Axial gap motor

Abstract

To provide an axial gap motor that can suppress noise and vibration caused by rotor deflection and deformation without hindering flattening. [Solution] In an axial gap motor 100 comprising a planar rotor 120 with a rotating shaft 130 as its center of rotation, a stator 150 positioned opposite one side of the rotor 120, and a bearing 140 that rotatably holds the rotor 120 relative to the stator 150, the inner ring portion 141 of the bearing 140 is fixed to the outer circumferential surface of the rotor 120, and the outer ring portion 142 of the bearing 140 is fixed to the inner circumferential surface 151c of the outer cylinder portion 151b of the stator 150.

Description

Technical Field

[0005] ,

[0001] The present invention relates to an axial gap motor, and particularly to an axial gap motor that realizes flattening and rotational stability.

Background Art

[0002] In the case of a general motor, bearings are provided at one end and the other end of the rotating shaft in order to configure the rotor and the rotating shaft to be rotatable with respect to the stator. In the case of an axial gap motor that realizes flattening by overlapping a disk-shaped rotor and a planar stator in the direction of the rotating shaft, if bearings are provided at both ends of the rotating shaft, it becomes impossible to configure the rotating shaft short, which has been preventing flattening.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the case of the axial gap motor described in Patent Document 1, in order to prioritize the flattening of the entire motor, two bearings are provided on the inner peripheral side in the same plane as the rotor and the stator. In the case of this axial gap motor, since the distance between the two bearings is short, the deflection and deformation of the rotor cannot be sufficiently suppressed. For this reason, there has been a problem of generating vibration and noise due to the rotation of the rotor.

[0005] In an axial gap motor, when bearings are provided on the inner peripheral side in the same plane as the rotor and the stator, in addition to the generation of noise and vibration, a new problem occurs in that the diameter of the rotating shaft is restricted. For this reason, there has been a demand for realizing an axial gap motor that can sufficiently suppress the deflection and deformation of the rotor without sacrificing flattening and does not cause problems of vibration and noise.

[0006] The present invention was made to solve the above-mentioned problems, and aims to provide an axial gap motor that can suppress noise and vibration caused by rotor deflection and deformation without hindering flattening. [Means for solving the problem]

[0007] The axial gap motor according to this invention comprises a disc-shaped rotor with a rotating shaft as its center of rotation, a stator positioned opposite one side of the rotor, and a bearing that rotatably holds the rotor relative to the stator, wherein the inner ring of the bearing is fixed to the outer circumferential surface of the rotor, and the outer ring of the bearing is fixed to the inner circumferential surface of the outer cylinder of the stator.

[0008] In the axial gap motor according to this invention, a cover portion is provided so as to face the other surface of the rotor, and the cover portion comprises a flat portion parallel to the rotor and an outer cylinder portion provided on the outer circumference of the flat portion, and the outer ring portion of the bearing may be fixed to the inner circumferential surface of the outer cylinder portion of the stator and the inner circumferential surface of the outer cylinder portion of the cover portion.

[0009] In the axial gap motor according to this invention, the stator is composed of a first stator arranged to face one side of the rotor and a second stator arranged to face the other side of the rotor, and the outer ring portion of the bearing may be fixed to the inner circumferential surface of the first stator and the inner circumferential surface of the second stator.

[0010] In the axial gap motor according to this invention, the bearing comprises a first bearing and a second bearing, the first bearing comprising an inner ring portion fixed to the outer circumferential surface of the rotor and an outer ring portion fixed to the inner circumferential surface of the first stator, and the second bearing comprising an inner ring portion fixed to the outer circumferential surface of the rotor and an outer ring portion fixed to the inner circumferential surface of the second stator.

