Stator and motor

Abstract

A stator includes a stator core (21), a winding (22x), and an insulator (23). The stator core (21) has a plurality of pole teeth (21a). The winding wire (22x) is wound in a concentrated manner with respect to each of the pole tooth portions. The insulator (23) is interposed between the stator core and the winding. The insulator has a pole tooth cover (32). The pole tooth covering part is provided with a pole tooth part end face covering part (32a), a side face covering part (32b) and a curved surface corner part (32d). The radius of curvature (R) of the outer curved surface of the curved surface corner portion satisfies the condition B / 4 < R < B.3 / 4 when the pole tooth portion width (B) in the width direction of the pole tooth portion is used, and the curved surface height (H) of the curved surface corner portion satisfies the condition B / 8 < H < B / 2 when the pole tooth portion width (B) is used.

Description

Citation of related applications

[0001] This application is based on Japanese Patent Application No. 2022-151612 filed on September 22, 2022, and the contents thereof are incorporated herein by reference. Technical Field

[0002] The present disclosure relates to a stator and a motor. Background Art

[0003] The stator included in the electric motor has windings wound around the pole teeth of the stator core to form coils. In order to prevent direct contact between the stator core and the windings, the parts of the stator core that can contact the windings are covered with an insulator made of insulating resin. For the purpose of achieving a high occupancy, etc., as the windings installed on the stator core, it is preferable to minimize bulging outward due to winding around the pole teeth. Therefore, with respect to the insulator sandwiched between the stator core and the windings, a structure is added to suppress bulging of the windings to the outside due to winding (for example, refer to Patent Document 1). Prior art literature Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2018-207717 Summary of the invention

[0005] When studying the miniaturization of electric motors, one of the countermeasures is to suppress the axial enlargement of the stator. In order to suppress the axial enlargement of the stator, it is necessary to adopt a structure in which the windings attached to the pole teeth of the stator core do not protrude significantly from the axial end surface of the stator core.

[0006] An object of the present disclosure is to provide a stator and a motor capable of appropriately suppressing both bulging of windings of pole teeth provided on a stator core toward the outside of the winding and protrusion height of the windings from an axial end surface of the stator core.

[0007] A stator according to one embodiment of the present disclosure includes: a stator core having a plurality of pole teeth extending in a radial direction; a winding wire, the winding wire being wound centrally with respect to each of the pole teeth to form a coil for each of the pole teeth; and an insulator, the insulator being interposed between the stator core and the winding wire and being used to prevent direct contact between the winding wire and the stator core, the insulator having a pole tooth covering portion covering a necessary portion of the pole tooth portion, the pole tooth covering portion having: a pole tooth portion end face covering portion, the pole tooth portion end face covering portion covering the axis of the pole tooth portion in the axial direction of the stator core To the end surface portion; the side covering portion, the above-mentioned side covering portion covers the two side portions of the above-mentioned pole tooth portion; and the curved corner portion, the above-mentioned curved corner portion is located between the above-mentioned pole tooth portion end surface covering portion and the above-mentioned side covering portion, and acts as a contact portion for the above-mentioned winding, and the above-mentioned stator is composed of a curvature radius (R) of the outer surface curved surface of the above-mentioned curved corner portion that satisfies the condition "B / 4<R<B·3 / 4" of the pole tooth portion width (B) in the width direction of the above-mentioned pole tooth portion, and the curved surface height (H) of the above-mentioned curved corner portion satisfies the setting of "B / 8<H<B / 2" of the above-mentioned pole tooth portion width (B).

[0008] Another embodiment of the electric motor disclosed herein includes: a stator, wherein the stator includes a stator core, a winding and an insulator, wherein the stator core has a plurality of pole teeth extending in a radial direction, the winding is wound around each of the pole teeth in a concentrated manner to form a coil for each of the pole teeth, the insulator is sandwiched between the stator core and the winding and is used to prevent the winding from directly contacting the stator core; and a rotor, wherein when a rotating magnetic field is generated in the stator based on energization of the stator, the rotor receives a rotating magnetic field generated in the stator 20 and is driven to rotate, the insulator of the stator having a pole tooth covering portion that covers a necessary portion of the pole tooth portion, the pole tooth covering portion having: a pole tooth portion end face The covering part, the end face covering part of the pole tooth part covers the axial end face part of the pole tooth part in the axial direction of the stator core part; the side covering part, the side covering part covers the two side face parts of the pole tooth part; and the curved corner part, the curved corner part is located between the end face covering part of the pole tooth part and the side covering part, and acts as a contact part of the winding, and the motor is composed of the curvature radius (R) of the outer surface curved surface of the curved corner part satisfies the condition "B / 4<R<B·3 / 4" of the pole tooth part width (B) in the width direction of the pole tooth part, and the curved surface height (H) of the curved corner part satisfies the condition "B / 8<H<B / 2" of the pole tooth part width (B).

