Stator and motor

Abstract

The present invention provides a stator and an electric motor. The stator (12) has a plurality of coils (24). The plurality of coils (24) includes a plurality of outer coils (24X) provided on the root side of the teeth (22) and a plurality of inner coils (24Y) provided on the front end side of the teeth (22). The plurality of outer coils (24X) and the plurality of inner coils (24Y) are alternately arranged along the circumferential direction of the stator core (20). The coil windings of the plurality of outer coils (24X) are in a non-fixed state, and the coil windings of the plurality of inner coils (24Y) are in a fixed state.

Description

Technical Field

[0001] The present invention relates to a stator and a motor. Background Art

[0002] A stator has a stator core, a plurality of teeth protruding toward the axial center side of the stator core, and coils respectively provided on the plurality of teeth. A concentrated winding motor is disclosed in Japanese Patent Application Laid-Open No. 2013-153615, in which a coil is mounted on a tooth by inserting a cylindrical coil bobbin from the protruding front end side of the tooth.

[0003] Problems to be Solved by the Invention

[0004] In the concentrated winding motor disclosed in Japanese Patent Application Laid-Open No. 2013-153615, a first coil mounted on one tooth and a second coil mounted on the other tooth are present in the gap between an adjacent one tooth and the other tooth.

[0005] In order to insulate the first coil and the second coil, it is necessary to provide a gap between the first coil and the second coil along the extending direction of the tooth. Therefore, there is a tendency for the proportion (space factor) of the coil in the gap between an adjacent one tooth and the other tooth to decrease. In addition, there is a tendency for the degree of decrease in the space factor to be greater as the length of the gap between an adjacent one tooth and the other tooth in the circumferential direction of the stator core is shorter. Summary of the Invention

[0006] Therefore, an object of the present invention is to provide a stator and a motor capable of suppressing a decrease in the space factor.

[0007] Means for Solving the Problems

[0008] A first aspect of the present invention is a stator having: a stator core; a plurality of teeth provided at intervals along the circumferential direction of the stator core and protruding from the stator core toward the axial center side of the stator core; and coils provided on each of the plurality of teeth, the plurality of coils including a plurality of outer coils provided on the root side of the teeth and a plurality of inner coils provided on the front end side of the teeth, the plurality of outer coils and the plurality of inner coils being alternately arranged along the circumferential direction of the stator core, the coil windings of the plurality of outer coils being in a non-fixed state, and the coil windings of the plurality of inner coils being in a fixed state.

[0009] A second aspect of the present invention is a motor including the above-described stator and a rotor.

[0010] Effects of the Invention

[0011] According to the aspect of the present invention, it is not necessary to provide a gap between the coils along the extending direction of the tooth, and a decrease in the space factor can be suppressed.

[0012] By the description of the following embodiments with reference to the accompanying drawings, the above objects, features, and advantages can be easily understood. Description of the Drawings

[0013] Figure 1 It is a perspective view showing a part of the motor of the embodiment.

[0014] Figure 2 It omits Figure 1 a diagram of the rotor in the motor of

[0015] Figure 3 It is a diagram showing a part of the stator viewed from the direction of the rotation axis of the motor. Detailed Embodiments

[0016] Hereinafter, preferred embodiments will be given, and the present invention will be described in detail with reference to the accompanying drawings.

[0017] [Embodiment]

[0018] Using Figure 1 and Figure 2 , the motor 10 of the embodiment will be described. The motor 10 includes a stator 12 and a rotor 14.

[0019] The stator 12 generates a force for rotating the rotor 14. The stator 12 has a stator core 20, a plurality of teeth 22, and a plurality of coils 24.

[0020] The stator core 20 is formed in a tubular shape. The stator core 20 may also be formed in a tubular shape by joining a plurality of iron core sheets in the circumferential direction.

[0021] The plurality of teeth 22 are provided on the stator core 20 at intervals in the circumferential direction of the stator core 20. The plurality of teeth 22 respectively project from the inner circumferential surface of the tubular stator core 20 toward the axis side of the stator core 20. In addition, the axis of the stator core 20 coincides with the rotation axis Ax of the motor 10.

