JP2018160605A - Non-contact power feeding mechanism - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a non-contact power feeding mechanism that is relatively easily to be disposed.SOLUTION: A non-contact power feeding mechanism that exchanges electric power between a shaft-like member 1 and an outer peripheral member 2 disposed so as to be relatively rotatable around the shaft-like member includes an inner coil 3 disposed along the circumferential surface of the shaft-like member and an outer coil 4 disposed on the outer peripheral member so as to face the inner coil and magnetically coupled to the inner coil. The inner coil and the outer coil includes at least one pair of linear portions 3a and 3b extending in the circumferential direction of the shaft-like member and having different current directions.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a non-contact power feeding mechanism.

  In various devices, a power feeding mechanism that transmits and receives electric power between a rotating body and a fixed body may be required. As such a power feeding mechanism, a method of bringing a contact member called a brush into sliding contact with a rotating body is common. However, for example, when it is necessary to make the rotational resistance very small, it may be desired to exchange electric power between the rotating body and the stationary body in a non-contact manner.

  For example, as a power feeding mechanism that transfers power in a non-contact manner between a rotating shaft and a fixed body having a hole into which the rotating shaft is inserted, the rotating shaft and the fixed body are perpendicular to the central axis of rotation and close to each other. There has been proposed a mechanism in which opposing plate-like bodies are arranged and annular planar coils concentric with the rotation shaft are arranged on both opposing surfaces of the plate-like bodies so as to face each other (International Publication No. 2015/2015). No. 108152).

International Publication No. 2015/108152

  In the non-contact power feeding mechanism disclosed in the above publication, electric power can be transmitted and received by causing an electromotive force to be generated in the other planar coil by electromagnetic induction by passing a current through the one planar coil.

  However, in the non-contact power feeding mechanism described in the above publication, the rotating shaft needs to penetrate the inside of the planar coil. Therefore, for example, when a sensor is arranged on an existing rotating shaft and power is supplied to this sensor, the planar coil May be difficult to arrange.

  This invention is made | formed based on the above situations, and makes it a subject to provide the non-contact electric power feeding mechanism with which arrangement | positioning is comparatively easy.

  A non-contact power feeding mechanism according to one aspect of the present invention, which has been made to solve the above-described problems, transmits and receives electric power between a shaft-shaped member and an outer peripheral member disposed around the shaft-shaped member so as to be relatively rotatable. A non-contact power feeding mechanism that includes an inner coil disposed along a circumferential surface of the shaft-shaped member, and an outer coil disposed on the outer circumferential member so as to face the inner coil and magnetically coupled to the inner coil. And the inner coil and the outer coil each have at least a pair of linear portions extending in the circumferential direction of the shaft-like member and having different current directions.

  The non-contact power feeding mechanism according to one embodiment of the present invention is relatively easy to dispose.

FIG. 1 is a schematic exploded perspective view showing a non-contact power feeding mechanism according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view of the non-contact power feeding mechanism of FIG. FIG. 3 is a circuit diagram of the non-contact power feeding mechanism of FIG. 4 is a development view of the inner coil of the non-contact power feeding mechanism of FIG. FIG. 5 is a schematic exploded perspective view showing a non-contact power feeding mechanism of an embodiment different from FIG. 1 of the present invention. FIG. 6 is a circuit diagram of the non-contact power feeding mechanism of FIG.

[Description of Embodiment of the Present Invention]
A non-contact power feeding mechanism according to an aspect of the present invention is a non-contact power feeding mechanism that transmits and receives electric power between a shaft-shaped member and an outer peripheral member that is rotatably disposed around the shaft-shaped member, An inner coil disposed along a circumferential surface of the shaft-shaped member; and an outer coil disposed on the outer circumferential member so as to face the inner coil and magnetically coupled to the inner coil. Each of the coils has at least a pair of linear portions extending in the circumferential direction of the shaft-like member and having different current directions.