[0009] According to the above-mentioned stator and motor, an insulator having a function of preventing direct contact between the winding and the stator core is provided between the stator core and the winding. The insulator has a curved corner portion as a contact portion for the winding between the end face covering portion of the pole tooth portion and the side covering portion of the pole tooth covering portion. The curved corner portion is a portion that abuts for setting the winding, and also serves as a fulcrum for bending the winding when the winding is wound. The radius of curvature (R) of the outer surface of such a curved corner portion is set to satisfy the condition "B / 4<R<B·3 / 4" using the width of the pole tooth portion (B), and the height of the curved surface (H) of the curved corner portion satisfies the condition "B / 8<H<B / 2". Thereby, the coil floating amount in the width direction of the pole tooth portion and the height of the coil side end in the axial direction of the stator core can be appropriately suppressed to be small (refer to Figure 5 In other words, in the stator, it is possible to appropriately suppress the bulging of the winding wires of the pole teeth provided in the stator core toward the outside of the winding and the protruding height of the winding wires from the axial end surface of the stator core. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The above objects, other objects, features and advantages of the present disclosure will become more apparent with reference to the accompanying drawings and the following detailed description. Figure 1 It is a structural diagram of a motor having a stator in one embodiment. Figure 2 It is a perspective view showing a pole tooth portion of a stator according to one embodiment. Figure 3 This is a cross-sectional view showing a pole tooth portion of a stator according to an embodiment. Figure 4 It is a cross-sectional view showing an insulator of a pole tooth portion according to one embodiment. Figure 5 This is a phase diagram for examining the winding state of the winding wire in one embodiment. Figure 6 1 is a cross-sectional view showing an insulator of a pole tooth portion in a modified example. Figure 7 2 is a cross-sectional view showing an insulator of a pole tooth portion in another modified example. Figure 8 2 is a cross-sectional view showing an insulator of a pole tooth portion in another modified example. Fig. 9 2 is a cross-sectional view showing an insulator of a pole tooth portion in another modified example. Fig.10 2 is a cross-sectional view showing an insulator of a pole tooth portion in another modified example. DETAILED DESCRIPTION

[0011] Hereinafter, one embodiment of the stator and the motor will be described. (Structure of electric motor M) like Figure 1 As shown, the motor M of the present embodiment includes: a rotor 10 supported to be rotatable; and a stator 20 configured in a substantially annular shape and arranged radially outside the rotor 10. When a rotating magnetic field is generated in the stator 20 based on energization of the stator 20, the rotor 10 receives the rotating magnetic field generated in the stator 20 and is rotationally driven.

[0012] (Structure of rotor 10) The rotor 10 of this embodiment includes a rotor body 11 and a rotating shaft 12. The detailed structure of the rotor body 11 is omitted in the figure, but it is configured as a surface magnet type in which a permanent magnet is fixed to the outer peripheral surface of the rotor core, or an embedded magnet type embedded in the radial inner part of the rotor core. The rotor 10 of this embodiment has a magnet pole portion composed of permanent magnets, for example, 10 poles or 14 poles.

[0013] (Structure of stator 20) The stator 20 of the present embodiment includes a stator core 21 made of magnetic metal, a plurality of coils 22 attached to the stator core 21 , and an insulator 23 made of insulating resin interposed between the coils 22 and the stator core 21 .

[0014] The stator core 21 is generally annular in shape. The stator core 21 includes: a plurality of pole teeth 21a, the front ends of the plurality of pole teeth 21a facing radially inward; and an annular portion 21b, the annular portion 21b being shaped so as to connect the base ends of the pole teeth 21a located radially outward to each other. In the present embodiment, each pole tooth 21a includes 12. In the present embodiment, each pole tooth 21a is formed into a generally rectangular shape of the same width extending from the base end to the front end. In the present embodiment, the core components 21x of the annular portion 21b of the same shape divided by each pole tooth 21a are connected to each other in an annular shape. The annular portion 21b functions as a back yoke. In addition, an integral structure in which the annular portion 21b is not divided in the circumferential direction may also be used.

