Power Transmission Device

Abstract

To provide a power transmission device capable of sufficiently securing structural strength of a magnetic core.SOLUTION: In a power transmission device 100 for transmitting electric power to a reception unit 20 from a transmission unit 10, the annular transmission unit 10 having an annular first magnetic core 31 and a transmission coil 61 and the annular reception unit 20 having an annular second magnetic core 33 and a reception coil 62 are provided to be arranged in the state of facing each other. The transmission unit 10 and the reception unit 20 can be relatively rotated around an axis 95 of rotation, which passes through a cavity within the transmission unit 10 and the reception unit 20. The first magnetic core 31 is structurally split into a plurality of first split cores 32 in a circumferential direction, and the second magnetic core 33 is structurally split into a plurality of second split cores 34 in a circumferential direction.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a power transfer device. [Background technology]

[0002] The power transfer device of Patent Document 1 includes a pair of coil units arranged opposite each other. Each coil unit includes a magnetic core formed in an annular shape, and each magnetic core has a plurality of concentric grooves in which windings are housed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2000-150277 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the investigations of the present inventors, the power transfer device of Patent Document 1 has room for improvement in terms of the structural strength of the magnetic core.

[0005] The present invention has been made in view of the above-mentioned problems, and provides a power transfer device that can ensure sufficient structural strength of the magnetic core. [Means for solving the problem]

[0006] According to the present invention, there is provided a transmission device that includes an annular transmitting unit having an annular first magnetic core and a transmitting coil, and an annular receiving unit having an annular second magnetic core and a receiving coil, arranged opposite to each other, and that transmits power from the transmitting unit to the receiving unit, the transmitting unit and the receiving unit are relatively rotatable about a rotation axis passing through the internal cavities of the transmitting unit and the receiving unit, The first magnetic core is divided into a plurality of first divided cores in the circumferential direction, The second magnetic core is divided into a plurality of second divided cores in the circumferential direction. the law of nature, the transmitting unit includes a first holder member made of resin that holds the first magnetic core; the receiving unit includes a second holder member made of resin that holds the second magnetic core; the first magnetic core has a first opposing surface that faces the second magnetic core in the axial direction, the second magnetic core has a second opposing surface that faces the first magnetic core in the axial direction, a portion of the first holder member having an annular shape and disposed along the first opposing surface; a portion of the second holder member having an annular shape and disposed along the second opposing surface; the portion of the first holder member and the portion of the second holder member are interposed between the first magnetic core and the second magnetic core in the axial direction, a surface of the portion of the first holder member facing the portion of the second holder member is a flat surface perpendicular to the axial direction, In the portion of the second holder member, a surface facing the portion of the first holder member is a flat surface perpendicular to the axial direction. A power transfer device is provided. [Effects of the Invention]

[0007] According to the present invention, the structural strength of the magnetic core can be sufficiently ensured. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a side view of a power transfer device according to an embodiment. [Figure 2] FIG. 2 is an exploded side view of the power transfer device according to the embodiment. [Figure 3] FIG. 2 is an exploded perspective view of a receiving unit according to the embodiment. [Figure 4] FIG. 1 is a plan view of a power transfer device according to an embodiment. [Figure 5] FIG. 2 is a plan view of a first magnetic core and a transmission coil in the embodiment. [Figure 6] FIG. 5 is a cross-sectional view taken along line AA in FIG. [Figure 7] FIG. 5 is an enlarged view of part A in FIG. [Figure 8] 8(a) and 8(b) show actual measured values ​​of each characteristic of the first magnetic core of the power transfer device according to the embodiment. [Figure 9]9(a) and 9(b) show actual measured values ​​of each characteristic of the first magnetic core of the power transfer device according to the first modified example. [Figure 10] FIG. 10 is a plan view of a power transfer device according to a second modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to Figures 1 to 8(b). In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted where appropriate.

[0010] As shown in any one of Figures 1 to 6, the power transmission device 100 of this embodiment comprises an annular transmitting unit 10 having an annular first magnetic core 31 and a transmitting coil 61, and an annular receiving unit 20 having an annular second magnetic core 33 and a receiving coil 62, arranged opposite each other, and transmits power from the transmitting unit 10 to the receiving unit 20. As shown in Figures 4 and 6, the transmitting unit 10 and the receiving unit 20 are rotatable relative to each other around a rotation axis 95 that passes through the internal cavities 11, 21 of the transmitting unit 10 and the receiving unit 20, and the first magnetic core 31 is divided into a plurality of first split cores 32 in the circumferential direction, and the second magnetic core 33 is divided into a plurality of second split cores 34 in the circumferential direction.

[0011] According to this embodiment, the first magnetic core 31 is divided into a plurality of first divided cores 32, and the second magnetic core 33 is divided into a plurality of second magnetic cores 33. That is, a desired power transmission efficiency can be achieved by an assembly of first divided cores 32 each having smaller dimensions than the first magnetic core 31, and an assembly of second divided cores 34 each having smaller dimensions than the second magnetic core 33. Therefore, compared to when the first magnetic core 31 and the second magnetic core 33 are each integrally molded, the structural strength (fracture resistance) and durability of the first magnetic core 31 and the second magnetic core 33 can be sufficiently ensured, and the ease of manufacturing the first magnetic core 31 and the second magnetic core 33 is also improved.

[0012] The transmitting unit 10 and the receiving unit 20 face each other with a reference plane 130 (see FIGS. 1 and 6) which is an imaginary plane between them. More specifically, the receiving unit 20 is disposed in close proximity to the transmitting unit 10 while not being in contact with the transmitting unit 10. The rotation axis 95 is, for example, an imaginary axis that is perpendicular to the reference plane 130 and passes through the center of the annular transmitting unit 10 and the center of the annular receiving unit 20, respectively. In this embodiment, the receiving unit 20 rotates relative to the transmitting unit 10 around a rotation axis 95. In this embodiment, the receiving unit 20 can freely rotate relative to the transmitting unit 10 in both the counterclockwise and clockwise directions. For ease of explanation, the following description will assume that the rotation axis 95 extends in the up-down direction (vertical direction) and describe the positional relationship of each component. Therefore, in the following description, the direction perpendicular to the rotation axis 95 is considered to be the horizontal direction. In addition, in the up-down direction, the side on which the transmitting unit 10 is arranged will be referred to as the bottom (lower side), and the side on which the receiving unit 20 is arranged will be referred to as the top (upper side). In addition, a direction passing through rotation axis 95 in a plane perpendicular to rotation axis 95 is referred to as a radial direction. Furthermore, in the radial direction, a direction approaching rotation axis 95 is referred to as a radially inner direction, and a direction away from rotation axis 95 is referred to as a radially outer direction. The circumferential direction is the direction around the axis of the rotary shaft 95 . Unless otherwise specified, the positional relationship of each part of the power transmission device 100 describes the positional relationship when the parts of the power transmission device 100 are assembled together to form the power transmission device 100. However, the direction of the rotation axis 95 when the power transfer device 100 is in use is not limited to the up-down direction.

[0013] Here, the power transmission device 100 is attached to the steering wheel (steering) of a vehicle such as an automobile and its surrounding area, for example, and supplies power to various loads (not shown) mounted on the steering wheel. That is, the receiving coil 62 of the receiving unit 20 is electrically connected to the load, and supplies the power transmitted from the transmitting coil 61 of the transmitting unit 10 to the load. In this embodiment, the transmitting unit 10 and the receiving unit 20 are arranged around a metal handle shaft 110. The handle shaft 110 includes a cylindrical shaft 115 with its axial direction extending vertically, and a connecting member 120 connected to the upper end of the shaft 115. Here, the handle shaft 110 being made of metal means that at least one of the shaft 115 and the connecting member 120 is made of metal, and preferably, both the shaft 115 and the connecting member 120 are made of metal. The handle shaft 110 is inserted, for example, through a cavity 11 of the transmitting unit 10 and a cavity 21 of the receiving unit 20. An outer peripheral surface 110a of the handle shaft 110 is arranged along an inner peripheral surface 10a of the transmitting unit 10 and an inner peripheral surface 20a of the receiving unit 20, and faces the inner peripheral surfaces 10a and 20a. In addition, the handle shaft 110 is disposed coaxially with the rotation axis 95 . The handle is connected, for example, to the tip (upper end) of the handle shaft 110. The handle shaft 110 is held by a base (not shown) in a state in which it can rotate around its own axis. In the configuration of the power transmission device 100, the transmitting unit 10 is provided on the base, and the receiving unit 20 is provided on the handle. Therefore, when the driver of the vehicle turns the steering wheel, the load and the receiving unit 20 turn along with the steering wheel, but the transmitting unit 10 provided on the base does not turn.

