Method of manufacturing stator for axial gap motor and stator for axial gap motor

Abstract

To provide a method of manufacturing a stator for an axial gap motor by which cost of manufacture is reduced and a strength is secured, and a stator for an axial gap motor.SOLUTION: A method of manufacturing a stator for an axial gap motor includes: a preparation step of preparing a first substrate including a first hole in which a first coil is disposed, a second substrate which includes a second hole in which a second coil is disposed and overlaps the first substrate in such a manner that the second hole at least partially overlaps the first hole, and a closing member which overlaps the second substrate so as to close the second hole from an opposite side of the first substrate; and an integration step of injecting a mold resin from the side of the first substrate into the first and second holes after implementation of the preparation step, thereby integrating the first and second substrates, the first and second coils and the closing member.SELECTED DRAWING: Figure 6

Description

[Technical Field]

[0001] The present invention relates to a method for manufacturing a stator of an axial gap motor and a stator of an axial gap motor. [Background technology]

[0002] The stator of an axial gap motor includes a substrate and a coil arranged on the substrate (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Publication No. 59-013082 Summary of the Invention [Problem to be solved by the invention]

[0004] It is conceivable to ensure the strength of the stator by integrating the substrate and coil with a molding resin. However, this requires placing the substrate and coil in a dedicated mold. Furthermore, after the molding resin hardens, the stator must be released from the mold. This makes the manufacturing process complicated, and there is a risk of increasing manufacturing costs.

[0005] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a method for manufacturing a stator of an axial gap motor, which reduces manufacturing costs and ensures strength, and a stator of an axial gap motor. [Means for solving the problem]

[0006] The above object can be achieved by a method for manufacturing a stator of an axial gap motor, comprising: a preparation step of preparing a first substrate having a first hole in which a first coil is arranged, a second substrate having a second hole in which a second coil is arranged and overlaid on the first substrate so that the second hole at least partially overlaps the first hole, and a blocking member overlaid on the second substrate so as to block the second hole from the opposite side of the first substrate; and an integration step of injecting molding resin into the first and second holes from the first substrate side after the preparation step, thereby integrating the first and second substrates, the first and second coils, and the blocking member.

[0007] The above object can also be achieved by a stator for an axial gap motor comprising: a first substrate having a first hole in which a first coil is arranged; a second substrate having a second hole in which a second coil is arranged and overlaid on the first substrate so that the second hole at least partially overlaps the first hole; a blocking member overlaid on the second substrate so as to block the second hole from the side opposite the first substrate; and a sealing resin portion filled in the first and second holes so as to integrate the first and second substrates, the first and second coils, and the blocking member. [Effects of the Invention]

[0008] It is possible to provide a manufacturing method for a stator of an axial gap motor and a stator of an axial gap motor that can reduce manufacturing costs and ensure strength. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a cross-sectional view of an axial gap motor. [Figure 2] FIG. 2 is a front view of the stator. [Figure 3] FIG. 3 is a front view of the stator with the sealing resin portion omitted. [Figure 4] FIG. 4 is a front view of the stator S with the sealing resin portion and the reinforcing plate omitted. [Figure 5] FIG. 5 is a cross-sectional view taken along line AA in FIG. [Figure 6]FIG. 6A is an explanatory diagram of a method for manufacturing a stator, and FIG. 6B is an explanatory diagram of an integration step. DETAILED DESCRIPTION OF THE INVENTION

[0010] [Outline of axial gap motor] FIG. 1 is a cross-sectional view of an axial gap motor 1. FIG. 1 shows a schematic diagram of the axial gap motor 1. The axial gap motor 1 includes a support shaft 10, a yoke 20, magnetic pole portions 30 and 40, and a stator S. The support shaft 10 rotatably supports the yoke 20. The yoke 20 and the magnetic pole portions 30 and 40 correspond to a rotor. The support shaft 10 includes a flange portion 11, a step portion 12, and a thin shaft portion 13. The step portion 12 has a smaller diameter than the flange portion 11. The thin shaft portion 13 has a smaller diameter than the step portion 12. Two bearings B are held by the thin shaft portion 13. The yoke 20 includes a cylindrical portion 22 and flange portions 23 and 24. The flange portions 23 and 24 are each flange-shaped. The flange portions 23 and 24 are spaced apart from each other in the axial direction A. The stator S includes a printed circuit board 50, a reinforcing plate 60, a blocking member 70, and a plurality of coils. The stator S is disposed between the flange portions 23 and 24. The printed circuit board 50, the reinforcing plate 60, and the blocking member 70 each have openings 51, 61, and 71 formed in their centers to allow the support shaft 10 to escape.