[0015] The coils 22 are respectively mounted on the pole teeth 21a of the stator core 21. Each coil 22 is wound by concentrated winding of the winding 22x with respect to each pole tooth 21a. As the winding 22x of this embodiment, for example, an enamel wire in which an insulating material is integrally covered on the outer surface of a single wire of a conductive material is used. There are 12 coils 22 mounted on each pole tooth 21a, and the stator 20 of this embodiment has, for example, 12-pole coil magnetic poles.

[0016] like Figure 2 and Figure 3As shown, the insulator 23 is provided so as to be sandwiched between the winding wire 22x constituting the coil 22 and the stator core 21. In order to prevent the winding wire 22x from directly contacting the stator core 21, the insulator 23 is provided so as to cover the part of the stator core 21 that can contact the winding wire 22x. The shape of the winding part of the insulator 23 of the winding wire 22x and the winding method of the winding wire 22x wound around the part will be described in detail later.

[0017] In addition, the insulator 23 of the present embodiment is divided for each core component 21x corresponding to the divided core components 21x of the stator core 21. In addition, regarding the insulator 23 of the present embodiment, the insulator 23 of the same shape is respectively installed from both axial sides of the stator core 21. In addition, the insulator 23 may also use an integral structure that is not divided in the circumferential direction. In addition, the insulator 23 may also be integrally formed with the stator core 21.

[0018] Here, the axial direction of the stator core 21 is the common motor axial direction of the stator 20 and the rotor 10. The axial direction of the stator core 21 as the motor axial direction is Figure 2 and Figure 3 In the figure, the L1 arrow is used. In addition, the radial direction of the stator core 21 is the extension direction of the pole tooth portion 21a, and is also the winding axis direction of the winding 22x. The extension direction of the pole tooth portion 21a, which is the winding axis direction of the winding 22x, is Figure 2 and Figure 3 Indicated by L2 arrow.

[0019] (Detailed Structure of Insulator 23) The insulator 23 of the present embodiment is divided for each core member 21x of the divided stator core 21. In addition, the insulator 23 of the present embodiment is attached to both sides of the stator core 21 in the axial direction.

[0020] Each insulator 23 has an annular covering portion 31 that covers a necessary portion of the annular portion 21b of the stator core 21 and a pole tooth covering portion 32 that covers a necessary portion of the pole tooth portion 21a. The annular covering portion 31 and the pole tooth covering portion 32 are integrally formed.

[0021] The annular covering portion 31 includes: an annular portion end surface covering portion 31a covering substantially the entire axial end surface of the annular portion 21b of the stator core 21; and an inner side covering portion 31b covering substantially the axial half of the radial inner side surface of the annular portion 21b. The annular portion end surface covering portion 31a and the inner side covering portion 31b are integrally formed. The annular portion end surface covering portion 31a and the inner side covering portion 31b are orthogonal to each other. The inner side covering portion 31b extends in the axial direction of the stator core 21 relative to the annular portion end surface covering portion 31a disposed on the axial end surface of the stator core 21. In addition, a pair of inner side covering portions 31b are provided relative to the annular portion end surface covering portion 31a. The paired inner side covering portions 31b cover a pair of radial inner side surfaces of the annular portion 21b located on both sides of the pole tooth portion 21a of the stator core 21, respectively. The annular portion end surface covering part 31a is provided with a restricting protrusion 31c that protrudes in the axial direction of the stator core 21. The restricting protrusion 31c restricts radially outward movement of the winding 22x in the radial direction of the stator core 21.

[0022] The pole tooth covering portion 32 includes: a pole tooth end face covering portion 32a that covers substantially the entire axial end face of the pole tooth portion 21a of the stator core 21; and a side face covering portion 32b that covers substantially half of the axial direction of both side faces of the pole tooth portion 21a. The pole tooth end face covering portion 32a and the side face covering portion 32b are integrally formed. The pole tooth end face covering portion 32a and the side face covering portion 32b are orthogonal to each other. The side face covering portion 32b extends in the axial direction of the stator core 21 relative to the pole tooth end face covering portion 32a disposed on the axial end face of the stator core 21. In addition, a pair of side face covering portions 32b are provided relative to the pole tooth end face covering portion 32a. The paired side face covering portions 32b respectively cover a pair of side faces located on both sides of the pole tooth portion 21a of the stator core 21. The pole tooth end surface covering portion 32a and the side surface covering portion 32b are provided with a restricting flange portion 32c that continuously protrudes in the axial direction and the circumferential direction of the stator core 21. The restricting flange portion 32c restricts radial inward movement of the winding 22x in the radial direction of the stator core 21.