[0014] The power transmission device 100 may be attached to other devices, such as amusement machines, game machines, and simulators, which have steering wheels. However, the power transmission device 100 may be an apparatus that does not have a steering wheel but has two parts that can rotate relative to one another, or an apparatus in which two parts are connected to each other so as to be rotatable relative to one another without using the steering wheel shaft 110.

[0015] Furthermore, the power transmission device 100 may be provided as a handle component in which the receiving unit 20 is pre-assembled in the handle, for example.

[0016] As shown in FIGS. 1 and 6, the transmitting unit 10 and the receiving unit 20 are formed symmetrically with respect to each other in the up-down direction with respect to a reference plane 130. More specifically, as shown in FIG. 6, the receiving unit 20 is disposed above the transmitting unit 10. In the following, first, the receiving unit 20 out of the transmitting unit 10 and the receiving unit 20 will be described in detail. As shown in FIGS. 3, 4 and 6, in this embodiment, the second magnetic core 33 is formed in an annular shape in plan view, for example. More specifically, the second magnetic core 33 has a plate-shaped portion 37 that is annular in plan view and centered on the rotation axis 95, an inner wall portion 35 that protrudes downward from the inner peripheral edge of the plate-shaped portion 37, and an outer wall portion 36 that protrudes downward from the outer peripheral edge of the plate-shaped portion 37. The upper and lower surfaces of the plate-like portion 37 are each formed flat, for example, and are disposed horizontally. Each of the inner peripheral wall portion 35 and the outer peripheral wall portion 36 is formed, for example, in a cylindrical shape with its axial direction extending in the up-down direction, and protrudes from the lower surface of the plate-like portion 37 . In this embodiment, in plan view, the plate-shaped portion 37, the inner peripheral wall portion 35, and the outer peripheral wall portion 36 are arranged concentrically with the rotation axis 95 as the center. The outer diameter of the plate-shaped portion 37 is set to a dimension equivalent to the outer diameter of the outer peripheral wall portion 36 , and the inner diameter of the plate-shaped portion 37 is set to a dimension equivalent to the inner diameter of the inner peripheral wall portion 35 . The height position of the lower end face of the inner peripheral wall portion 35 and the height position of the lower end face of the outer peripheral wall portion 36 are set to be at the same height position. In this embodiment, the inner peripheral wall portion 35, the outer peripheral wall portion 36, and the plate-like portion 37 form a groove portion 38 that is annular in plan view, and the groove portion 38 is open, for example, downward. Furthermore, one surface of the second magnetic core 33 (hereinafter, sometimes referred to as the first surface 33a) is formed by the lower end surface of the inner wall portion 35 and the lower end surface of the outer wall portion 36, and the surface opposite to the one surface 33a of the second magnetic core 33 (hereinafter, sometimes referred to as the second surface 33b) is formed by the upper surface of the plate-shaped portion 37.

[0017] As described above, the second magnetic core 33 is divided into a plurality of second divided cores . 3 and 4, each second divided core 34 is formed, for example, into a shape obtained by dividing the second magnetic core 33 into six equal parts in the circumferential direction. That is, the planar shape of each second divided core 34 is formed into a fan shape with a central angle of 60 degrees, and the second magnetic core 33 is constituted by an assembly of six second divided cores 34. However, the number of second divided cores 34 included in the second magnetic core 33 is not limited to the above example, and may be at least two or more. The second split core 34 has, for example, a plate-shaped portion 34a which, when viewed in a plane, has the shape of a ring centered on the rotation axis 95 divided into six equal parts, i.e., a fan-shaped portion with a central angle of 60 degrees, an inner wall portion 34b protruding downward from the inner peripheral edge of the plate-shaped portion 34a, and an outer wall portion 34c protruding downward from the outer peripheral edge of the plate-shaped portion 34a. The assembly of the plate-shaped portions 34a constitutes the plate-shaped portion 37 of the second magnetic core 33. The assembly of the inner circumferential wall portions 34b constitutes the inner circumferential wall portion 35 of the second magnetic core 33, and the assembly of the outer circumferential wall portions 34c constitutes the outer circumferential wall portion 36 of the second magnetic core 33. Therefore, the combined part of the lower end surfaces of the inner peripheral wall portions 34b and the lower end surfaces of the outer peripheral wall portions 34c constitutes the first surface 31a of the second magnetic core 33. The combined part of the upper surfaces of the plate-like portions 34a constitutes the second surface 33b of the second magnetic core 33. Here, it is preferable that a gap is formed between each of the second divided cores 34 in the circumferential direction, but the gap does not necessarily have to be formed. In addition, in this embodiment, a pair of notch-shaped portions 39 are formed in the outer wall portion 34c of each second split core 34, and each notch-shaped portion 39 is engaged with a second engaging protrusion portion 56 described later. Each notch 39 is formed, for example, in a portion of the outer peripheral wall 34c in the circumferential direction. Each notch 39 is formed, for example, from the upper end to the lower end of the outer peripheral wall portion 34c, and penetrates the outer peripheral wall portion 34c in the thickness direction (radial direction).

[0018] In this embodiment, the receiving unit 20 includes a second holder member 51 made of resin that holds the second magnetic core 33. As shown in Figures 2 and 6, the second holder member 51 has, for example, second upright wall portions 57 arranged along the outer peripheral surface 33c of the second magnetic core 33, and the second upright wall portions 57 are arranged at multiple locations in the circumferential direction. More specifically, the second holder member 51 has a second annular portion 54 that is formed in a substantially annular shape with the rotation axis 95 as the center in a plan view, for example. The upper and lower surfaces of the second annular portion 54 are, for example, flat and arranged horizontally. Each second upright wall portion 57 stands upward from, for example, the outer circumferential edge portion of the upper surface of the second annular portion 54. The second upright wall portions 57 are formed, for example, to have the same dimensions and shape as one another, and are arranged intermittently in the circumferential direction. Each second upright wall portion 57 is formed, for example, in an arc shape with the rotation axis 95 as the center in a plan view. The outer circumferential surface of each second upright wall portion 57 is on the same cylindrical surface as the outer circumferential surface of the second annular portion 54 . In each second upright wall portion 57, the height position of the upper end of the portion excluding the second engagement claw portion 58 described later is set to a height position approximately equal to the height position of the second surface 33b of the second magnetic core 33.

[0019] In this embodiment, the second upright wall portion 57 has, for example, a second engaging claw portion 58 that engages with the second surface 33b of the second magnetic core 33. More specifically, of the plurality of second divided cores 34 of the second magnetic core 33, a common second engaging claw portion 58 engages with two second divided cores 34 adjacent to each other. More specifically, each second engagement claw 58 is formed, for example, on the upper end of each second upright wall 57. Each second engagement claw 58 protrudes radially inward from the upper end of the portion of each second upright wall 57 excluding the second engagement claw 58, and extends circumferentially. In addition, in the radial direction, the tip of each second engagement claw portion 58 is disposed inside the inner circumferential surface of the portion of each second upright wall portion 57 excluding the second engagement claw portion 58 . The dimension of the second engagement claws 58 in the circumferential direction is set to be smaller than the dimension of the portions of each second upright wall 57 excluding the second engagement claws 58 in the circumferential direction. The upper and lower surfaces of the second engagement claw 58 are each formed to be approximately flat and arranged horizontally. However, the tip end portion of the second engagement claw 58 (the tip end in the protruding direction) is formed with, for example, a chamfered portion. The upper side of the chamfered portion has, for example, a C-chamfered shape. This allows the second engagement claw 58 to smoothly engage with the second surface 33b of the second magnetic core 33. Furthermore, the lower side of the chamfered portion has, for example, an R-chamfered shape. This allows the second engagement claw 58 to softly contact the second magnetic core 33. When the second engagement claw portion 58 is engaged with the second surface 33b of the second magnetic core 33, the lower surface of the second engagement claw portion 58 is in surface contact with the upper surface of the plate-shaped portion 37 of the second magnetic core 33.

