device that contactlessly transmits electric power, and to a motor apparatus including such an electric power transmission device.
    • Background Art
  • Examples of a motor include an electrically excited synchronous motor (EESM). Such a motor includes a stator on which a winding is wound and a rotor on which a winding is wound. In the motor, a current to be fed through the winding wound on the rotor may be varied in accordance with a rotation speed of the motor. This makes it possible to achieve improved efficiency of the motor.
  • Some devices allow for transmission of electric power between a stator and a rotor. For example, Patent Literature 1 discloses a rotary transformer that includes a stator on which a winding is wound and a rotor on which a winding is wound, and that allows for transmission of electric power between the stator and the rotor.
    • Citation List Patent Literature
  • Patent Literature 1: Japanese Unexamined Patent Application Publication No. 2002-75760
    • Summary of the Invention
  • What is desired of a motor apparatus is to be high in efficiency of a motor, and expectations are placed on further improvement in efficiency of the motor.
  • It is desirable to provide an electric power transmission device and a motor apparatus that each make it possible to increase efficiency of a motor.
  • An electric power transmission device according to one embodiment of the invention includes a magnetic core, a first winding, a rotary member, a second winding, and a first magnetic body. The magnetic core has a ring shape including a through hole through which a shaft extends. The magnetic core includes therein a cavity along a circumferential direction about an axis of rotation of the shaft, and has a first opening provided along the circumferential direction in a first surface in contact with the through hole. The first opening couples the through hole and the cavity to each other. The first winding is provided in the cavity and wound along the circumferential direction. The rotary member is provided at a position corresponding to the first opening in an axial direction of the axis of rotation, and is rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft. The second winding is provided on the rotary member and wound along the circumferential direction. The first magnetic body is provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core.
  • A motor apparatus according to one embodiment of the invention includes a motor, a shaft, an inverter, a magnetic core, a first winding, a rotary member, a second winding, a first magnetic body, and a rectifying circuit. The motor includes a motor stator and a motor rotor. The motor stator includes a first motor magnetic core and a first motor winding. The motor rotor includes a second motor magnetic core and a second motor winding. The shaft is coupled to the motor rotor. The magnetic core has a ring shape including a through hole through which the shaft extends. The magnetic core includes therein a cavity along a circumferential direction about an axis of rotation of the shaft, and has a first opening provided along the circumferential direction in a first surface in contact with the through hole. The first opening couples the through hole and the cavity to each other. The first winding is coupled to the inverter, provided in the cavity, and wound along the circumferential direction. The rotary member is provided at a position corresponding to the first opening in an axial direction of the axis of rotation, and is rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft. The second winding is provided on the rotary member and wound along the circumferential direction. The first magnetic body is provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core. The rectifying circuit is provided in a path coupling the second winding and the second motor winding to each other.
  • The electric power transmission device and the motor apparatus according to the respective embodiments of the invention each make it possible to increase efficiency of the motor.
    • Brief Description of Drawings
    • [FIG. 1] FIG. 1 is a block diagram illustrating a configuration example of a motor apparatus according to one embodiment of the invention.
    • [FIG. 2] FIG. 2 is a perspective diagram illustrating a configuration example of an electric power transmission device illustrated in FIG. 1.
    • [FIG. 3] FIG. 3 is a cross-sectional diagram illustrating a configuration example of the electric power transmission device illustrated in FIG. 2.
    • [FIG. 4] FIG. 4 is an explanatory diagram illustrating a configuration example of a stator illustrated in FIG. 3.
    • [FIG. 5] FIG. 5 is an explanatory diagram illustrating a configuration example of a rotor illustrated in FIG. 3.
    • [FIG. 6] FIG. 6 is an explanatory diagram illustrating an operation example of the electric power transmission device illustrated in FIG. 3.
    • [FIG. 7] FIG. 7 is an explanatory diagram illustrating an example of a magnetic flux in the electric power transmission device illustrated in FIG. 3.
    • [FIG. 8] FIG. 8 is an explanatory diagram illustrating an example of a magnetic flux in an electric power transmission device according to a reference example.
    • [FIG. 9] FIG. 9 is an explanatory diagram illustrating a configuration example of a rotor according to a modification example.
    • [FIG. 10] FIG. 10 is an explanatory diagram illustrating a configuration example of a rotor according to another modification example.
    • [FIG. 11] FIG. 11 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 12] FIG. 12 is a perspective diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 13] FIG. 13 is a cross-sectional diagram illustrating a configuration example of the electric power transmission device illustrated in FIG. 12.
    • [FIG. 14] FIG. 14 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 15] FIG. 15 is an explanatory diagram illustrating a configuration example of a rotor illustrated in FIG. 14.
    • [FIG. 16] FIG. 16 is an explanatory diagram illustrating an example of a magnetic flux in the electric power transmission device illustrated in FIG. 14.
    • [FIG. 17] FIG. 17 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 18] FIG. 18 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 19] FIG. 19 is an explanatory diagram illustrating a configuration example of a rotor illustrated in FIG. 18.
    • [FIG. 20] FIG. 20 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 21] FIG. 21 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 22] FIG. 22 is an explanatory diagram illustrating a configuration example of a rotor illustrated in FIG. 21.
    • [FIG. 23] FIG. 23 is an explanatory diagram illustrating an operation example of the electric power transmission device illustrated in FIG. 21.
    • [FIG. 24] FIG. 24 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    • [FIG. 25] FIG. 25 is an explanatory diagram illustrating a configuration example of a rotor illustrated in FIG. 24.
    • [FIG. 26] FIG. 26 is a cross-sectional diagram illustrating a configuration example of an electric power transmission device according to another modification example.
    Modes for Carrying Out the Invention
  • In the following, a description will be given in detail of embodiments of the invention with reference to the drawings.
    • <Embodiment> <Configuration Example>
  • FIG. 1 illustrates a configuration example of a motor apparatus 1 including an electric power transmission device according to an embodiment of the invention. The motor apparatus 1 is coupled to an external control apparatus 8 and a direct-current power supply 9. The external control apparatus 8 is configured to provide an instruction on a rotation speed to the motor apparatus 1. The direct-current power supply 9 is configured to supply direct-current electric power to the motor apparatus 1. The motor apparatus 1 is configured to generate a driving force, which is mechanical energy, based on an instruction from the external control apparatus 8 and through the use of the direct-current electric power supplied from the direct-current power supply 9. The motor apparatus 1 includes a driver 10 and a motor 30.