  The non-contact power feeding mechanism includes an inner coil disposed along a circumferential surface of the shaft-shaped member, and an outer coil disposed on the outer circumferential member so as to face the inner coil and magnetically coupled to the inner coil. By providing, the output of electric power can be obtained from the other coil by the input of electric power to one coil by mutual induction of the inner coil and the outer coil. Here, the inner coil and the outer coil each have at least a pair of linear portions extending in the circumferential direction of the shaft-like member so as to be linear when being developed in a plane, and having different current directions. Since the change in the overlapping area due to the change in the relative rotational position between the outer coil and the outer coil can be suppressed, and the magnetic coupling can be maintained in a relatively large state, the power feeding efficiency becomes relatively large. Moreover, since the non-contact power feeding mechanism can be formed by winding a planar coil around the peripheral surface of the shaft-shaped member from the outside in the radial direction, the arrangement is relatively easy.

  The linear portion may have a length of ½ or more around the shaft-shaped member. As described above, since the linear portion has a length of ½ or more around the shaft member, the magnetic coupling between the inner coil and the outer coil is further increased, and the power feeding efficiency is further increased.

  Of the inner and outer coils, the power receiving side impedance is preferably equal to or higher than the power feeding side impedance. Thus, when the impedance on the power receiving side of the inner coil and the outer coil is equal to or higher than the lower limit, the ratio of the output on the power receiving side to the input on the power feeding side can be made relatively large.

  The inner coil and the outer coil may be formed from a conductive pattern laminated on at least one surface side of a flexible sheet-like base material. In this way, the inner coil and the outer coil are formed from a conductive pattern laminated on at least one surface side of a sheet-like base material having flexibility and insulation, so that the inner coil and the outer coil are formed. The accuracy of the shape can be improved, and the shaft member and the outer peripheral member can be disposed relatively easily along the circumferential surface.

  An alternating current is applied to the inner capacitor connected in series with the inner coil, the outer capacitor connected in series with the outer coil, and the series circuit of the inner coil and inner capacitor or the series circuit of the outer coil and outer capacitor. A power supply to be applied, and the resonance frequency of the inner coil and the inner capacitor and the resonance frequency of the outer coil and the outer capacitor may be equal to the frequency of the alternating current of the power supply. As described above, the apparatus further includes an inner capacitor, an outer capacitor, and a power source, and the resonance frequency of the inner coil and the inner capacitor and the resonance frequency of the outer coil and the outer capacitor are equal to the frequency of the AC current of the power source, thereby Since the system transmits electric power, the power supply efficiency can be further improved.

  Here, the resonance frequency is equal in the frequency characteristic of the impedance of the inner coil and the outer coil, one resonance frequency is the impedance value at the resonance frequency and the peak value of the impedance closest to the low frequency side of the resonance frequency. It means that it is in the frequency range that is below the average value of.

[Details of the embodiment of the present invention]
Hereinafter, embodiments of a non-contact power feeding mechanism according to the present invention will be described in detail with reference to the drawings.

[First embodiment]
The power feeding mechanism according to one embodiment of the present invention shown in FIGS. 1 and 2 transmits and receives electric power between a shaft-shaped member 1 and an outer peripheral member 2 disposed around the shaft-shaped member 1 so as to be relatively rotatable. This is a non-contact power feeding mechanism.

  The non-contact power feeding mechanism includes an inner coil 3 disposed along the peripheral surface of the shaft-shaped member 1 and an outer member disposed on the outer member 2 so as to face the inner coil 3 and magnetically coupled to the inner coil 3. A coil 4. In addition, in FIG. 1, the inner side coil 3 and the outer side coil 4 show the state expand | deployed on the plane.

  As shown in FIG. 3, the non-contact power feeding mechanism is connected in parallel with the inner capacitor 5 connected in series with the inner coil 3, the outer capacitor 6 connected in series with the outer coil 4, and the outer coil 4. A parallel capacitor 7 and an alternating current source 8 for applying an alternating current to the series circuit of the inner coil 3 and the inner capacitor 5. That is, the non-contact power feeding mechanism in FIG. 1 is a mechanism that feeds power from the shaft-shaped member 1 to the outer peripheral member 2, and delivers power from the inner coil 3 on the power feeding side to the outer coil 4 on the power receiving side.

