Stator

Abstract

The purpose of the present disclosure is to provide a stator 1 with which it is possible to improve detection accuracy. The stator of the present disclosure comprises an arc-shaped yoke part 11, which is a ring or part of ring, a stator body 10 having a plurality of teeth 12 that extend from the yoke part 11 toward the inside in the radial direction of the ring, and a plurality of coils 15 disposed so as to be wound around the teeth 12, wherein: the stator body 10 has one or more magnetic stator members 20 and one or more non-magnetic stator members 30; the magnetic stator members 20 are composed of a magnetic material; the non-magnetic stator members 30 are composed of a non-magnetic material; and the stator body 10 is constituted so that the magnetic stator members 20 and the non-magnetic stator members 30 are layered along the central axis of the ring.

Description

Stator

[0001] The present disclosure relates to a stator.

[0002] Conventionally, in order to reduce manufacturing costs, resolver stators made of a single metal plate have been known in which a portion of the metal plate is folded in the axial direction and laminated to provide large-volume teeth (see, for example, Patent Document 1).

[0003] JP 2011-239531 A

[0004] In conventional resolver stators, the teeth extend in the axial direction, so when coils are wound around the teeth, the air gap between the teeth and the rotor becomes larger, resulting in a problem of reduced detection accuracy.

[0005] In order to solve the above problems, an object of the present disclosure is to provide a stator that allows for improved detection accuracy.

[0006] The stator according to the present disclosure comprises a yoke portion which is a circular ring or an arc which is a part of the circular ring, a stator body having a plurality of teeth extending from the yoke portion radially inward of the circular ring, and a plurality of coils wound around each of the teeth, the stator body having one or more magnetic stator members and one or more non-magnetic stator members, the magnetic stator members being made of a magnetic material, the non-magnetic stator members being made of a non-magnetic material, and the stator body being constructed by stacking the magnetic stator members and the non-magnetic stator members along the central axis direction of the circular ring.

[0007] According to the stator according to the present disclosure, it is possible to improve detection accuracy.

[0008] FIG. 1 is a schematic diagram showing a stator according to embodiment 1. FIG. 2 is a schematic diagram showing details of the stator of FIG. 1. FIG. 3 is a cross-sectional view showing a cross section taken along line III-III of FIG. 1. FIG. 4 is a cross-sectional view showing a stator body in a first modified example of embodiment 1. FIG. 5 is a cross-sectional view showing a stator body in embodiment 2. FIG. 6 is a cross-sectional view showing a stator body in a first modified example of embodiment 2. FIG. 7 is a cross-sectional view showing a stator body in embodiment 3. FIG. 8 is a cross-sectional view showing a stator body in a first modified example of embodiment 3. FIG. 9 is a schematic diagram showing a non-magnetic stator member in embodiment 4. FIG. 11 is a schematic diagram showing a part of a magnetic stator member in embodiment 5. FIG. 12 is a schematic diagram showing a part of a non-magnetic stator member in embodiment 6.

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Embodiment 1. Fig. 1 is a schematic diagram showing a stator 1 according to embodiment 1. Fig. 2 is a schematic diagram showing details of the stator 1 of Fig. 1. Fig. 3 is a cross-sectional view showing a cross section taken along line III-III of Fig. 1. The stator 1 can be used as a stator for a resolver or a torque sensor.

[0010] The stator 1 has a substantially circular ring shape. The central axis of the ring of the stator 1 is defined as the central axis L. That is, the central axis L is an axis that passes through the center of the stator 1. A rotating body 50 such as a rotor is disposed in a hole opened in the center of the ring of the stator 1. The central axis L and the rotation axis of the rotating body 50 coincide with each other.

[0011] The stator 1 and the rotating body 50 are arranged in a non-contact state. The resolver or torque sensor can detect physical quantities such as the rotation angle, rotation speed, or rotational torque of the rotating body 50 using the stator 1.

[0012] The stator 1 includes a stator body 10 and fourteen coils 15. The stator body 10 has a yoke portion 11 that is an annular ring, and fourteen teeth 12 that extend radially inward from the yoke portion 11. Each coil 15 is disposed on one of the teeth 12.

[0013] The axis passing through the center of the ring that is the yoke portion 11 is the same as the central axis L. The number of teeth 12 and coils 15 is not limited to 14, and any number may be provided.

[0014] Coil installation portions 12a are formed on the teeth 12 at portions continuing from the yoke 11, and tooth tip portions 12b are formed at the tips of the teeth 12 continuing from the coil installation portions 12a. The tooth tip portions 12b are wider than the coil installation portions 12a.

[0015] The radially innermost ends of the teeth 12 are formed in an arc shape when viewed along the central axis L. The radially innermost ends of the tooth tip portions 12b are formed so as to follow the same circumference when viewed together.

[0016] When the rotor 50 is disposed on the stator 1, an air gap is formed between each tooth tip 12b and the rotor 50. The tooth tip 12b and the rotor 50 are not in contact with each other.

[0017] A coil 15 is wound around the coil installation portion 12a of each tooth portion 12. The coil 15 is formed by winding a conductor wire multiple times. Note that the coil 15 does not have to be formed by winding a conductor wire multiple times. For example, one coil 15 may be composed of a pair of coil members formed in a C-shape. One coil 15 may be formed by sandwiching the coil installation portion 12a between a pair of C-shaped coil members and connecting the pair of opposing coil members.