  • The driver 10 is configured to drive the motor 30. The driver 10 includes inverters 11 and 12, an electric power transmission device 20, a rectifying circuit 14, and a control circuit 19.
  • The inverter 11 is configured to convert direct-current electric power supplied from the direct-current power supply 9 into three-phase (U-phase, V-phase, and W-phase) alternating-current electric power, based on an instruction from the control circuit 19. In addition, the inverter 11 supplies the three-phase alternating-current electric power to a winding 31B of a stator 31 of the motor 30. The winding 31B will be described later.
  • The inverter 12 is configured to convert direct-current electric power supplied from the direct-current power supply 9 into single-phase alternating-current electric power, based on an instruction from the control circuit 19. In addition, the inverter 12 supplies the alternating-current electric power to a winding 21B of a stator 21 of the electric power transmission device 20. The winding 21B will be described later.
  • The electric power transmission device 20 is configured to supply alternating-current electric power to the rectifying circuit 14 by contactless transmission. The electric power transmission device 20 includes the stator 21, a rotor 22, and a shaft 24.
  • FIG. 2 illustrates a configuration example of the electric power transmission device 20. FIG. 3 illustrates an example of a cross-sectional structure of the electric power transmission device 20 in a plane including an axis of rotation AZ. FIG. 4 illustrates a configuration example of the stator 21. FIG. 4 also depicts a cross-sectional structure of the stator 21 in a plane including the axis of rotation AZ as viewed in an arrowed direction IV-IV. FIG. 5 illustrates a configuration example of the rotor 22. FIG. 5 also depicts a cross-sectional structure of the rotor 22 in a plane including the axis of rotation AZ as viewed in an arrowed direction V-V.
  • The stator 21 is what is called a stator, and is fixed to an unillustrated housing of the motor apparatus 1. The stator 21 includes a magnetic core 21A and the winding 21B, as illustrated in FIGs. 2 and 3.
  • The magnetic core 21A includes a magnetic material, such as ferrite. Magnetic cores 21A1 and 21A2 are disposed at a predetermined distance from each other in a Z direction, with the rotor 22 interposed therebetween. Here, the Z direction is a direction in which the axis of rotation AZ extends, and is from the motor 30 toward the electric power transmission device 20. The magnetic core 21A includes the magnetic core 21A1 and the magnetic core 21A2. The magnetic core 21A1 is a ring-shaped magnetic member having a through hole 120 through which the shaft 24 extends. In this example, the magnetic core 21A1 has the form of a flat plate. The magnetic core 21A2 is a ring-shaped magnetic member having the through hole 120 through which the shaft 24 extends. In the magnetic core 21A2, a recess 121 having a groove shape is provided along a circumferential direction A (FIG. 4) about the axis of rotation AZ in a surface S21 (FIGs. 3 and 4) facing the rotor 22. With such a configuration, the magnetic core 21A including the magnetic cores 21A1 and 21A2 is provided with a cavity 122 along the circumferential direction A, and with openings 123 and 124. The opening 123 couples the cavity 122 and a space on an inner side of the magnetic core 21A in a radial direction (i.e., a horizontal direction in FIG. 3) to the axis of rotation AZ to each other. The opening 124 couples the cavity 122 and a space on an outer side of the magnetic core 21A in the radial direction to each other.
  • The winding 21B is wound multiple times along the recess 121 of the magnetic core 21A2. The winding 21B is coupled to the inverter 12 through a hole (not illustrated) provided in the magnetic core 21A2, for example.
  • The rotor 22 is what is called a rotor, and is configured to rotationally move about the axis of rotation AZ. The rotor 22 is so disposed as to be interposed between the magnetic core 21A1 and the magnetic core 21A2 of the stator 21 in the Z direction, and is fixed to the shaft 24. As illustrated in FIGs. 3 and 5, the rotor 22 includes a substrate 22A, a winding 22B, a magnetic body 22C, and a magnetic body 22E.
  • The substrate 22A is a printed circuit board (PCB), for example. The substrate 22A is coupled to the shaft 24 and rotationally moves in the circumferential direction A about the axis of rotation AZ with a rotation of the shaft 24.
  • The winding 22B includes a patterned wiring provided on the substrate 22A, and is wound multiple times along the circumferential direction A (FIG. 5) about the axis of rotation AZ. The winding 22B includes a metal material, such as copper. In this example, the winding 22B is provided on both surfaces of the substrate 22A. Note that this is non-limiting, and the winding 22B may be provided on one of both surfaces of the substrate 22A. Further, when the substrate 22A is a multilayer substrate, the winding 22B may include a patterned wiring within the substrate 22A. One end and another end of the winding 22B are coupled to the rectifying circuit 14 via a part 22D of the substrate 22A and an unillustrated wiring provided on the shaft 24. The part 22D will be described later.
  • The magnetic body 22C includes a magnetic material, such as ferrite, and is provided at a position in the rotor 22 corresponding to the opening 123 of the stator 21, as illustrated in FIG. 3. As illustrated in FIG. 5, the magnetic body 22C is so provided as to extend along the circumferential direction A about the axis of rotation AZ. In this example, the magnetic body 22C has a shape of "C" of the alphabet. Specifically, the substrate 22A is provided with a cutout in the shape of "C" of the alphabet, and the magnetic body 22C is placed in this cutout of the substrate 22A. Of the substrate 22A, a part located on an inner side relative to the magnetic body 22C and a part located on an outer side relative to the magnetic body 22C are coupled to each other by the part 22D of the substrate 22A. Note that this is non-limiting, and the magnetic body 22C may have a ring shape. In such a case, for example, an insulating film may be provided on a surface of a part of the magnetic body 22C, and a wiring that couples the one end and the other end of the winding 22B to the rectifying circuit 14 may be provided on the insulating film. In this example, a width in the radial direction (i.e., the horizontal direction in FIG. 3) of the magnetic body 22C is equal to a width in the radial direction of one projection, of two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123.