[0022] The plurality of coils 24 are respectively provided on one tooth 22. That is, the plurality of coils 24 are in a one-to-one relationship with the plurality of teeth 22. The coil winding (coil wire) of the coil 24 may be a round wire with a circular cross-section or a flat wire with a rectangular cross-section.

[0023] The rotor 14 rotates according to the force generated by the stator 12. The rotor 14 includes a rotor core 30 and a rotor shaft 32.

[0024] The rotor core 30 is disposed with a gap from the inner peripheral surface of the tubular stator core 20 within the through-hole of the stator core 20. The rotor shaft 32 extends outward from the rotor core 30 along the axis of the stator core 20. Further, the axis of the rotor shaft 32 coincides with the rotation axis Ax of the motor 10.

[0025] Use Figure 3 The stator 12 will be further described in detail. In the stator 12 of the present embodiment, the plurality of teeth 22 include a plurality of trapezoidal teeth 22X and a plurality of rectangular teeth 22Y.

[0026] The plurality of trapezoidal teeth 22X are respectively teeth 22 whose shape is trapezoidal when viewed in the direction along the axis of the stator core 20. The plurality of rectangular teeth 22Y are respectively teeth 22 whose shape is rectangular when viewed in the direction along the axis of the stator core 20. The plurality of trapezoidal teeth 22X and the plurality of rectangular teeth 22Y are alternately arranged along the circumferential direction of the stator core 20.

[0027] In addition, in the stator 12 of the present embodiment, the plurality of coils 24 include a plurality of outer coils 24X and a plurality of inner coils 24Y.

[0028] The plurality of outer coils 24X are respectively coils 24 provided on the root side of one trapezoidal tooth 22X, and the plurality of inner coils 24Y are respectively coils 24 provided on the front end side of one rectangular tooth 22Y. The plurality of outer coils 24X and the plurality of inner coils 24Y are alternately arranged along the circumferential direction of the stator core 20.

[0029] The coil windings of the plurality of outer coils 24X are in a non-fixed state. The non-fixed state means a state where they are not wound around a bobbin or the like and no welding material used in a self-welding type coil winding is attached. That is, the plurality of outer coils 24X do not have a bobbin and a welding material respectively. The plurality of outer coils 24X are respectively wound in such a way that a coil winding without a welding material forms a cavity, and are inserted through the trapezoidal teeth 22X through the formed cavity, thereby being provided on the root side of the trapezoidal teeth 22X.

[0030] The coil windings of each of the plurality of inner coils 24Y are in a fixed state. The so-called fixed state refers to a state of being wound around a bobbin or a state of being fixed using a welding material. That is, each of the plurality of inner coils 24Y has either a bobbin or a welding material. The method of providing the inner coil 24Y to the rectangular tooth 22Y is not particularly limited. For example, the inner coil 24Y is wound around an insulating bobbin that can be fitted into the rectangular tooth 22Y, and the wound bobbin is fitted into the rectangular tooth 22Y, thereby being provided on the front end side of the rectangular tooth 22Y. Additionally, for example, the inner coil 24Y may be formed to be capable of being fitted to the rectangular tooth 22Y in a state where the self-welding type coil windings wound around each other are fixed with a welding material, and is provided on the front end side of the rectangular tooth 22Y by being fitted to the rectangular tooth 22Y.

[0031] Thus, each of the plurality of outer coils 24X is provided on the root side of the tooth 22 in a state where the coil winding is not fixed, while each of the plurality of inner coils 24Y is provided on the front end side of the tooth 22 in a state where the coil winding is fixed.

[0032] Accordingly, there is no need to provide a gap between the outer coil 24X and the inner coil 24Y along the extending direction of the tooth 22 in the gap between one adjacent tooth 22 and the other tooth 22, and a reduction in the duty factor can be suppressed.

[0033] In addition, since the coil winding of the inner coil 24Y is in a fixed state, even if the coil winding of the outer coil 24X is in a non-fixed state, it is possible to prevent the coil from protruding from or falling off the tooth 22.

[0034] In addition, by the inner coil 24Y with the fixed coil winding, the outer coil 24X with the non-fixed coil winding can be formed. Therefore, the bobbin for winding the outer coil 24X can be saved, and the number of components can be suppressed.