[0020] Furthermore, the second holder member 51 has, for example, a plurality of second outer peripheral edge portions 52 that are arranged along the outer peripheral surface 33c of the second magnetic core 33 and are each arranged between two second standing wall portions 57 that are adjacent to each other in the circumferential direction. More specifically, the second outer peripheral edge portions 52 and the second standing wall portions 57 are arranged alternately in the circumferential direction. The second outer peripheral edges 52 are formed to have, for example, the same dimensions and shapes as each other. Each second outer peripheral edge portion 52 is formed, for example, in a plan view, in an arc shape centered on the rotation axis 95, and stands slightly upward from the outer peripheral edge portion of the upper surface of the second annular portion . The outer peripheral surface of each second outer peripheral edge portion 52 is disposed on the same cylindrical surface as the outer peripheral surface of the second annular portion 54 and the outer peripheral surface of the second upright wall portion 57 . Furthermore, the thickness dimension (diameter dimension) of each second outer peripheral edge portion 52 is set to be equal to the thickness dimension (diameter dimension) of each second upright wall portion 57. The height position of the upper end surface of each second outer peripheral edge portion 52 is disposed, for example, lower than the height position of the upper end surface of each second upright wall portion 57. In the circumferential direction, the second outer peripheral edge portion 52 and the second upright wall portion 57 are arranged at a distance from each other, and a slit portion 54b (see Figure 4) is formed in each gap between the second outer peripheral edge portion 52 and the second upright wall portion 57 in the circumferential direction. The slits 54b extend, for example, in the radial direction. The slits 54b penetrate the second annular portion 54 in the up-down direction and are open outward in the radial direction. Furthermore, the second holder member 51 has an opening 57a (see FIG. 3) formed along the inner circumferential surface of the second upright wall portion 57. The opening 57a extends, for example, in the circumferential direction and penetrates the second annular portion 54 in the up-down direction. In the circumferential direction, the length of the opening 57a is, for example, smaller than the length of the second upright wall portion 57. According to the above-described configuration, the second holder member 51 can easily elastically deform in the radial direction, and therefore the second magnetic core 33 can be suitably housed inside the second holder member 51. More specifically, when the second magnetic core 33 is attached to the second holder member 51, the second holder member 51 easily elastically deforms (expands in diameter) radially outward, and after the attachment of the second magnetic core 33 is complete, the second holder member 51 elastically returns to its original shape (reduced in diameter) radially inward with good performance.

[0021] The number of second upright wall portions 57 is, for example, six. On the other hand, the number of second outer peripheral edge portions 52 is, for example, five. In this embodiment, as shown in Figures 3 and 4, in one of the spaces between two second upright wall portions 57 adjacent to each other in the circumferential direction, no second outer peripheral edge portion 52 is arranged, and instead, a second terminal holding portion 72, which will be described later, is arranged in that space.

[0022] Here, in this embodiment, the second holder member 51 has, for example, a second engagement protrusion 56 that engages with the second split core 34, and the second engagement protrusion 56 regulates the positional deviation of the second split core 34 in the circumferential direction. More specifically, the second engaging protrusions 56 are formed to have, for example, the same dimensions and shapes as one another. Each second engagement protrusion 56 protrudes upward from the upper surface of the second annular portion 54 near the outer circumferential edge of the upper surface of the second annular portion 54 . Each second engagement protrusion 56 is formed, for example, in a substantially rectangular parallelepiped shape with a radial dimension longer than a circumferential dimension. The width dimension of each second engagement protrusion 56 in the circumferential direction is set to be substantially constant. One radial surface of each second engagement protrusion 56 is connected to the inner peripheral surface of the second outer peripheral edge portion 52. As a result, even if the second split core 34 is displaced in the radial direction, the second engaging protrusion 56 can be engaged well with the notched portion 39 of the second split core 34. Furthermore, it is preferable that the height position of the upper end of the second engaging protrusion 56 is located, for example, higher than the height position of the upper end surface of the second outer peripheral edge portion 52. This ensures good engagement of the second engaging protrusion 56 with the second magnetic core 33. In the present embodiment, for example, individual second engaging protrusions 56 are connected to both ends (both ends in the circumferential direction) of one second outer peripheral edge portion 52. Therefore, the number of second engaging protrusions 56 that the second holder member 51 has is, for example, 10. As described above, each second split core 34 has a pair of cutout portions 39, and each second engagement protrusion 56 engages with the corresponding cutout portion 39. However, in this embodiment, the second holder member 51 has ten second engagement protrusions 56, while the second magnetic core 33 has six second split cores 34. Therefore, the second engagement protrusion 56 does not engage with the cutout portion 39 of any one of the six second split cores 34, and instead, the lead wiring portion 66 (described in detail later) of the receiving coil 62 is led out of the second magnetic core 33 through the cutout portion 39.

[0023] The second holder member 51 also has, for example, a second inner peripheral edge portion 53 arranged along the inner peripheral surface of the second magnetic core 33, and a plurality of upright portions 53a standing upward from the upper end of the second inner peripheral edge portion 53. The second inner peripheral edge portion 53 is formed in a circumferential shape, for example, rising slightly upward from the inner peripheral edge portion of the upper surface of the second annular portion 54. The upright portions 53a are, for example, arranged intermittently in the circumferential direction. Each of the upright portions 53a is formed, for example, in an arc shape with the rotation axis 95 as the center in a plan view. The inner peripheral surface of the second inner peripheral edge portion 53 and the inner peripheral surfaces of the upright portions 53a are arranged, for example, on the same cylindrical surface as the inner peripheral surface of the second annular portion . The height position of the upper end of each standing portion 53a is, for example, approximately the same as the height position of the second surface 33b of the second magnetic core 33 or is arranged higher than this height position. By forming the standing portion 53a, when the handle shaft 110 is inserted into the cavity 11 of the transmitting unit 10, the handle shaft 110 is guided by the standing portion 53a and is smoothly inserted into the power transmission device 100. In addition, the standing portion 53a can prevent the handle shaft 110 and the second magnetic core 33 from interfering with each other. In this embodiment, the number of the upright portions 53a of the second holder member 51 is six, for example.

[0024] Furthermore, the second holder member 51 has, for example, a second terminal holding portion 72 that holds a terminal portion 80, which will be described later. More specifically, the second terminal holding portion 72 has, for example, an arc-shaped fourth upstanding wall portion 75 that stands upward from the upper surface of the outer peripheral edge portion of the second annular portion 54, and a flat second plate-shaped portion 76 that protrudes radially outward from the upper edge portion of the fourth upstanding wall portion 75. The fourth upright wall portion 75 is formed, for example, in an arc shape with the rotation axis 95 as the center in a plan view. Furthermore, a notch-shaped portion 77 (see FIG. 4) is formed between the fourth upright wall portion 75 and the second upright wall portion 57 in the circumferential direction. In this embodiment, the outer circumferential surface of the fourth upright wall portion 75 and the outer circumferential surface of the second outer circumferential edge portion 52 are disposed on the same cylindrical surface. Furthermore, the thickness dimension (diameter dimension) of the fourth upright wall portion 75 is set to a dimension equivalent to the thickness dimension (diameter dimension) of each second outer peripheral edge portion 52, for example. The second plate-shaped portion 76 is formed, for example, in a substantially rectangular shape in a plan view. The upper and lower surfaces of the second plate-shaped portion 76 are, for example, horizontally disposed. The height position of the upper surface of the second plate-shaped portion 76 is set to be, for example, the same as the height position of the upper end of the second upright wall portion 57 excluding the second engaging claw portion 58. Furthermore, the inner peripheral surface of the fourth standing wall portion 75 is disposed along the outer peripheral surface of, for example, any one of the six second split cores 34. More specifically, of the six second split cores 34, the second split core 34 with which the above-mentioned second engaging protrusion 56 is not engaged is disposed alongside the fourth standing wall portion 75 in the radial direction.