<Shaft-shaped member>
The shaft-shaped member 1 is at least partially formed into a shape having a circumferential surface such as a columnar shape or a cylindrical shape. The shaft-shaped member 1 is typically a rotating shaft or a fixed shaft that rotatably supports an outer peripheral member 2 or a member to which the outer peripheral member 2 is attached.

  The material, diameter, length, etc. of the shaft-shaped member 1 are not particularly limited.

<Outer peripheral member>
The outer peripheral member 2 only needs to rotate relative to the shaft-shaped member 1. When the shaft-shaped member 1 is a rotating shaft, it may be formed integrally with a housing of the bearing. You may arrange | position to the flame | frame etc. of the apparatus which has.

  In some cases, the outer peripheral member 2 may be divided into a plurality of parts in the circumferential direction in order to facilitate disposition.

<Inner coil>
As shown in FIGS. 1 and 2, the inner coil 3 is laminated on at least one surface side of a sheet-like base material (base film) 8 having flexibility and insulation that is adhered to the shaft-like member 1. The conductive pattern may be formed. That is, the inner coil 3 can be formed by a conductive pattern of a flexible printed wiring board. Thus, by forming the inner coil 3 with the conductive pattern of the flexible printed wiring board, the shape accuracy of the inner coil 3 can be improved, and the electromagnetic characteristics can be made relatively stable.

  The inner coil 3 is preferably formed so that both ends in the circumferential direction of the shaft-shaped member 1 do not overlap in order to efficiently form a magnetic flux.

(Base material)
As a material of the base material 9, for example, a flexible resin such as polyimide, liquid crystal polymer, fluororesin, polyethylene terephthalate, polyethylene naphthalate, etc. can be used. Among these, polyimide having excellent insulation and strength is used. Particularly preferred.

  The thickness of the base material 9 is appropriately selected in consideration of the diameter of the shaft-like member 1 (bending required for the base material 9) and the required strength. For example, the average thickness of the base material 9 The lower limit of the thickness is preferably 5 μm, and more preferably 12 μm. On the other hand, the upper limit of the average thickness of the substrate 9 is preferably 0.5 mm, and more preferably 0.2 mm. When the average thickness of the base material 9 is less than the above lower limit, the strength of the base material 9 becomes small, and thus the inner coil 3 may not be sufficiently damaged before being attached to the peripheral surface of the shaft-shaped member 1. There is. On the contrary, when the average thickness of the base material 9 exceeds the above upper limit, the inner coil 3 can be adhered along the peripheral surface of the shaft-like member 1 due to insufficient flexibility of the base material 9. May not be easy.

  As shown in the development view of FIG. 4, the planar shape of the inner coil 3 has at least a pair of straight portions (one or a plurality of first straight portions 3 a and one or a plurality of straight portions) extending in the circumferential direction of the shaft-shaped member 1. The second straight line portion 3b) and one or a plurality of connection portions 3c for connecting the first straight line portion 3a and the second straight line portion 3b so that the directions of the currents are different from each other. Specifically, the inner coil 3 is preferably a flat coil having a flat spiral shape when the peripheral surface of the shaft-shaped member 1 is developed in a flat shape.

  As a minimum of the length of the 1st straight part 3a and the 2nd straight part 3b, 1/2 of the length which makes the circumference of shaft-like member 1 is preferred, and 3/5 is more preferred. On the other hand, as an upper limit of the length of the 1st linear part 3a and the 2nd linear part 3b, 19/20 of the length which makes the shaft-shaped member 1 1 round is preferable, and 9/10 is more preferable. If the lengths of the first straight portion 3a and the second straight portion 3b are less than the lower limit, the coupling with the outer coil 4 may be reduced, leading to insufficient power supply efficiency and unstable output voltage. There is a fear. Conversely, when the lengths of the first straight portion 3a and the second straight portion 3b exceed the above upper limit, the both ends of the inner coil 3 may interfere with each other, making it difficult to dispose the shaft-like member 1 on the peripheral surface. is there.