[0011] The magnetic pole portion 30 is provided on the surface of the flange portion 23 facing the stator S. The magnetic pole portion 40 is provided on the surface of the flange portion 24 facing the stator S. Each of the magnetic pole portions 30 and 40 is annular permanent magnets. The surfaces of the magnetic pole portions 30 and 40 facing the stator S are magnetized with polarities that alternate in the circumferential direction. In this embodiment, each of the magnetic pole portions 30 and 40 has eight poles in the circumferential direction. Note that each of the magnetic pole portions 30 and 40 may be a plurality of permanent magnets lined up in the circumferential direction. In this case, too, the surfaces of these plurality of permanent magnets facing the stator S are magnetized with polarities that alternate in the circumferential direction.

[0012] A plurality of coils, which will be described in detail later, are held on the printed circuit board 50 and the reinforcing plate 60. These coils face the magnetic pole portions 30 and 40 across gaps in the axial direction A. By controlling the energization state of these coils, the yoke 20 rotates relative to the support shaft 10 in response to the magnetic forces generated between the coils and the magnetic pole portion 30 and between the coils and the magnetic pole portion 40. The outer peripheral end of the stator S is held by a holder (not shown), preventing it from rotating relative to the yoke 20.

[0013] Fig. 2 is a front view of the stator S. Fig. 3 is a front view of the stator S omitting the sealing resin part M. Fig. 4 is a front view of the stator S omitting the sealing resin part M and the reinforcing plate 60. The printed circuit board 50 and the reinforcing plate 60 are each circular, as is the blocking member 70.

[0014] As shown in FIGS. 2 and 3, coils U1, W1, V2, U3, W3, and V4 embedded in a sealing resin portion M are held at 60-degree intervals in the circumferential direction C by the reinforcing plate 60. The reinforcing plate 60 is an example of a first substrate. The coils U1, W1, V2, U3, W3, and V4 are examples of first coils. As shown in FIG. 4, coils V1, U2, W2, V3, U4, and W4 are held at 60-degree intervals in the circumferential direction C by the printed circuit board 50. The printed circuit board 50 is an example of a second substrate. The coils V1, U2, W2, V3, U4, and W4 are examples of second coils. That is, the printed circuit board 50 and the reinforcing plate 60 hold U-phase coils U1 to U4, V-phase coils V1 to V4, and W-phase coils W1 to W4. The coils U1 to U4 are configured by distributed winding. The same is true for coils V1 to V4 and W1 to W4. Coils U1 to U4, V1 to V4, and W1 to W4 are electrically connected to the printed circuit board 50. Coils U1, V1, W1, U2, V2, W2, U3, V3, W3, U4, V4, and W4 are lined up in the circumferential direction C (counterclockwise in FIG. 4). Coils U1 to U4 are arranged at 90-degree intervals in the circumferential direction C. Coils V1 to V4 are arranged at 90-degree intervals in the circumferential direction C. Coils W1 to W4 are arranged at 90-degree intervals in the circumferential direction C. The number of coils held by the reinforcing plate 60 and the number of coils held by the printed circuit board 50 are the same, six.

[0015] As shown in Figures 2 and 3, coils U1, W1, V2, U3, W3, and V4 are embedded in a sealing resin portion M while being fitted into holes 63 in a reinforcing plate 60, respectively. This reinforces these coils. Hole 63 is an example of a first hole. Notches 64 and 65 are continuously formed in hole 63 to allow lead wires from each coil to escape. Sealing resin portion M is also formed inside notches 64 and 65.

[0016] As shown in FIG. 4, each of coils V1, U2, W2, V3, U4, and W4 is held so as to fit into hole 53 of printed circuit board 50. Hole 53 is an example of a second hole. Although not shown in FIG. 4, the coils in hole 53 are embedded in sealing resin portion M. This ensures the strength of these coils. In this way, sealing resin portion M is filled into hole 63, notches 64 and 65, and hole 53 that partially overlaps them in the axial direction A, along with the held coils. The sealing resin portion M will be described in detail later.