[0025] As described above, the transmitting unit 10 is formed symmetrically with the receiving unit 20 with respect to the reference plane 130. Therefore, the first magnetic core 31 of the transmitting unit 10, like the second magnetic core 33, has a plate-shaped portion 37, an inner peripheral wall portion 35, and an outer peripheral wall portion 36. One surface of the first magnetic core 31 (hereinafter, sometimes referred to as the first surface 31a) is formed by the upper end surface of the inner wall portion 35 and the upper end surface of the outer wall portion 36 of the first magnetic core 31, and the surface opposite to the one surface (first surface 31a) of the first magnetic core 31 (hereinafter, sometimes referred to as the second surface 31b) is formed by the lower surface of the plate-shaped portion 37 of the first magnetic core 31. Similarly to the second split core 34, each first split core 32 is formed, for example, in a shape obtained by dividing the first magnetic core 31 into six equal parts in the circumferential direction, and has a plate-shaped portion 32a similar to the plate-shaped portion 34a, an inner wall portion 32b similar to the inner wall portion 34b, and an outer wall portion 32c similar to the outer wall portion 34c (see Figure 5). Similarly to the second split cores 34, a pair of notch-shaped portions 39 are formed in the outer peripheral wall portion 32c of each first split core 32, and each first engaging protrusion 46 (described later) of a first holder member 41 (described later) engages with the notch-shaped portion 39 of the corresponding first split core 32. Furthermore, the first engaging protrusion 46 does not engage with the notch-shaped portion 39 of any one of the six first split cores 32, and instead, a lead-out wiring portion 66 (described later in detail) of the transmission coil 61 is led out of the first magnetic core 31 through the notch-shaped portion 39. Furthermore, the transmitting unit 10 includes a first holder member 41 similar to the second holder member 51. Therefore, the first holder member 41 includes a first annular portion 44 similar to the second annular portion 54, a first engaging protrusion 46 similar to the second engaging protrusion 56, a first standing wall portion 47 similar to the second standing wall portion 57, a first outer peripheral edge portion 42 similar to the second outer peripheral edge portion 52, a first inner peripheral edge portion 43 similar to the second inner peripheral edge portion 53, and a standing portion 43a similar to the standing portion 53a. The first holder member 41 further includes a first terminal holding portion 71 that holds the terminal portion 80. Like the second terminal holding portion 72, the first terminal holding portion 71 includes, for example, a third upright wall portion 73 similar to the fourth upright wall portion 75 and a first plate-like portion 74 similar to the second plate-like portion 76. The inner peripheral surface of the third standing wall portion 73 is disposed along the outer peripheral surface of, for example, any one of the six first divided cores 32. More specifically, of the six first divided cores 32, the first divided core 32 with which the above-mentioned first engaging protrusion 46 is not engaged is disposed alongside the third standing wall portion 73 in the radial direction.

[0026] In this way, the transmitting unit 10 has a first holder member 41 made of resin that holds the first magnetic core 31, and the receiving unit 20 has a second holder member 51 made of resin that holds the second magnetic core 33, the first holder member 41 being annular and arranged along one surface (first surface 31a) of the first magnetic core 31 in the axial direction, and the second holder member 51 being annular and arranged along one surface (first surface 33a) of the second magnetic core 33 in the axial direction. This allows the distance between the first magnetic core 31 and the second magnetic core 33 to be kept constant, thereby realizing more stable characteristics of the power transfer device 100. As described above, the first magnetic core 31 is divided into a plurality of first divided cores 32, and the second magnetic core 33 is divided into a plurality of second divided cores 34. This allows, for example, when a temperature change occurs in the environment surrounding the power transfer device 100, even if thermal stress occurs in the first magnetic core 31 due to thermal deformation of the first holder member 41 caused by the difference in the thermal expansion coefficients of the first magnetic core 31 and the first holder member 41, the thermal stress can be absorbed by expanding or contracting the gaps between the first divided cores 32. Similarly, even if thermal stress occurs in the second magnetic core 33 due to thermal deformation of the second holder member 51, the thermal stress can be absorbed by expanding or contracting the gaps between the second divided cores 34. This allows for more stable characteristics of the power transfer device 100. Furthermore, the fracture resistance of the first magnetic core 31 and the second magnetic core 33 can be improved.

[0027] In addition, the first holder member 41 has a first engagement protrusion 46 that engages with the first split core 32, and the first engagement protrusion 46 regulates the circumferential displacement of the first split core 32, and the second holder member 51 has, for example, a second engagement protrusion 56 that engages with the second split core 34, and the second engagement protrusion 56 regulates the circumferential displacement of the second split core 34.

[0028] Furthermore, the first holder member 41 has, for example, a first upright wall portion 47 arranged along the outer peripheral surface 31c of the first magnetic core 31, and the first upright wall portion 47 is arranged at multiple locations in the circumferential direction, and the second holder member 51 has, for example, a second upright wall portion 57 arranged along the outer peripheral surface 33c of the second magnetic core 33, and the second upright wall portion 57 is arranged at multiple locations in the circumferential direction. In addition, the first upright wall portion 47 has a first engaging claw portion 48 that engages with the opposite surface (second surface 31b) of the first magnetic core 31 from one surface (first surface 31a), and the second upright wall portion 57 has, for example, a second engaging claw portion 58 that engages with the opposite surface (second surface 33b) of the second magnetic core 33 from one surface (first surface 33a). That is, the first holder member 41 has a first upright wall portion 47 arranged along the outer peripheral surface 31c of the first magnetic core 31, and the first upright wall portion 47 has a first engaging claw portion 48 that engages with the opposite surface (second surface 31b) of the first magnetic core 31 from one surface (first surface 31a), and the second holder member 51 has a second upright wall portion 57 arranged along the outer peripheral surface 33c of the second magnetic core 33, and the second upright wall portion 57 has a second engaging claw portion 58 that engages with the opposite surface (second surface 33b) of the second magnetic core 33 from one surface (first surface 33a). This allows the first holder member 41 to hold the first magnetic core 31 well, and the second holder member 51 to hold the second magnetic core 33 well.

[0029] Furthermore, of the multiple first split cores 32 of the first magnetic core 31, a common first engaging claw portion 48 engages with two adjacent first split cores 32, and of the multiple second split cores 34 of the second magnetic core 33, a common second engaging claw portion 58 engages with two adjacent second split cores 34. This allows each first split core 32 to be well maintained in a state where it is held by the first holder member 41 with a smaller number of first engaging claw portions 48, and allows each second split core 34 to be well maintained in a state where it is held by the second holder member 51 with a smaller number of second engaging claw portions 58. Furthermore, the height positions (vertical positions) of the upper surfaces of adjacent second divided cores 34 can be aligned. Similarly, the height positions (vertical positions) of the lower surfaces of adjacent first divided cores 32 can be aligned.