[0018] The stator body 10 has a magnetic stator member 20 and a non-magnetic stator member 30. The stator body 10 is configured by stacking the magnetic stator member 20 and the non-magnetic stator member 30 along the central axis L.

[0019] The stator body 10 is constructed by stacking magnetic stator members 20 and non-magnetic stator members 30, which have approximately the same external shapes, in a direction along the central axis L. The magnetic stator members 20 and non-magnetic stator members 30 are stacked using conventionally known processing methods such as caulking and bonding.

[0020] The magnetic stator member 20 is made of a magnetic material such as electromagnetic steel, permalloy, ferrite, nanocrystalline soft magnetic alloy, or amorphous alloy.

[0021] The non-magnetic stator member 30 is made of a non-magnetic material, such as non-magnetic stainless steel or resin, and does not include an adhesive layer that bonds the magnetic stator members 20 together.

[0022] The non-magnetic stator member 30 has through holes 30a formed therethrough in a direction along the central axis L. A plurality of through holes 30a are formed at locations of the non-magnetic stator member 30 corresponding to the yoke portions 11.

[0023] If the direction along the central axis L of the magnetic stator member 20 and the non-magnetic stator member 30 is defined as the thickness direction of each, the thickness of the magnetic stator member 20 is thinner than the thickness of the non-magnetic stator member 30. The thicknesses of the magnetic stator member 20 and the non-magnetic stator member 30 can be determined based on the detection accuracy required of the resolver.

[0024] The resolver can measure the rotation angle of the rotor 50. The operating principle of a resolver using the stator 1 of the present disclosure is well known, and therefore a description thereof will be omitted.

[0025] As shown in Figure 1, a rotor 50 with a circular cross section is inserted into a hole opening in the center of the ring of the stator 1. When current is applied to each coil 15 in this state, the coil 15 is excited and generates a magnetic field. The magnetic flux Φ of the magnetic field generated by the coil 15 flows through the magnetic path formed by the stator 1.

[0026] One magnetic path formed by the stator 1 runs from any one of the teeth 12 through the yoke 11 to reach the teeth 12 adjacent to the tooth 12 in the circumferential direction. The magnetic path then passes through a space that is a hole opened in the center of the ring of the stator 1 and returns to the tooth 12.

[0027] A rotor 50 is disposed in a hole that opens in the center of the ring of the stator 1. When the posture of the rotor 50 changes, the magnetic flux Φ flowing through the magnetic path changes accordingly. The change in the posture of the rotor 50 can be detected based on this change in the magnetic flux Φ.

[0028] It is also possible to add a configuration to the rotor 50 that makes it easier to check changes in the attitude of the rotor 50, i.e., changes in the magnetic flux Φ due to the rotation of the rotor 50. For example, multiple regions with different magnetic permeabilities may be formed on the outer circumferential surface of the rotor 50 that the tooth tips 12b face. Also, the cross section of the rotor 50 may be non-circular so that the air gap distances are different.

[0029] Generally, the magnetic path formed in a stator is formed in a magnetic member. When the magnetic path is viewed as a magnetic circuit formed in the stator, the magnetic resistance Rm of the magnetic circuit is determined by the length l of the magnetic path, the cross-sectional area S of the magnetic path, and the magnetic permeability μ of the member forming the magnetic path, as follows: Rm=l / μS

[0030] As shown in the above formula, the thickness of the magnetic member where the magnetic path is formed affects the magnetic resistance Rm. That is, as the thickness of the magnetic member where the magnetic path is formed increases, the cross-sectional area S of the magnetic path increases, and the magnetic resistance Rm decreases. If the magnetic resistance Rm of the magnetic circuit decreases, a resolver using this stator can detect even slight changes in magnetic flux caused by slight rotations of the rotor, improving the detection accuracy of the resolver.

[0031] The magnetic members are relatively expensive among the materials used in the entire stator, so the manufacturing cost of the stator can be reduced by reducing the amount of magnetic members used, for example by reducing the thickness of the stator depending on the detection accuracy of the resolver.

[0032] On the other hand, as the thickness of the teeth decreases, the length of the coils wound around the teeth also decreases, lowering the input impedance. This weakens the magnetic field strength generated by each coil. This reduces the magnetic flux Φ, and the amount of change in magnetic flux Φ due to changes in the rotor's posture also decreases, reducing the detection accuracy of the resolver.

[0033] In this way, if the amount of magnetic material used is reduced and the thickness of the stator is made thinner in order to hold down manufacturing costs, the input impedance of the coils will decrease and the detection accuracy of the stator will deteriorate. However, in the first embodiment, even if the thickness of the magnetic stator member 20 is made thinner in order to reduce the amount of magnetic material used, the input impedance of each coil 15 will not decrease and the detection accuracy of the resolver using the stator 1 will not decrease because the non-magnetic stator member 30 is laminated on the magnetic stator member 20.

[0034] The stator 1 of the first embodiment includes the yoke portion 11 that is annular. However, this is not limiting. The yoke portion 11 may be an arc that is a portion of an annular ring. For example, the yoke portion 11 may be a quarter arc, i.e., an arc-shaped yoke portion 11 with a central angle of 90 degrees. The stator 1 that includes the arc-shaped yoke portion 11 can be used as the stator 1 of a resolver that detects the rotation angle of the rotor 50 by arranging the stator 1 along the outer periphery of the rotor 50. This allows for further reduction in the manufacturing cost of the stator 1. Furthermore, when detecting the rotation angle of an existing rotating shaft, the arc-shaped stator 1 can be easily installed on the existing shaft.