[0017] As shown in FIG. 4 , coil U1 is spaced apart from coils W4 and V1 in the axial direction A and partially overlaps them in the axial direction A. Coil W1 is spaced apart from coils V1 and U2 in the axial direction A and partially overlaps them in the axial direction A. Coil V2 is spaced apart from coils U2 and W2 in the axial direction A and partially overlaps them in the axial direction A. Coil U3 is spaced apart from coils W2 and V3 in the axial direction A and partially overlaps them in the axial direction A. Coil W3 is spaced apart from coils V3 and U4 in the axial direction A and partially overlaps them in the axial direction A. Coil V4 is spaced apart from coils U4 and W4 in the axial direction A and partially overlaps them in the axial direction A. Coil V1 is spaced apart from coils U1 and W1 in the axial direction A and partially overlaps them in the axial direction A. Coil U2 is spaced apart from coils W1 and V2 in the axial direction A and partially overlaps them in the axial direction A. Coil W2 is spaced apart from coils V2 and U3 in the axial direction A and partially overlaps them in the axial direction A. Coil V3 is spaced apart from coils U3 and W3 in the axial direction A and partially overlaps them in the axial direction A. Coil U4 is spaced apart from coils W3 and V4 in the axial direction A and partially overlaps them in the axial direction A. Coil W4 is spaced apart from coils V4 and U1 in the axial direction A and partially overlaps them in the axial direction A. This prevents the axial gap motor 1 from becoming too large in the axial direction A.

[0018] As shown in Figure 4, each of the coils U1 to U4, V1 to V4, and W1 to W4 is wound in a frame shape. This ensures the strength of these coils. Furthermore, the coils U1 to U4, V1 to V4, and W1 to W4 all have the same shape. The winding process for these coils is the same, making the process easy. Furthermore, the coils are easy to handle during assembly.

[0019] As shown in Fig. 4, position sensors P1, P2, and P3 are surrounded by coils W1, V2, and U3, respectively, and are mounted on a printed circuit board 50. In this way, position sensors P1 to P3 are prevented from interfering with coils W1, V2, and U3, respectively. As a result, sufficient installation area is secured for coils U1 to U4, V1 to V4, and W1 to W4. Each of position sensors P1 to P3 is a Hall element.

[0020] 4, position sensor P1 is installed between coils V1 and U2 that are adjacent to each other in the circumferential direction C. Position sensor P2 is installed between coils U2 and W2 that are adjacent to each other in the circumferential direction C. Position sensor P3 is installed between coils W2 and V3 that are adjacent to each other in the circumferential direction C. In this way, the dead space on the printed circuit board 50 is effectively utilized.

[0021] 5 is a cross-sectional view taken along the line AA in FIG. 2. The position sensor P3, which is surrounded by the coil U3, does not protrude from the end face of the reinforcing plate 60. This ensures that the stator S is thin in the axial direction A. The same is true for the position sensors P1 and P2. Furthermore, the coil U3 is disposed within the hole 63 so as not to protrude from the end face of the reinforcing plate 60. Similarly, the coils V3 and W2 are also disposed within the hole 53 so as not to protrude from the end face of the printed circuit board 50. The same is true for the other coils.

[0022] As described above, coils U1 to U4, V1 to V4, and W1 to W4 constitute three-phase coils. The total number of these coils is 12, which is an even number. Furthermore, the number of poles in each of the magnetic pole portions 30 and 40 is 8. In this way, the total number of coils is 1.5 times the number of poles.

[0023] As another example, the total number of coils may be an even number of six, and the number of poles in the magnetic pole section may be four. In this case, the number of coils for each of the U phase, V phase, and W phase is two. For example, three coils may be mounted on a printed circuit board, and the remaining three coils may be embedded in the printed circuit board. In this case, the total number of coils is also 1.5 times the number of poles.

[0024] As yet another example, the total number of coils may be 18, which is an even number, and the number of poles in the magnetic pole portion may be 6. In this case, the number of coils for each of the U phase, V phase, and W phase is 6. For example, 9 coils may be installed on a printed circuit board, and the remaining 9 coils may be embedded in the printed circuit board. In this case, the total number of coils is three times the number of poles.