  • The magnetic body 22E includes a magnetic material, such as ferrite, and is provided at a position in the rotor 22 corresponding to the opening 124 of the stator 21, as illustrated in FIG. 3. As illustrated in FIG. 5, the magnetic body 22E is so provided as to extend along the circumferential direction A about the axis of rotation AZ. In this example, the magnetic body 22E has a ring shape. Specifically, the substrate 22A is provided with a ring-shaped cutout, and the magnetic body 22E is placed in this cutout of the substrate 22A. In this example, a width in the radial direction (i.e., the horizontal direction in FIG. 3) of the magnetic body 22E is equal to a width in the radial direction of another projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
  • In the electric power transmission device 20, as illustrated in FIG. 3, a gap G is provided between the magnetic core 21A1 and the magnetic body 22C in the vicinity of the opening 123, and a gap G is provided between the magnetic core 22C and the projection of the magnetic core 21A2 in the vicinity of the opening 123. Thus, in the vicinity of the opening 123 in the electric power transmission device 20, the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic body 22C. Similarly, a gap G is provided between the magnetic core 21A1 and the magnetic body 22E in the vicinity of the opening 124, and a gap G is provided between the magnetic core 22E and the projection of the magnetic core 21A2 in the vicinity of the opening 124. Thus, in the vicinity of the opening 124 in the electric power transmission device 20, the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic body 22E. With such a configuration, the electric power transmission device 20 converts alternating-current electric power supplied from the inverter 12 in accordance with a ratio between the number of turns of the winding 21B and the number of turns of the winding 22B, and supplies the converted alternating-current electric power to the rectifying circuit 14. The electric power transmission device 20 is also called a rotary transformer.
  • The shaft 24 is coupled to a rotor 32 of the motor 30, and is configured to rotate about the axis of rotation AZ, based on a driving force generated by the motor 30.
  • The rectifying circuit 14 (FIG. 1) is configured to rectify alternating-current electric power supplied from the winding 22B of the rotor 22 and to supply the rectified electric power to a winding 32B of the rotor 32 of the motor 30. The winding 32B will be described later. Although not illustrated, the rectifying circuit 14 is coupled to the shaft 24. More specifically, because the winding 22B and the rotor 32 of the motor 30 are coupled to the shaft 24, the rectifying circuit 14 is also coupled to the shaft 24. Note that although the electric power rectified by the rectifying circuit 14 is directly supplied to the winding 32B in this example, this is non-limiting. Alternatively, for example, the electric power rectified by the rectifying circuit 14 may be supplied to the winding 32B via a stabilizing circuit including a capacitor.
  • The control circuit 19 is configured to control an operation of each of the inverters 11 and 12, based on an instruction from the external control apparatus 8 and a control signal, supplied from the motor 30, that indicates a rotation speed. Specifically, based on the instruction from the external control apparatus 8 and the control signal indicating the rotation speed of the motor 30, the control circuit 19 controls the operation of the inverter 11 to thereby control the rotation speed of the motor 30. Further, based on the control signal indicating the rotation speed supplied from the motor 30, the control circuit 19 controls the operation of the invertor 12 to thereby control intensity of a magnetic field to be generated by the rotor 32 of the motor 30. Specifically, for example, when the rotation speed of the motor 30 is low, the control circuit 19 intensifies the magnetic field to be generated by the rotor 32 of the motor 30, and when the rotation speed of the motor 30 is high, the control circuit 19 weakens the magnetic field to be generated by the rotor 32 of the motor 30.
  • The motor 30 is an electrically excited synchronous motor. The motor 30 includes the stator 31, the rotor 32, and a sensor 33.
  • The stator 31 is what is called a stator, and is fixed to an unillustrated housing of the motor 30. The stator 31 includes a magnetic core 31A and the winding 31B. The winding 31B is to be supplied with the three-phase (U-phase, V-phase, and W-phase) alternating-current electric power generated by the inverter 11.
  • The rotor 32 is what is called a rotor, and is configured to rotate about the axis of rotation AZ. The rotor 32 includes a magnetic core 32A and the winding 32B. The winding 32B is to be supplied with a signal rectified by the rectifying circuit 14.
  • The sensor 33 is configured to detect a rotation speed of the rotor 32. In addition, the sensor 33 supplies a control signal indicating the rotation speed of the rotor 32 to the control circuit 19.
  • With such a configuration, in the motor apparatus 1, the rotation speed of the motor 30 is controlled based on the three-phase (U-phase, V-phase, and W-phase) alternating-current electric power generated by the inverter 11, and the magnetic field to be generated by the rotor 32 of the motor 30 is controlled based on the single-phase alternating-current electric power generated by the inverter 12. In the motor apparatus 1, for example, when the rotation speed of the motor 30 is low, the magnetic field to be generated by the rotor 32 of the motor 30 is intensified, and when the rotation speed of the motor 30 is high, the magnetic field to be generated by the rotor 32 of the motor 30 is weakened. This makes it possible for the motor apparatus 1 to increase efficiency of the motor 30 over a wide rotation speed range.
  • Here, the shaft 24 corresponds to a specific example of a "shaft" in one embodiment of the disclosure. The axis of rotation AZ corresponds to a specific example of an "axis of rotation" in one embodiment of the disclosure. The magnetic core 21A corresponds to a specific example of a "magnetic core" in one embodiment of the disclosure. The cavity 122 corresponds to a specific example of a "cavity" in one embodiment of the disclosure. The opening 123 corresponds to a specific example of a "first opening" in one embodiment of the disclosure. The winding 21B corresponds to a specific example of a "first winding" in one embodiment of the disclosure. The substrate 22A corresponds to a specific example of a "rotary member" in one embodiment of the disclosure. The winding 22B corresponds to a specific example of a "second winding" in one embodiment of the disclosure. The magnetic body 22C corresponds to a specific example of a "first magnetic body" in one embodiment of the disclosure. The opening 124 corresponds to a specific example of a "second opening" in one embodiment of the disclosure. The magnetic body 22E corresponds to a specific example of a "second magnetic body" in one embodiment of the disclosure.
  • The stator 31 corresponds to a specific example of a "motor stator" in one embodiment of the disclosure. The magnetic core 31A corresponds to a specific example of a "first motor magnetic core" in one embodiment of the disclosure. The winding 31B corresponds to a specific example of a "first motor winding" in one embodiment of the disclosure. The rotor 32 corresponds to a specific example of a "motor rotor" in one embodiment of the disclosure. The magnetic core 32A corresponds to a specific example of a "second motor magnetic core" in one embodiment of the disclosure. The winding 32B corresponds to a specific example of a "second motor winding" in one embodiment of the disclosure. The inverter 12 corresponds to a specific example of an "inverter" in one embodiment of the disclosure. The rectifying circuit 14 corresponds to a specific example of a "rectifying circuit" in one embodiment of the disclosure.
