JP2017204554A - Relative rotating part electric transmission device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electric transmission device of a relative rotating part capable of efficiently transmitting electric power and signals without causing problems such as disconnection, operating temperature and environmental problems and without increasing the size. A pair of magnetic elements (1A, 1B) that can rotate relative to each other coaxially is provided. Each of the pair of magnetic elements 1A and 1B is composed of a coil 3 and a core 2, and the coils 3 are located inside and outside in the radial direction and are magnetically coupled to each other. Either one or both of electric power and electric signals are transmitted by this magnetic coupling. One magnetic element 1A has a convex shape, and the other magnetic element 1B has a concave shape, and they fit into each other. [Selection diagram] Figure 1

Description

  The present invention relates to an electric transmission device of a relative rotation unit that is arranged in the relative rotation unit and transmits electric power or a signal in a non-contact manner in a mechanical device having a relative rotation unit such as a robot, an assist suit, and other joints.

When power and signal transmission paths include working parts such as joints and rotating parts, in general, a movable range is secured by bending a cable, and power and signals are transmitted. This cable is repeatedly bent and stretched by operating the joint part and the rotating part. There is a concern that the cable may be disconnected by repeatedly bending the cable made of copper, aluminum, or the like. In addition, when a cable is used, the range of motion is limited. In power assist suits, etc., the cable may be caught by surrounding objects, causing not only disconnection but also a disaster such as the fall of the person wearing it.

  On the other hand, these can be eliminated by using a slip ring for the movable part. However, as a disadvantage of the slip ring, generation of wear powder in the electrical contact can be mentioned. A rotary connector using a conductive liquid metal can be cited as an alternative. However, there is a concern that the operating temperature is limited, environmental pollution is concerned, or it is very expensive.

  In addition, as shown in FIGS. 10 and 11, magnetically coupled electric devices in which magnetic elements 51 and 51 having a general pot-shaped core 52 are opposed to each other and a gap is disposed in the vicinity of the coil in which leakage magnetic flux is easily absorbed. A structure of a transmission apparatus has been proposed. Each magnetic element 51 includes a core 52 and a coil 53, and both the magnetic elements 51 and 51 face each other with a gap G between the coil 53 and the core 52. Patent Document 1 is an example of such a configuration.

JP 11-354348 A Japanese Patent Laying-Open No. 2015-6266

  As described above, a device that secures a movable range by bending a cable may be broken by repeatedly bending and stretching, and is particularly unsafe because it is worn by a human in a power suit or the like. Slip rings generate wear powder, and rotary connectors using liquid metal have problems in terms of temperature limitations, environmental pollution concerns, and cost.

  The electric transmission device using magnetic coupling does not have the above-described problems, but has a configuration in which the pair of magnetic elements 51 and 51 are opposed to each other via the gap G in the axial direction. As a result, power and electric signal transmission efficiency is poor. In order to improve the inductance value and increase the efficiency, it is necessary to increase the core size.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an electric transmission device for a relative rotation unit that is free from disconnection, operating temperature, and environmental problems, and that can efficiently transmit power and signals without increasing the size.

  An electrical transmission device for a relative rotation part according to the present invention includes a pair of magnetic elements that can rotate relative to each other on the same axis, the pair of magnetic elements each including a coil and a core, and the coils are radially connected to each other. The magnetic coupling is located inside and outside of the antenna and transmits one or both of electric power and electric signal.

  According to this configuration, the pair of magnetic elements are excellent in magnetic coupling since the coils are located radially inside and outside, excellent in power and electric signal transmission efficiency, and avoiding an increase in size. Is done. In addition, because of magnetic coupling, there are no disconnections, operating temperatures, or environmental problems.