[0035] The stator 1 in the first embodiment includes a yoke portion 11, which is a circular ring or an arc that is a portion of the circular ring, a stator body 10 having a plurality of teeth 12 extending radially inward from the yoke portion 11, and a plurality of coils 15 wound around each of the teeth 12. The stator body 10 also includes one or more magnetic stator members 20 and one or more non-magnetic stator members 30. The magnetic stator members 20 are made of a magnetic material, and the non-magnetic stator members 30 are made of a non-magnetic material. The stator body 10 is configured by stacking the magnetic stator members 20 and the non-magnetic stator members 30 along the central axis of the ring. As a result, in the stator body 10 in which the magnetic stator member 20 and the non-magnetic stator member 30 are stacked, each coil 15 can be arranged on each tooth 12 extending radially inward from the yoke portion 11, and the radially innermost end of each tooth 12 can be arranged to face the rotor 50. This reduces the air gap between the rotor 50 and the teeth 12, thereby improving the detection accuracy of sensors such as resolvers using the stator 1. This also allows the distance between the teeth 12 and the yoke portion 11 to be maintained constant. This reduces the increase in leakage magnetic flux, thereby improving detection accuracy. Furthermore, because the teeth 12 on which each coil 15 is installed are configured by stacking the magnetic stator member 20 and the non-magnetic stator member 30, the input impedance of the coil 15 can be reduced. Therefore, the input impedance of the coil 15 can be set to an appropriate value while the amount of magnetic material used in the magnetic stator member 20 is appropriate for detection accuracy. Therefore, the detection accuracy of the sensor using the stator 1 can be improved while maintaining an appropriate amount of magnetic material. Also, a magnetic stator member 20 having the required volume according to the required detection accuracy can be prepared. Therefore, the amount of magnetic material used can be set to an optimal amount, and manufacturing costs can be reduced. Furthermore, even if the thickness of the magnetic stator member 20 is reduced, the mechanical strength of the magnetic stator member 20 can be ensured because the magnetic stator member 20 and the non-magnetic stator member 30 are stacked.

[0036] In the stator 1 of the first embodiment, the magnetic stator member 20 and the non-magnetic stator member 30 have different thicknesses in the stacking direction. This allows the thickness of the magnetic stator member 20 to be designed taking into account the magnetic resistance of the magnetic path formed in the stator 1. On the other hand, the thickness of the non-magnetic stator member 30 can be designed taking into account the input impedance of the coil 15 and the mechanical strength of the stator 1. This allows the amount of magnetic material used in the stator 1 to be reduced while maintaining the detection accuracy of a sensor using the stator 1. Furthermore, the stator 1 can have the required mechanical strength regardless of the amount of magnetic material used.

[0037] In the stator 1 of the first embodiment, the thickness of the magnetic stator member 20 in the stacking direction of the magnetic stator member 20 and the non-magnetic stator member 30 is thinner than the non-magnetic stator member 30. As a result, even in the case of the magnetic stator member 20 that is configured with the minimum necessary amount of magnetic material, by making the non-magnetic stator member 30 thick, it is possible to provide the stator 1 with the necessary mechanical strength.

[0038] In the stator 1 of the first embodiment, the non-magnetic stator member 30 has a plurality of through holes 30a formed therein, which penetrate in the direction in which the magnetic stator member 20 and the non-magnetic stator member 30 are stacked. This contributes to reducing the weight of the stator 1. This also contributes to reducing the amount of non-magnetic material used to construct the non-magnetic stator member 30, thereby reducing manufacturing costs.

[0039] In the stator 1 of the first embodiment, each through hole 30a is formed at a position corresponding to the yoke portion 11 of the non-magnetic stator member 30. This allows the weight of the non-magnetic stator member 30 to be reduced and the amount of material used for the non-magnetic stator member 30 to be reduced without significantly reducing the mechanical strength of the non-magnetic stator member 30.

[0040] Variation 1 of Embodiment 1. The stator 1 in Variation 1 of Embodiment 1 differs from the stator 1 of Embodiment 1 in that the stator body 10 has two magnetic stator members 20 and two non-magnetic stator members 30.

[0041] Fig. 4 is a cross-sectional view showing the stator body 10 according to the first modification of the first embodiment. Fig. 4 shows a cross-sectional view of the stator body 10 according to the first modification of the first embodiment, taken along the same line as line III-III in Fig. 1.

[0042] The stator body 10 has two magnetic stator members 20 and two non-magnetic stator members 30. The stator body 10 is configured by alternately stacking the magnetic stator members 20 and the non-magnetic stator members 30.

[0043] In other words, in the stacking direction, the non-magnetic stator member 30 is stacked below the magnetic stator member 20, and when viewed as a single block, two such blocks are stacked to form the stator body 10. The other configuration of the stator 1 in the first modification of the first embodiment is the same as the configuration of the stator 1 in the first embodiment, and therefore description thereof will be omitted.

[0044] The stator 1 in the first modification of the first embodiment has two magnetic stator members 20 and two non-magnetic stator members 30. However, this is not limited to this. The stator 1 may have two or more magnetic stator members 20 and two or more non-magnetic stator members 30. Furthermore, one magnetic stator member 20 and one non-magnetic stator member 30 may be alternately stacked.