    • <Operation and Workings>
  • Next, a description will be given of operation and workings of the motor apparatus 1 of the present embodiment.
    • <Outline of Overall Operation>
  • The control circuit 19 controls the operation of each of the inverters 11 and 12, based on the instruction from the external control apparatus 8 and the control signal, supplied from the motor 30, that indicates the rotation speed. Based on the instruction from the control circuit 19, the inverter 11 converts direct-current electric power supplied from the direct-current power supply 9 into three-phase (U-phase, V-phase, and W-phase) alternating-current electric power, and supplies the three-phase alternating-current electric power to the winding 31B of the stator 31 of the motor 30. Based on the instruction from the control circuit 19, the inverter 12 converts the direct-current electric power supplied from the direct-current power supply 9 into single-phase alternating-current electric power, and supplies the alternating-current electric power to the winding 21B of the stator 21 of the electric power transmission device 20. The electric power transmission device 20 supplies the alternating-current electric power to the rectifying circuit 14 by contactless transmission. The rectifying circuit 14 rectifies the alternating-current electric power supplied from the winding 22B of the rotor 22, and supplies the rectified electric power to the winding 32B of the rotor 32 of the motor 30. The motor 30 generates the driving force, which is mechanical energy, based on the three-phase (U-phase, V-phase, and W-phase) alternating-current electric power supplied from the inverter 11. This causes the shaft 24 to rotate about the axis of rotation AZ. The sensor 33 of the motor 30 supplies the control signal indicating the rotation speed of the motor 30 to the control circuit 19.
    • <Operation and Workings>
  • Next, a description will be given of operation and workings of the electric power transmission device 20 of the present embodiment.
  • The alternating-current electric power is supplied from the inverter 12 to the winding 21B of the stator 21 of the electric power transmission device 20. The rotor 22 rotationally moves in the circumferential direction A illustrated in FIG. 2, for example, about the axis of rotation AZ.
  • FIG. 6 illustrates a cross-sectional view of the stator 21 and the rotor 22 in the electric power transmission device 20. The winding 21B of the stator 21 generates a magnetic field, based on the alternating-current electric power supplied from the inverter 12. In the vicinity of the opening 123, the magnetic core 21A1 and the projection of the magnetic core 21A2 in the vicinity of the opening 123 are magnetically coupled to each other via the magnetic body 22C. In the vicinity of the opening 124, the magnetic core 21A1 and the projection of the magnetic core 21A2 in the vicinity of the opening 124 are magnetically coupled to each other via the magnetic body 22E.
  • FIG. 7 illustrates an example of a magnetic flux in each of the openings 123 and 124 of the electric power transmission device 20. Note that FIG. 7 omits the illustration of a part of the electric power transmission device 20. Leakage fluxes occur in the vicinities of the openings 123 and 124. Directions of the leakage fluxes vary depending on a polarity of the alternating-current electric power. In the vicinity of the opening 123, in this example, there occurs a leakage flux in a direction from the magnetic core 21A2 toward the magnetic body 22C, and there occurs a leakage flux in a direction from the magnetic body 22C toward the magnetic core 21A1. In this way, in the vicinity of the opening 123, the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic body 22C. Further, in the vicinity of the opening 124, in this example, there occurs a leakage flux in a direction from the magnetic core 21A1 toward the magnetic body 22E, and there occurs a leakage flux in a direction from the magnetic body 22E toward the magnetic core 21A2. In this way, in the vicinity of the opening 124, the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic body 22E.
  • In the electric power transmission device 20, as illustrated in FIG. 6, a magnetic path MP is thus generated that passes through the magnetic core 21A1, the magnetic body 22C, the magnetic core 21A2, and the magnetic body 22E.
  • In addition, the winding 22B of the rotor 22 generates alternating-current electric power, based on a magnetic field in the magnetic path MP, and supplies the generated alternating-current electric power to the rectifying circuit 14. In this way, it is possible for the electric power transmission device 20 to supply alternating-current electric power to the rectifying circuit 14 by contactless transmission.
  • As described above, the electric power transmission device 20 transmits electric power by contactless transmission. This makes it possible to increase reliability as compared with a case of transmitting electric power by contact transmission through the use of, for example, a slip ring and a brush.
  • The rectifying circuit 14 rectifies the alternating-current electric power supplied from the winding 22B of the rotor 22, and supplies the rectified electric power to the winding 32B of the rotor 32 of the motor 30. A magnetic field is thus generated at the rotor 32 of the motor 30. For example, when the rotation speed of the motor 30 is low, the control circuit 19 intensifies the magnetic field to be generated by the rotor 32 of the motor 30, and when the rotation speed of the motor 30 is high, the control circuit 19 weakens the magnetic field to be generated by the rotor 32 of the motor 30. This makes it possible for the motor apparatus 1 to increase efficiency of the motor 30 over a wide rotation speed range.
  • As described above, in the electric power transmission device 20, the rotor 22 includes the substrate 22A on which the winding 22B is provided. This makes it possible for the rotor 22 to be lightweight as compared with a rotor including a rotor iron core as described in Patent Literature 1, for example. Accordingly, it is possible to reduce a moment of rotation and to reduce an inertial force.
  • Further, in the electric power transmission device 20, the provision of the magnetic body 22C makes it possible to suppress spreading of the leakage fluxes in the vicinity of the opening 123, and thus makes it possible to reduce a possibility that any of the leakage fluxes enter the shaft 24 or the winding 22B. Further, the provision of the magnetic body 22E makes it possible to suppress spreading of the leakage fluxes in the vicinity of the opening 124, and thus makes it possible to reduce the possibility that any of the leakage fluxes enter the winding 22B. As a result, it is possible for the electric power transmission device 20 to reduce energy loss and to increase efficiency of the motor.