  In this invention, of the pair of magnetic elements, the core of the magnetic element in which the coil is located on the inner side in the radial direction is formed from a cylindrical portion located on the inner periphery of the coil of the magnetic element and one end of the cylindrical portion It has an L-shaped cross section that extends to the outer diameter side and has an outer diameter end formed by a flange portion having a diameter larger than that of the coil of the other magnetic element. A cylindrical portion whose one end face is opposed to the flange portion of the core of the one magnetic element, and extends from the other end of the cylindrical portion to the inner diameter side, and an inner diameter end is the cylindrical portion of the core of the other magnetic element You may make it consist of a flange part which opposes this through the gap.

Alternatively, of the pair of magnetic elements, the core of the magnetic element in which the coil is located on the inner side in the radial direction has a cylindrical portion located on the inner periphery of the coil of the magnetic element and an outer diameter from one end of the cylindrical portion. The outer diameter end is L-shaped in cross section formed by a flange portion facing the inner peripheral surface of the core end portion of the other magnetic element with a gap extending to the side,
The core of the other magnetic element is positioned on the outer periphery of the coil of the magnetic element, and an inner peripheral surface of one end thereof is opposed to the flange portion of the core of the one magnetic element, and the cylindrical part The other end of the magnetic element may extend to the inner diameter side, and the inner diameter end may be a flange portion having a smaller diameter than the coil of the other magnetic element.

In other words, in this configuration, one of the pair of magnetic elements has a convex shape in which one drum-shaped flange is omitted, and the other has a cup-shaped concave shape. According to this configuration, since the distance between the coil and the gap is larger than that in the conventional example, the magnetic flux consumed in the coil is reduced because the leakage magnetic flux generated in the gap is less likely to be absorbed by the coil.
The inductance value is improved. Further, since one of the coils on the power feeding side and the power receiving side can be arranged on the other inner diameter side, the degree of coupling can be improved and the leakage magnetic flux can be reduced. As a result, the inductance value is improved, and the core size can be further reduced. In addition, because of the uneven shape, it is easy to distinguish the magnetic elements on both sides, and erroneous assembly can be prevented.

In this invention, a resonance circuit including a leakage inductance caused by a leakage magnetic flux generated in a gap between the pair of magnetic elements and a capacitor includes a coil on a receiving side of the pair of magnetic elements and a capacitor connected to the coil. The structure comprised by these may be sufficient.
Efficiency can be improved by a resonance circuit including a leakage inductance caused by magnetic flux leaking into the gap and a capacitor connected to the coil of the magnetic element on the power receiving side.

  In the present invention, one of the pair of magnetic elements may be fixed to the shaft body, and the other magnetic element may be installed on the shaft body via a radial rolling bearing. In the case of this configuration, the shaft body and the radial rolling bearing can support the pair of magnetic elements so that they can rotate relative to each other, and the electric transmission device can be singly supported, and the assembly to the mechanical device becomes easy.

In the present invention, either one of the magnetic elements is attached to one relative bending part of the pair of relative bending parts constituting the joint portion of the mechanical device, and the other magnetic element is attached to the other relative bending part. Also good.
When used in a joint portion of a mechanical device, each effect of the electric transmission device of the present invention is effectively exhibited.

In the case of this configuration, a power assist suit that is attached to a human body and assists the movement of the arm, hand, leg, or foot of the human body with a drive source may be used.
In the case of a power assist suit, there is a strong demand for transmission reliability and miniaturization. Therefore, the reliability and downsizing effect of the electric transmission device of the relative rotation part of the present invention are more effectively exhibited.

  An electrical transmission device for a relative rotation part according to the present invention includes a pair of magnetic elements that can rotate relative to each other on the same axis, the pair of magnetic elements each including a coil and a core, and the coils are radially connected to each other. Because it is magnetically coupled to the inside and outside, and transmits one or both of electric power and electric signal by this magnetic coupling, there is no disconnection, operating temperature, environmental problems, and it is efficient without upsizing Power and signal can be transmitted.