[0045] The stator 1 in the first modification of the first embodiment is formed by alternately stacking magnetic stator members 20 and non-magnetic stator members 30 one by one. This allows a uniform magnetic field to be formed over a long range along the stacking direction while minimizing the amount of magnetic material used. Therefore, physical quantities such as the rotation angle can be detected at any position along the longitudinal direction of the rotor 50 while minimizing the amount of magnetic material used. This allows the rotor 50 to be observed along the longitudinal direction of the rotor 50 while minimizing the increase in the amount of magnetic material used.

[0046] Embodiment 2 Fig. 5 is a cross-sectional view showing a stator body 10 according to embodiment 2. Fig. 5 shows a cross-sectional view of the stator body 10 according to embodiment 2 taken along the same line as line III-III in Fig. 1.

[0047] The stator 1 in the second embodiment differs from the stator 1 in the first embodiment in that the stator body 10 has two magnetic stator members 20 and one non-magnetic stator member 30 .

[0048] The stator body 10 has a laminated body 40 configured by stacking two magnetic stator members 20 with one non-magnetic stator member 30 sandwiched therebetween. In the second embodiment, the stator body 10 is configured with one laminated body 40. The other configuration of the stator 1 in the second embodiment is the same as the configuration of the stator 1 in the first embodiment, and therefore description thereof will be omitted.

[0049] In the stator 1 of the second embodiment, when the magnetic stator member 20 is the first member and the non-magnetic stator member 30 is the second member, the stator body 10 has a lamination body 40 in which at least two first members are stacked with at least one second member sandwiched between them. That is, the magnetic stator members 20 are stacked with the non-magnetic stator member 30 sandwiched between them. This allows the pair of magnetic stator members 20 to be arranged with an appropriate gap between them. Therefore, it is possible to detect physical quantities at corresponding locations on the rotor 50 along the lamination direction while suppressing an increase in the amount of magnetic material used.

[0050] The stator body 10 in the second embodiment has a laminated body 40 in which two magnetic stator members 20 and one non-magnetic stator member 30 are stacked. However, this is not limited to this. The stator body 10 may have two or more magnetic stator members 20 and two or more non-magnetic stator members 30. For example, the stator body 10 may have a laminated body 40 in which two laminated non-magnetic stator members 30 are sandwiched between a pair of magnetic stator members 20. This allows the spacing between the pair of magnetic stator members 20 to be changed by changing the number of non-magnetic stator members 30, making it easy to manufacture a stator 1 that corresponds to the detection location of the rotating body 50. Furthermore, for example, the stator body 10 may have a laminated body 40 in which one non-magnetic stator member 30 is sandwiched between two stacked magnetic stator members 20. That is, the laminated body 40 may be stacked in the order of two magnetic stator members 20, one non-magnetic stator member 30, and two magnetic stator members 20. This allows the strength of the magnetic flux to be changed by changing the number of magnetic stator members 20, and the stator 1 can be easily adapted to the required detection accuracy.

[0051] Variation 1 of Embodiment 2 The stator 1 in Variation 1 of Embodiment 2 differs from the stator 1 of Embodiment 2 in that the stator body 10 has four magnetic stator members 20 and two non-magnetic stator members 30.

[0052] Fig. 6 is a cross-sectional view showing the stator body 10 according to the first modification of the second embodiment. Fig. 6 shows a cross-sectional view of the stator body 10 according to the first modification of the second embodiment taken along the same line as line III-III in Fig. 1.

[0053] The stator body 10 has four magnetic stator members 20 and two non-magnetic stator members 30. When two magnetic stator members 20 are stacked with one non-magnetic stator member 30 sandwiched between them to form one laminated body 40, the stator body 10 of this embodiment is configured by continuously stacking two laminated bodies 40. The other configuration of the stator 1 in the first modification of the second embodiment is the same as the configuration of the stator 1 of the second embodiment, and therefore description thereof will be omitted.

[0054] The stator 1 in the first modification of the second embodiment is configured by continuously stacking two laminations 40. However, this is not limited to this. For example, the stator body 10 may be configured by continuously stacking three or more laminations 40.

[0055] In the stator 1 according to the first modification of the second embodiment, the stator body 10 is configured by continuously stacking two or more laminations 40. This allows for easy prediction of the characteristics of the stator 1 including the stator body 10 in which one lamination 40 is continuously stacked. That is, based on the characteristics of one lamination 40, which is one non-magnetic stator member 30 and two magnetic stator members 20 sandwiching the non-magnetic stator member 30, the characteristics of the stator body 10 in which multiple laminations 40 are continuously stacked can be predicted. This reduces the design cost and shortens the design period for the stator 1. This also allows for the stator body 10 to be manufactured by manufacturing multiple laminations 40 and continuously stacking the required number of laminations 40 as needed. This reduces the manufacturing cost and shortens the manufacturing period for the stator body 10.

[0056] Embodiment 3 Fig. 7 is a cross-sectional view showing a stator body 10 according to embodiment 3. Fig. 7 shows a cross-sectional view of the stator body 10 according to embodiment 3 taken along the same line as line III-III in Fig. 1.