[0023] Here, when a pair of insulators 23 are installed from both sides of the axial direction of the stator core 21, the annular portion end surface covering portion 31a and the inner side covering portion 31b of the annular covering portion 31 cover the entire necessary portion of the annular portion 21b of the stator core 21. In addition, the pole tooth portion end surface covering portion 32a and the side surface covering portion 32b of the pole tooth covering portion 32 cover the entire necessary portion of the pole tooth portion 21a. The winding 22x is wound around the pole tooth portion end surface covering portion 32a and the side surface covering portion 32b covering the periphery of the pole tooth portion 21a with respect to the pole tooth portion 21a located between the limiting protrusion 31c and the limiting flange portion 32c in the radial direction of the stator core 21. The outer surface of the pole tooth portion end surface covering portion 32a and the outer surface of the side surface covering portion 32b are respectively flat surfaces that are orthogonal to each other.

[0024] When the winding wire 22x is wound, Figure 3 As shown, when viewed along the extension direction of the pole tooth portion 21a as the winding axis, the winding wire 22x abuts against the corner between the pole tooth portion end surface covering portion 32a and the side surface covering portion 32b. Figure 3 , the winding 22x is briefly depicted. There are four corners between the pole tooth end face covering portion 32a and the side covering portion 32b in the winding of the winding 22x. In the present embodiment, the four corners between the pole tooth end face covering portion 32a and the side covering portion 32b are configured as curved corners 32d. The curved corners 32d are formed into a curved shape convex to the outside. In addition, the curved corners 32d are continuously formed into the same shape in the extension direction of the pole tooth portion 21a, that is, in the winding axial direction of the winding 22x. The curved corners 32d are the abutment portions of the wound winding 22x, and are also the portions that act as fulcrums for bending the winding 22x during winding. The insulator 23 is configured to have a line-symmetric shape in the width direction of the pole tooth 21 a orthogonal to the axial direction and radial direction of the stator core 21 , including the pole tooth end surface covering portion 32 a , the side surface covering portion 32 b , and the curved corner portion 32 d therebetween.

[0025] like Figure 3 and Figure 4 As shown, the curved corner portion 32 d of the insulator 23 of the present embodiment is set based on the pole tooth portion width B including the pair of side surface covering portions 32 b of the insulator 23 .

[0026] The boundary position between the side cover portion 32b and the curved corner portion 32d is defined as the base point Pa, and the substantial axial length of the curved corner portion 32d from the base point Pa to the boundary position between the curved corner portion 32d and the pole tooth portion end surface cover portion 32a is defined as the curved surface height H in this embodiment. In this embodiment, the boundary position between the side cover portion 32b and the curved corner portion 32d, which is the base point Pa of the curved surface height H, is set to a position slightly offset axially outward from the axial end surface of the stator core 21. In addition, the boundary position between the side cover portion 32b and the curved corner portion 32d, which is the base point Pa of the curved surface height H, may be set to the same position as the axial end surface of the stator core 21, or may be set to a position slightly offset axially inward from the axial end surface of the stator core 21. Furthermore, in this embodiment, the curved surface height H of the curved corner portion 32d is set to 1 / 4 of the pole tooth portion width B, that is, "H=B / 4".

[0027] The curvature radius R of the outer surface of the curved corner portion 32d is the radius of the curvature circle having its center on the reference line La in the width direction of the pole tooth portion 21a passing through the base point Pa. In the present embodiment, the curvature radius R of the outer surface of the curved corner portion 32d is set to 1 / 2 of the pole tooth portion width B, that is, "R=B / 2". By the way, in the present embodiment in which the curvature radius R of the outer surface of the curved corner portion 32d is set to 1 / 2 of the pole tooth portion width B, the outer surface of the curved corner portions 32d on both sides of the pole tooth portion 21a is on the same circumference. The curved corner portion 32d of the insulator 23 is a portion that contacts the winding 22x in order to set the winding 22x, and is also a portion that acts as a fulcrum for the winding 22x to bend when the winding 22x is wound.