  The lower limit of the planar aspect ratio (the ratio of the circumferential maximum diameter Da of the axial member 1 to the axial maximum diameter Db) in the deployed state of the inner coil 3 is preferably 5, and more preferably 7. On the other hand, the upper limit of the aspect ratio of the inner coil 3 is preferably 20, and more preferably 15. When the aspect ratio of the inner coil 3 is less than the lower limit, the inner coil 3 becomes unnecessarily large, which may make it difficult to dispose the non-contact power feeding mechanism. On the other hand, when the aspect ratio of the inner coil 3 exceeds the upper limit, the output may easily fluctuate due to the axial displacement of the shaft member 1 between the inner coil 3 and the outer coil 4.

  The planar shape, wiring cross-sectional area, number of turns, and the like of the inner coil 3 can be appropriately selected according to, for example, the power to be supplied. For example, the inductance in a state where the inner coil 3 on the power feeding side is expanded in a planar shape can be 0.00001 μH or more and 10000 μH or less.

  The inner coil 3 may be made of any material as long as it has conductivity, and copper, aluminum, gold, silver, nickel, iron, and the like can be used. However, copper that is relatively inexpensive and excellent in conductivity and deformability is used. Preferably used. Moreover, the surface of the inner coil 3 may be plated with gold, silver, tin, or the like.

  Further, as shown in FIGS. 1 and 2, the flexible printed wiring board having the inner coil 3 has a soft magnetic material (having a relatively large permeability and a relatively low coercive force on the side of the shaft member 1 relative to the inner coil 3. It is preferable to have a magnetic flux guide layer 10 formed from a small material. Thus, since the flexible printed wiring board in which the inner coil 3 is formed has the magnetic flux guide layer 10, the magnetic coupling between the inner coil 3 and the outer coil 4 can be increased, and the contactless power feeding mechanism Power transmission efficiency can be improved.

  As the magnetic flux guide layer 10, a material in which a ferromagnetic material is dispersed in a synthetic resin can be used, and a commercially available material such as a noise suppression sheet can be used.

<Outer coil>
As shown in FIG. 2, the outer coil 4 can be attached to the inner peripheral surface of the outer peripheral member 2 to reduce the distance to the inner coil 3 and increase the magnetic coupling. When the magnetic resistance (magnetic permeability and thickness) of the member 2 is sufficiently small, the outer coil 4 is disposed on the outer peripheral surface of the outer peripheral member 2 or is inserted into the outer peripheral member 2. May be simplified.

  The material of the outer coil 4 can be the same as that of the inner coil 3.

  Further, the outer coil 4 may be formed as a conductive pattern of a flexible printed wiring board, similarly to the inner coil 3. That is, the outer coil 4 may be formed from a conductive pattern that is laminated on a sheet-like base material 11 having flexibility and insulation. Also, the flexible printed wiring board having the outer coil 4 is a magnetic flux guide layer 12 formed of a soft magnetic material on the side farther from the shaft-like member 1 than the outer coil 4 in the same manner as the flexible printed wiring board having the inner coil 3. It is good to have.

  The outer coil 4 is preferably formed so that both ends in the circumferential direction of the shaft-shaped member 1 do not overlap in order to efficiently convert the magnetic flux formed by the inner coil 3 into electric power.

  When the outer peripheral member 2 is divided and formed, a flexible printed wiring board that forms the outer coil 4 may be used as a hinge that connects a plurality of portions of the outer peripheral member 2 so that the ring can be opened. As described above, the outer peripheral member 2 and the outer coil 4 are simultaneously arranged around the shaft-shaped member 1 from the radially outer side by connecting the portions of the outer peripheral member 2 with the flexible printed wiring board that forms the outer coil 4. Can be set.

  As in the case of the inner coil 3, the planar shape of the outer coil 4 is at least a pair of straight portions (first straight portion 4a and second straight portion 4b) extending in the circumferential direction of the outer peripheral member 2, and the first straight portion. 4a and the 2nd linear part 4b have the some connection part 4c which connects so that the direction of an electric current may mutually differ. Specifically, the outer coil 4 is preferably a single flat spiral coil when the peripheral surface of the outer peripheral member 2 is developed into a flat shape.

