JP6710573B2 - Relative rotating part electrical transmission device - Google Patents

Description

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

When the power and signal transmission path includes an operating part such as a joint part and a rotating part, generally, the range of motion is secured by bending the cable to transmit the power and the signal. This cable is repeatedly bent and stretched by moving joints and rotating parts. There is a concern that the cable may break due to repeated bending of the cable made of copper or aluminum. Moreover, when a cable is used, the range of motion is limited. In power assist suits and the like, the cables may get caught in surrounding objects, causing not only wire breaks but also accidents such as the fall of the person wearing them.

On the other hand, it is possible to solve these problems by using a slip ring for the movable portion, but a drawback of the slip ring is that abrasion powder is generated in the electrical contacts. A rotary connector using a conductive liquid metal is given as an alternative, but it has a limitation in use temperature, there is a concern of environmental pollution, and it is very expensive.

In addition to this, as shown in FIGS. 10 and 11, magnetic elements 51, 51 having a general pot-shaped core 52 are opposed to each other, and a gap is arranged in the vicinity of the coil where the leakage magnetic flux is easily absorbed. The structure of a transmission device has been proposed. Each magnetic element 51 is composed of a core 52 and a coil 53, and in the magnetic elements 51, 51, the coil 53 and the core 52 face each other with a gap G therebetween. As an example of such a configuration, Patent Document 1 can be cited.

JP, 11-354348, A JP, 2005-6266, A

As described above, a cable that bends and secures a range of motion has a risk of disconnection due to repeated bending and stretching. In particular, a power suit or the like is worn by humans, and thus lacks safety. The slip ring generates abrasion powder, and the rotary connector using liquid metal has a problem in terms of temperature limitation, environmental pollution, and price.

The electric transmission device by magnetic coupling does not have the above-mentioned problems, but since the pair of magnetic elements 51, 51 are opposed to each other via the gap G in the axial direction, the inductance value due to the arranged gap G is large. Is greatly reduced, which results in inefficient transmission of electric power and electric signals. 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 of a relative rotating part that can efficiently transmit electric power and signals without causing problems such as disconnection, operating temperature and environmental problems and without increasing the size.

The electric transmission device of the relative rotation unit of the premise includes a pair of magnetic elements that are rotatable relative to each other on a coaxial center, and each of the pair of magnetic elements includes a coil and a core, and the coils are arranged in a radial direction. Are located inside and outside of and are magnetically coupled to transmit either or both of electric power and electric signals.

According to this configuration, the coils of the pair of magnetic elements are located inside and outside in the radial direction, so that the degree of magnetic coupling is excellent, the efficiency of transmission of electric power and electric signals is excellent, and the size is prevented from increasing. To be done. Further, because of the magnetic coupling, there are no disconnection, operating temperature, and environmental problems.

Electrical transmission device of the relative rotation of the first invention in this inventions is Oite the premise construction, of the pair of magnetic elements, said core of the magnetic element in which the coil is located inside in the radial direction, The magnetic element has a cylindrical portion positioned on the inner circumference of the coil, and an L-shaped cross section having an outer diameter end extending from one end of the cylindrical portion to the outer diameter side and having an outer diameter end having a larger diameter than the coil of the other magnetic element. The core of the other magnetic element is located at the outer periphery of the coil of the magnetic element, and the end face at one end faces the flange portion of the core of the one magnetic element and the cylindrical portion of the cylindrical portion. ing between the flange inner diameter end extending radially inwardly from the other end are opposed with a gap to the end face of the cylindrical portion of the core of the other magnetic element.

In the electric transmission device of the relative rotating part according to the second aspect of the present invention, in the prerequisite structure, the core of the magnetic element of the pair of magnetic elements in which the coil is located radially inside is the magnetic element. A cylindrical portion located on the inner circumference of the coil, and a flange portion extending from one end of the cylindrical portion to the outer diameter side and having an outer diameter end facing the inner circumferential surface of the core end portion of the other magnetic element via a gap. Is L-shaped in cross section,
The core of the other magnetic element is located at the outer periphery of the coil of the magnetic element, and the inner peripheral surface of one end of the magnetic element faces the flange portion of the core of the one magnetic element, and the cylindrical portion. an inner diameter end extending radially inward from the other end of ing at the small diameter of the flange portion than the coil of the other magnetic element.

This structure is, so to speak, one of the pair of magnetic elements having a convex shape in which one flange of the drum shape is omitted and the other having a cup-shaped concave shape. According to this configuration, the distance between the coil and the gap becomes larger than that of the conventional example, so that the leakage magnetic flux generated in the gap is less likely to be absorbed by the coil, and the magnetic energy consumed in the coil is reduced,
The inductance value is improved. Further, since one of the coils on the power feeding side and the coil on the power receiving side can be arranged on the inner diameter side of the other, the coupling degree 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. Further, because of the concavo-convex shape, it is easy to distinguish the magnetic elements on both sides, and misassembly can be prevented.