[0011] In the axial gap motor according to this invention, the bearing may be an angular contact bearing that receives radial loads and bidirectional axial loads. [Effects of the Invention]

[0012] In the axial gap motor according to this invention, by mounting the bearing on the outer circumference of the rotor, noise and vibration caused by rotor deflection and deformation can be effectively suppressed. Furthermore, since the bearing is not located around the rotating shaft, it does not hinder the flattening of the motor and does not affect the diameter of the rotating shaft. [Brief explanation of the drawing]

[0013] [Figure 1] This is an exploded perspective view showing the components of the axial gap motor according to Embodiment 1 in a disassembled state. [Figure 2] This is a perspective view showing the components of each part of the axial gap motor according to Embodiment 1, as well as the completed state. [Figure 3] This is a cross-sectional view showing a cross-section of an axial gap motor according to Embodiment 1. [Figure 4] This is a cross-sectional view showing a cross-section of an axial gap motor according to Embodiment 2. [Figure 5] This is a cross-sectional view showing a cross-section of an axial gap motor according to Embodiment 3. [Modes for carrying out the invention]

[0014] Embodiments of the axial gap motor of the present invention will be described below with reference to the drawings. In each figure, the same parts are denoted by the same reference numerals. Embodiment 1. First, the structure of the axial gap motor 100 in Embodiment 1 will be described using Figures 1 to 3. Figure 1 is an exploded perspective view showing the components of the axial gap motor 100 according to Embodiment 1 in a disassembled state. Figure 2 is a perspective view showing the components of each part of the axial gap motor 100 according to Embodiment 1 and the completed state. Figure 3 is a cross-sectional view showing a cross-section of the axial gap motor 100 according to Embodiment 1.

[0015] Figs. 2 and 3(a) show the lid part 110, Figs. 2 and 3(b) show the rotor 120, the rotating shaft 130, and the bearing 140, Figs. 2 and 3(c) show the stator 150, and Figs. 2 and 3(d) show the entire axial gap motor 100.

[0016] The axial gap motor 100 mainly has a lid part 110, a rotor 120, a rotating shaft 130, a bearing 140, and a stator 150. The lid part 110, the rotor 120, and the stator 150 are in a state of being stacked in the axial direction. Here, the direction along the axis of the rotating shaft 130 provided at the center of rotation of the rotor 120 is defined as the axial direction, the direction along the radius of the rotor 120 etc. is defined as the radial direction, and the direction along the rotation direction of the rotor 120 is defined as the circumferential direction.

[0017] The lid part 110 is provided so as to face one surface of the rotor 120. The lid part 110 constitutes the housing of the axial gap motor 100 together with the stator 150. The lid part 110 is composed of a flat part 110a, an outer cylinder part 110b, and a center hole part 110h. The flat part 110a is configured in parallel with the disk-shaped rotor 120. The outer cylinder part 110b is provided on the outer side in the radial direction of the flat part 110a, that is, on the outer periphery. The center hole part 110h is configured so that the rotation of the rotating shaft 130 can be taken out to the outside.

[0018] The rotor 120 is configured in a perforated disk shape having a center hole for fixing the rotating shaft 130, and is arranged rotatably about the rotating shaft 130 in the space provided between the lid part 110 and the stator 150. The rotor 120 includes a magnet holding part 121a, a magnet holding part 121b, and magnets 122.

[0019] The magnet holding part 121a and the magnet holding part 121b sandwich a plurality of magnets 122 from both sides in the axial direction. The plurality of magnets 122 are magnetized so as to have alternating polarities in the axial direction.

[0020] The rotating shaft 130 is fixed to the central hole of the rotor 120 and is configured to be rotatable together with the rotor 120. The fixing of the rotating shaft 130 to the central hole of the rotor 120 is performed by any method such as adhesion, press-fitting, or screwing. Although the case where the rotating shaft 130 is a hollow shaft is illustrated, it may also be a solid shaft.

[0021] The bearing 140 holds the rotor 120 rotatably with respect to the stator 150 on the radially outer side, i.e., the outer circumference of the rotor 120. The bearing 140 is provided with an inner ring portion 141, an outer ring portion 142, and a rolling element portion 143. The inner ring portion 141 is fixed to the outer peripheral surface on the radially outer side of the rotor 120. The outer ring portion 142 is fixed to the inner peripheral surface 151c on the radially inner side of the outer cylinder portion 151b of the stator 150 and the inner peripheral surface 110c on the radially inner side of the outer cylinder portion 110b of the lid portion 110.