[0028] (Regarding Winding of the Winding Wire 22x Around the Pole Tooth Portion 21a Through the Insulator 23) like Figures 1 to 3 As shown, the winding 22x is wound around each pole tooth portion 21a of the stator core 21 by concentrated winding, so that the coil 22 is respectively formed in each pole tooth portion 21a. Before the winding 22x is wound around each pole tooth portion 21a, the insulator 23 is installed in the stator core 21. The insulator 23 covers the necessary parts of each pole tooth portion 21a and the like of the stator core 21. The winding 22x is wound on the insulator 23 installed so as to cover each pole tooth portion 21a and the like. The winding 22x is arranged to abut against the curved corner portion 32d of the insulator 23.

[0029] During the winding process of the winding 22x, the winding 22x abuts against the outer surface of the curved corner 32d, and is wound while bending along the outer surface of the curved corner 32d. In one continuous winding cycle, the winding 22x is wound using the curved corners 32d at four locations as fulcrums for bending. On the other hand, the winding 22x abuts against each curved corner 32d, but the portion of the winding 22x between the adjacent curved corners 32d bulges toward the outside of the winding. Therefore, the portion of the winding 22x between the adjacent curved corners 32d does not abut against the side covering portion 32b and the pole tooth end face covering portion 32a of the pole tooth covering portion 32, respectively. That is, the winding 22x floats from the outer surface of the side covering portion 32b and the outer surface of the pole tooth end face covering portion 32a, respectively. The winding 22x floats from the adjacent curved corners 32d in a manner that is roughly curved. The degree of floating of the winding 22x increases as the distance from the curved surface corner portion 32d and the vicinity of the middle portion of the adjacent curved surface corner portion 32d increases.

[0030] Here, the relationship between the curved surface height H and the curvature radius R of the curved surface corner portion 32d of the insulator 23 and the floating degree of the winding 22x set on the pole tooth portion 21a by winding is described using the winding floating amount Lx and the coil side end height Ly. The winding floating amount Lx is the distance of the portion that floats the most with the outer surface of the side cover portion 32b of the pole tooth cover portion 32 as the base point in the width direction of the pole tooth portion 21a. The coil side end height Ly is the distance of the portion that floats the most from the outer surface of the pole tooth portion end surface cover portion 32a with the middle part of the pole tooth portion 21a as the base point in the axial direction of the stator core portion 21. The winding floating amount Lx and the coil side end height Ly include the floating degree of the winding 22x floating from the pole tooth portion 21a. Regarding the winding floating amount Lx and the coil side end height Ly, the transition when the curved surface height H is changed relative to the pole tooth portion width B is observed. Regarding the curvature radius R, the change when "R=B / 2" is fixed is observed.

[0031] like Figure 5 As shown, when the surface height H of the curved corner 32d gradually increases, the coil side end height Ly also gradually increases compared to this. The pure increase in the height of the curved surface height H also affects the increase in the coil side end height Ly. However, in the present embodiment, since the radius of curvature R of the curved corner 32d is set to the relationship of "R=B / 2", the shape of the flat surface of the pole tooth end surface covering portion 32a is left before the curved surface height H becomes "H=B / 2". That is, since the space on the flat surface of the pole tooth end surface covering portion 32a can be used for the configuration of the winding 22x, the winding 22x can be made into a curved shape that is closer to a flat surface than the extension line of the curve along the outer curved surface of the curved corner 32d (refer to Figure 3 and Figure 4). If the curved surface height H is set to be less than "H=B / 2", the coil side end height Ly can be effectively suppressed. In the present embodiment where the curved surface height H is set to "H=B / 4", the coil side end height Ly can be more effectively suppressed.

[0032] On the other hand, regarding the relationship between the curved surface height H of the curved surface corner 32d and the winding floating amount Lx, the winding floating amount Lx can be suppressed to the minimum when the curved surface height H is set to "H = B / 4" in the present embodiment. If the curved surface height H is less than "H = B / 4", the winding floating amount Lx will increase. The degree of increase in the winding floating amount Lx is also relatively large. If the curved surface height H is greater than "H = B / 4", although the winding floating amount Lx increases slightly to "H = B·5 / 16", it becomes almost a constant value thereafter.

[0033] (Function of this embodiment) The operation of this embodiment will be described. As described above, considering the winding floating amount Lx and the coil side end height Ly relative to the change of the curved surface height H of the curved surface corner 32d, the inventors believe that it is most appropriate to set the curved surface height H to "H = B / 4". Therefore, in the present embodiment, by setting the curved surface height H of the curved surface corner 32d to "H = B / 4", the winding floating amount Lx and the coil side end height Ly can be appropriately suppressed to be small. That is, in the stator 20, the bulging of the winding 22x provided on the pole tooth portion 21a of the stator core 21 to the outside of the winding and the protruding height of the winding 22x from the axial end surface of the stator core 21 can be appropriately suppressed. While achieving a high occupancy of the winding 22x of the stator 20, the stator 20 and even the motor M can be miniaturized.

