Rotating transformer

Abstract

To provide a rotating transformer capable of improving efficiency by suppressing magnetic flux leakage from an air gap.SOLUTION: A rotating transformer includes a rotor configured with a first coil disposed on a first magnetic body, a stator configured with a second coil disposed on a second magnetic body, and a rolling bearing portion using a magnetic material for connecting the rotor and stator.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to rotary transformers. [Background technology]

[0002] Patent Document 1 discloses a rotary transformer in which a first coil and a second coil are concentrically arranged in a first tubular part and a second tubular part made of a magnetic material, which are arranged coaxially so that the outer surface of one can rotate relative to the inner surface of the other, and which transmits power by electromagnetic induction between the first coil and the second coil. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4955691 Summary of the Invention [Problem to be solved by the invention]

[0004] The conventional rotary transformer described in Patent Document 1 has a structure in which an air gap (gap) is provided between the first tubular part and the second tubular part to allow relative rotation. Therefore, the conventional rotary transformer has a problem in that magnetic flux leakage (loss) occurs from the air gap, resulting in a decrease in efficiency.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and aims to provide a rotary transformer that can suppress magnetic flux leakage from the air gap and improve efficiency. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the disclosed technology is a rotary transformer including a rotor configured with a first coil arranged on a first magnetic body, a stator configured with a second coil arranged on a second magnetic body, and a rolling bearing portion using a magnetic material for connecting the rotor and the stator. [Effects of the Invention]

[0007] According to the rotary transformer of the present disclosure, the rotor and stator are connected not by an air gap but by a rolling bearing structure using a magnetic material, thereby suppressing magnetic flux leakage from the air gap and improving efficiency. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a structural cross-sectional view of a rotary transformer according to an embodiment of the present disclosure; [Figure 2] A structural cross-sectional view of an application example of a rotary transformer according to this embodiment. [Figure 3] A structural cross-sectional view of an application example of a rotary transformer according to this embodiment. [Figure 4] A structural cross-sectional view of an application example of a rotary transformer according to this embodiment. [Figure 5] A structural cross-sectional view of an application example of a rotary transformer according to this embodiment. [Figure 6] A structural cross-sectional view of an application example of a rotary transformer according to this embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0009] <Embodiment> [structure] 1 is a cross-sectional view showing a schematic structure of a rotary transformer 10 according to an embodiment of the present disclosure. The rotary transformer 10 shown in FIG. 1 includes a rotor 100, a stator 200, and a rolling bearing unit 300.

[0010] Rotor 100 is a rotating part (shaft). Rotor 100 includes magnetic body 110 (first magnetic body) that serves as a core, and coil 120 (first coil) that is disposed on magnetic body 110.

[0011] The stator 200 is a component (housing) that generates a force for rotating the rotor 100. The stator 200 is configured to include a magnetic body 210 (second magnetic body) that serves as a core, and a coil 220 (second coil) that is arranged on the magnetic body 210.

[0012] Rolling bearing section 300 is a component (bearing) for rotatably supporting rotor 100 on stator 200. Rolling bearing section 300 is configured to include bearing rail 310, which serves as an inner ring provided on the rotor 100 side, bearing rail 320, which serves as an outer ring provided on the stator 200 side, and bearing balls 330 sandwiched between bearing rail 310 and bearing rail 320. Bearing rail 310, bearing rail 320, and bearing balls 330 are formed of a magnetic material with a higher magnetic permeability than air.

[0013] [Actions and Effects] In rotary transformer 10 of the present disclosure with this structure, magnetic flux generated in coil 220 of stator 200 is transmitted through magnetic body 210 of stator 200, and then transmitted to magnetic body 110 of rotor 100 through rolling bearing section 300, which has a magnetic permeability higher than that of air, generating an electric charge in coil 120 of rotor 100. This causes rotor 100 to rotate around its axis (the dashed line in FIG. 1).

[0014] Because the rotor 100 and stator 200 are coupled (connected) by a magnetic material (rolling bearing section 300) rather than an air gap, magnetic flux leakage is reduced, resulting in reduced loss. Furthermore, by integrating the existing bearing structure with the rolling bearing section 300, space can be saved compared to arranging transformers as is, as in conventional technology. Furthermore, gap fluctuations caused by vibration of the magnetic material due to magnetic force are reduced, resulting in stable power supply.

[0015] It is desirable to set the magnetic permeability of bearing rail 310, bearing rail 320, and bearing ball 330 higher than that of magnetic body 110 and magnetic body 210. By setting the magnetic permeability in this way, it is possible to further reduce magnetic flux leakage.

[0016] [Application example] (1) Change in bearing type The rolling bearing unit 300 can be not only a single-row ball bearing or a double-row ball bearing, but also a needle bearing, a tapered needle bearing, etc. Also, the gaps between the bearing rails 310 and 320 and the bearing balls 330 may be filled with magnetic fluid.

[0017] (2) Improved assembly As shown in the cross-sectional view of Fig. 2, the rotary transformer may have a structure in which the rotor 100 (shaft) can be assembled from the left side of the drawing and the stator 200 (housing) can be assembled from the right side of the drawing. Note that the rotary transformer may have a structure in which the left and right sides are reversed from that shown in Fig. 2.

[0018] (3) Thrust bearing structure The cross-sectional view shown in FIG. 3 is an example of a rotary transformer structure that receives loads from both the left and right.

[0019] (4) Radial + thrust bearing structure The cross-sectional view shown in FIG. 4 is an example of a rotary transformer structure that receives loads from above, below, left and right.

[0020] (5) Bearing shape change example 1 The cross-sectional view shown in Figure 5 is an example of a rotary transformer structure that uses needle bearings 340 as the rolling bearing structure. Magnetic flux leakage can be reduced by arranging the needles along the magnetic flux leakage. It is preferable to make the bearing portion wider to prevent magnetic flux leakage from the gap.

[0021] (6) Bearing shape change example 2 The cross-sectional view shown in Figure 6 is an example of a rotary transformer structure that uses a double-row ball bearing 350 as a rolling bearing structure. Magnetic flux leakage can be reduced by arranging the double-row bearings so that they are aligned with the magnetic flux leakage. To further enhance the effect of reducing magnetic flux leakage, it is preferable to arrange the bearing balls so that they capture the magnetic flux that is about to leak.

[0022] (7) Integrated bearing rail Bearing rail 310 of rolling bearing unit 300 may be formed integrally with magnetic body 110 of rotor 100. Also, bearing rail 320 of rolling bearing unit 300 may be formed integrally with magnetic body 210 of stator 200. [Industrial Applicability]

[0023] The structure of the rotary transformer of the present disclosure is useful when it is desired to improve efficiency by suppressing magnetic flux leakage from the air gap. [Explanation of symbols]

[0024] 10 RPM transformer 100 rotors 110 Magnetic material (first magnetic material) 120 coil (first coil) 200 Stator 210 Magnetic material (second magnetic material) 220 coil (second coil) 300 Rolling bearing part 310 Bearing rail (rotor side) 320 Bearing rail (stator side) 330 bearing ball 340 needle bearing 350 double row ball bearing

Claims

[Claim 1] a rotor configured by disposing a first coil on a first magnetic body; a stator configured by disposing a second coil on a second magnetic body; a rolling bearing portion using a magnetic material for coupling the rotor and the stator, Rotating transformer.

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