[0022] The fixing of the inner ring portion 141 of the bearing 140 to the outer peripheral surface of the rotor 120, and the fixing of the outer ring portion 142 of the bearing 140 to the inner peripheral surface 151c of the outer cylinder portion 151b of the stator 150 and the inner peripheral surface 110c of the outer cylinder portion 110b of the lid portion 110 are performed by any method such as adhesion, press-fitting, or screwing.

[0023] The stator 150 is provided so as to face the surface of the rotor 120 opposite to the lid portion 110. The stator 150 includes a yoke 151, a core 152, and a coil 153.

[0024] The yoke 151 constitutes the magnetic path of the stator 150 and includes a flat portion 151a, an outer cylinder portion 151b, and an inner cylinder portion 151h. The flat portion 151a is configured to be parallel to the rotor 120. The outer cylinder portion 151b is provided on the radially outer side, i.e., the outer circumference of the flat portion 151a. An inner peripheral surface 151c is provided on the radially inner side, i.e., the inner peripheral surface side of the outer cylinder portion 151b. The outer ring portion 142 of the bearing 140 is fixed to the inner peripheral surface 151c. The inner cylinder portion 151h is configured such that the rotation of the rotating shaft 130 can be taken out to the outside.

[0025] The core 152 is configured as a magnetic path that protrudes at equal angular intervals from the flat portion 151a of the yoke 151 toward the rotor 120. A coil 153 is wound around the core 152.

[0026] The coil 153 generates a rotating magnetic field by a drive current supplied from an external drive circuit (not shown). In response to this rotating magnetic field, attractive and repulsive forces act on the magnet 122 of the rotor 120, causing the rotor 120 to rotate in synchronization with the rotating magnetic field generated by the drive current. The rotation of the rotor 120 is transmitted to an external shaft (not shown) attached to the rotating shaft 130.

[0027] The outer cylinder portion 110b of the lid portion 110 and the outer cylinder portion 151b of the stator portion 150 are configured to have the same outer diameter and are fixed to each other by either adhesive or screws.

[0028] Figures 2(d) and 3(d) show a state in which one end of the rotating shaft 130 coincides with the axially outer side of the flat portion 110a of the cover portion 110, and the other end of the rotating shaft 130 coincides with the axially outer side of the flat portion 151a of the yoke 151, but the configuration is not limited to this. That is, the end of the rotating shaft 130 may be located inside the axial gap motor 100, or it may protrude axially outward from the axial gap motor 100.

[0029] [Effects obtained by Embodiment 1] The axial gap motor 100 according to Embodiment 1 can achieve the following effects.

[0030] The axial gap motor 100 according to Embodiment 1 includes a planar rotor 120 with a rotating shaft 130 as its center of rotation, a stator 150 positioned opposite one side of the rotor 120, and a bearing 140 that rotatably holds the rotor 120 relative to the stator 150. Here, the inner ring portion 141 of the bearing 140 is fixed to the outer circumferential surface of the rotor 120, and the outer ring portion 142 of the bearing 140 is fixed to the inner circumferential surface 151c of the outer cylinder portion 151b of the stator 150.

[0031] In other words, in the axial gap motor 100 of Embodiment 1, by attaching the bearing 140 to the outer circumference of the rotor 120, the deflection and deformation of the rotor 120 during rotation, which tend to have larger amplitudes near the outer circumference, can be efficiently suppressed compared to the case where the bearing 140 is attached to the rotating shaft 130. By suppressing the deflection and deformation of the rotor 120 during rotation, noise and vibration generated from the rotating rotor 120 can be effectively suppressed. Furthermore, since the bearing 140 is not located around the rotating shaft 130, it does not hinder the flattening of the axial gap motor 100. Also, since the bearing 140 is not located around the rotating shaft 130, it does not affect the diameter of the rotating shaft 130 and does not hinder the enlargement of the rotating shaft 130.

[0032] In the axial gap motor 100 according to Embodiment 1, a stator 150 is provided facing one side of the rotor 120, and a cover portion 110 is provided facing the other side of the rotor 120. Here, the cover portion 110 comprises a flat portion 110a parallel to the rotor 120 and an outer cylindrical portion 110b provided on the outer circumference of the flat portion 110a, and the outer ring portion 142 of the bearing 140 is fixed to the inner circumferential surface 151c of the outer cylindrical portion 151b of the stator 150 and the inner circumferential surface 110c of the outer cylindrical portion 110b of the cover portion 110.