[0034] In addition, in the present embodiment, although the curved surface height H is set to "H = B / 4", it is considered that the winding floating amount Lx and the coil side end height Ly can be sufficiently suppressed even in the range A1 of "B·3 / 16<H<B·5 / 16". In addition, it is considered that the winding floating amount Lx and the coil side end height Ly can be suppressed even in the range A2 of "B / 8<H<B / 2". Therefore, the curved surface height H can also be set within the range A1 or the range A2 to configure the stator 20.

[0035] (Effects of this embodiment) The effects of this embodiment will be described. (1) The insulator 23 of the stator 20 in this embodiment has a curved surface corner portion 32d as the abutting portion of the winding 22x between the pole tooth portion end surface covering portion 32a and the side surface covering portion 32b of the pole tooth covering portion 32. The curved surface corner portion 32d is the portion that abuts for arranging the winding 22x, and also serves as the fulcrum for the winding 22x to bend when the winding 22x is wound. The radius of curvature R of the outer surface of such a curved surface corner portion 32d is set to satisfy the condition "B / 4 < R < B·3 / 4" using the width B of the pole tooth portion, and the surface height H of the curved surface corner portion 32d satisfies the condition "B / 8 < H < B / 2". In this embodiment, the radius of curvature R considered to be the most suitable in each condition is set to "R = B / 2", and the surface height H is set to "H = B / 4". Thereby, the floating amount Lx of the winding in the width direction of the pole tooth portion 21a and the height Ly of the coil side end portion in the axial direction of the stator core 21 can be appropriately suppressed to be small (refer to Figure 5 ). In other words, in the stator 20, the bulging of the winding 22x provided on the pole tooth portion 21a of the stator core 21 toward the outside of winding and the protruding height of the winding 22x protruding from the axial end surface of the stator core 21 can be appropriately suppressed. This can achieve miniaturization of the stator 20 and even the motor M while realizing a high space factor of the winding 22x of the stator 20.

[0036] (2) In this embodiment, since the radius of curvature R considered to be the most suitable in each of the above conditions is set to "R = B / 2" and the surface height H is set to "H = B / 4", a higher effect can be expected.

[0037] (Variant example) This embodiment can be changed and implemented as follows. This embodiment and the following variant examples can be combined and implemented with each other within a technically non - contradictory range.

[0038] · Regarding the radius of curvature R of the outer surface of the curved surface corner portion 32d, the radius of curvature R can also be set other than "R = B / 2". In Figure 6 an example shown, the radius of curvature R is set to "R > B / 2". The radius of curvature R is preferably appropriately changed within the range of "B·3 / 8 < R < B·5 / 8" of the condition using the width B of the pole tooth portion, and can also be appropriately changed within the condition range of "B / 4 < R < B·3 / 4".

[0039] · The shape of the insulator 23 can also be appropriately changed. For example, the pole tooth portion end surface covering portion 32a of the pole tooth covering portion 32 is set to a flat surface, but it can also be appropriately changed. As Figure 7As shown in the example, a triangular recess 32e may be provided at the flat surface of the pole tooth end surface cover portion 32a. The recess 32e is formed in a concave shape over the entire width direction of the pole tooth 21a and is formed in a concave shape that is most concave in the width direction center of the pole tooth 21a.

[0040] In addition, if Figure 8 As shown in the example, a concave arc-shaped concave portion 32f may be provided at the flat surface of the pole tooth end surface covering portion 32a. The concave portion 32f is also formed in a concave shape in the entire width direction of the pole tooth portion 21a, and is formed in a concave shape that is most concave in the width direction center of the pole tooth portion 21a.

[0041] In addition, if Fig. 9 As shown in the example, a rectangular recess 32g may be provided at a portion of the flat surface of the pole tooth portion end surface covering portion 32a. That is, the recess 32g is formed into a concave shape smaller than the width of the flat surface of the pole tooth portion end surface covering portion 32a. In addition, the recess 32g is located in the center of the width direction of the pole tooth portion 21a. In addition, the recess 32g is formed into a concave shape with a depth smaller than the thickness of the pole tooth portion end surface covering portion 32a, that is, the curved surface height H of the curved surface corner portion 32d.