[0035] In addition, when inserting the inner coil 24Y (or the outer coil 24X) into the tooth 22, it will not interfere with the outer coil 24X (or the inner coil 24Y) of the adjacent tooth 22 inserted into the tooth 22 and be difficult to insert. Therefore, it is easy to insert the outer coil 24X and the inner coil 24Y into the tooth 22.

[0036] In the present embodiment, the tooth 22 includes a plurality of trapezoidal teeth 22X and a plurality of rectangular teeth 22Y, and each of the plurality of outer coils 24X is provided on the trapezoidal tooth 22X, and each of the plurality of inner coils 24Y is provided on the rectangular tooth 22Y.

[0037] Thus, compared with the case where the plurality of teeth 22 are each only a rectangular tooth 22Y, the heat dissipation performance of the coil 24 can be improved. In addition, generally, it is difficult to wind a coil winding around a bobbin to form a coil 24 that matches the shape of the trapezoidal tooth 22X. In contrast, in the stator 12 of the present embodiment, as described above, even if the outer coil 24X is not formed to match the shape of the trapezoidal tooth 22X, the outer coil 24X can be formed by the inner coil 24Y. Therefore, a decrease in the duty factor can be suppressed.

[0038] Insulating papers 26 are respectively provided on the plurality of outer coils 24X and inner coils 24Y. The plurality of insulating papers 26 respectively cover the sides of the stator core 20 other than the side of the coil surface on the axis side of the stator core 20 among the four sides of one coil 24 when viewed from the direction along the axis of the stator core 20, and have a substantially "∏" shape.

[0039] In other words, the plurality of insulating papers 26 respectively cover the coil side on the trapezoidal tooth 22X side, the coil side on the rectangular tooth 22Y side, and the coil surface on the stator core 20 side, and do not cover the coil side on the axis side of the stator core 20. That is, the plurality of insulating papers 26 respectively cover the portions of the circumferential side surface of one coil 24 (outer coil 24X or inner coil 24Y) other than the coil surface on the axis side of the stator core 20.

[0040] Thus, compared with the case of covering the entire circumferential side surface of one coil 24, the insulating papers 26 provided in the gap between the trapezoidal tooth 22X and the rectangular tooth 22Y adjacent in the circumferential direction of the stator core 20 do not overlap. That is, the insulating paper 26 for one outer coil 24X disposed in the gap between the adjacent trapezoidal tooth 22X and rectangular tooth 22Y and the insulating paper 26 for one inner coil 24Y disposed in the gap are provided in a non-contact manner. Therefore, compared with the case of covering the entire circumferential side surface of one coil 24, the density of the coil 24 in the gap between the trapezoidal tooth 22X and the rectangular tooth 22Y adjacent in the circumferential direction of the stator core 20 is likely to be higher. In addition, the circumferential side surface of the coil 24 is the surface of the coil portion other than the pair of coil ends on both ends of the coil 24 in the direction along the axis of the stator core 20.

[0041] [Modification Example]

[0042] Among the plurality of teeth 22 in the above-described embodiment, the plurality of trapezoidal teeth 22X may not exist. That is, each of the plurality of teeth 22 may be a rectangular tooth 22Y. Even so, similar to the above-described embodiment, there is no need to provide a gap between the coils along the extending direction of the teeth 22, and a decrease in the duty factor can be suppressed.

[0043] Alternatively, a plurality of outer coils 24X and a plurality of inner coils 24Y may be fixed to the teeth 22 by an impregnating material respectively. Thereby, structural reinforcement can be achieved. In addition, the impregnating material is different from the welding material used for the self-welding type coil winding and contains components different from those of the welding material. Examples of the impregnating material include varnish and the like.

[0044] In addition, as an example of the fixing method for fixing the coil 24 to the tooth 22 using the impregnating material, the following fixing method can be cited: After placing the stator 12 in a tank filled with the impregnating material in a molten state (liquid) and then taking it out, the molten state impregnating material attached to the taken-out stator 12 is dried. By using such a fixing method, an impregnating material (coating film) in a cured state (solid) that fixes the plurality of outer coils 24X and the plurality of inner coils 24Y to the teeth 22 respectively can be formed.