[0033] In other words, in the axial gap motor 100 of Embodiment 1, the outer ring portion 142 of the bearing 140 is fixed to both the stator 150 and the cover portion 110, so that the bearing 140 can be kept in a stable state. As a result, stable rotation of the rotor 120 held by the bearing 140 can be achieved, deflection and deformation of the rotor 120 during rotation can be suppressed, and noise and vibration can be effectively suppressed.

[0034] Embodiment 2. The configuration of the axial gap motor 100 in Embodiment 2 will be explained with reference to Figure 4. Figure 4 is a cross-sectional view showing a cross-section of the axial gap motor 100 according to Embodiment 2. Figure 4(a) shows a cross-section of the first stator 150A, Figure 4(b) shows a cross-section of the rotor 120, the rotating shaft 130, and the bearing 140, Figure 4(c) shows a cross-section of the second stator 150B, and Figure 4(d) shows a cross-section of the entire axial gap motor 100.

[0035] In Figure 4, the same reference numerals are used for parts identical to those in Figures 1 to 3 of Embodiment 1, thereby omitting redundant explanations and focusing on the differences. The axial gap motor 100 mainly comprises a rotor 120, a rotating shaft 130, a bearing 140, and a stator 150. The stator 150 is composed of a first stator 150A and a second stator 150B.

[0036] Here, a first stator 150A is provided facing one side of the rotor 120, and a second stator 150B is provided facing the other side of the rotor 120. The outer cylinder portion 151b of the first stator 150A and the outer cylinder portion 151b of the second stator 150B have the same outer diameter and are fixed to each other by adhesive or screw fastening.

[0037] The outer ring portion 142 of the bearing 140 is fixed to the radially inward inner circumferential surface 151c of the outer cylinder portion 151b of the first stator 150A and the radially inward inner circumferential surface 151c of the outer cylinder portion 151b of the second stator 150B. In other words, the outer ring portion 142 of the bearing 140 is supported from both sides in the axial direction by the first stator 150A and the second stator 150B. The rotor 120 and the bearing 140 are enclosed within the first stator 150A and the second stator 150B.

[0038] The coils 153 of the first stator 150A and the second stator 150B generate a rotating magnetic field due to a drive current supplied from an external drive circuit (not shown). In response to this rotating magnetic field, attractive and repulsive forces act on the magnet 122, causing the rotor 120 to rotate in synchronization with the rotating magnetic field caused by the drive current. The rotation of the rotor 120 is transmitted to an external shaft (not shown) attached to the rotating shaft 130.

[0039] Figure 4(d) shows a state in which one end of the rotating shaft 130 coincides with the axially outer side of the planar portion 151a of the yoke 151 of the first stator 150A, and the other end of the rotating shaft 130 coincides with the axially outer side of the planar portion 151a of the yoke 151 of the second stator 150B, but is not limited to this. That is, the end of the rotating shaft 130 may be located inside the axial gap motor 100, or it may protrude axially outward from the axial gap motor 100.

[0040] [Effects obtained by Embodiment 2] The axial gap motor 100 according to Embodiment 2 can achieve the following effects.

[0041] In the axial gap motor 100 according to Embodiment 2, the stator 150 is composed of a first stator 150A positioned to face one side of the rotor 120 and a second stator 150B positioned to face the other side of the rotor 120. Here, the outer ring portion 142 of the bearing 140 is fixed to the inner circumferential surface 151c of the first stator 150A and the inner circumferential surface 151c of the second stator 150B.

[0042] In other words, in the axial gap motor 100 of the second embodiment, the outer ring portion 142 of the bearing 140 is supported from both sides in the axial direction by the first stator 150A and the second stator 150B. Therefore, the bearing 140 can be kept in a stable state. As a result, stable rotation of the rotor 120 held by the bearing 140 can be achieved, deflection and deformation of the rotor 120 during rotation can be suppressed, and noise and vibration can be effectively suppressed.