[0042] The outer surface curved surface of the curved corner portion 32d is composed of the same curved surface, but it can also be composed of two or more composite curved surfaces by providing other curved surfaces continuously with the main outer surface curved surface composed of the setting of the curvature radius R. Fig.10 As shown in the example, the outer surface curved surface having a curvature radius r which is continuous with the main outer surface curved surface formed by setting the curvature radius R and smaller than the main outer surface curved surface may be connected to the pole tooth portion end surface covering portion 32a. In this way, the boundary portion between the curved surface corner portion 32d and the pole tooth portion end surface covering portion 32a becomes a more smoothly continuous curved surface shape.

[0043] In cases other than the above, the structure of the stator 20 may be appropriately changed. For example, although the insulator 23 is attached to the stator core 21 from both axial sides, the insulator may be attached from one axial side. The insulator may be integrally molded with the stator core.

[0044] In addition, although a split stator core 21 is used, a one-piece stator core that is not split in the circumferential direction may be used. Although a stator core 21 with the tip of the pole teeth 21a facing radially inward is used, a stator core with the tip of the pole teeth facing radially outward may be used. The number of pole teeth 21a, that is, the number of coil poles, may be appropriately changed.

[0045] Although the present disclosure is described based on the embodiments, it should be understood that the present disclosure is not limited to the above embodiments and structures. The present disclosure also includes various modifications and modifications within the scope of equivalents. In addition, various combinations and methods, and other combinations and methods including only one element, above or below them, also belong to the scope and concept of the present disclosure.

[0046] (Note) The technical ideas that can be grasped from the above-mentioned embodiments and modifications are described. [1] A stator, the stator (20) comprising: A stator core (21), the stator core having a plurality of pole teeth (21a) extending in the radial direction; a winding (22x) which is wound centrally with respect to each of the pole teeth to form a coil (22) for each of the pole teeth; and an insulator (23), the insulator being interposed between the stator core and the winding and being used to prevent the winding from directly contacting the stator core, The insulator has a pole tooth covering portion (32) covering a necessary portion of the pole tooth portion, the pole tooth covering portion comprising: a pole tooth end face covering portion (32a), the pole tooth end face covering portion covering an axial end face portion of the pole tooth portion in the axial direction of the stator core; a side face covering portion (32b), the side face covering portion covering both side faces of the pole tooth portion; and a curved surface corner portion (32d), the curved surface corner portion being located between the pole tooth end face covering portion and the side face covering portion and functioning as a contact portion for the winding. The above stator is composed of the following settings: The curvature radius (R) of the outer surface curved surface of the curved corner portion satisfies the condition "B / 4<R<B·3 / 4" using the width (B) of the polar tooth portion in the width direction of the polar tooth portion. Furthermore, the curved surface height (H) of the curved surface corner portion satisfies the condition “B / 8<H<B / 2” using the pole tooth portion width (B). [2] The stator as described in [1] above is configured such that the curved surface height (H) of the curved surface corner portion of the insulator satisfies the condition "B·3 / 16<H<B·5 / 16" using the pole tooth width (B). [3] The stator as described in the above [1] is configured such that the curved surface height (H) of the curved surface corner portion of the insulator satisfies the condition "H=B / 4" using the pole tooth width (B). [4] The stator as described in any one of [1] to [3] above, wherein the curvature radius (R) of the outer surface curved surface of the curved corner portion of the insulator is set to satisfy the condition "R=B / 2" using the pole tooth width (B). [5] A stator as described in any one of items [1] to [4] above, wherein the outer surface curved surface which is continuous with the main outer surface curved surface formed by the above-mentioned setting of the curvature radius (R) of the outer surface curved surface of the above-mentioned curved surface corner portion in the above-mentioned insulator and whose curvature radius (r) is smaller than that of the above-mentioned main outer surface curved surface is connected to the above-mentioned pole tooth portion end face covering portion. [6] An electric motor, the electric motor (M) comprising: A stator (20), the stator comprising a stator core (21), a winding (22x), and an insulator (23), the stator core having a plurality of pole teeth (21a) extending in a radial direction, the winding being wound centrally around each of the pole teeth to form a coil (22) for each of the pole teeth, the insulator (23) being interposed between the stator core and the winding and used to prevent the winding from directly contacting the stator core; and a rotor (10) which receives the rotating magnetic field generated in the stator and is driven to rotate when a rotating magnetic field is generated in the stator due to energization of the stator. The insulator of the stator has a pole tooth covering portion (32) covering a necessary portion of the pole tooth portion, the pole tooth covering portion having: a pole tooth end face covering portion (32a), the pole tooth end face covering portion covering an axial end face portion of the pole tooth portion in the axial direction of the stator core; a side face covering portion (32b), the side face covering portion covering two side faces of the pole tooth portion; and a curved corner portion (32d), the curved corner portion being located between the pole tooth end face covering portion and the side face covering portion and functioning as a contact portion for the winding. The above motor is configured as follows: The curvature radius (R) of the outer surface curved surface of the curved corner portion satisfies the condition "B / 4<R<B·3 / 4" using the width (B) of the polar tooth portion in the width direction of the polar tooth portion. The curved surface height (H) of the curved surface corner portion satisfies the condition "B / 8" using the polar tooth width (B).