  • More specifically, for example, in a case without the magnetic body 22C as illustrated in FIG. 8, the gap G in the vicinity of the opening 123 is to be provided between the magnetic core 21A1 and the projection of the magnetic core 21A2 in the vicinity of the opening 123. This results in an increase in length of the gap G. Accordingly, as illustrated in FIG. 8, the leakage fluxes can spread over a larger area in the radial direction (i.e., the horizontal direction in FIG. 8). If any of the leakage fluxes enter the shaft 24, an eddy current would occur in the shaft 24 to result in energy loss. Further, if any of the leakage fluxes enter the winding 22B, an eddy current would occur in the winding 22B to result in energy loss. Similarly, in a case without the magnetic body 22E, the gap G in the vicinity of the opening 124 is to be provided between the magnetic core 21A1 and the projection of the magnetic core 21A2 in the vicinity of the opening 124. This results in an increase in length of the gap G. Accordingly, as illustrated in FIG. 8, the leakage fluxes can spread over a larger area in the radial direction (i.e., the horizontal direction in FIG. 8). If any of the leakage fluxes enter the winding 22B, an eddy current would occur in the winding 22B to result in energy loss.
  • In contrast, the electric power transmission device 20 is provided with the magnetic bodies 22C and 22E, which makes it possible for the gaps G to be shorter, and thus makes it possible to suppress spreading of the leakage fluxes in the radial direction (i.e., the horizontal direction in FIG. 7). Accordingly, it is possible to reduce the possibility that any of the leakage fluxes enter the shaft 24 or the winding 22B. This makes it possible to reduce energy loss and to increase efficiency of the motor.
  • As described above, the electric power transmission device 20 includes the magnetic core 21A, the first winding (the winging 21B), the substrate 22A, the second winding (the winding 22B), and the first magnetic body (the magnetic body 22C). The magnetic core 21A has a ring shape including the through hole 120 through which the shaft 24 extends. The magnetic core 21A includes therein the cavity 122 along the circumferential direction A about the axis of rotation AZ of the shaft 24, and has the first opening (the opening 123) provided along the circumferential direction A in a first surface in contact with the through hole 120. The first opening (the opening 123) couples the through hole 120 and the cavity 122 to each other. The first winding (the winding 21B) is provided in the cavity 122 and wound along the circumferential direction A. The substrate 22A is provided at a position corresponding to the first opening (the opening 123) in an axial direction of the axis of rotation AZ, and is rotationally movable, inside the cavity 122, in the circumferential direction A with the rotation of the shaft 24. The second winding (the winding 22B) is provided on the substrate 22A and wound along the circumferential direction A. The first magnetic body (the magnetic body 22C) is provided along the circumferential direction A in a part of the substrate 22A corresponding to the first opening (the opening 123) of the magnetic core 21A. This makes it possible to suppress spreading of the leakage fluxes in the vicinity of the opening 123, and to reduce the possibility that any of the leakage fluxes enter the shaft 24 or the winding 22B. As a result, it is possible for the electric power transmission device 20 to reduce energy loss and to increase efficiency of the motor.
  • The electric power transmission device 20 further includes the second magnetic body (the magnetic body 22E). The magnetic core 21A has the second opening (the opening 124) provided in a second surface at a position corresponding to the first opening (the opening 123) in the axial direction. The second surface is opposite to the first surface in the radial direction to the axis of rotation AZ. The second magnetic body (the magnetic body 22E) is provided along the circumferential direction A in a part of the substrate 22A corresponding to the second opening (the opening 124) of the magnetic core 21A. This makes it possible to suppress spreading of the leakage fluxes in the vicinity of the opening 124, and to reduce the possibility that any of the leakage fluxes enter the winding 22B. As a result, it is possible for the electric power transmission device 20 to reduce energy loss and to increase efficiency of the motor.
    • <Effects>
  • As described above, a magnetic core, a first winding, a substrate, a second winding, and a first magnetic body are provided in the present embodiment. The magnetic core has a ring shape including a through hole through which a shaft extends. The magnetic core includes therein a cavity along a circumferential direction about an axis of rotation of the shaft, and has a first opening provided along the circumferential direction in a first surface in contact with the through hole. The first opening couples the through hole and the cavity to each other. The first winding is provided in the cavity and wound along the circumferential direction. The substrate is provided at a position corresponding to the first opening in an axial direction of the axis of rotation, and is rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft. The second winding is provided on the substrate and wound along the circumferential direction. The first magnetic body is provided along the circumferential direction in a part of the substrate corresponding to the first opening of the magnetic core. This makes it possible to increase efficiency of the motor.
  • In the present embodiment, a second magnetic body is further provided. The magnetic core has a second opening provided in a second surface at a position corresponding to the first opening in the axial direction. The second surface is opposite to the first surface in a radial direction to the axis of rotation. The second magnetic body is provided along the circumferential direction in a part of the substrate corresponding to the second opening of the magnetic core. This makes it possible to increase efficiency of the motor.
    • <Modification Example 1>
  • In the foregoing embodiment, as illustrated in FIG. 5, for example, the magnetic body 22C is configured of a single magnetic body; however, this is non-limiting. Alternatively, as illustrated in FIG. 9, for example, the magnetic body 22C may include a plurality of magnetic bodies. In an example of FIG. 9, the magnetic body 22C includes two magnetic bodies.
    • <Modification Example 2>
  • In the foregoing embodiment, as illustrated in FIGs. 3 and 5, for example, the magnetic body 22E is provided; however, this is non-limiting. Alternatively, as illustrated in FIG. 10, for example, no magnetic body 22E may be provided.
    • <Modification Example 3>
  • In the foregoing embodiment, as illustrated in FIG. 3, for example, the width in the radial direction (i.e., the horizontal direction in FIG. 3) of the magnetic body 22C is equal to the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123; however, this is non-limiting. Alternatively, as illustrated in FIG. 11, for example, the width in the radial direction (i.e., the horizontal direction in FIG. 11) of the magnetic body 22C may be greater than the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123.
