Rotary electric machine, annular coil body used for the same, and method for mounting annular coil body on rotary electric machine

Abstract

To reliably maintain a fixed state (non-rotary state) of an annular coil body even when in use for a long time.SOLUTION: In a rotary electric machine according to the present invention, a non-rotary annular coil body 18 and a rotor including yokes 20, 22 having magnets 26 opposed to the coil body 18, are put together with a gap therebetween, the annular coil body 18 is cantilevered with an inner side at annular one end fitted to a non-rotary fixing member 28 and the other end being a free end, the outside of the one end fitted to the fixing member 28 is further fastened toward the fixing member 28 in such a way that a fixing tool 30 abuts on the annular part, and the fixing tool 30 is a separate member from the fixing member 28 and is disposed with a gap from the rotor. An adhesive agent is used when the annular coil body 18 is fitted to the fixing member 28, and the fixing tool 30 is formed of a plurality of arc bodies, and is disposed so as to fasten the annular coil body 18 toward the fixing member 28 from outside with the arc bodies fastened together at fastened portions 36 of both ends of each arc body.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a rotating electric machine, and more particularly to a rotating electric machine using a toric coil that is suitable for a coreless type, a toric coil body used therein, and a method for mounting the toric coil body on the rotating electric machine. [Background technology]

[0002] Coreless motors are known for their high output, high efficiency, and low current consumption compared to cored motors. The present inventor has previously developed and proposed coreless motors that combine a non-rotating annular coil body with a rotor (Patent Document 1). In the coreless motor of Patent Document 1, the annular coil body is supported non-rotatingly on one side, and a structure such as a gear mechanism can be built inside the annular coil body. The annular coil body is sandwiched between an inner yoke and an outer yoke with a gap therebetween, and a permanent magnet is fixed to the coil body facing surface of either the inner yoke or the outer yoke or both of them with a gap therebetween. The inner yoke, outer yoke, and permanent magnet form the rotor. There are wheel-in types in which the rotor movement is linked to the casing, and types in which the casing is fixed.

[0003] Incidentally, a method for forming a toric coil body is known from Patent Document 2. This proposes a method for forming a coil body as a measure against weight imbalance caused by the winding method. However, Patent Document 1 does not disclose how to fix the toric coil body to a casing when it is used in a non-rotating manner.

[0004] When using a cantilevered toroidal coil body that is not rotating, the method of fixing it to the casing requires that the attachment position of the toroidal coil body be precisely specified (misalignment can lead to accidents where the coil body comes into contact with the yoke or magnet (i.e., rotor component)), and for this reason it is fixed with a fixing member from the inside of the ring. However, there is a concern that magnetic force or heat generation may cause the fixing member and the coil body to separate from each other when the rotating electric machine is used for long periods of time (for example, if the coil body is fixed with adhesive, the adhesive strength may decrease due to deterioration of the adhesive, etc.). If the toroidal coil is not rotating, this may be an unnecessary worry, and the inventor is not aware of any such accidents occurring, but safety is always important when handling rotating bodies. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 6589215 [Patent Document 2] JP 2019-54628 A Summary of the Invention [Problem to be solved by the invention]

[0006] Therefore, the inventors' objective is to provide a rotating electric machine in which the toric coil body can be steadily maintained in a fixed (non-rotating) state even under long-term use, a toric coil body used therein, and a method for attaching the toric coil body to a rotating electric machine.

[0007] The rotating electric machine of the present invention is a rotating electric machine comprising a toroidal coil body and a yoke arranged facing the outer and inner circumferences of the coil body, characterized in that the toroidal coil body is cantilevered on a fixed member, and the cantilevered portion is held by a fixed member that fits into the base end of the coil body and a fixing device that presses the outer surface of the base end of the coil body against the fixed member.

[0008] The present invention also provides a method for manufacturing a rotor comprising: a non-rotating, annular coil body; and a rotor including a yoke in which magnets are arranged opposite the coil body, with a gap therebetween; the annular coil body is supported by a cantilever such that the inside of one end of the ring is fitted into a non-rotating fixed member and the other end is a free end; the fixing device is tightened in the direction of the fixing member so that the fixing device contacts the annular shape from the outside of the one end portion fitted into the fixing member; the fixing device is separate from the fixing member and arranged with a gap between it and the rotor.