[0057] The stator 1 in the third embodiment differs from the stator 1 in the first embodiment in that the stator body 10 has two non-magnetic stator members 30 and one magnetic stator member 20 .

[0058] The stator body 10 has a laminated body 40 configured by stacking two non-magnetic stator members 30 with one magnetic stator member 20 sandwiched between them. In the third embodiment, the stator body 10 is configured by one laminated body 40. The other configuration of the stator 1 in the third embodiment is the same as the configuration of the stator 1 in the first embodiment, and therefore description thereof will be omitted.

[0059] In the stator 1 of the third embodiment, when the non-magnetic stator member 30 is the first member and the magnetic stator member 20 is the second member, the stator body 10 has a laminated body 40 in which at least two first members are stacked with at least one second member sandwiched between them. That is, the laminated body 40 is formed by stacking the non-magnetic stator members 30 with the magnetic stator members 20 sandwiched between them. As a result, the magnetic stator member 20 is protected by being sandwiched between the non-magnetic stator members 30, and there is no risk of damage such as bending even if it interferes with other members. Therefore, the magnetic stator member 20 can be made as thin as necessary, and even if the magnetic stator member 20 is made thin, the possibility of the magnetic stator member 20 being damaged can be reduced.

[0060] The stator body 10 in the third embodiment includes a laminated body 40 in which one magnetic stator member 20 is sandwiched between two non-magnetic stator members 30. However, this is not limited to this. The stator body 10 may also include a laminated body 40 in which two or more magnetic stator members 20 and two or more non-magnetic stator members 30 are stacked. For example, two stacked magnetic stator members 20 may be sandwiched between a pair of non-magnetic stator members 30 to form the laminated body 40. This allows the magnetic flux strength to be changed by adjusting and changing the number of magnetic stator members 20, making it relatively easy to design and manufacture the stator 1 according to the required detection accuracy. Furthermore, for example, the laminated body 40 may include one magnetic stator member 20 sandwiched between two stacked non-magnetic stator members 30. That is, the laminated body 40 may include two non-magnetic stator members 30, one magnetic stator member 20, and two non-magnetic stator members 30 stacked in this order. This prevents a decrease in the input impedance of each coil 15. Therefore, the stator 1 can be easily manufactured based on the input impedance of each coil 15.

[0061] Variation 1 of Embodiment 3 The stator 1 in Variation 1 of Embodiment 3 differs from the stator 1 of Embodiment 3 in that the stator body 10 has four non-magnetic stator members 30 and two magnetic stator members 20.

[0062] Fig. 8 is a cross-sectional view showing the stator body 10 according to the first modification of the third embodiment. Fig. 8 shows a cross-sectional view of the stator body 10 according to the first modification of the third embodiment, taken along the same line as line III-III in Fig. 1.

[0063] The stator body 10 has four non-magnetic stator members 30 and two magnetic stator members 20. When one magnetic stator member 20 is sandwiched between two non-magnetic stator members 30 and stacked to form one laminated body 40, the stator body 10 is configured by continuously stacking two laminated bodies 40. The other configuration of the stator 1 in the first modification of the third embodiment is the same as the configuration of the stator 1 in the third embodiment, and therefore description thereof will be omitted.

[0064] In the stator body 10 in the first modification of the third embodiment, when one magnetic stator member 20 and two non-magnetic stator members 30 sandwiching the magnetic stator member 20 are viewed as one laminated body 40, two laminated bodies 40 are stacked to form the stator body 10. However, this is not limited to this. For example, the stator body 10 may be formed by stacking three or more laminated bodies 40 in succession.

[0065] In the stator 1 according to the first modification of the third embodiment, the stator body 10 is configured by continuously stacking two or more laminations 40. This allows for easy prediction of the characteristics of the stator body 10, which is configured by continuously stacking one lamination 40. That is, based on the characteristics of one lamination 40, which is configured by sandwiching one magnetic stator member 20 between two non-magnetic stator members 30, the characteristics of the stator body 10, which is configured by continuously stacking multiple laminations 40, can be easily predicted. This reduces the design cost and shortens the design period for the stator 1. Furthermore, this allows for the stator body 10 to be manufactured by manufacturing multiple laminations 40 in advance and then continuously stacking the required number of laminations 40 as needed. This reduces the manufacturing cost and shortens the manufacturing period for the stator body 10.

[0066] Embodiment 4 The stator 1 in embodiment 4 differs from the stator 1 in embodiment 1 in that the outer shape of the non-magnetic stator member 30 is different from the outer shape of the magnetic stator member 20. Figure 9 is a schematic diagram showing the non-magnetic stator member 30 in embodiment 4.

[0067] When viewed along the central axis L, the outer shape of the non-magnetic stator member 30 is different from the outer shape of the magnetic stator member 20. A plurality of recesses 30b are formed on the outer periphery of the non-magnetic stator member 30.

[0068] The recess 30b is formed in a part of the portion corresponding to the outer peripheral edge of the yoke portion 11 of the stator body 10. The recess 30b is also formed in a portion corresponding to the tooth tip portion 12b of the stator body 10, on the surface facing the rotor 50.

[0069] The recess 30b is not formed over the entire periphery of the portion corresponding to the outer peripheral edge of the yoke portion 11 of the stator body 10. The recess 30b is not formed in the portion corresponding to the coil installation portion 12a of the teeth portion 12 of the stator body 10.