1 is a partially cutaway perspective view of an electric transmission device for a relative rotation unit according to a first embodiment of the present invention. It is a cross section of the same electric transmission device. It is explanatory drawing which shows the flow of the magnetic flux of the transmission apparatus. It is an electric circuit diagram of the electric transmission apparatus. It is a partially cutaway perspective view of the example which used the electric transmission device with a bearing. FIG. 6 is a partially cutaway perspective view of an example in which a lead wire is added to the electric transmission device of FIG. 5. It is explanatory drawing of an example of the power assist suit using the same electric transmission apparatus. It is sectional drawing of the electric transmission apparatus of the relative rotation part concerning other embodiment. It is explanatory drawing of the analysis result which shows the flow of the magnetic flux of the electric transmission apparatus which concerns on said 1st embodiment, another embodiment, and a prior art example. It is a partially cutaway perspective view of a conventional example. It is sectional drawing of the same prior art example.

A first embodiment of the present invention will be described with reference to FIGS. The electrical transmission device of the relative rotation unit is a kind of transformer, and includes a pair of magnetic elements 1A and 1B that can rotate relative to each other on the same axis. The pair of magnetic elements 1A and 1B are each composed of a coil 3 and a core 2, and the coils 3 and 3 are magnetically coupled to each other in the radial direction with a gap G therebetween. Transmit either or both electrical signals. One of the pair of magnetic elements 1A, 1B, for example, the magnetic element 1A is fixed to the outer periphery of the shaft body 4, and the other magnetic element 1B is rotatably installed on the outer periphery of the shaft body 4. .
The shaft body 4 is installed in one housing 5 of a pair of housings 5 and 6 that rotate relative to each other, and the other magnetic element 1B is installed in the other housing 6.

Of the pair of magnetic elements 1A and 1B, one magnetic element 1A has a convex shape, and the other magnetic element 1B has a concave shape.
Specifically, the core 2 of the magnetic element 1A in which the coil 3 is located on the inner side in the radial direction has a cylindrical portion 2a located on the inner periphery of the coil 3 and an outer diameter extending from one end of the cylindrical portion 2a to the outer diameter side. The end has an L-shaped cross section formed by a flange portion 2b having a diameter larger than that of the coil 3 of the other magnetic element 1B. The core 2 and the coil 3 constitute the convex pot-shaped magnetic element 1A.
The core 2 of the other magnetic element 1B is located on the outer periphery of the coil 3 of this magnetic element 1B, and the outer surface of one end faces the flange 2b of the core 2 of the one magnetic element 1A via the gap G1. A cylindrical portion 2c on the side, and a flange portion 2d extending from the other end of the cylindrical portion 2c to the inner diameter side and having an inner diameter end facing the end surface of the cylindrical portion 2a of the core 2 of one magnetic element 1A via a gap G2. The cross section is L-shaped.

  Although the coil 3 of each of the magnetic elements 1A and 1B is schematically shown in the drawing, a bobbin in which a flat conductive wire is wound in a single layer may be used, even if a bobbin is wound with a coated conductive wire made of a round wire. It may be none. The core 2 of each of the magnetic elements 1A and 1B is a ferromagnetic body, and is composed of a dust-molded magnetic body, an injection-molded magnetic body, a laminated steel plate or the like.

  Specifically, the compression-molded magnetic material is, for example, pure iron-based soft magnetic material such as iron powder or iron nitride powder, Fe-Si-Al alloy (Sendust) powder, super Sendust powder, Ni-Fe alloy (Permalloy) Magnetic materials such as iron-based alloy soft magnetic materials such as powder, Co—Fe alloy powder, and Fe—Si—B alloy powder, ferrite magnetic materials, amorphous magnetic materials, and fine crystal materials can be used as raw materials.

Specifically, the injection-molded magnetic body is obtained by blending a binder resin with the raw powder of the compression-molded magnetic body and injection-molding this mixture. The magnetic powder is preferably an amorphous metal powder from the viewpoint of easy injection molding, easy maintenance of the shape after injection molding, and excellent magnetic properties of the composite magnetic body. As the amorphous metal powder, the above-described iron alloy series, cobalt alloy series, nickel alloy series, mixed alloy series amorphous, or the like can be used. The insulating coating described above is formed on the surface of these amorphous metal powders.
As the binder resin, a thermoplastic resin capable of injection molding can be used. Polyethylene and other various resins can be used as the thermoplastic resin.