[0009] The fixing device may be annular and may include an adjustment section for adjusting the pressure contact. It is preferable that an adhesive is used to fit the annular coil to the fixing member, and that the fixing device is composed of a plurality of arc bodies, and is arranged so that the arc bodies are fastened to each other at fastening sections at both ends of each of the arc bodies to tighten the annular coil body from the outside toward the fixing member. The conductor of the coil body may be a copper wire, and the fixing device may be a material having a lower thermal expansion coefficient than the copper wire. Alternatively, the fixing device may be a non-magnetic material. It is practical for the fixing member to be made of aluminum in terms of weight reduction and strength, and it is preferable for the fixing device to be a non-magnetic material, such as stainless steel.

[0010] The toric coil body for a rotating electric machine of the present invention is a toric coil body arranged to face a magnet attached to a yoke with a gap therebetween, and is characterized in that one end of the toric coil body is fitted inside a fixing member and is fastened from the outside by a fixing tool so that the fixing tool contacts the toric coil body. It is preferable that an adhesive is used to fit the toric coil into the fixing member, and that the fixing tool is composed of a plurality of arc bodies, and is arranged so that the arc bodies are fastened to each other at fastening parts at both ends of each arc body to fasten the toric coil body from the outside toward the fixing member.

[0011] The present invention is suitable for coreless and slotless types. If the fixing device is made of multiple arc bodies as described above, there is no need to worry about damaging the coil body when screwing it into the end of the coil body. This is because the coil body has an insulating coating that can be damaged. Furthermore, the number of arc bodies is set to two, making it a combination of semicircular arcs, and both ends of the semicircular arc bodies serve as fastening parts for the semicircular arc bodies. It is desirable to fasten these fastening parts with an adjustment tool such as a spiral, which also reduces assembly costs. In this way, the degree of fastening of one end of the toric coil to the fixing member can be adjusted. Effect of the Invention

[0012] The present invention has the effect of steadily and safely maintaining the fixed (non-rotating) state of the toric coil body even under long-term use. The main body of the coil body is generally made of copper, and the fixing member is made of aluminum in order to reduce the weight of the rotating electric machine. Even if the two members are fixed with adhesive, there is a concern that they may separate due to the difference in physical properties of the two members. However, the fixing member holds down the ring from the outside and clamps one end of the ring, so that the fixing member can be securely fixed. Furthermore, if the fixing member is made of a non-magnetic material such as stainless steel, there is no concern that it will have a negative effect on the operation of the rotating electric machine. [Brief description of the drawings]

[0013] [Figure 1] 1 is a cross-sectional view of an example of a rotating electric machine of the present invention; [Diagram 2] 2 is a perspective view of an example of a toric coil body with a fixing member to be incorporated in the rotating electric machine of FIG. 1. FIG. [Diagram 3] 3 is a perspective view of an example of the circular toric coil body of FIG. 2. [Figure 4] FIG. 3 is an explanatory diagram of an example of the fixing device in FIG. 2. [Diagram 5] FIG. 2 is a perspective view of the reinforcing ring shown in FIG. 1 . DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. A cross-sectional view of an example of a rotating electric machine is shown in Fig. 1. This rotating electric machine has a cylindrical casing 10 forming an outer shell, a casing lid 12 covering the opening of the casing, and a rotating shaft 14 penetrating the center. The rotating shaft 14 is configured to generate rotational output via a bearing 16 between the casing 10 and the casing lid 12. However, the casing 10 is not limited to being cylindrical.

[0015] Inside the casing 10, the annular coil body 18 is disposed as a stator, and an outer yoke 20 and an inner yoke 22, which face the outer peripheral surface and the inner peripheral surface of the annular coil body 18, are disposed as a rotor. That is, an end plate 24 is disposed close to the casing cover 12 so as to be perpendicular to the rotating shaft 14, and is fixed to the rotating shaft 14. The end plate 24 is provided with a cylindrical outer yoke 20 centered on the rotating shaft 14 and an inner yoke 22 with a slightly smaller diameter than the outer yoke 20, facing the bottom of the casing 10. The annular coil body 18 is raised from the bottom of the cylindrical casing 10 as a stator so as to enter the gap between the two, and is located in the cylindrical gap between the yokes 20 and 22, so that it can rotate relative to the rotating yokes 20 and 22. A magnet 26 is disposed at a position of the yokes 20 and 22 facing the annular coil body 18, and the yokes 20 and 22 as rotors can rotate due to their polarity.