In the present invention, the leakage inductance due to leakage magnetic flux generated in the gap between the pair of magnetic elements, a resonance circuit consisting of a capacitor, connected to the coil and receiving-side of the coil in the pair of magnetic elements capacitor It may be configured by and.
The efficiency can be improved by the resonance circuit including the leakage inductance due to the magnetic flux leaking into the gap and the 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 this structure, the shaft body and the radial rolling bearing can support the pair of magnetic elements so that the magnetic elements can rotate relative to each other, and the electric transmission device can be independently mounted, so that the mechanical transmission device can be easily assembled.

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

In the case of this configuration, it may be 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.
In the case of a power assist suit, reliability of transmission and miniaturization are strongly demanded. Therefore, the reliability and miniaturization effect of the electric transmission device of the relative rotation part of the present invention can be more effectively exhibited.

Electrical transmission device of the relative rotation of the first invention in this inventions is provided with a relatively rotatable pair of magnetic elements on the same axis to each other, the pair of magnetic elements are each made in the coils and the core, and the coil is magnetically coupled positioned inside and outside in the radial directions, in the electrical transmission device of the relative rotary part you transmit either one or both of power and an electric signal by the magnetic coupling, of the pair of magnetic elements The core of the magnetic element in which the coil is located inside in the radial direction includes a cylindrical portion located on the inner circumference of the coil of the magnetic element and an outer diameter end extending from one end of the cylindrical portion to the outer diameter side and the other outer diameter end. Of the magnetic element has a flange portion having a diameter larger than that of the coil of the magnetic element, and the core of the other magnetic element is located on the outer periphery of the coil of the magnetic element, and one end face of the one core is A cylindrical portion facing the flange portion of the core of the magnetic element with a gap, and a flange portion extending from the other end of the cylindrical portion toward the inner diameter side and having an inner diameter end facing the end surface of the cylindrical portion of the core of the other magnetic element. and because the a sectional inverted L-shape made of, disconnection or use temperature causes no environmental problems, and allows transmission of power efficiently and signal without increasing the size of.
An electric transmission device of a relative rotating part of a second aspect of the present invention includes a pair of magnetic elements that can rotate relative to each other coaxially with each other, and each of the pair of magnetic elements includes a coil and a core. In the electric transmission device of the relative rotating part, wherein the coils are magnetically coupled to each other inside and outside in the radial direction, and either or both of electric power and electric signal are transmitted by the magnetic coupling, in 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 end extending from one end of the cylindrical portion to the outer diameter side of the other magnetic element. The core of the element has an L-shaped cross-section consisting of an inner peripheral surface and a flange portion opposed to each other through a gap, and the core of the other magnetic element is located at the outer periphery of the coil of the magnetic element and has one end. A cylindrical portion whose inner peripheral surface of the end portion faces the flange portion of the core of the one magnetic element, and an inner diameter end extending from the other end of the cylindrical portion toward the inner diameter side and having a diameter smaller than that of the coil of the other magnetic element. Since it has an inverted L-shape in cross section with the flange portion, there is no problem of disconnection, operating temperature and environment, and power and signals can be transmitted efficiently without increasing the size.

FIG. 3 is a partially cutaway perspective view of the electric transmission device of the relative rotation unit according to the first embodiment of the present invention. A cross-sectional view of the electric transmission system. It is explanatory drawing which shows the flow of the magnetic flux of the same transmission device. It is an electric circuit diagram of the electric transmission device. FIG. 3 is a partially cutaway perspective view of an example in which the electric transmission device is provided 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 the said 1st embodiment, other embodiment, and a prior art example. It is a partially notched perspective view of a prior art 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 electric transmission device of the relative rotation unit is a type of transformer, and includes a pair of magnetic elements 1A and 1B that are rotatable relative to each other coaxially. The pair of magnetic elements 1A and 1B are composed of a coil 3 and a core 2, respectively, and the coils 3 and 3 are magnetically coupled to each other by being located inside and outside in the radial direction via a gap G. Transmits either or both electrical signals. One of the pair of magnetic elements 1A and 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, and they are fitted to each other.
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 circumference of the coil 3 and an outer diameter extending from one end of the cylindrical portion 2a to the outer diameter side. It has an L-shaped cross section, the end of which is a flange portion 2b having a larger diameter than the coil 3 of the other magnetic element 1B. The core 2 and the coil 3 form 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 the magnetic element 1B, and one end face of the core 2 faces the flange portion 2b of the core 2 of the one magnetic element 1A via a gap G1. Side cylindrical portion 2c and a flange portion 2d extending from the other end of the cylindrical portion 2c toward 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. It has an L-shaped cross section.

Although the coil 3 of each of the magnetic elements 1A and 1B is schematically shown in the figure, a bobbin may be formed by winding a covered conductive wire made of a round wire, or a bobbin obtained by winding a rectangular conductive wire in a single layer. It may be none. The core 2 of each of the magnetic elements 1A and 1B is a ferromagnetic material, and is made of a powder compact magnetic material, an injection magnetic material, a laminated steel plate, or the like.