[0030] In this embodiment, the inner diameter of each of the first magnetic core 31 and the second magnetic core 33 is larger than the outer diameter of each of the first inner peripheral edge portion 43 and the second inner peripheral edge portion 53. In addition, the outer diameter of each of the first magnetic core 31 and the second magnetic core 33 is smaller than the inner diameter of each of the second outer peripheral edge portion 52 and the second inner peripheral edge portion 53. The height position of the upper end of each of the second inner peripheral edge portion 53 and the second outer peripheral edge portion 52 is located below the height position of the upper surface of the plate-shaped portion 37 of the second magnetic core 33. In addition, the height position of the lower end of each of the first inner peripheral edge portion 43 and the first outer peripheral edge portion 42 is located above the height position of the lower surface of the plate-shaped portion 37 of the first magnetic core 31. 6, the second magnetic core 33 is disposed between the second outer peripheral edge portion 52 and the second inner peripheral edge portion 53. More specifically, the outer peripheral surface 33c of the second magnetic core 33 is disposed along the inner peripheral surface of the second outer peripheral edge portion 52, and the inner peripheral surface of the second magnetic core 33 is disposed along the outer peripheral surface of the second inner peripheral edge portion 53. That is, the second magnetic core 33, the second outer peripheral edge portion 52, and the second inner peripheral edge portion 53 are disposed concentrically and closely adjacent to each other. The first surface 33a of the second magnetic core 33 is in surface contact with the upper surface of the second annular portion 54. Similarly, the first magnetic core 31 is disposed between the first outer peripheral edge portion 42 and the first inner peripheral edge portion 43. More specifically, the outer peripheral surface 31c of the first magnetic core 31 is disposed along the inner peripheral surface of the first outer peripheral edge portion 42, and the inner peripheral surface of the first magnetic core 31 is disposed along the outer peripheral surface of the first inner peripheral edge portion 43. That is, the first magnetic core 31, the first outer peripheral edge portion 42, and the first inner peripheral edge portion 43 are disposed concentrically and closely adjacent to each other. Furthermore, the first surface 31a of the first magnetic core 31 is in surface contact with the lower surface of the first annular portion 44.

[0031] In addition, in this embodiment, the internal cavity 11 of the transmitting unit 10 is defined by the inner surface 10a of the transmitting unit 10, and the inner surface 10a of the transmitting unit 10 is composed of the inner surface of the first annular portion 44, the inner surfaces of each first inner peripheral edge portion 43, and the inner surfaces of each upright portion 43a. Similarly, the internal cavity 21 of the receiving unit 20 is defined by the inner surface 20a of the receiving unit 20, and the inner surface 20a of the receiving unit 20 is composed of the inner surface of the second annular portion 54, the inner surfaces of each second inner peripheral edge portion 53, and the inner surfaces of each upright portion 53a. In addition, the outer surface of the transmitting unit 10 is formed by the outer surface of the first annular portion 44, the outer surface of each first upright wall portion 47, and the outer surface of each first outer peripheral edge portion 42, and the outer surface of the receiving unit 20 is formed by the outer surface of the second annular portion 54, the outer surface of each second upright wall portion 57, and the outer surface of each second outer peripheral edge portion 52. Here, the thickness dimension (radial dimension) of each of the first inner circumferential edge portion 43 and the standing portion 43a is smaller than the thickness dimension (radial dimension) of the first outer circumferential edge portion 42. Similarly, the thickness dimension (radial dimension) of each of the second inner circumferential edge portion 53 and the standing portion 53a is smaller than the thickness dimension (radial dimension) of the second outer circumferential edge portion 52, for example. This allows the diameters of the cavities 11 and 21 to be sufficiently secured without changing the outer diameter of the transmitting unit 10 and the outer diameter of the receiving unit 20.

[0032] In this embodiment, the transmitting coil 61 and the receiving coil 62 are each made of, for example, an insulatingly coated metal wire. Each of the transmitting coil 61 and the receiving coil 62 has a winding portion 65 formed by winding the wire around the inner circumferential wall portion 35, and a pair of lead wiring portions 66 formed by both ends of the wire. The winding portion 65 of the receiving coil 62 is housed inside the groove portion 38 of the second magnetic core 33, and the opening of the groove portion 38 is closed by the second annular portion 54. Similarly, the winding portion 65 of the transmitting coil 61 is housed inside the groove portion 38 of the first magnetic core 31, and the opening of the groove portion 38 is closed by the first annular portion 44. Each of the lead-out wiring portions 66 of the receiving coil 62 is led out to the outside of the outer wall portion 36, for example, through the cutout-shaped portion 39 of the second split core 34, which is arranged opposite the above-mentioned second terminal holding portion 72. Similarly, each of the lead-out wiring portions 66 of the transmitting coil 61 is led out to the outside of the outer wall portion 36, for example, through the cutout-shaped portion 39 of the first split core 32, which is arranged opposite the above-mentioned first terminal holding portion 71. Here, the receiving coil 62 and the second magnetic core 33 may be fixed to each other by, for example, double-sided adhesive tape (not shown). Furthermore, the double-sided fixing tape is formed, for example, in a circular ring shape in plan view, which is substantially the same as the plate-like portion 37 of the second magnetic core 33. It is also preferable that each of the second divided cores 34 is arranged in a circular pattern along the fixing tape. This makes it possible to prevent the second divided cores 34 from being displaced relative to one another. Similarly, the transmission coil 61 and the first magnetic core 31 may be fixed to each other by, for example, double-sided adhesive tape (not shown).

[0033] In this embodiment, as shown in Figures 1, 2, 3 and 4, the power transmission device 100 has terminal portions 80, for example, a first terminal portion 81, a second terminal portion 82, a third terminal portion 83 and a fourth terminal portion 84. Each of the first terminal portion 81 and the second terminal portion 82 is held by the first terminal holding portion 71 of the first holder member 41 and is electrically connected to the transmitting coil 61. Each of the third terminal portion 83 and the fourth terminal portion 84 is held by the second terminal holding portion 72 of the second holder member 51 and is electrically connected to the receiving coil 62. The first terminal portion 81 to the fourth terminal portion 84 are formed by, for example, bending a long plate-shaped metal member (for example, by bending it by 90 degrees). More specifically, the third terminal 83 has an L-shape in front view, and includes a vertical portion extending in the up-down direction and a horizontal portion extending horizontally from the lower end of the vertical portion. The vertical portion is an external terminal 85 that is externally connected when the power transfer device 100 is mounted, and the horizontal portion is a crimp terminal 86 to which the lead-out wiring portion 66 of the receiving coil 62 is fixed. The lower portion of the external terminal 85 of the third terminal portion 83 is embedded in the second plate-shaped portion 76 of the second terminal holding portion 72, and the upper portion of the external terminal 85 is exposed to the outside from the upper surface of the second plate-shaped portion 76. On the other hand, the crimp terminal 86 extends horizontally along the lower surface of the second plate-shaped portion 76 (extending generally in a tangential direction to the outer periphery of the second annular portion 54 in a plan view). Furthermore, in this embodiment, a groove (not shown) having a shape corresponding to the crimp terminal 86 of the third terminal portion 83 is formed on the lower surface of the second plate-shaped portion 76. A portion of the crimp terminal 86 of the third terminal portion 83 is housed in the groove and is arranged horizontally along the bottom surface of the groove. In addition, the tip of the crimp terminal 86 (the end opposite the external terminal 85) forms a fitting portion 87 that is horizontal and curved into an approximately cylindrical shape with its axial direction perpendicular to the extension direction of the crimp terminal 86. Then, with one of the pair of lead wiring portions 66 of the receiving coil 62 inserted into the inner cavity of the fitting portion 87, the lead wiring portion 66 can be fitted into the fitting portion 87 by closing the tip end of the fitting portion 87 and the base end of the fitting portion 87. That is, by crimping the fitting portion 87, the lead wiring portion 66 can be fixed to the crimp terminal 86 while being inserted into the inner cavity of the fitting portion 87. In this state, for example, further fixing is performed by welding or soldering.

[0034] For example, the fourth terminal portion 84 is formed symmetrically to the third terminal portion 83 with respect to a plane including the rotation axis 95 and the radial direction of the second holder member 51 from the rotation axis 95 toward the second terminal holding portion 72. Thus, like the third terminal portion 83, the fourth terminal portion 84 has an external terminal 85, a crimp terminal 86, and a fitting portion 87. The other of the pair of lead-out wiring portions 66 of the receiving coil 62 (the lead-out wiring portion 66 not connected to the third terminal portion 83) is fixed to the crimp terminal 86 at the fitting portion 87, similar to the third terminal portion 83. Further, a groove (not shown) having a shape corresponding to the crimp terminal 86 of the fourth terminal portion 84 is formed on the lower surface of the second plate-shaped portion 76. A portion of the crimp terminal 86 of the fourth terminal portion 84 is housed in the groove and is arranged horizontally along the bottom surface of the groove.