  FIG. 4 shows an example of an electric circuit using the electric transmission apparatus A for power supply. One of the pair of magnetic elements 1A and 1B, for example, the coil 3 of the magnetic element 1A is the primary side and is connected to the AC power source 7. The coil 3 of the other magnetic element 1B is on the secondary side, that is, the power receiving side, and is connected to a load 8 such as a motor. A capacitor 9 is connected in parallel with the power receiving side coil 3, and the resonance circuit 10 is constituted by the leakage inductance due to the leakage magnetic flux generated in the power receiving side coil 3 and the capacitor 9. An electric signal source (not shown) is provided in place of the AC power supply 7 or superimposed on the AC voltage output from the AC power supply 7, and a demodulation circuit (not shown) is used instead of the load 8 or together with the load 8. The electrical signal can be transmitted.

According to the electric transmission apparatus A having this configuration, the pair of magnetic elements 1A and 1B have excellent magnetic coupling because the coils 3 and 3 are located inside and outside in the radial direction, and transmit electric power and electric signals. It is excellent in efficiency and avoids an increase in size. In addition, because of magnetic coupling, there are no disconnections, operating temperatures, or environmental problems. The magnetic flux B of the coils 3 and 3 passes as shown by the arrow B in FIG. The gaps G1 and G2 are air layers or insulating layers that cross perpendicularly to the magnetic path.
The gaps G1 and G2 are air layers in this embodiment, but may be insulating layers with an insulator such as a resin material interposed.

Specifically, this electric transmission device has a configuration in which one magnetic element 1A of the pair of magnetic elements 1A and 1B is convex and the other magnetic element 1B is concave. For this reason, the gaps G1 and G2 are provided outside the vicinity of the coil where the leakage magnetic flux is easily absorbed, so that the inductance value is improved. Further, since one of the coils 3 and 3 on the power feeding side and the power receiving side is positioned on the other inner diameter side, the degree of coupling is improved and the leakage magnetic flux can be reduced. As a result, the inductance value is improved, and the core size can be further reduced. In addition, because of the concave and convex shape, it is easy to distinguish the magnetic elements 1A and 1B on both sides, and erroneous assembly can be prevented.
The efficiency can be improved by the resonance circuit 10 including the leakage inductance generated by the magnetic flux leaking into the air, that is, the gaps G1 and G2, and the capacitor 9 connected to the coil 3 of the magnetic element 1B on the power receiving side.
In this example, the coils 3 and 3 on the power feeding side and the power receiving side have the same number of turns. However, the number of turns may be different from each other and may have a boosting or step-down function.

Thus, according to the electric transmission apparatus A of this embodiment, the following effects can be obtained.
・ Cables used for joint power or signal transmission are disconnected due to repeated stress due to bending, but by applying this electrical transmission device A with which the core can operate relatively, power or signals can be transmitted without disconnection To do.
In this electrical transmission device A, since the pot-type inductor is divided into the concave magnetic element 1B and the convex magnetic element 1A, the leakage magnetic flux can be suppressed from being absorbed by the coil. Further, since one coil 3 is disposed on the inner diameter of the other coil 3, the coupling coefficient is improved.
The efficiency can be improved by the resonance circuit 10 including the leakage inductance generated by the leakage magnetic flux generated in the gap portions G1 and G2 and the capacitor 9, and there is no need to increase the size of the electric transmission device.