Specific examples of the compression-molded magnetic body include pure iron-based soft magnetic materials such as iron powder and iron nitride powder, Fe—Si—Al alloy (Sendust) powder, super Sendust powder, and Ni—Fe alloy (Permalloy). Magnetic materials such as powder, Co—Fe alloy powder, Fe—Si—B alloy powder, and other iron-based alloy soft magnetic materials, ferrite magnetic materials, amorphous magnetic materials, and microcrystalline materials can be used as raw materials.

Specifically, the injection-molded magnetic body is obtained by mixing a raw material powder of the compression-molded magnetic body with a binder resin and injection-molding the mixture. The magnetic powder is preferably an amorphous metal powder because it is easy to perform injection molding, the shape can be easily maintained after injection molding, and the magnetic properties of the composite magnetic body are excellent. As the amorphous metal powder, the above-mentioned iron alloy system, cobalt alloy system, nickel alloy system, mixed alloy system amorphous of these and the like can be used. The above-mentioned insulating coating is formed on the surface of these amorphous metal powders.
As the binder resin, an injection-moldable thermoplastic resin can be used. As the thermoplastic resin, polyethylene and various other resins can be used.

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

According to the electrical transmission device A having this configuration, the pair of magnetic elements 1A and 1B have excellent coupling degree of magnetic coupling because the coils 3 and 3 are located inside and outside in the radial direction, and transmit power and electrical signals. It is highly efficient and avoids upsizing. Further, because of the magnetic coupling, there are no disconnection, operating temperature, and environmental problems. The magnetic flux B of the coils 3 and 3 passes as indicated by an arrow B in FIG. The gaps G1 and G2 are air layers or insulating layers that intersect perpendicularly to the magnetic path.
Although the gaps G1 and G2 are air layers in this embodiment, they 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 has a convex shape and the other magnetic element 1B has a concave shape. Therefore, since the gaps G1 and G2 are provided other than the vicinity of the coil where the leakage magnetic flux is easily absorbed, the inductance value is improved. Further, one of the coils 3 and 3 on the power feeding side and the coil on the power receiving side is located on the inner diameter side of the other, so that 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. Further, because of the concavo-convex shape, it is easy to distinguish the magnetic elements 1A and 1B on both sides, and it is possible to prevent misassembly.
The efficiency can be improved by the resonance circuit 10 including the leakage inductance generated by the magnetic flux leaking to 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.
The coils 3 and 3 on the power feeding side and the coil on the power receiving side have the same number of turns in this example, but the number of turns may be different from each other to have a step-up or step-down function.

As described above, according to the electric transmission device A of this embodiment, the following effects can be obtained.
-Cables used for power or signal transmission at joints are disconnected due to repeated stress due to bending, but by applying this electrical transmission device A, which allows the core to operate relatively, power or signals are transmitted without disconnection. To do.
In this electric transmission device A, since the pot type inductor is divided into the concave magnetic element 1B and the convex magnetic element 1A, it is possible to suppress the leakage magnetic flux from being absorbed by the coil. In addition, since the one coil 3 is arranged inside the other coil 3, the coupling coefficient is improved.
The efficiency can be improved by the leakage inductance generated by the leakage magnetic flux generated in the gap portions G1 and G2 and the resonance circuit 10 including the capacitor 9, and it is not necessary to upsize 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 taking out the cable/signal line (blue) in the embodiment of FIG. In this example, with respect to the concave magnetic element 1B, the lead wire 3a is taken out from the outer diameter portion of the core 2. The lead wire 3a may be taken out from the end surface of the core 2. Regarding the convex magnetic element 1A fixed to the shaft body 4, the coil 3 has a lead wire 3b taken out from an inner diameter hole of the hollow shaft body 4. This makes it possible to take out the lead wire 3a, 3 b is without power cable / signal line to interfere with members of the housing side.

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

In the power assist suit 20, reliability of transmission of electric power and electric signals and miniaturization of electric transmission devices at joints are strongly demanded. Therefore, the reliability and the effect of miniaturization 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 inside the coil 3 of the magnetic element 1A. A section L composed 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 has a letter shape.
The core 2 of the other magnetic element 1B is located on the outer circumference of the coil 3 of the magnetic element 1B, and the inner peripheral surface at one end is opposed to 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 the inner diameter end smaller in diameter than the coil 3 of the other magnetic element 1B.

Also in the case of this configuration, since the gap is provided other than 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 coil on the power receiving side can be arranged in the inner diameter of the other, the coupling degree 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. Further, because of the concavo-convex shape, it is easy to distinguish the magnetic elements 1A and 1B on both sides, and it is possible to prevent misassembly.
Other configurations and effects of this embodiment are similar to those of the first embodiment described above with reference to FIGS.

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

The embodiments for carrying out the present invention have been described above based on the embodiments, but the embodiments disclosed this time are exemplifications in all points and not restrictive. The scope of the present invention is shown not by the above description but by the scope of the claims, and is intended to include meanings equivalent to the scope of the claims and all modifications within the scope.

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

Claims (6)

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

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