[0016] In this example, the casing 10 does not rotate, but the rotating shaft 14 rotates, and the rotor (outer yoke 20, inner yoke 22, end plate 24) linked to the rotating shaft 14 rotates, and the rotating shaft 14 is supported by bearings 16 on the casing 10. Reference numeral 12 denotes a cover of the casing 10. The rotor (outer yoke 20, inner yoke 22, end plate 24) is formed like a double cylinder in the axial direction, with the outer yoke 20 on the outside and the inner yoke 22 on the inside. In this example, the magnets 26 are arranged facing the coil body side of each of the yokes 20 and 22, but the magnets 26 may be arranged on one side of the yoke instead of both yokes. In addition, if the motor is applied to a slotless motor instead of a coreless motor, the part corresponding to the outer yoke 20 is joined to the annular coil body 18, and the present invention is also applicable to such a form.

[0017] The toric coil body 18 does not rotate and is indirectly fixed to a non-rotating member, in this example the casing 10, with the fixing member 28 being the fixing means. A fixing device 30 is also in contact with the outside of the toric coil body 18. Reference numeral 32 denotes a yoke spacer, and reference numeral 34 denotes a reinforcing ring. The reinforcing ring 34 has the function of preventing deformation of the free end of the cantilever-supported toric coil body 18. The fixing member 28 and the fixing device 30 are separate bodies.

[0018] The method of combining the fixing member 28 and the fixture 30 of the toric coil body 18 in FIG. 1 will be described with reference to FIG. 2. In the example shown in this figure, the fixture 30 is composed of two semicircular arc bodies, and a fastening portion 36 that is bent outward is formed like a flange at each end of both semicircular arc bodies, and the fastening portion 36 is screwed. The tightening to the toric coil body 18 can be adjusted by the degree of screwing. The fixing member 28 shown in the figure is made of aluminum material, and is also adhesively fixed when fitted inside the coil body 18. Stainless steel is used for the fixture 30. Stainless steel is a non-magnetic material and does not hinder the generation of a magnetic field, but since it protrudes outside the coil body 18, a gap is formed so that it does not interfere with the mechanical structure of the yoke and magnets when assembling the rotating electrical machine.

[0019] Since the main material of the coil body 18 is copper, while the fixing member 28 is made of aluminum, there is a difference in physical properties, particularly thermal expansion, and there is concern that the two members may peel off after long-term use. An adhesive is used to address this issue, but the coil body 18 generates heat during use, and depending on the temperature, there is concern that the adhesive may melt or deteriorate. The fixing device 30 is intended to eliminate these concerns. As a method of fixing the toroidal coil body 18, it is possible to make an annular recess on the fixing member side and fit one end of the toroidal coil body 18 into this recess, as disclosed in Japanese Utility Model Laid-Open Publication No. 60-62878, but there is a difference in width dimension at one end of the coil body 18, which leads to a slight difference in the fixing position, and if the coil body is made of wire, the fitting operation is difficult. Also, as in Japanese Patent Laid-Open Publication No. 2004-32842, there is a case in which the entire outer surface of the toroidal coil body 18 is coated with resin to resemble a reinforcing layer, but this is merely a protective layer that protects the coil body 18 from external dust and the like, and does not contribute to strict positional fixation of the toroidal coil body 18. In the first place, such a coating is extremely thin in order to maintain a gap between the magnet and the yoke, and therefore does not regulate the separation of the toric coil body 18 from the fixed member 28. It should be noted that the present invention does not deny the use of such a protective layer in combination.

[0020] If it is assumed that the toric coreless motor will be operated at high speed for a long time, it is necessary to reliably fix it in an accurate position and to ensure that the position does not deviate for a long time. In this embodiment, the fastening portion 36 protrudes outward, and the ring body of the fixing device 30 protrudes outward from the coil body 18 to begin with, but the dimensions and positions of these can be determined so that a gap is formed so that they do not interfere with each other when assembling the rotor side. This toric coil body is available in two types: one with woven conductor wire and one made of copper plate, and the woven conductor wire type, especially the Litz wire type, is preferred from the viewpoint of the degree of freedom of wiring and eddy current loss of copper.

[0021] FIG. 3 shows an example of the toric coil body 18 used in the examples of FIG. 1 and FIG. 2, where each coil 181 is a coil (so-called tortoise shell winding), and 182 is the virtual center axis of the coil body. There are various ideas for stacking the coils 181, but the most representative are those proposed by the present inventor in Patent No. 6948748 and Patent No. 6989204. In these examples, one tortoise shell forms one coil, and if it is three-phase, three sheets are stacked with a shift. It is not necessary to stick to the tortoise shell shape, and for example, multiple wires may be made to meander like an S-shape and finished into a ring, in which case the number of wires is equivalent to the number of coils. In any case, constructing the coil from wire eliminates copper eddy current loss compared to copper plate. It is also possible to further reduce copper eddy current loss by using Litz wire for this wire.