[0035] For example, the first terminal portion 81 is formed in a shape that is vertically symmetrical to the third terminal portion 83. Thus, like the third terminal portion 83, the first terminal portion 81 has an external terminal 85, a crimp terminal 86, and a fitting portion 87. One of the pair of lead-out wiring portions 66 of the transmission coil 61 is fixed to the crimp terminal 86 at the fitting portion 87, similar to the third terminal portion 83. Similarly, for example, the second terminal portion 82 is formed in a shape that is vertically symmetrical to the fourth terminal portion 84. Therefore, the second terminal portion 82 has an external terminal 85, a crimp terminal 86, and a fitting portion 87. The other of the pair of lead-out wiring portions 66 of the transmitting coil 61 (the lead-out wiring portion 66 not connected to the first terminal portion 81) is fixed to the crimp terminal 86 at the fitting portion 87, similar to the third terminal portion 83.

[0036] The first divided core 32 and the second divided core 34 are each integrally formed from a magnetic material. Each of the first holder member 41 and the second holder member 51 is, for example, integrally molded entirely from an insulating material such as resin.

[0037] In this embodiment, the transmitting unit 10 is connected to a power supply (not shown), and a current is applied from the power supply to the transmitting coil 61. When a current is applied to the transmitting coil 61, a magnetic field is generated around the transmitting coil 61, and an induced electromotive force is generated in the receiving coil 62. That is, in the power transfer device 100, power is transferred from the transmitting coil 61 of the transmitting unit 10 to the receiving coil 62 of the receiving unit 20 by electromagnetic induction.

[0038] In this embodiment, the power transfer device 100 further includes a magnetic seal 90. The magnetic seal 90 is arranged along the outer surface 110a of the handle shaft 110, from the gap between the outer surface 110a of the handle shaft 110 and the inner surface 10a of the transmitting unit 10 to the gap between the outer surface 110a of the handle shaft 110 and the inner surface 20a of the receiving unit 20. This results in a magnetic seal 90 being placed around the handle shaft 110, so that even if the handle shaft 110 is made of a metal material, the generation of eddy currents on the surface of the outer surface 110a of the handle shaft 110 can be suppressed, thereby improving the power transmission efficiency of the power transmission device 100. More specifically, in the power transfer device 100, the power transfer efficiency is expressed as the product of the degree of coupling between the transmitting coil 61 and the receiving coil 62 and the quality factor (Q) of each of the transmitting coil 61 and the receiving coil 62. Therefore, in order to improve the power transfer efficiency, it is necessary to increase the Q factor. Furthermore, with the above-described configuration, the resistance value of the transmitting coil 61 can be reduced by suppressing the generation of eddy currents, and therefore the Q factor of the transmitting coil 61 can be increased. Furthermore, because the magnetic seal 90 suppresses the generation of eddy currents on the surface of the outer circumferential surface 110a of the handle shaft 110, good power transmission efficiency of the power transmission device 100 can be achieved even if the inner circumferential surface 10a of the transmitting unit 10 and the inner circumferential surface 20a of the receiving unit 20 are disposed closer to the handle shaft 110. This allows the power transmission device 100 to be made even more compact.

[0039] 8(a) and 8(b) show an example of measured values ​​of each characteristic of the transmitting coil 61 measured using the power transfer device 100 according to this embodiment, and FIGS. 9(a) and 9(b) show an example of measured values ​​of each characteristic of the transmitting coil 61 measured using the power transfer device 100 according to a first modified example (a power transfer device 100 without a magnetic seal 90) described later. Of these, FIGS. 8(a) and 9(a) show, in tables, the measured values ​​of the inductance of the transmitting coil 61 (L [uH] in FIGS. 8(a) and 9(a)), the measured values ​​of the resistance of the transmitting coil 61 (R [mohm] [Ω] in FIGS. 8(a) and 9(a)), and the measured values ​​of the Q value of the transmitting coil 61 (Q in FIGS. 8(a) and 9(a)), respectively, at each frequency [kHz] of the power supply. Fig. 8(b) shows a profile obtained by plotting the measured values ​​of the resistance [mohm] [Ω] of the transmitting coil 61 in Fig. 8(a) and the measured values ​​of the Q factor of the transmitting coil 61. Fig. 9(b) shows a profile obtained by plotting the measured values ​​of the resistance [mohm] [Ω] of the transmitting coil 61 in Fig. 9(a) and the measured values ​​of the Q factor of the transmitting coil 61. In Fig. 8(b) and Fig. 9(b), the vertical axis on the right side represents the Q factor of the transmitting coil 61, the vertical axis on the left side represents the resistance [mohm], and the horizontal axis represents the frequency [kHz].

[0040] As shown in Figures 8(a) and 8(b), when using the power transfer device 100 of the present embodiment, the actual measured value of the resistance of the transmitting coil 61 is smaller, while the actual measured value of the Q value of the transmitting coil 61 is larger, compared to when using the power transfer device 100 of the first modified example described below (see Figures 9(a) and 9(b)). More specifically, for example, when the frequency of the power supply is 100 kHz, an example of the actual measured value of the resistance of the transmitting coil 61 measured using the power transmission device 100 of this embodiment is 107 mohm, and an example of the Q value of the transmitting coil is 100. On the other hand, for example, when the power supply frequency is 100 kHz, an example of the actual measured value of the resistance of the transmitting coil measured using a power transmission device 100 that does not have a magnetic seal 90 is 200 mohm, and an example of the Q value of the transmitting coil is 39. In this way, by disposing the magnetic seal 90 around the handle shaft 110, the Q value of the transmission coil 61 can be increased, and therefore the power transmission efficiency of the power transmission device 100 can be improved.

[0041] 7, the magnetic material seal 90 includes, for example, a sheet-like substrate 91, a plurality of magnetic materials 92 arranged on one surface of the substrate 91, and an adhesive layer 93 formed on the other surface of the substrate 91. Note that Fig. 7 is a cross-sectional view taken along the radial direction. The base material 91 is made of, for example, a soft resin material. The plurality of magnetic bodies 92 are each formed, for example, in the shape of a thin plate, and the shape of each magnetic body 92 is not particularly limited, but may be, for example, a substantially rectangular shape. The plurality of magnetic bodies 92 are arranged, for example, in an array over substantially the entire one surface of the base material 91. The magnetic bodies 92 are, for example, sintered ferrite, which has high magnetic permeability. Therefore, the magnetic seal 90 can effectively suppress leakage of magnetic flux generated around the transmission coil 61. The magnetic material seal 90 is fixed to the outer peripheral surface 110a of the handle shaft 110, for example, via an adhesive layer 93. More specifically, the opposite surface of the substrate 91 on which the adhesive layer 93 is formed is arranged along the outer peripheral surface 110a of the handle shaft 110. Furthermore, one surface of the substrate 91 on which the plurality of magnetic materials 92 are arranged is arranged along each of the inner peripheral surface 10a of the transmitting unit 10 and the inner peripheral surface 20a of the receiving unit 20. The magnetic material seal 90 is fixed to the handle shaft 110 via the adhesive layer 93, for example, in a state where it is wrapped around the outer peripheral surface 110a of the handle shaft 110. Here, when the magnetic material seal 90 is wrapped around the handle shaft 110, the plurality of magnetic materials 92 are arranged in an array, so that the magnetic material seal 90 can be easily deformed into a shape that fits the outer peripheral surface 110a of the handle shaft 110. However, the magnetic seal 90 may be disposed, for example, along each of the inner circumferential surface 10a of the transmitting unit 10 and the inner circumferential surface 20a of the receiving unit 20. In this case, the opposite surface of the base material 91 on which the adhesive layer 93 is formed is disposed along each of the inner circumferential surface 10a of the transmitting unit 10 and the inner circumferential surface 20a of the receiving unit 20.