  As a minimum of the length of the 1st straight part 4a and the 2nd straight part 4b, 1/2 of the length which makes a round of outer peripheral member 2 is preferred, and 3/5 is more preferred. On the other hand, as an upper limit of the length of the 1st linear part 4a and the 2nd linear part 4b, 19/20 of the length which makes the outer periphery member 2 1 round is preferable, and 9/10 is more preferable. If the lengths of the first straight portion 4a and the second straight portion 4b are less than the lower limit, the coupling with the inner coil 3 may be reduced, leading to insufficient power supply efficiency and unstable output voltage. There is a fear. Conversely, when the lengths of the first straight portion 4a and the second straight portion 4b exceed the upper limit, it is possible that both ends of the outer coil 4 interfere with each other and it becomes difficult to dispose the outer peripheral member 2 on the peripheral surface. .

  The lower limit of the aspect ratio of the planar shape in the developed state of the outer coil 4 is preferably 5, and more preferably 7. On the other hand, the upper limit of the aspect ratio of the outer coil 4 is preferably 20, and more preferably 15. When the aspect ratio of the outer coil 4 is less than the lower limit, the outer coil 4 becomes unnecessarily large, which may make it difficult to dispose the non-contact power feeding mechanism. On the other hand, when the aspect ratio of the outer coil 4 exceeds the upper limit, the output may easily fluctuate due to the axial displacement of the shaft member 1 between the inner coil 3 and the outer coil 4.

  The wiring cross-sectional area and the number of turns of the outer coil 4 can be appropriately selected so as to satisfy, for example, the required inductance and electric resistance according to the power to be supplied.

  Specifically, the lower limit of the inductance of the outer coil 4 on the power receiving side is preferably 1 times the inductance of the inner coil 3 on the power feeding side, and more preferably 3 times. On the other hand, the upper limit of the inductance of the outer coil 4 on the power receiving side is preferably 20 times the inductance of the inner coil 3 on the power feeding side, and more preferably 10 times. When the inductance of the outer coil 4 on the power receiving side is less than the lower limit, the induced electromotive force of the outer coil 4 on the power receiving side may be insufficient. On the contrary, when the inductance of the outer coil 4 on the power receiving side exceeds the above upper limit, the resistance value of the outer coil 4 on the power receiving side may increase, resulting in inefficiency.

  As a minimum of the average space | interval of the inner side coil 3 and the outer side coil 4, 0.5 mm is preferable and 1 mm is more preferable. On the other hand, the upper limit of the average distance between the inner coil 3 and the outer coil 4 is preferably 15 mm, and more preferably 10 mm. When the average interval between the inner coil 3 and the outer coil 4 is less than the lower limit, the inner coil 3 and the outer coil 4 may come into contact with each other due to a relative positional shift between the shaft-shaped member 1 and the outer peripheral member 2. On the contrary, when the average interval between the inner coil 3 and the outer coil 4 exceeds the upper limit, the magnetic coupling between the inner coil 3 and the outer coil 4 may be reduced, so that the power supply efficiency may be reduced.

<Capacitor>
The inner capacitor 5 is connected in series with the inner coil 3, and an alternating current is applied to the series circuit of the inner coil 3 and the inner capacitor 5 from the alternating current source 8. On the other hand, the outer capacitor 6 is connected in series with the outer coil 4, and both ends of the series circuit of the outer coil 4 and the outer capacitor 6 are output terminals of the non-contact power feeding mechanism.

  The resonance frequency (resonance frequency between the inner coil 3 and the inner capacitor 5) of the power supply side circuit including the inner coil 3 and the inner capacitor 5 is the resonance frequency (outer coil of the power receiving side circuit including the outer coil 4 and the outer capacitor 6). 4 and the resonance frequency of the outer capacitor 6). Furthermore, the frequency of the circuit on the power feeding side and the circuit frequency on the power receiving side are equal to the frequency of the alternating current output from the alternating current source 8 described later.