[0025] As in the example above, when the coils are wound in a distributed manner, the position sensor is surrounded by one of the coils, and the position sensor is placed between two other coils that are spaced apart from that coil in the axial direction A and adjacent to each other in the circumferential direction C, it is best to configure three-phase coils as in the example above, with an even number of coils in total and 1.5 or 3 times the number of poles. This allows the coils and position sensor to be placed in their theoretical positions without interfering with each other. Furthermore, 1.5 times the number of poles is preferable. This is because if the number of poles is increased, such as 3 times the number of poles, more coils are required, which makes the configuration more complex and makes manufacturing more difficult.

[0026] [Manufacturing method of stator] Next, a manufacturing method of the stator S will be described. FIG. 6A is an explanatory diagram of the manufacturing method of the stator S. The manufacturing method of the stator S includes a preparation step (step S1) and a subsequent integration step (step S2). The preparation step includes, for example, first and second arrangement steps, first and second conductive connection steps, a stacking step, and a closing step. In the first arrangement step, coils V1, U2, W2, V3, U4, and W4 are arranged in the multiple holes 53 of the printed circuit board 50 in which the position sensors P1 to P3 are provided. In the second arrangement step, coils U1, W1, V2, U3, W3, and V4 are arranged in the multiple holes 63 of the reinforcing plate 60. In the first conductive connection step, the coils V1, U2, W2, V3, U4, and W4 are conductively connected to the printed circuit board 50. In the second conductive connection step, the coils U1, W1, V2, U3, W3, and V4 are conductively connected to the printed circuit board 50. In the laminating process, the printed circuit board 50 and the reinforcing plate 60 are positioned taking into consideration the relative positions of the coils held on the printed circuit board 50 and the coils held on the reinforcing plate 60, and the reinforcing plate 60 is placed on the printed circuit board 50, and the printed circuit board 50 and the reinforcing plate 60 are, for example, bonded together. In the closing process, a closing member 70 is placed on the printed circuit board 50 from the opposite side of the reinforcing plate 60 so as to close the multiple holes 53, and the printed circuit board 50 and the closing member 70 are, for example, bonded together. In this way, a precursor S' of the stator S is formed.

[0027] The order of the first and second arrangement steps, the first and second conductive connection steps, the lamination step, and the closing step is not limited to this. For example, the order may be the first arrangement step, the first conductive connection step, the second arrangement step, the second conductive connection step, the closing step, and the lamination step. The order may be the first arrangement step, the first conductive connection step, the closing step, the second arrangement step, the second conductive connection step, and the lamination step. The order may also be the closing step, the first arrangement step, the first conductive connection step, the second arrangement step, the second connection step, and the lamination step. In the closing step, the printed circuit board 50 and the closing member 70 may be manufactured simultaneously. For example, the printed circuit board 50 and the closing member 70 may be manufactured integrally with each other, with the closing member 70 superimposed on the printed circuit board 50 so as to close the multiple holes 53.

[0028] In the integration process, molding resin is injected into the multiple holes 63 in the reinforcing plate 60 of the precursor S' from the side opposite the printed circuit board 50, using, for example, a dispenser. FIG. 6B is an explanatory diagram of the integration process. FIG. 6B corresponds to FIG. 5. As a result, the molding resin flows from the holes 63 into the notches 64 and 65 and also into the holes 53 that overlap the holes 63 in the axial direction A, filling these. Here, the closing member 70 overlapping the printed circuit board 50 prevents the molding resin from leaking out of the holes 53. When the molding resin hardens to form the sealing resin portion M shown in FIG. 2, the printed circuit board 50, the reinforcing plate 60, the closing member 70, the coils U1 to U4, V1 to V4, and W1 to W4, and the position sensors P1 to P3 are integrated. This ensures the strength of the stator S.

[0029] In this way, the use of the blocking member 70 eliminates the need for a dedicated molding die for integrating the printed circuit board 50, the reinforcing plate 60, the coils U1-U4, V1-V4, and W1-W4, and the position sensors P1-P3. Because such a die is not required, the process of releasing the stator S from the die after the molding resin has hardened is also unnecessary. This allows the manufacturing cost to be reduced and the stator S to be manufactured with ensured strength.

[0030] Here, the blocking member 70 is an insulating plate-like member. Because the blocking member 70 is insulating, even if any of the coils come into contact with the blocking member 70, there is no electrical effect. The blocking member 70 is thinner and lighter than both the printed circuit board 50 and the reinforcing plate 60. This prevents the stator S from becoming larger in size in the axial direction A, and also reduces the weight of the stator S.