[0070] The recesses 30b are not formed in the portions corresponding to the ends of the tooth tip portions 12b of the tooth portions 12 of the stator body 10. The rest of the structure of the stator 1 in the fourth embodiment is the same as that in the first embodiment, and therefore description thereof will be omitted.

[0071] In the stator 1 of the fourth embodiment, when viewed along the central axis L of the stator 1, the magnetic stator member 20 and the non-magnetic stator member 30 have different outer shapes. As a result, by providing the recess 30b, the weight of the non-magnetic stator member 30 can be reduced, and ultimately the weight of the stator 1 can be reduced. Furthermore, the non-magnetic stator member 30 can be manufactured using less material. This reduces the manufacturing cost of the non-magnetic stator member 30.

[0072] Furthermore, in the stator 1 of the fourth embodiment, the recess 30b is not formed over the entire periphery of the portion of the stator body 10 that corresponds to the outer peripheral edge of the yoke portion 11. As a result, the magnetic stator member 20 and the non-magnetic stator member 30 are stacked in a portion of the portion of the stator body 10 that corresponds to the outer peripheral edge of the yoke portion 11. Therefore, the magnetic stator member 20 is supported by the non-magnetic stator member 30 in the portion that corresponds to the outer peripheral edge of the yoke portion 11 of the stator body 10, and maintains the necessary strength. This reduces the possibility of the magnetic stator member 20 being damaged in the portion that corresponds to the outer peripheral edge of the yoke portion 11 of the stator body 10.

[0073] Furthermore, according to the stator 1 of the fourth embodiment, the recesses 30b are not formed in the portions corresponding to the coil mounting portions 12a of the teeth 12 of the stator body 10. As a result, even when the coils 15 are wound around the coil mounting portions 12a, the magnetic stator member 20 maintains the necessary strength by being supported by the non-magnetic stator member 30. This reduces the possibility of the magnetic stator member 20 being damaged in the portions corresponding to the coil mounting portions 12a of the teeth 12 of the stator body 10.

[0074] Furthermore, according to the stator 1 of the fourth embodiment, the recesses 30b are not formed at the ends of the tooth tips 12b of the teeth 12 of the stator body 10. As a result, the magnetic stator members 20 corresponding to the ends of the tooth tips 12b of the teeth 12 of the stator body 10 are supported by the non-magnetic stator member 30, thereby maintaining the necessary strength. This reduces the possibility of the magnetic stator members 20 being damaged in the portions corresponding to the ends of the tooth tips 12b of the teeth 12 of the stator body 10.

[0075] In the fourth embodiment, the outer shape of the non-magnetic stator member 30, excluding the recess 30b, is the same as the outer shape of the corresponding portion of the magnetic stator member 20. However, this is not limited to this. For example, the outer shape of the non-magnetic stator member 30 may be larger than the outer shape of the magnetic stator member 20. This allows, for example, when the stator 1 interferes with another object, the largely protruding non-magnetic stator member 30 interferes with the object first, thereby preventing damage to the magnetic stator member 20. This further reduces the possibility of damage to the magnetic stator member 20.

[0076] Furthermore, the non-magnetic stator member 30 in the fourth embodiment does not have a through hole 30a. However, this is not limited to this. The non-magnetic stator member 30 may have one or more through holes 30a in addition to a plurality of recesses 30b. This can further reduce the weight of the non-magnetic stator member 30 and manufacturing costs.

[0077] Embodiment 5. The magnetic stator member 20 in embodiment 5 differs from the stator 1 in embodiment 1 in that it is configured by connecting a plurality of magnetic stator pieces 25. Figure 10 is a schematic diagram showing a part of the magnetic stator member 20 in embodiment 5.

[0078] The magnetic stator member 20 has a plurality of magnetic stator pieces 25. The magnetic stator member 20 is formed by connecting a plurality of magnetic stator pieces 25. Each magnetic stator piece 25 has a magnetic tooth portion 26 corresponding to the tooth portion 12 of the stator body 10, and a magnetic yoke portion 27 corresponding to a part of the yoke portion 11.

[0079] A magnetic convex portion 25a is formed at one circumferential end of the arc-shaped magnetic yoke portion 27 of each magnetic stator piece 25. A magnetic concave portion 25b is formed at the other circumferential end opposite to the one end of the arc-shaped magnetic yoke portion 27. When the magnetic stator pieces 25 are connected together, the magnetic convex portion 25a of one magnetic stator piece 25 is connected to the magnetic concave portion 25b of another magnetic stator piece 25, thereby connecting the two magnetic stator pieces 25 to each other.

[0080] A plurality of magnetic stator pieces 25 are connected to form a ring or an arc, which constitutes the magnetic stator member 20. The other structures of the stator 1 in the fifth embodiment are the same as those in the first embodiment, and therefore will not be described here.

[0081] According to the stator 1 of the fifth embodiment, each magnetic stator member 20 has a plurality of magnetic stator pieces 25. The magnetic stator member 20 is formed by connecting a plurality of magnetic stator pieces 25. Each magnetic stator piece 25 is formed with magnetic tooth portions 26 corresponding to the tooth portions 12 and magnetic yoke portions 27 corresponding to part of the yoke portion 11. This allows the magnetic steel sheet to be used without waste when cutting out the magnetic stator pieces 25 from the magnetic steel sheet, thereby reducing manufacturing costs.