  • Similarly, although the width in the radial direction (i.e., the horizontal direction in FIG. 3) of the magnetic body 22E is equal to the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124, this is non-limiting. Alternatively, as illustrated in FIG. 11, for example, the width in the radial direction (i.e., the horizontal direction in FIG. 11) of the magnetic body 22E may be greater than the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
    • <Modification Example 4>
  • In the foregoing embodiment, as illustrated in FIG. 3, for example, the magnetic core 21A has the opening 123 and the opening 124; however, this is non-limiting. Alternatively, as illustrated in FIGs. 12 and 13, for example, the magnetic core 21A may have the single opening 123 alone. In this example, as illustrated in FIG. 13, a part of the magnetic core 21A1 on an outer side in the radial direction (i.e., the horizontal direction in FIG. 13) bends in the Z direction and is coupled to the magnetic core 21A2 at a coupling part 125. In a process of manufacturing this electric power transmission device 20, the magnetic core 21A1, the rotor 22, and the magnetic core 21A2 are arranged in this order in the Z direction, and the magnetic core 21A1, the rotor 22, and the magnetic core 21A2 are brought close to each other to cause the magnetic core 21A1 and the magnetic core 21A2 to be bonded to each other, for example, at the coupling part 125. The electric power transmission device 20 is provided with no opening 124, and is thus free from any leakage flux at the opening 124. This makes it possible to reduce energy loss, and to increase efficiency of the motor.
    • <Modification Example 5>
  • In the foregoing embodiment, as illustrated in FIG. 5, for example, the magnetic bodies 22C and 22E are placed in the cutouts of the substrate 22A; however, this is non-limiting. Alternatively, as illustrated in FIGs. 14 and 15, for example, the magnetic bodies 22C and 22E may be provided on the surfaces of the substrate 22A. In this example, the rotor 22 includes the magnetic bodies 22C (magnetic bodies 22C1 and 22C2) and the magnetic bodies 22E (magnetic bodies 22E1 and 22E2). As illustrated in FIG. 14, the magnetic body 22C1 is provided on one surface, of the substrate 22A, on a side where the magnetic core 21A1 is provided, and the magnetic body 22C2 is provided on another surface, of the substrate 22A, on a side where the magnetic core 21A2 is provided. In this example, the magnetic body 22C1 and the magnetic body 22C2 each have a ring shape. The one end and the other end of the winding 22B are coupled to the rectifying circuit 14 at a part 22D1, for example, via the patterned wiring within the substrate 22A. The magnetic body 22E1 is provided on the one surface, of the substrate 22A, on the side where the magnetic core 21A1 is provided, and the magnetic body 22E2 is provided on the other surface, of the substrate 22A, on the side where the magnetic core 21A2 is provided.
  • FIG. 16 illustrates an example of the magnetic flux in each of the openings 123 and 124 of the electric power transmission device 20 according to the present modification example. In the vicinity of the opening 123, in this example, there occurs a leakage flux in a direction from the magnetic core 21A2 toward the magnetic body 22C2, there occurs a leakage flux in a direction from the magnetic body 22C2 toward the magnetic body 22C1, and there occurs a leakage flux in a direction from the magnetic body 22C1 toward the magnetic core 21A1. In this way, in the vicinity of the opening 123, the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic bodies 22C1 and 22C2. Further, in the vicinity of the opening 124, in this example, there occurs a leakage flux in a direction from the magnetic core 21A1 toward the magnetic body 22E1, there occurs a leakage flux in a direction from the magnetic body 22E1 toward the magnetic body 22E2, and there occurs a leakage flux in a direction from the magnetic body 22E2 toward the magnetic core 21A2. In this way, in the vicinity of the opening 124, the magnetic core 21A1 and the magnetic core 21A2 are magnetically coupled to each other via the magnetic bodies 22E1 and 22E2.
  • The electric power transmission device 20 according to the present modification example is provided with the magnetic bodies 22C (the magnetic bodies 22C1 and 22C2) and the magnetic bodies 22E (the magnetic bodies 22E1 and 22E2). This makes it possible for the gaps G to be even shorter than those in the foregoing embodiment (FIG. 7), and thus makes it possible to further suppress spreading of the leakage fluxes in the radial direction (i.e., the horizontal direction in FIG. 16). Accordingly, it is possible to further reduce the possibility that any of the leakage fluxes enter the shaft 24 or the winding 22B. This makes it possible to reduce energy loss and to increase efficiency of the motor.
  • Note that in this example, the width in the radial direction (i.e., the horizontal direction in FIG. 14) of each of the magnetic bodies 22C1 and 22C2 is equal to the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123; however, this is non-limiting. Alternatively, as illustrated in FIG. 17, for example, the width in the radial direction (i.e., the horizontal direction in FIG. 17) of each of the magnetic bodies 22C1 and 22C2 may be greater than the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123.
  • Similarly, although the width in the radial direction (i.e., the horizontal direction in FIG. 14) of each of the magnetic bodies 22E1 and 22E2 is equal to the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124, this is non-limiting. Alternatively, as illustrated in FIG. 17, for example, the width in the radial direction (i.e., the horizontal direction in FIG. 17) of each of the magnetic bodies 22E1 and 22E2 may be greater than the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
    • <Modification Example 6>
  • In the foregoing embodiment, as illustrated in FIG. 5, for example, the magnetic bodies 22C and 22E are placed in the cutouts of the substrate 22A; however, this is non-limiting. Alternatively, as illustrated in FIGs. 18 and 19, for example, the magnetic bodies 22C and 22E may be buried within the substrate 22A. In this example, the magnetic bodies 22C and 22E each have a ring shape. The magnetic body 22C is provided within the substrate 22A in a part of the substrate 22A corresponding to the opening 123. The one end and the other end of the winding 22B are coupled to the rectifying circuit 14 at a part 22D2, for example, via a patterned wiring on the surface of the substrate 22A in which the magnetic body 22C is buried. The magnetic body 22E is provided within the substrate 22A in a part of the substrate 22A corresponding to the opening 124.
  • Note that in this example, the width in the radial direction (i.e., the horizontal direction in FIG. 18) of the magnetic body 22C is equal to the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123; however, this is non-limiting. Alternatively, as illustrated in FIG. 20, for example, the width of the magnetic body 22C in the radial direction (i.e., the horizontal direction in FIG. 20) may be greater than the width in the radial direction of the one projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 123.
  • Similarly, although the width in the radial direction (i.e., the horizontal direction in FIG. 18) of the magnetic body 22E is equal to the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124, this is non-limiting. Alternatively, as illustrated in FIG. 20, for example, the width in the radial direction (i.e., the horizontal direction in FIG. 20) of the magnetic body 22E may be greater than the width in the radial direction of the other projection, of the two projections of the magnetic core 21A2 on both sides of the recess 121, that is in the vicinity of the opening 124.