[0043] Embodiment 3. The configuration of the axial gap motor 100 in Embodiment 3 will be explained with reference to Figure 5. Figure 5 is a cross-sectional view showing a cross-section of the axial gap motor 100 according to Embodiment 3. Figure 5(a) shows a cross-section of the first stator 150A, Figure 5(b) shows a cross-section of the rotor 120, the rotating shaft 130, and the bearing 140, Figure 5(c) shows a cross-section of the second stator 150B, and Figure 5(d) shows a cross-section of the entire axial gap motor 100.

[0044] In Figure 5, the same reference numerals are used for parts identical to those in Figure 4 of Embodiment 2, thereby omitting redundant explanations and focusing on the differences. The axial gap motor 100 mainly comprises a rotor 120, a rotating shaft 130, bearings 140, and a stator 150. The bearings 140 are composed of a first bearing 140A and a second bearing 140B. The stator 150 is composed of a first stator 150A and a second stator 150B.

[0045] A first stator 150A is provided facing one side of the rotor 120, and a second stator 150B is provided facing the other side of the rotor 120. The outer cylinder portion 151b of the first stator 150A and the outer cylinder portion 151b of the second stator 150B have the same outer diameter and are fixed to each other by adhesive or screws.

[0046] As bearings 140, a first bearing 140A is provided corresponding to the first stator 150A, and a second bearing 140B is provided corresponding to the second stator 150B. The first bearing 140A and the second bearing 140B rotatably hold the rotor 120 with respect to the first stator 150A and the second stator 150B.

[0047] Here, the first bearing 140A comprises an inner ring portion 141A fixed to the radially outer outer circumferential surface of the rotor 120 and an outer ring portion 142A fixed to the inner circumferential surface 151c of the first stator 150A. The second bearing 140B comprises an inner ring portion 141B fixed to the radially outer circumferential surface of the rotor 120 and an outer ring portion 142B fixed to the inner circumferential surface 151c of the second stator 150B.

[0048] The inner ring portion 141 of the first bearing 140A and the inner ring portion 141 of the second bearing 140B are fixed to the outer circumferential surface of the rotor 120. The outer ring portion 142 of the first bearing 140A is fixed to the inner circumferential surface 151c of the outer cylinder portion 151b of the first stator 150A. The outer ring portion 142 of the second bearing 140B is fixed to the inner circumferential surface 151c of the outer cylinder portion 151b of the second stator 150B.

[0049] The fixing of the inner ring portions 141 of the first bearing 140A and the second bearing 140B to the outer circumferential surface of the rotor 120, the fixing of the outer ring portion 142 of the first bearing 140A to the inner circumferential surface 151c of the outer cylinder portion 151b of the first stator 150A, and the fixing of the outer ring portion 142 of the second bearing 140B to the inner circumferential surface 151c of the outer cylinder portion 151b of the second stator 150B are carried out by one of the following methods: bonding, press-fitting, or screw fastening.

[0050] A bearing 140 having a first bearing 140A and a second bearing 140B can be an angular contact bearing that receives radial loads and bidirectional axial loads. In this case, the first bearing 140A receives radial loads and a first-direction axial load, while the second bearing 140B receives radial loads and a second-direction axial load different from the first. This makes it possible for the bearing 140 to handle moment loads.

[0051] The coils 153 of the first stator 150A and the second stator 150B generate a rotating magnetic field due to a drive current supplied from an external drive circuit (not shown). In response to this rotating magnetic field, attractive and repulsive forces act on the magnet 122, causing the rotor 120 to rotate in synchronization with the rotating magnetic field caused by the drive current. The rotation of the rotor 120 is transmitted to an external shaft (not shown) attached to the rotating shaft 130.

[0052] [Effects obtained by Embodiment 3] The axial gap motor 100 according to Embodiment 3 can achieve the following effects.

[0053] In the axial gap motor 100 according to Embodiment 3, the bearing 140 is comprised of a first bearing 140A having an inner ring portion 141A fixed to the outer circumferential surface of the rotor 120 and an outer ring portion 142A fixed to the inner circumferential surface 151c of the first stator 150A, and a second bearing 140B having an inner ring portion 141B fixed to the outer circumferential surface of the rotor 120 and an outer ring portion 142B fixed to the inner circumferential surface 151c of the second stator 150B, and the stator 150 is comprised of a first stator 150A arranged to face one side of the rotor 120 and a second stator 150B arranged to face the other side of the rotor 120.