[0031] The blocking member 70 may be, for example, an insulating substrate. In this case, the blocking member 70 may be, for example, a rigid printed circuit board that is not flexible, or a flexible printed circuit board that is flexible. For example, when the blocking member 70 is a rigid printed circuit board or a flexible printed circuit board, a conductor pattern formed on the board may be electrically connected to either the coil or the position sensor described above. The blocking member 70 may be an adhesive tape that has insulating properties. The blocking member 70 may be a rubber member that has insulating properties and elasticity. The blocking member 70 may be a sheet that has insulating properties and flexibility.

[0032] A printed circuit board may be used instead of the reinforcing plate 60. For example, the coils U1, W1, V2, U3, W3, and V4 may be electrically connected to this printed circuit board. Alternatively, the coils U1 to U4, V1 to V4, and W1 to W4 may be electrically connected to this printed circuit board, and a reinforcing plate may be used instead of the printed circuit board 50.

[0033] At least one of the coils U1 to U4, V1 to V4, and W1 to W4 may be wound around a frame, and the coil wound around the frame may be held together with the frame in hole 53 or 63. In this case, it is preferable that an opening is provided in the frame so that the molding resin can spread around the frame in hole 53 or 63 in the above-mentioned integration step.

[0034] Although the preferred embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and modifications and variations are possible within the scope of the gist of the present invention as defined in the claims. [Explanation of symbols]

[0035] 1 Axial gap motor U1, W1, V2, U3, W3, V4 coils (first coil) V1, U2, W2, V3, U4, W4 coils (second coils) S Stator 50 Printed circuit board (first board) 53 hole (1st hole) 60 Reinforcement plate (second board) 63 hole (2nd hole) 70 Closure member

Claims

1. a preparation step of preparing a first substrate having a first hole in which a first coil is disposed, a second substrate having a second hole in which a second coil is disposed and overlaid on the first substrate such that the second hole at least partially overlaps the first hole, and a closing member overlaid on the second substrate so as to close the second hole from the opposite side to the first substrate; an integration step of injecting a molding resin into the first and second holes from the first substrate side after the preparation step, thereby integrating the first and second substrates, the first and second coils, and the blocking member together; A method for manufacturing a stator of an axial gap motor comprising:

2. a position sensor for detecting a rotational position of a rotor is provided on a surface of the second substrate facing the first substrate; the position sensor is located in the first hole and surrounded by the first coil; 2. The method for manufacturing a stator of an axial gap motor according to claim 1, wherein the integration step integrates the first and second substrates, the first and second coils, the blocking member, and the position sensor.

3. At least one of the first and second coils is electrically connected to at least one of the first and second substrates; The method for manufacturing a stator of an axial gap motor according to claim 2 , wherein the position sensor is electrically connected to the second substrate.

4. a plurality of the first holes are formed in the first substrate; a plurality of the second holes are formed in the second substrate; a plurality of the first coils are disposed in the plurality of first holes, respectively; a plurality of the second coils are disposed in the plurality of second holes, respectively; the position sensor is located between two adjacent second holes and is surrounded by one of the first coils; 4. The method for manufacturing a stator of an axial gap motor according to claim 2, wherein the integration step integrates the first and second substrates, the plurality of first coils, the plurality of second coils, the blocking member, and the position sensor.

5. the rotor includes a rotatably supported yoke, and magnetic pole portions fixed to the yoke and magnetized with alternately different polarities in a circumferential direction around a rotation axis of the yoke, each of the plurality of first coils and the plurality of second coils is wound in a distributed winding manner; the plurality of first coils and the plurality of second coils constitute a three-phase coil, 5. The method for manufacturing a stator of an axial gap motor according to claim 4, wherein the total number of the plurality of first coils and the plurality of second coils is an even number, and is 1.5 or 3 times the number of poles of the magnetic pole portion.

6. 4. The method for manufacturing a stator of an axial gap motor according to claim 1, wherein the blocking member has insulating properties and is thinner and lighter than both the first and second substrates.

7. a first substrate having a first hole in which a first coil is disposed; a second substrate having a second hole in which a second coil is disposed, the second substrate being overlaid on the first substrate such that the second hole at least partially overlaps the first hole; a blocking member overlapping the second substrate so as to block the second hole from the opposite side to the first substrate; a sealing resin portion filled in the first and second holes so as to integrate the first and second substrates, the first and second coils, and the blocking member; axial gap motor stator having

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