  FIG. 5 shows an example in which the electric transmission device A of the relative rotating portion is installed in the housings 5 and 6 (see FIG. 2) as a configuration having a pair of bearings 11 and 11. The bearing 11 is a radial bearing and is a deep groove ball bearing. In this example, the outer ring 11a of the bearing 11 and the concave magnetic element 1B are fixed to the housing, and the inner ring 11b of the bearing 11 and the convex magnetic element 1A are fixed to a shaft body such as a support shaft. When power is supplied from the housing side, power can be supplied to the device fixed to the shaft body in a non-contact manner via this electric transmission device.

  FIG. 6 shows an example of extraction of the cable / signal line (blue) in the embodiment of FIG. In this example, with respect to the concave magnetic element 1 </ b> B, the lead wire 3 a is taken out from the outer diameter portion of the core 2. The lead wire 3 a may be taken out from the end surface of the core 2. For the convex magnetic element 1 </ b> A fixed to the shaft body 4, the coil 3 takes out the lead wire 3 b from the inner diameter hole of the hollow shaft body 4. As a result, the lead-out wires a and 4b, which are power cables / signal wires, can be taken out without interfering with members on the housing side.

  FIG. 7 shows an example in which the mechanical device equipped with the electric transmission device of the relative rotating portion is the power assist suit 20. The power assist suit 20 includes a body part 20a to be worn on a human body and an arm part 20b extending from the body part 20a. The arm portion 20b has an upper arm portion 20ba and a lower arm portion 20bb which are a pair of relative bending parts, and an elbow joint portion 20ac which is a relative bending portion between both the portions 20ba and 20bb is arranged around the axis O. It is a rotatable joint part with one degree of freedom. There is a power source 7 in the body portion 20a, and a load 8 such as an electric motor for driving the wrist or hand is provided at the tip of the lower arm portion 20ba. A wiring (not shown) connected from the power source 7 to the load 8 is connected by the electric transmission device A of the embodiment at the joint 20ac serving as the elbow.

  In the power assist suit 20, there is a strong demand for reliability of transmission of electric power and electric signals and miniaturization of the electric transmission device at the joint. Therefore, the reliability and downsizing effect of the electric transmission device of the relative rotation unit of this embodiment are more effectively exhibited.

FIG. 8 shows another embodiment of the present invention. In this embodiment, of the pair of magnetic elements 1A and 1B, the core 2 of the magnetic element 1A in which the coil 3 is located radially inside is located on the inner periphery of the coil 3 of the magnetic element 1A. A cross section L formed of a cylindrical portion 2a and a flange portion 2b extending from one end of the cylindrical portion 2a to the outer diameter side and having an outer diameter end facing the inner peripheral surface of the core end portion of the other magnetic element 1B via a gap G3. It is a letter shape.
The core 2 of the other magnetic element 1B is located on the outer periphery of the coil 3 of the magnetic element 1B, and the inner peripheral surface of one end thereof faces the flange portion 2b of the core 2 of the one magnetic element 1A. The cylindrical portion 2c and the flange portion 2d extending from the other end of the cylindrical portion 2c to the inner diameter side and having a smaller diameter than the coil 3 of the other magnetic element 1B.

Also in this configuration, since the gap is provided in the vicinity of the coil where the leakage magnetic flux is easily absorbed, the inductance value is improved. Further, since one of the coils 3 and 3 on the power feeding side and the power receiving side can be arranged on the inner diameter of the other, the degree of coupling can be improved and the leakage magnetic flux can be reduced. As a result, the inductance value is improved, and the core size can be further reduced. In addition, because of the concave and convex shape, it is easy to distinguish the magnetic elements 1A and 1B on both sides, and erroneous assembly can be prevented.
Other configurations and effects in this embodiment are the same as those in the first embodiment described above with reference to FIGS.

  FIGS. 9A to 9C show magnetic flux flow analysis results in the first embodiment, the other embodiments, and the conventional examples of FIGS. 10 and 11, respectively. As can be seen from the figure, each of the above embodiments is provided with a gap other than the vicinity of the coil in which the leakage magnetic flux is easily absorbed, so that the inductance value is improved.