[0045] As another example of the fixing method for fixing the coil 24 to the tooth 22, a method of filling resin into the inside of the stator 12 in a state where the coil 24 is inserted into the tooth 22 and curing it can be cited. Examples of the resin that can be cured after filling include thermosetting epoxy resin.

[0046] [Invention obtained according to the embodiment]

[0047] The invention that can be grasped based on the above-described embodiment and modification examples is described as follows.

[0048] (First invention)

[0049] The first invention is a stator 12 having: a stator core 20; a plurality of teeth 22 that are provided at intervals along the circumferential direction of the stator core 20 and project from the stator core 20 toward the axial center side of the stator core 20; and coils 24 that are provided on each of the plurality of teeth 22. The plurality of coils 24 include a plurality of outer coils 24X provided on the root side of the teeth 22 and a plurality of inner coils 24Y provided on the front end side of the teeth 22, the plurality of outer coils 24X and the plurality of inner coils 24Y are alternately arranged along the circumferential direction of the stator core 20, the coil windings of the plurality of outer coils 24X are in a non-fixed state, and the coil windings of the plurality of inner coils 24Y are in a fixed state.

[0050] Thereby, there is no need to provide a gap between the coils along the extending direction of the teeth 22, and a decrease in the space factor can be suppressed.

[0051] Alternatively, a plurality of outer coils 24X and a plurality of inner coils 24Y may be fixed to the teeth 22 by an impregnating material or resin respectively. Thereby, structural reinforcement can be achieved.

[0052] It is also possible that the multiple teeth 22 include a plurality of trapezoidal teeth 22X whose shape is a trapezoid when viewed from the direction along the axial core of the stator core 20 and a plurality of rectangular teeth 22Y whose shape is a rectangle when viewed from the direction along the axial core of the stator core 20, the plurality of trapezoidal teeth 22X and the plurality of rectangular teeth 22Y are alternately arranged along the circumferential direction of the stator core 20, the plurality of outer coils 24X are respectively arranged on the trapezoidal teeth 22X, and the plurality of inner coils 24Y are respectively arranged on the rectangular teeth 22Y.

[0053] Thus, compared with the case where each of the plurality of teeth 22 is only the rectangular teeth 22Y, it is possible to improve the heat dissipation of the coil 24. In addition, even if the outer coil 24X is not formed to match the shape of the trapezoidal teeth 22X, the outer coil 24X can be formed by the inner coil 24Y. Therefore, it is possible to suppress the reduction of the space factor.

[0054] (Second Invention)

[0055] The second invention is an electric motor 10 including the above-mentioned stator 12 and the rotor 14. In the electric motor 10, since the above-mentioned stator 12 is provided, it is possible to suppress a decrease in the space factor.

Claims

1. A stator having: A stator core; A plurality of teeth provided at intervals along the circumferential direction of the stator core and protruding from the stator core toward the axial center side of the stator core; and Coils provided on each of the plurality of teeth, The stator is characterized in that The plurality of coils include a plurality of outer coils provided on the root side of the teeth and a plurality of inner coils provided on the front end side of the teeth, The plurality of outer coils and the plurality of inner coils are alternately arranged along the circumferential direction of the stator core, The coil windings of the plurality of outer coils are in a non-fixed state, and the coil windings of the plurality of inner coils are in a fixed state, The inner coils are provided on the teeth via a bobbin capable of winding the coil winding or a welding material for fixing the coil winding, The outer coils are provided on the teeth without passing through the bobbin or the welding material.

2. The stator according to claim 1, characterized in that The plurality of outer coils and the plurality of inner coils are respectively fixed to the teeth by an impregnating material or resin.

3. The stator according to claim 1 or 2, characterized in that The plurality of teeth include a plurality of trapezoidal teeth having a trapezoidal shape when viewed in the direction along the axial center of the stator core and a plurality of rectangular teeth having a rectangular shape when viewed in the direction along the axial center of the stator core, The plurality of trapezoidal teeth and the plurality of rectangular teeth are alternately arranged along the circumferential direction of the stator core, The plurality of outer coils are respectively provided on the trapezoidal teeth, and the plurality of inner coils are respectively provided on the rectangular teeth.

4. A motor, characterized in that, Comprising: The stator according to any one of claims 1 to 3; and A rotor.

Images