[0082] In the fifth embodiment, the magnetic stator pieces 25 are formed with magnetic protrusions 25a and magnetic recesses 25b for connecting the pieces together. However, this is not a limitation. A well-known structure can be used for connecting the magnetic stator pieces 25.

[0083] Sixth Embodiment A non-magnetic stator member 30 in a sixth embodiment differs from the stator 1 in that it is configured by connecting a plurality of non-magnetic stator pieces 35. Fig. 11 is a schematic diagram showing a portion of the non-magnetic stator member 30 in the sixth embodiment.

[0084] The non-magnetic stator member 30 has a plurality of non-magnetic stator pieces 35. The non-magnetic stator member 30 is formed by connecting a plurality of non-magnetic stator pieces 35. Each non-magnetic stator piece 35 has a non-magnetic tooth portion 36 corresponding to the tooth portion 12 of the stator body 10, and a non-magnetic yoke portion 37 corresponding to a part of the yoke portion 11.

[0085] A non-magnetic convex portion 35a is formed at one circumferential end of the arc-shaped non-magnetic yoke portion 37 of each non-magnetic stator piece 35. A non-magnetic concave portion 35b is formed at the other circumferential end opposite the one end of the arc-shaped non-magnetic yoke portion 37. When the non-magnetic stator pieces 35 are connected together, the non-magnetic convex portion 35a of one non-magnetic stator piece 35 is connected to the non-magnetic concave portion 35b of another non-magnetic stator piece 35, thereby connecting the two non-magnetic stator pieces 35 to each other.

[0086] A plurality of non-magnetic stator pieces 35 are connected to form a ring or an arc, which constitutes the non-magnetic stator member 30. The other structures of the stator 1 in the sixth embodiment are the same as those in the first embodiment, and therefore will not be described here.

[0087] According to the stator 1 of the sixth embodiment, each non-magnetic stator member 30 has a plurality of non-magnetic stator pieces 35. The non-magnetic stator member 30 is formed by connecting a plurality of non-magnetic stator pieces 35. Each non-magnetic stator piece 35 has a non-magnetic tooth portion 36 corresponding to the tooth portion 12 and a non-magnetic yoke portion 37 corresponding to a part of the yoke portion 11. This eliminates the need for larger molds and resin molding equipment required for resin molding, compared to manufacturing a large non-magnetic stator member 30. This reduces the manufacturing cost of the non-magnetic stator member 30. This also reduces the storage space required compared to storing large manufactured non-magnetic stator members 30, thereby reducing the storage costs of the parts.

[0088] The stator 1 can also be manufactured using the magnetic stator pieces 25 of embodiment 5 and the non-magnetic stator pieces 35 of embodiment 6. In this case, first, the magnetic stator pieces 25 and the corresponding non-magnetic stator pieces 35 are stacked. Next, the coils 15 are installed in positions corresponding to the teeth 12. After that, the stator 1 can be manufactured by connecting multiple intermediate products in which the magnetic stator pieces 25 with the coils 15 installed and the non-magnetic stator pieces 35 are stacked. Manufacturing in this manner makes it easier to install the coils 15, and reduces manufacturing costs.

[0089] In the sixth embodiment, the non-magnetic stator pieces 35 are formed with non-magnetic protrusions 35a and non-magnetic recesses 35b for connecting the pieces together. However, this is not a limitation. A well-known structure can be used for the connecting mechanism of the non-magnetic stator pieces 35.

[0090] Furthermore, each of the configurations described in embodiment 1, variant 1 of embodiment 1, embodiment 2, variant 1 of embodiment 2, embodiment 3, variant 1 of embodiment 3, embodiment 4, embodiment 5, and embodiment 6 can be adapted to other embodiments.

[0091] Various aspects of the present disclosure are summarized below as appendices.