  As mentioned above, although the form for implementing this invention based on embodiment was demonstrated, embodiment disclosed this time is an illustration and restrictive at no points. The scope of the present invention is defined by the terms of the claims, rather than the description above, and is intended to include any modifications within the scope and meaning equivalent to the terms of the claims.

1A, 1B: Magnetic element 2 ... Core 3 ... Coil 4 ... Shaft body 5, 6 ... Member 2a, 2c ... Cylindrical part 2b, 2d ... Flange part 7 ... AC power supply 8 ... Load 9 ... Capacitor 10 ... Resonant circuit 11 ... Bearing 20 ... Power assist suit (machinery)
20b ... arm portion 20ba ... upper arm portion (relative bending part)
20bb ... Lower arm (relative bending parts)
20bc ... Joint part (relative rotation part)
G1, G2, G3, G4 ... Gap

Claims (7)

  A pair of magnetic elements that can rotate relative to each other on the same axis is provided. Each of the pair of magnetic elements is composed of a coil and a core, and the coils are located on the inside and outside in the radial direction and are magnetically coupled. An electric transmission device of a relative rotating unit that transmits one or both of electric power and electric signal by coupling.   2. The electrical transmission device for a relative rotation unit according to claim 1, wherein, of the pair of magnetic elements, the core of the magnetic element in which the coil is located on the inner side in the radial direction is formed on an inner periphery of the coil of the magnetic element. A cylindrical portion that is positioned and extending from one end of the cylindrical portion to the outer diameter side, the outer diameter end having an L-shaped cross section formed by a flange portion that is larger in diameter than the coil of the other magnetic element; The core is located on the outer periphery of the coil of the magnetic element, and has an end surface at one end facing the flange portion of the core of the one magnetic element via a gap and from the other end of the cylindrical part to the inner diameter side. An electrical transmission device for a relative rotating portion having an inverted L-shaped cross section that extends and has a flange portion facing an end surface of the cylindrical portion of the core of the other magnetic element. In the electric transmission device of the relative rotation unit according to claim 1,
Of the pair of magnetic elements, the core of the magnetic element in which the coil is located on the inner side in the radial direction has a cylindrical portion located on the inner circumference of the coil of the magnetic element and an outer diameter side from one end of the cylindrical portion. The outer diameter end has an L-shaped cross section formed by a flange portion facing the inner peripheral surface of the core end portion of the other magnetic element through a gap,
The core of the other magnetic element is positioned on the outer periphery of the coil of the magnetic element, and an inner peripheral surface of one end thereof is opposed to the flange portion of the core of the one magnetic element, and the cylindrical part An electrical transmission device for a relative rotating portion having an inverted L-shaped cross section that extends from the other end to the inner diameter side and has an inner diameter end that is a flange portion having a smaller diameter than the coil of the other magnetic element.   3. The electric transmission apparatus for a relative rotating unit according to claim 1 or 2, wherein a resonance circuit including a leakage inductance caused by a leakage magnetic flux generated in a gap between the pair of magnetic elements and a capacitor is the pair of magnetic elements. An electrical transmission device for a relative rotating part, which is composed of a coil on a receiving side of an element and a capacitor connected to the coil.   4. The electrical transmission device for a relative rotation unit according to claim 1, wherein one of the pair of magnetic elements is fixed to a shaft body, and the other magnetic element is An electrical transmission device for a relative rotating portion installed on the shaft body via a radial rolling bearing.   5. The electrical transmission device for a relative rotation part according to claim 1, wherein one of the magnetic elements is one of a pair of relative bending parts constituting a joint part of the mechanical device. An electrical transmission device for a relative rotating portion in which the other magnetic element is attached to the relative bending component and the other relative bending component, respectively.   6. The electrical transmission device for a relative rotation unit according to claim 5, wherein the mechanical device is a power assist suit that is attached to a human body and assists the movement of the arm, leg, hand, or foot of the human body with a drive source. Electric transmission device for rotating parts.

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