  For this reason, the circuit on the power feeding side including the inner coil 3 and the inner capacitor 5 and the circuit on the power receiving side including the outer coil 4 and the outer capacitor 6 mutually exchange current due to magnetic coupling between the inner coil 3 and the outer coil 4. Build up. In other words, in the non-contact power feeding mechanism, the power feeding side circuit and the power receiving side circuit are electromagnetically resonantly coupled (magnetic resonant coupling).

  Thereby, the contactless power supply mechanism has a relatively high power transmission efficiency from the power supply side circuit to the power reception side circuit even when the coupling coefficient between the inner coil 3 and the outer coil 4 is relatively small. Therefore, even when the rotational positions of the inner coil 3 and the outer coil 4 are shifted and the coupling coefficient between the inner coil 3 and the outer coil 4 is reduced, the power supply efficiency is not greatly reduced, and a stable output can be obtained. .

<Power supply>
The frequency of the alternating current output from the alternating current source 8 is equal to the resonance frequency of the power supply side circuit and the power reception side circuit. In other words, the capacity of the inner capacitor 5 is selected such that the resonance frequency of the circuit on the power supply side is equal to the output frequency of the AC current source 8, and the capacity of the outer capacitor 6 is the resonance frequency of the circuit on the power reception side. It is selected to be equal to the output frequency of the alternating current source 8. Thus, power can be supplied to the power supply side circuit in synchronization with the resonance of the power supply side circuit and the power reception side circuit, and can be efficiently transmitted to the power reception side circuit.

  The alternating current output from the alternating current source 8 may be a sine wave, but may be a rectangular wave that is relatively easily obtained by switching of a direct current power source.

  The lower limit of the frequency of the alternating current output from the alternating current source 8 is preferably 1 kHz, and more preferably 10 kHz. On the other hand, the upper limit of the frequency of the alternating current output from the alternating current source 8 is preferably 10 GHz, and more preferably 10 MHz. When the frequency of the alternating current output from the alternating current source 8 is less than the lower limit, the inner capacitor 5 and the outer capacitor 6 are selected so that the inner coil 3 and the inner capacitor 5 and the outer coil 4 and the outer capacitor 6 resonate. May become difficult. On the other hand, when the frequency of the alternating current output from the alternating current source 8 exceeds the upper limit, the impedance of the power supply circuit and the power reception circuit may increase and power supply efficiency may decrease.

<Advantages>
The non-contact power feeding mechanism can obtain an output of electric power from the outer coil 4 by inputting electric power to the inner coil 3 by mutual induction of the inner coil 3 and the outer coil 4.

  Here, the inner coil 3 has a first straight portion 3 a and a second straight portion 3 b that extend in the circumferential direction of the shaft-like member 1 and are connected so that the directions of currents are different from each other, and the outer coil 4. However, since it has the 1st linear part 4a and the 2nd linear part 4b which are extended in the circumferential direction of the shaft-shaped member 1, and are connected so that the direction of an electric current may mutually differ, the magnetic coupling of the inner side coil 3 and the outer side coil 4 is carried out Is relatively large, and power can be transmitted from the inner coil 3 to the outer coil 4 relatively efficiently.

  Further, the non-contact power feeding mechanism can be disposed relatively easily by winding the planarly formed inner coil 3 around the peripheral surface of the shaft-shaped member 1 from the outside in the radial direction.

[Second Embodiment]
The power supply mechanism according to another embodiment of the present invention shown in FIG. 5 is a non-electric power supply / reception unit that exchanges electric power between the shaft-shaped member 1 and the outer peripheral member 2 disposed around the shaft-shaped member 1 so as to be relatively rotatable. It is a contact power supply mechanism. The shaft-like member 1 and the outer peripheral member 2 in the present embodiment are the same as the shaft-like member 1 and the outer peripheral member 2 in the power feeding mechanism of FIG.

  The non-contact power feeding mechanism includes an inner coil 13 disposed along the peripheral surface of the shaft-shaped member 1, and an outer member disposed on the outer member 2 so as to face the inner coil 13 and magnetically coupled to the inner coil 13. A coil 14.