    • <Modification Example 7>
  • In the foregoing embodiment, as illustrated in FIG. 3, for example, the magnetic body 22C is provided only at the position corresponding to the opening 123; however, this is non-limiting. Alternatively, as illustrated in FIGs. 21 and 22, for example, the magnetic body 22C may be provided within the substrate 22A in a region, of the substrate 22A in an XY plane, that includes the part corresponding to the opening 123 of the magnetic core 21A and a part on an outer side thereof. In this example, the present modification example is applied to the electric power transmission device 20 according to Modification Example 4 (FIGs. 12 and 13). The magnetic body 22C is buried within the substrate 22A. In the electric power transmission device 20, in the vicinity of the opening 123, a gap G is provided between the magnetic core 21A1 and the magnetic body 22C, and a gap G is provided between the magnetic body 22C and the projection of the magnetic core 21A2 in the vicinity of the opening 123. Further, a gap G is provided between an outer end of the magnetic body 22C in the radial direction (i.e., the horizontal direction in FIG. 21) and the magnetic core 21A2.
  • FIG. 23 illustrates a cross-sectional view of the stator 21 and the rotor 22 in the electric power transmission device 20 according to the present modification example. The winding 21B of the stator 21 generates a magnetic field, based on alternating-current electric power supplied from the inverter 12. In the vicinity of the opening 123, the magnetic core 21A1 and the magnetic body 22C are magnetically coupled to each other, and the magnetic body 22C and the projection of the magnetic core 21A2 in the vicinity of the opening 123 are magnetically coupled to each other. Further, the outer end of the magnetic body 22C in the radial direction (i.e., the horizontal direction in FIG. 23) and the magnetic core 21A2 are magnetically coupled to each other. Thus, in the electric power transmission device 20, as illustrated in FIG. 6, a magnetic path MP is generated that passes through the magnetic core 21A1, the magnetic body 22C, and the magnetic core 21A2, and a magnetic path MP is generated that passes through the magnetic body 22C and the magnetic core 21A2. This makes it possible to reduce a possibility that any of the leakage fluxes in the vicinity of the opening 123 enter the shaft 24 or the winding 22B. Accordingly, it is possible to reduce energy loss and to increase efficiency of the motor.
    • <Modification Example 8>
  • In the foregoing embodiment, the rotor 22 includes the substrate 22A; however, this is non-limiting, and the rotor 22 may include any of various members that are able to support the winding 22B. The present modification example will be described in detail below.
  • FIGs. 24 and 25 illustrate a configuration example of the electric power transmission device 20 according to the present modification example. In this example, the present modification example is applied to the electric power transmission device 20 according to Modification Example 4 (FIGs. 12 and 13). The electric power transmission device 20 includes a rotor 42. The rotor 42 includes a support member 42A, a winding 42B, and a magnetic body 42C.
  • In this example, the support member 42A includes a resin. The support member 42A is coupled to the shaft 24 and rotationally moves about the axis of rotation AZ with the rotation of the shaft 24. In the support member 42A, a recess 142 having a groove shape is provided along the circumferential direction A (FIG. 25) about the axis of rotation AZ.
  • The winding 42B is wound multiple times along the recess 142 of the support member 42A. One end and another end of the winding 42B are coupled to the rectifying circuit 14 via a part 42D of the support member 42A and via an unillustrated wiring provided on the shaft 24. The part 42D will be described later.
  • As illustrated in FIG. 24, the magnetic body 42C is provided at a position in the rotor 42 corresponding to the opening 123 of the stator 21. As illustrated in FIG. 25, the magnetic body 42C is so provided as to extend along the circumferential direction A about the axis of rotation AZ. In this example, the magnetic body 42C has a shape of "C" of the alphabet. Specifically, the support member 42A is provided with a cutout in the shape of "C" of the alphabet, and the magnetic body 42C is placed in this cutout of the support member 42A. Of the support member 42A, a part located on an inner side relative to the magnetic body 42C and a part located on an outer side relative to the magnetic body 42C are coupled to each other by the part 42D of the support member 42A. Note that this is non-limiting, and the magnetic body 42C may have a ring shape. In such a case, for example, an insulating film may be provided on a surface of a part of the magnetic body 42C, and a wiring that couples the one end and the other end of the winding 42B to the rectifying circuit 14 may be provided on the insulating film.
  • Here, the support member 42A corresponds to a specific example of the "rotary member" in one embodiment of the disclosure. The winding 42B corresponds to a specific example of the "second winding" in one embodiment of the disclosure. The magnetic body 42C corresponds to a specific example of the "first magnetic body" in one embodiment of the disclosure.
    • <Modification Example 9>
  • In the foregoing embodiment, as illustrated in FIGs. 3 and 4, for example, the winding 21B is wound directly on the magnetic core 21A2 along the recess 121 of the magnetic core 21A2; however, this is non-limiting. Alternatively, for example, as illustrated in FIG. 26, a bobbin 21C on which the winding 21B is wound may be placed in the recess 121 of the magnetic core 21A2. The bobbin 21C includes a resin, for example.
    • <Other Modification Examples>
  • Further, two or more of these modification examples may be combined.
  • The invention has been described hereinabove with reference to the embodiment and the modification examples. However, the invention is not limited to the embodiment, etc., and may be modified in a variety of ways.
  • For example, the shapes of the stator 21 and the rotors 22 and 42 disclosed in the foregoing embodiment, etc. are mere examples, and their shapes are not limited to the disclosed ones.
  • The effects described in the present specification are mere examples, and effects of the disclosure are not limited to those described in the present specification. Accordingly, the disclosure may achieve any other effect.
  • Further, the disclosure may encompass the following embodiments.
    1. (1) An electric power transmission device including:
      • a magnetic core having a ring shape including a through hole through which a shaft extends, the magnetic core including therein a cavity along a circumferential direction about an axis of rotation of the shaft, and having a first opening provided along the circumferential direction in a first surface in contact with the through hole, the first opening coupling the through hole and the cavity to each other;
      • a first winding provided in the cavity and wound along the circumferential direction;
      • a rotary member provided at a position corresponding to the first opening in an axial direction of the axis of rotation, the rotary member being rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft;
      • a second winding provided on the rotary member and wound along the circumferential direction; and
      • a first magnetic body provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core.