[0054] In other words, in the axial gap motor 100 of Embodiment 3, the first bearing 140A and the second bearing 140B are provided corresponding to the first stator 150A and the second stator 150B. Therefore, the first bearing 140A and the second bearing 140B can maintain stable rotation of the rotor 120. As a result, deflection and deformation of the rotor 120 during rotation can be suppressed, and noise and vibration can be effectively suppressed.

[0055] In the axial gap motor 100 according to Embodiment 3, the bearing 140 having a first bearing 140A and a second bearing 140B can be an angular contact bearing that receives radial loads and bidirectional axial loads. This allows the bearing 140 to handle moment loads. As a result, more stable rotation of the rotor 120 held by the bearing 140 can be achieved, and noise and vibration associated with the rotation of the rotor 120 can be suppressed.

[0056] Other embodiments The bearings 140 in Embodiments 1 and 2 can be angular contact bearings that receive radial loads and bidirectional axial loads, similar to the bearing 140 in Embodiment 3. This allows the bearings 140 in Embodiments 1 and 2 to handle moment loads. As a result, more stable rotation of the rotor 120 held by the bearing 140 can be achieved, and noise and vibration associated with the rotation of the rotor 120 can be suppressed. [Explanation of Symbols]

[0057] 100 Axial gap motor, 110 Cover, 110a Flat section, 110b Outer cylinder section, 110c Inner circumferential surface, 110h Center hole section, 120 Rotor, 121a, 121b Magnet holder section, 122 Magnet, 130 Rotating shaft, 140 Bearing, 140A First bearing, 140B Second bearing, 141 Inner ring section, 142 Outer ring section, 143 Rolling section, 150 Stator, 150A First stator, 150B Second stator, 151 Yoke, 151a Flat section, 151b Outer cylinder section, 151c Inner circumferential surface, 151h Inner cylinder section, 152 Core, 153 Coil.

Claims

1. A disc-shaped rotor (120) with a rotating shaft (130) as its center of rotation, A stator (150) is positioned to face one side of the rotor (120), The stator (150) is supported by a bearing (140) that rotatably holds the rotor (120), The inner ring portion (141) of the bearing (140) is fixed to the outer circumferential surface of the rotor (120), The outer ring portion (142) of the bearing (140) is fixed to the inner circumferential surface (151c) of the outer cylinder portion (151b) of the stator (150). Axial gap motor.

2. A cover portion (110) is provided so as to face the other side of the rotor (120), The lid portion (110) comprises a flat portion (110a) parallel to the rotor (120) and an outer cylindrical portion (110b) provided on the outer circumference of the flat portion (110a). The outer ring portion (142) of the bearing (140) is fixed to the inner circumferential surface (151c) of the outer cylinder portion (151b) of the stator (150) and the inner circumferential surface (110c) of the outer cylinder portion (110b) of the cover portion (110). The axial gap motor according to claim 1.

3. The stator (150) is composed of a first stator (150A) positioned facing one side of the rotor (120) and a second stator (150B) positioned facing the other side of the rotor (120). The outer ring portion (142) of the bearing (140) is fixed to the inner circumferential surface (151c) of the first stator (150A) and the inner circumferential surface (151c) of the second stator (150B). The axial gap motor according to claim 1.

4. The bearing (140) comprises a first bearing (140A) and a second bearing (140B). The first bearing (140A) is, The inner ring portion (141A) is fixed to the outer circumferential surface of the rotor (120), The first stator (150A) comprises an outer ring portion (142A) fixed to the inner circumferential surface (151c), The second bearing (140B) is, The inner ring portion (141B) is fixed to the outer circumferential surface of the rotor (120), The second stator (150B) comprises an outer ring portion (142B) fixed to the inner circumferential surface (151c), The axial gap motor according to claim 3.

5. The bearing (140) is an angular contact bearing that receives radial loads and bidirectional axial loads. An axial gap motor according to any one of claims 1 to 4.

Images