  As shown in FIG. 6, the non-contact power feeding mechanism is connected in series with the inner capacitor 15 connected in series with the inner coil 13, the parallel capacitor 16 connected in parallel with the inner coil 13, and the outer coil 14. An outer capacitor 17 and an alternating current source 18 for applying an alternating current to the series circuit of the outer coil 14 and the outer capacitor 17. That is, the non-contact power feeding mechanism in FIG. 6 is a mechanism that feeds power from the outer peripheral member 2 to the shaft-like member 1 and delivers power from the outer coil 14 on the power feeding side to the inner coil 13 on the power receiving side.

  The outer coil 14, the outer capacitor 17, the inner coil 13, the inner capacitor 15, the parallel capacitor 16 and the alternating current source 18 in the circuit of FIG. 6 are electrically connected to the inner coil 3 and the inner capacitor 5 in the circuit of FIG. The coil 4, the outer capacitor 6, the parallel capacitor 7, and the alternating current source 8 are the same. However, in the circuit of FIG. 6 in which the inner coil 13 is a power receiving coil and the outer coil 14 is a power feeding coil, the coupling between the inner coil 13 and the outer coil 14 is easy to increase, and therefore the power feeding is performed as compared with the circuit of FIG. It is considered easy to increase the efficiency.

[Other Embodiments]
The embodiment disclosed this time should be considered as illustrative in all points and not restrictive. The scope of the present invention is not limited to the configuration of the embodiment described above, but is defined by the scope of the claims, and is intended to include all modifications within the meaning and scope equivalent to the scope of the claims. The

  In the non-contact power feeding mechanism, the inner coil and the outer coil may be formed by winding an electric wire.

  The inner coil or the outer coil of the non-contact power feeding mechanism may be a plurality of coils that are arranged side by side in the circumferential direction and are electrically connected in series or in parallel.

  In the non-contact power feeding mechanism, the inner coil and the outer coil may be multilayer planar coils. That is, the inner coil and the outer coil may be formed by a plurality of conductive patterns of the multilayer wiring board.

  The non-contact power feeding mechanism according to the embodiment of the present invention can be suitably used for supplying power to the rotating body.

DESCRIPTION OF SYMBOLS 1 Shaft-shaped member 2 Outer periphery member 3,13 Inner coil 3a 1st linear part 3b 2nd linear part 3c Connection part 4,14 Outer coil 4a 1st linear part 4b 2nd linear part 4c Connection part 5,15 Inner capacitor 6, 17 Outer capacitors 7, 16 Parallel capacitors 8, 18 AC current source 9 Base material 10 Magnetic flux guide layer 11 Base material 12 Magnetic flux guide layer

Claims (5)

A non-contact power feeding mechanism for transferring power between a shaft-shaped member and an outer peripheral member disposed so as to be relatively rotatable around the shaft-shaped member,
An inner coil disposed along the circumferential surface of the shaft-shaped member;
An outer coil disposed on the outer circumferential member so as to face the inner coil, and magnetically coupled to the inner coil;
A non-contact power feeding mechanism in which the inner coil and the outer coil each have at least a pair of linear portions extending in the circumferential direction of the shaft-like member and having different current directions.   The non-contact power feeding mechanism according to claim 1, wherein the linear portion has a length of ½ or more around the shaft-like member.   The non-contact power feeding mechanism according to claim 1, wherein an impedance on a power receiving side of the inner coil and the outer coil is equal to or higher than an impedance on a power feeding side.   The said inner coil and an outer coil are formed from the electrically conductive pattern laminated | stacked on the at least one surface side of the sheet-like base material which has flexibility and insulation. Non-contact power feeding mechanism. An inner capacitor connected in series with the inner coil;
An outer capacitor connected in series with the outer coil;
A power supply for applying an alternating current to the series circuit of the inner coil and the inner capacitor or the series circuit of the outer coil and the outer capacitor;
5. The non-contact power feeding mechanism according to claim 1, wherein a resonance frequency of the inner coil and the inner capacitor and a resonance frequency of the outer coil and the outer capacitor are equal to a frequency of an alternating current of the power source.

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