[0042] Here, the handle shaft 110 has a cylindrical shaft 115 as described above, and for example, a connecting member 120 (see FIGS. 1 and 2, etc.) is attached to the upper end of this shaft 115. For example, a handle is attached to the connecting member 120, and the handle is connected to the upper end of the shaft 115 via the connecting member 120. Note that FIGS. 1 and 6 show a state in which the connecting member 120 is inserted into the cavity 11 of the transmitting unit 10 and the cavity 21 of the receiving unit 20. When a rotation operation is performed on the handle, the shaft 115 rotates around the axis of the shaft 115 (around the axis of the handle shaft 110) along with the handle and the connecting member 120. More specifically, the connecting member 120 has a cylindrical portion 121 formed in a cylindrical shape with the vertical direction as the axial direction, a through hole 123 penetrating the cylindrical portion 121 in the vertical direction, and a flange portion 124 extending outward from the upper edge of the cylindrical portion 121. In this embodiment, the handle is attached to the connecting member 120 by fitting a portion of the handle into the through-hole 123 of the connecting member 120 . Furthermore, the lower part of the cylindrical part 121 is fitted onto the shaft 115 , so that the connecting member 120 is attached to the upper end of the shaft 115 . More specifically, the lower part of the cylindrical portion 121 of the connecting member 120 forms a stepped fitting portion 122, and the outer diameter of the connecting member 120 tapers downward in two steps. The fitting portion 122 fits into the inner cavity of the upper end of the shaft 115, thereby attaching the connecting member 120 and the handle to the shaft 115. The upper part of the cylindrical portion 121 is located higher than the upper end of the shaft 115, and the outer peripheral surface of the upper part faces the inner peripheral surface 20a of the receiving unit 20. The outer peripheral surface of the upper part of the cylindrical portion 121 is also arranged on the same cylindrical surface as the outer peripheral surface of the shaft 115. The cylindrical portion 121 of the connecting member 120 is inserted into the cavity 11 of the transmitting unit 10 and the cavity 21 of the receiving unit 20 .

[0043] As shown in FIG. 6, in this embodiment, the magnetic seal 90 is arranged in a circular shape along the outer circumferential surface of the upper part of the cylindrical portion 121 and the outer circumferential surface of the upper end of the shaft 115, for example, so as to cover the portion from the upper part of the cylindrical portion 121 to the upper end of the shaft 115. As a result, the magnetic seal 90 encases the upper part of the cylindrical portion 121 and the upper end of the shaft 115 together, so that the state in which the connecting member 120 is attached to the upper end of the shaft 115 can be maintained in a good condition. As described above, the outer peripheral surface 110a of the handle shaft 110 is disposed along the inner peripheral surface 10a of the transmitting unit 10 and the inner peripheral surface 20a of the receiving unit 20. More specifically, the outer peripheral surface of the upper part of the cylindrical portion 121 is disposed along the inner peripheral surface 20a of the receiving unit 20, and the outer peripheral surface of the upper end part of the shaft 115 is disposed along the inner peripheral surface 10a of the transmitting unit 10. Therefore, the outer peripheral surface of the magnetic material seal 90 is disposed along the inner peripheral surface 10a of the transmitting unit 10 and also along the inner peripheral surface 20a of the receiving unit 20. In this embodiment, a gap is formed between the outer peripheral surface of the magnetic seal 90 and each of the inner peripheral surface 10 a of the transmitting unit 10 and the inner peripheral surface 20 a of the receiving unit 20 . In this embodiment, the magnetic seal 90 is wrapped around the outer circumferential surface 110a of the handle shaft 110, for example, one or more times.

[0044] <First Modification> 9(a) and 9(b) show a first modified example of the embodiment. The power transfer device 100 according to this modified example differs from the power transfer device 100 according to the above embodiment in that it does not include a magnetic seal 90. In other respects, the power transfer device 100 has the same configuration as the power transfer device 100 according to the above embodiment. As described above, when the power supply frequency is 100 kHz, an example of the actual measured value of the resistance of the transmitting coil measured using a power transmission device 100 without a magnetic seal 90 is 200 mohm, and an example of the Q value of the transmitting coil is 39.

[0045] <Second Modification> Next, a second modification of the embodiment will be described with reference to Fig. 10. The power transfer device 100 according to this modification differs from the power transfer devices 100 according to the above embodiment and the first modification in the points described below, but is otherwise configured similarly to the power transfer devices 100 according to the above embodiment and the first modification.

[0046] In this modified example, the first holder member 41 has first protrusions (not shown) that are respectively arranged between two adjacent first split cores 32 in the circumferential direction, and the second holder member 51 has second protrusions 59 (see Figure 10) that are respectively arranged between two adjacent second split cores 34 in the circumferential direction. This can prevent the first divided core 32 from being displaced in the circumferential direction, and also prevent the second divided core 34 from being displaced in the circumferential direction.

[0047] In this modified example, for example, the second holder member 51 has a second protrusion 59 instead of the second engagement protrusion 56. In addition, a notch 39 is formed between two adjacent first divided cores 32, and the second protrusion 59 engages with the notch 39. More specifically, each second protrusion 59 is different from, for example, the second engagement protrusion 56 and is a protrusion that extends radially inward from the inner circumferential surface of each second upright wall 57. Further, notch-shaped portions 39a, 39b are formed at both circumferential ends of each second split core 34. For example, the notch-shaped portion 39a passes through the second split core 34 in the up-down direction and is open to one side in the circumferential direction, while the notch-shaped portion 39b passes through the second split core 34 in the up-down direction and is open to the other side in the circumferential direction. Of the two adjacent second divided cores 34, the cutout-shaped portion 39a of one second divided core 34 and the cutout-shaped portion 39b of the other second divided core 34 are combined to form the cutout-shaped portion 39. Similar to the second holder member 51, the first holder member 41 has, for example, a first protrusion instead of the first engagement protrusion 46. Also, a notch 39 is formed between two adjacent first divided cores 32, and the first protrusion engages with the notch 39.

[0048] In this modified example, the number of second upright wall portions 57 that the second holder member 51 has is, for example, six. Therefore, the number of second protrusion portions 59 that the second holder member 51 has is also, for example, six. However, the number of second protrusion portions 59 is not particularly limited. Similarly, the number of first upright wall portions 47 included in the first holder member 41 is, for example, six. Therefore, the number of first protrusions included in the first holder member 41 is also, for example, six. However, the number of first protrusions is not particularly limited.

[0049] Although the embodiments have been described above with reference to the drawings, these are merely examples of the present invention, and various other configurations can also be adopted.

[0050] For example, in the above description, an example has been described in which the method for transmitting power from the transmitting unit 10 to the receiving unit 20 is electromagnetic induction, but the present invention is not limited to this example, and a magnetic field resonance method may also be used.

[0051] In the above description, for example, the first upstanding wall portions 47 are disposed at a plurality of positions in the circumferential direction, and the second upstanding wall portions 57 are disposed at a plurality of positions in the circumferential direction. However, in the present invention, for example, the first upstanding wall portions 47 may be formed circumferentially along the outer circumferential edge of the first annular portion 44, and the second upstanding wall portions 57 may be formed circumferentially along the outer circumferential edge of the second annular portion 54.