[0092] (Supplementary Note 1) A stator comprising: a yoke portion (11) which is a ring or an arc that is a part of the ring; and a plurality of teeth portions (12) extending from the yoke portion (11) radially inward of the ring; and a plurality of coils (15) wound around each of the teeth portions (12), wherein the stator body (10) has one or more magnetic stator members (20) and one or more non-magnetic stator members (30), wherein the magnetic stator members (20) are made of a magnetic material, and the non-magnetic stator members (30) are made of a non-magnetic material, and the stator body (10) is configured by stacking the magnetic stator members (20) and the non-magnetic stator members (30) along the central axis of the ring. (Supplementary Note 2) The stator according to Supplementary Note 1, wherein the magnetic stator member (20) and the non-magnetic stator member (30) have different outer shapes when viewed along the central axis (L) of the stator (1). (Supplementary Note 3) The stator according to Supplementary Note 1 or Supplementary Note 2, wherein the magnetic stator member (20) and the non-magnetic stator member (30) have different thicknesses in the stacking direction. (Supplementary Note 4) The stator according to any one of Supplementary Notes 1 to 3, wherein the magnetic stator member (20) and the non-magnetic stator member (30) have thinner thicknesses in the stacking direction than the non-magnetic stator member (30). (Supplementary Note 5) The stator according to any one of Supplementary Notes 1 to 4, wherein the non-magnetic stator member (30) has a plurality of through holes (30a) formed therethrough in a direction in which the magnetic stator member (20) and the non-magnetic stator member (30) are stacked. (Supplementary Note 6) The stator according to Supplementary Note 5, wherein each of the through holes (30a) is formed at a position corresponding to the yoke portion (11) of the non-magnetic stator member (30).(Appendix 7) The stator according to any one of Appendices 1 to 6, wherein when one of the magnetic stator member (20) and the non-magnetic stator member (30) is a first member and the other of the magnetic stator member (20) and the non-magnetic stator member (30) different from the first member is a second member, the stator main body (10) has a laminate (40) in which at least two of the first members are laminated with at least one of the second members sandwiched between them. (Appendix 8) The stator according to Appendices 7, wherein the stator main body (10) is configured by continuously laminating two or more of the laminates (40). (Appendix 9) The stator according to any one of Appendices 1 to 6, wherein the magnetic stator members (20) and the non-magnetic stator members (30) are laminated alternately one by one. (Appendix 10) A stator according to any one of appendices 1 to 9, wherein each of the magnetic stator members (20) has a plurality of magnetic stator pieces (25), the magnetic stator member (20) is formed by connecting the plurality of magnetic stator pieces (25), and each of the magnetic stator pieces (25) is formed with a magnetic tooth portion (26) corresponding to the tooth portion (12) and a magnetic yoke portion (27) corresponding to a part of the yoke portion (11). (Appendix 11) A stator according to any one of appendices 1 to 10, wherein each of the non-magnetic stator members (30) has a plurality of non-magnetic stator pieces (35), the non-magnetic stator member (30) is formed by connecting the plurality of non-magnetic stator pieces (35), and each of the non-magnetic stator pieces (35) is formed with a non-magnetic tooth portion (36) corresponding to the tooth portion (12) and a non-magnetic yoke portion (37) corresponding to a part of the yoke portion (11).

[0093] 1 Stator, 10 Stator body, 11 Yoke portion, 12 Teeth portion, 12a Coil mounting portion, 12b Teeth tip portion, 15 Coil, 20 Magnetic stator member, 25 Magnetic stator piece, 25a Magnetic convex portion, 25b Magnetic concave portion, 26 Magnetic teeth portion, 27 Magnetic yoke portion, 30 Non-magnetic stator member, 30a Through hole, 30b Concave portion, 35 Non-magnetic stator piece, 35a Non-magnetic convex portion, 35b Non-magnetic concave portion, 36 Non-magnetic teeth portion, 37 Non-magnetic yoke portion, 40 Laminated body, 50 Rotor, L Central axis.

Claims

1. A stator comprising: a stator body (10) having a yoke portion (11) which is a ring or an arc that is a part of the ring, and a plurality of teeth (12) extending from the yoke portion (11) toward the inside in the radial direction of the ring; and a plurality of coils (15) wound around each of the teeth (12), wherein the stator body (10) has one or more magnetic stator members (20) and one or more non-magnetic stator members (30), wherein the magnetic stator members (20) are made of a magnetic material, and the non-magnetic stator members (30) are made of a non-magnetic material, and the stator body (10) is constructed by stacking the magnetic stator members (20) and the non-magnetic stator members (30) along the central axis of the ring.

2. The stator according to claim 1, wherein the outer shape of the magnetic stator member (20) and the outer shape of the non-magnetic stator member (30) are different when viewed along the central axis (L) of the stator (1).

3. The stator according to claim 1, wherein the magnetic stator member (20) and the non-magnetic stator member (30) have different thicknesses in the stacking direction.

4. The stator according to claim 1, wherein the thickness of the magnetic stator member (20) and the non-magnetic stator member (30) in the stacking direction is thinner than that of the non-magnetic stator member (30).

5. The stator according to claim 1, wherein the non-magnetic stator member (30) has a plurality of through holes (30a) formed therein, which penetrate the non-magnetic stator member (30) in the direction in which the magnetic stator member (20) and the non-magnetic stator member (30) are stacked.

6. A stator according to claim 5, wherein each of the through holes (30a) is formed at a position corresponding to the yoke portion (11) of the non-magnetic stator member (30).

7. The stator according to claim 1, wherein when one of the magnetic stator member (20) and the non-magnetic stator member (30) is a first member and the other of the magnetic stator member (20) and the non-magnetic stator member (30) that is different from the first member is a second member, the stator body (10) has a laminate (40) in which at least two of the first members are stacked with at least one of the second members sandwiched between them.

8. A stator according to claim 7, wherein the stator body (10) is constructed by stacking two or more of the laminations (40) in succession.

9. A stator according to claim 1, wherein the magnetic stator members (20) and the non-magnetic stator members (30) are stacked alternately one by one.

10. A stator according to claim 1, wherein each of the magnetic stator members (20) has a plurality of magnetic stator pieces (25), the magnetic stator member (20) is formed by connecting the plurality of magnetic stator pieces (25), and each of the magnetic stator pieces (25) is formed with a magnetic tooth portion (26) corresponding to the tooth portion (12) and a magnetic yoke portion (27) corresponding to a part of the yoke portion (11).

11. A stator according to claim 1, wherein each of the non-magnetic stator members (30) has a plurality of non-magnetic stator pieces (35), the non-magnetic stator member (30) is formed by connecting the plurality of non-magnetic stator pieces (35), and each of the non-magnetic stator pieces (35) is formed with a non-magnetic tooth portion (36) corresponding to the tooth portion (12) and a non-magnetic yoke portion (37) corresponding to a part of the yoke portion (11).

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