[0022] Figure 4 shows the annular fixture 30 of Figure 2. In this way, in this example, two half rings are joined together at the fastening parts 36 to form a ring, and the fastening parts 36 are screwed together to adjust the tightening of not only the fixture 30 itself but also the annular ring body 18 to the fixing member 28.

[0023] FIG. 5 shows a reinforcing ring 34 for the free end of the annular ring body 18, which is fitted onto the free end side of the annular coil body 18 and contributes to maintaining the annular shape of the annular coil body 18.

[0024] In the above embodiment, the case has been described where the casing is non-rotating and the rotor inside rotates, while the toroidal coil body facing the rotor is non-rotating, so the fixing member of the toroidal coil is fixed to the casing, but the present invention can be applied to cases where the central shaft rotates or is non-rotating. Also, in the case of a so-called wheel-in type where the casing rotates, the casing rotates in conjunction with the operation of the rotor via an internal gear mechanism (in the opposite direction to the rotor rotation direction depending on the gear mechanism), but if the shaft becomes non-rotating, the fixing member can be fixed to the shaft and the toroidal coil body will also become non-rotating.

[0025] Rotating electric machines using a toric coil body have space inside the coil body (more precisely, inside the inner yoke), so mechanisms such as gears can be inserted. Of course, when inserting such equipment, a gap is formed to prevent accidental contact with the rotor or coil body.

[0026] The present invention can be applied to both motors and generators, and the coil body can be either wire or copper plate type. Also, the present invention is not limited to coreless type, but can be applied to slotless type as long as it uses a toric coil body. [Industrial Applicability]

[0027] The present invention relates to a rotating electric machine such as a motor or generator, which has a rotating rotor, in which the coil is annular and non-rotating. [Explanation of symbols]

[0028] 10...Cylindrical casing, 12...Casing cover, 14...rotation axis, 16...Bearings, 18...Circular coil body, 20...Outer York, 22...Inner York, 24...end plate, 26...Magnet, 28...Fixing member, 30...Fixing tools, 32...Yoke spacer, 34... Reinforcement ring, 36... Fastening part

Claims

1. A rotating electric machine comprising an annular coil body and a yoke disposed facing the outer periphery and inner periphery of the coil body, a cantilever supported by a fixed member, the cantilever supported portion being held by a fixed member that fits into a base end of the coil body and a fastener that presses an outer surface of the base end of the coil body toward the fixed member.

2. A rotating electric machine comprising: a non-rotating toroidal coil body; and a rotor including a yoke in which a magnet is arranged opposite the coil body, combined with a gap; the toroidal coil body is supported as a cantilever so that the inside of one end of the ring is fitted into a non-rotating fixed member and the other end is a free end; a fixing device is also pressed against the toroidal coil body in the direction of the fixing member from the outside of the one end portion fitted into the fixing member, the fixing device being separate from the fixing member and arranged with a gap between it and the rotor.

3. 3. The rotating electrical machine of claim 2, wherein said fastener is annular and includes an adjustment portion for said pressure contact.

4. 3. A rotating electric machine according to claim 2, characterized in that an adhesive is used when fitting the annular coil body to the fixing member, and the fixing device is composed of a plurality of arc bodies, and fastening portions at both ends of each of the arc bodies are arranged to fasten the annular coil body from the outside toward the fixing member, thereby serving as an adjustment portion for the pressure welding.

5. 5. The rotating electric machine according to claim 2, wherein the conductor of said coil body is a copper wire, and said fixing member is a member having a thermal expansion coefficient lower than that of said copper wire.

6. 6. The coreless type rotating electric machine according to claim 2, wherein the fixing member is made of a non-magnetic material.

7. A toric coil body for a rotating electric machine, which is arranged opposite a magnet attached to a yoke with a gap therebetween, and characterized in that one end of the toric coil body is fitted into a fixed member on the inside and a fixing tool is pressed against the toric coil body from the outside.

8. 8. A toric coil body for a rotating electric machine according to claim 7, characterized in that an adhesive is used to fit the toric coil body to the fixing member, and the fixing device is composed of a plurality of arc bodies, and is arranged so that the arc bodies are fastened to each other at fastening portions at both ends of each arc body to tighten the toric coil body from the outside toward the fixing member.

9. A method for mounting a toroidal coil body to a rotating electric machine, comprising: fitting and adhering a fixing member for positioning the toroidal coil body inside one end of the toroidal coil body; and then attaching a fixing device for pressing the toroidal coil body from the outside of the toroidal coil body in the direction of the adhesive surface of the fixing member.

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