[0052] The present embodiment encompasses the following technical ideas. (1) A transmission device comprising: an annular transmitting unit having an annular first magnetic core and a transmitting coil; and an annular receiving unit having an annular second magnetic core and a receiving coil, arranged opposite to each other; and transmitting power from the transmitting unit to the receiving unit, the transmitting unit and the receiving unit are relatively rotatable about a rotation axis passing through the internal cavities of the transmitting unit and the receiving unit, The first magnetic core is divided into a plurality of first divided cores in the circumferential direction, The second magnetic core is a power transfer device having a structure in which the second magnetic core is divided into a plurality of second divided cores in the circumferential direction. (2) The transmitting unit includes a first holder member made of resin that holds the first magnetic core, the receiving unit includes a second holder member made of resin that holds the second magnetic core; the first holder member is annular and arranged along one surface of the first magnetic core in the axial direction, The power transfer device according to (1), wherein the second holder member is annular and arranged along one surface of the second magnetic core in the axial direction. (3) The first holder member has a first engagement protrusion that engages with the first split core, and the first engagement protrusion restricts the first split core from being displaced in the circumferential direction. The second holder member has a second engagement protrusion that engages with the second split core, and the second engagement protrusion restricts circumferential displacement of the second split core. (4) The first holder member has a first upright wall portion disposed along an outer peripheral surface of the first magnetic core, and the first upright wall portion is disposed at a plurality of positions in the circumferential direction, The second holder member has a second upright wall portion arranged along the outer peripheral surface of the second magnetic core, and the second upright wall portion is arranged at multiple locations in the circumferential direction.A power transfer device as described in (2) or (3). (5) The first upright wall portion has a first engaging claw portion that engages with a surface of the first magnetic core opposite to the one surface, The power transfer device according to (4), wherein the second upright wall portion has a second engaging claw portion that engages with a surface of the second magnetic core opposite to the one surface. (6) The first holder member has a first upright wall portion disposed along an outer circumferential surface of the first magnetic core, the first upright wall portion has a first engaging claw portion that engages with a surface of the first magnetic core opposite to the one surface, the second holder member has a second upright wall portion disposed along an outer circumferential surface of the second magnetic core, The power transfer device according to (2) or (3), wherein the second upright wall portion has a second engaging claw portion that engages with a surface of the second magnetic core opposite to the one surface. (7) The first engaging claw portion is commonly engaged with two adjacent first divided cores among the plurality of first divided cores of the first magnetic core, A power transfer device according to (5) or (6), wherein the second engaging claw portion is commonly engaged with two adjacent second divided cores among the plurality of second divided cores of the second magnetic core. (8) The transmitting unit and the receiving unit are arranged around a metal handle shaft, The power transmission device further includes a magnetic seal; The magnetic seal is arranged along the outer surface of the handle shaft, from the gap between the outer surface of the handle shaft and the inner surface of the transmitting unit to the gap between the outer surface of the handle shaft and the inner surface of the receiving unit. A power transmission device described in any one of (1) to (7). [Explanation of symbols]

[0053] 10 Transmitting Unit 10a Inner surface 11 Cavity 20 receiving unit 20a Inner surface 21 Cavity 31 First magnetic core 31a Side 1 (one side) 31b 2nd side (opposite side) 31c Outer surface 32 First divided core 32a Plate-shaped part 32b Inner peripheral wall 32c Outer wall 33 Second magnetic core 33a Side 1 (one side) 33b 2nd side (opposite side) 33c Outer surface 34 Second divided core 34a Plate-shaped part 34b Inner peripheral wall 34c Outer wall 35 Inner peripheral wall 36 Outer wall 37 Plate-shaped part 38 Groove 39 Notched portion 39a, 39b Notch shape part 41 first holder member 42 First outer peripheral edge 43 First inner periphery 43a Standing part 44 First Circular Section 44b Slit section 46 First engaging protrusion 47 1st standing wall section 48 First engaging claw 51 second holder member 52 Second outer periphery 53 Second inner periphery 53a Standing part 54 Second Circular Section 54b Slit section 56 Second engagement protrusion 57 Second standing wall section 57a opening 58 Second engagement claw 59 Second protrusion 61 Transmitting coil 62 receiving coil 65 Winding section 66 Output wiring section 70 Terminal holding part 71 1st terminal holding part 72 2nd terminal holding part 73 Third standing wall section 74 First plate-shaped part 75 4th standing wall section 76 Second plate-shaped part 77 Notched section 80 Terminal section 81 1st terminal section 82 2nd terminal section 83 3rd terminal section 84 4th terminal section 85 External terminal 86 Crimp terminal 87 Fitting part 90 Magnetic seal 91 Base material 92 Magnetic material 93 Adhesive layer 95 Rotation axis 100 Power transmission device 110 Handle shaft 115 shaft 120 Connecting member 121 Cylinder 122 fitting part 123 Through Hole 124 flange 130 Virtual Reference Plane

Claims

1. A transmission device comprising: an annular transmitting unit having an annular first magnetic core and a transmitting coil; and an annular receiving unit having an annular second magnetic core and a receiving coil, the transmitting unit and the receiving unit being arranged opposite each other; the transmission device transmitting power from the transmitting unit to the receiving unit, the transmitting unit and the receiving unit are relatively rotatable about a rotation axis passing through the internal cavities of the transmitting unit and the receiving unit, The first magnetic core is divided into a plurality of first divided cores in the circumferential direction, The second magnetic core is divided into a plurality of second divided cores in the circumferential direction, the transmitting unit includes a first holder member made of resin that holds the first magnetic core, the receiving unit includes a second holder member made of resin that holds the second magnetic core, the first magnetic core has a first opposing surface that faces the second magnetic core in the axial direction, the second magnetic core has a second opposing surface that faces the first magnetic core in the axial direction, a portion of the first holder member having an annular shape and disposed along the first opposing surface, a portion of the second holder member having an annular shape and disposed along the second opposing surface, the portion of the first holder member and the portion of the second holder member are interposed between the first magnetic core and the second magnetic core in the axial direction, a surface of the portion of the first holder member facing the portion of the second holder member is a flat surface perpendicular to the axial direction, A power transmission device in which the surface of the portion of the second holder member that faces the portion of the first holder member is a flat surface that is perpendicular to the axial direction.

2. the first holder member has a first engaging protrusion that engages with the first split core, and the first engaging protrusion restricts displacement of the first split core in a circumferential direction; The power transfer device according to claim 1, wherein the second holder member has a second engagement protrusion portion that engages with the second split core, and the second engagement protrusion portion regulates circumferential displacement of the second split core.

3. the first holder member has a first upright wall portion disposed along an outer circumferential surface of the first magnetic core, the first upright wall portion being disposed at a plurality of positions in a circumferential direction, A power transfer device as described in claim 1 or 2, wherein the second holder member has a second upright wall portion arranged along the outer peripheral surface of the second magnetic core, and the second upright wall portion is arranged at multiple locations in the circumferential direction.

4. the first upright wall portion has a first engaging claw portion that engages with a surface of the first magnetic core opposite to the first opposing surface, The power transfer device according to claim 3 , wherein the second upright wall portion has a second engagement claw portion that engages with a surface of the second magnetic core on an opposite side to the second opposing surface.

5. the first holder member has a first upright wall portion disposed along an outer circumferential surface of the first magnetic core, the first upright wall portion has a first engaging claw portion that engages with a surface of the first magnetic core opposite to the first opposing surface, the second holder member has a second upright wall portion disposed along an outer circumferential surface of the second magnetic core, The power transfer device according to claim 1 or 2, wherein the second upright wall portion has a second engaging claw portion that engages with a surface of the second magnetic core on an opposite side to the second opposing surface.

6. the first magnetic core has a plurality of first divided cores, and the first engaging claw portion is engaged with two adjacent first divided cores of the first magnetic core; The power transfer device according to claim 4 or 5, wherein the second engaging claw portion is commonly engaged with two adjacent second divided cores of the second magnetic core.

7. The transmitting unit and the receiving unit are disposed around a metal handle shaft, The power transmission device further includes a magnetic seal; the magnetic seal is disposed along the outer circumferential surface of the handle shaft, from a gap between the outer circumferential surface of the handle shaft and the inner circumferential surface of the transmitting unit to a gap between the outer circumferential surface of the handle shaft and the inner circumferential surface of the receiving unit, 7. A power transmission device as described in any one of claims 1 to 6, wherein the magnetic seal has a sheet-shaped substrate and a plurality of magnetic bodies arranged in an array on one side of the substrate, and is wrapped around the outer circumferential surface of the handle shaft.

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