    2. (2) The electric power transmission device according to (1), in which
      • the rotary member has a cutout in the part of the rotary member corresponding to the first opening of the magnetic core, the cutout extending in the circumferential direction, and
      • the first magnetic body is provided in the cutout of the rotary member.
    3. (3) The electric power transmission device according to (1), in which the first magnetic body is provided on a surface of the part of the rotary member corresponding to the first opening of the magnetic core.
    4. (4) The electric power transmission device according to (1), in which the first magnetic body is provided within the rotary member in the part of the rotary member corresponding to the first opening of the magnetic core.
    5. (5) The electric power transmission device according to (1), in which the first magnetic body is provided within the rotary member in a region, of the rotary member in a plane intersecting the axis of rotation, that includes the part of the rotary member corresponding to the first opening of the magnetic core and a part of the rotary member where the second winding is provided.
    6. (6) The electric power transmission device according to any one of (1) to (4), further including
      • a second magnetic body, in which
      • the magnetic core has a second opening provided in a second surface at a position corresponding to the first opening in the axial direction, the second surface being opposite to the first surface in a radial direction to the axis of rotation, and
      • the second magnetic body is provided along the circumferential direction in a part of the rotary member corresponding to the second opening of the magnetic core.
    7. (7) A motor apparatus including:
      • a motor including a motor stator and a motor rotor, the motor stator including a first motor magnetic core and a first motor winding, the motor rotor including a second motor magnetic core and a second motor winding;
      • a shaft coupled to the motor rotor;
      • an inverter;
      • a magnetic core having a ring shape including a through hole through which the shaft extends, the magnetic core including therein a cavity along a circumferential direction of the shaft, and having a first opening provided along the circumferential direction in a first surface in contact with the through hole, the first opening coupling the through hole and the cavity to each other;
      • a first winding coupled to the inverter, provided in the cavity, and wound along the circumferential direction;
      • a rotary member provided at a position corresponding to the first opening in an axial direction of the shaft, the rotary member being rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft;
      • a second winding provided on the rotary member and wound along the circumferential direction;
      • a first magnetic body provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core; and
      • a rectifying circuit provided in a path coupling the second winding and the second motor winding to each other.

Claims (7)

  1. An electric power transmission device comprising:
    a magnetic core having a ring shape including a through hole through which a shaft extends, the magnetic core including therein a cavity along a circumferential direction about an axis of rotation of the shaft, and having a first opening provided along the circumferential direction in a first surface in contact with the through hole, the first opening coupling the through hole and the cavity to each other;
    a first winding provided in the cavity and wound along the circumferential direction;
    a rotary member provided at a position corresponding to the first opening in an axial direction of the axis of rotation, the rotary member being rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft;
    a second winding provided on the rotary member and wound along the circumferential direction; and
    a first magnetic body provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core.
  2. The electric power transmission device according to claim 1, wherein
    the rotary member has a cutout in the part of the rotary member corresponding to the first opening of the magnetic core, the cutout extending in the circumferential direction, and
    the first magnetic body is provided in the cutout of the rotary member.
  3. The electric power transmission device according to claim 1, wherein the first magnetic body is provided on a surface of the part of the rotary member corresponding to the first opening of the magnetic core.
  4. The electric power transmission device according to claim 1, wherein the first magnetic body is provided within the rotary member in the part of the rotary member corresponding to the first opening of the magnetic core.
  5. The electric power transmission device according to claim 1, wherein the first magnetic body is provided within the rotary member in a region, of the rotary member in a plane intersecting the axis of rotation, that includes the part of the rotary member corresponding to the first opening of the magnetic core and a part of the rotary member where the second winding is provided.
  6. The electric power transmission device according to claim 1, further comprising
    a second magnetic body, wherein
    the magnetic core has a second opening provided in a second surface at a position corresponding to the first opening in the axial direction, the second surface being opposite to the first surface in a radial direction to the axis of rotation, and
    the second magnetic body is provided along the circumferential direction in a part of the rotary member corresponding to the second opening of the magnetic core.
  7. A motor apparatus comprising:
    a motor including a motor stator and a motor rotor, the motor stator including a first motor magnetic core and a first motor winding, the motor rotor including a second motor magnetic core and a second motor winding;
    a shaft coupled to the motor rotor;
    an inverter;
    a magnetic core having a ring shape including a through hole through which the shaft extends, the magnetic core including therein a cavity along a circumferential direction of the shaft, and having a first opening provided along the circumferential direction in a first surface in contact with the through hole, the first opening coupling the through hole and the cavity to each other;
    a first winding coupled to the inverter, provided in the cavity, and wound along the circumferential direction;
    a rotary member provided at a position corresponding to the first opening in an axial direction of the shaft, the rotary member being rotationally movable, inside the cavity, in the circumferential direction with a rotation of the shaft;
    a second winding provided on the rotary member and wound along the circumferential direction;
    a first magnetic body provided along the circumferential direction in a part of the rotary member corresponding to the first opening of the magnetic core; and
    a rectifying circuit provided in a path coupling the second winding and the second motor winding to each other.
EP23922638.4A 2023-02-14 2023-02-14 Power transmission device and motor device Pending EP4668300A1 (en)

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PCT/JP2023/004991 WO2024171299A1 (en) 2023-02-14 2023-02-14 Power transmission device and motor device

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Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002075760A (en) 2000-08-29 2002-03-15 Tamagawa Seiki Co Ltd Rotating non-contact connector and non-rotating non-contact connector

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JPS433767Y1 (en) * 1966-05-02 1968-02-17
JPS6047104U (en) * 1983-09-07 1985-04-03 シャープ株式会社 Rotating magnetic head drum device
JPS60129905A (en) * 1983-12-19 1985-07-11 Matsushita Electric Ind Co Ltd rotary transformer
JPS62154506U (en) * 1986-03-20 1987-10-01
JPS6322716U (en) * 1986-07-30 1988-02-15
JP2512732Y2 (en) * 1990-11-16 1996-10-02 株式会社豊田中央研究所 Optical telemeter device
US12224113B2 (en) * 2020-05-12 2025-02-11 Ut-Battelle, Llc Wireless excitation system

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2002075760A (en) 2000-08-29 2002-03-15 Tamagawa Seiki Co Ltd Rotating non-contact connector and non-rotating non-contact connector

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