Claims

1. A stator, the stator (20) comprising: A stator core (21), the stator core having a plurality of pole teeth (21a) extending in a radial direction; a winding (22x) which is wound centrally with respect to each of the pole teeth to form a coil (22) for each of the pole teeth; as well as an insulator (20) which is interposed between the stator core and the winding and is used to prevent the winding from directly contacting the stator core, The insulator has a pole tooth covering portion (32) covering a necessary portion of the pole tooth portion, the pole tooth covering portion having: a pole tooth end face covering portion (32a), the pole tooth end face covering portion covering an axial end face portion of the pole tooth portion in the axial direction of the stator core portion; a side face covering portion (32b), the side face covering portion covering two side faces of the pole tooth portion; and a curved surface corner portion (32d), the curved surface corner portion being located between the pole tooth end face covering portion and the side face covering portion and functioning as a contact portion for the winding. The stator is configured as follows: The curvature radius (R) of the outer surface curved surface of the curved corner portion satisfies the condition "B / 4<R<B·3 / 4" using the width (B) of the polar tooth portion in the width direction of the polar tooth portion, The curved surface height (H) of the curved surface corner portion satisfies the condition "B / 8<H<B / 2" using the pole tooth portion width (B).

2. The stator according to claim 1, characterized in that The stator is set so that the curved surface height (H) of the curved surface corner portion in the insulator satisfies the condition "B·3 / 16<H<B·5 / 16" using the pole tooth portion width (B).

3. The stator according to claim 1, characterized in that: The stator is set so that the curved surface height (H) of the curved surface corner portion in the insulator satisfies the condition "H=B / 4" using the pole tooth portion width (B).

4. The stator according to any one of claims 1 to 3, characterized in that: The stator is set so that the curvature radius (R) of the outer surface curved surface of the curved corner portion in the insulator satisfies the condition "R=B / 2" using the pole tooth portion width (B).

5. The stator according to any one of claims 1 to 4, characterized in that: The curvature radius (R) of the outer surface curved surface of the curved surface corner portion of the insulator is connected to the pole tooth portion end surface covering portion through an outer surface curved surface that is continuous with the main outer surface curved surface configured by the setting and has a smaller curvature radius (r) than the main outer surface curved surface.

6. An electric motor, the electric motor (M) comprising: A stator (20), the stator comprising a stator core (21), a winding (22x), and an insulator (23), the stator core having a plurality of pole teeth (21a) extending in a radial direction, the winding being wound centrally with respect to each of the pole teeth to form a coil (22) for each of the pole teeth, the insulator being interposed between the stator core and the winding and used to prevent the winding from directly contacting the stator core; as well as a rotor (10) which receives the rotating magnetic field generated in the stator and is driven to rotate when a rotating magnetic field is generated in the stator due to energization of the stator. The insulator of the stator has a pole tooth covering portion (32) covering a necessary portion of the pole tooth portion, the pole tooth covering portion having: a pole tooth end face covering portion (32a), the pole tooth end face covering portion covering an axial end face portion of the pole tooth portion in the axial direction of the stator core; a side face covering portion (32b), the side face covering portion covering both side faces of the pole tooth portion; and a curved surface corner portion (32d), the curved surface corner portion being located between the pole tooth end face covering portion and the side face covering portion and functioning as a contact portion for the winding. The motor is configured as follows: The curvature radius (R) of the outer surface curved surface of the curved corner portion satisfies the condition "B / 4<R<B·3 / 4" using the width (B) of the polar tooth portion in the width direction of the polar tooth portion, The curved surface height (H) of the curved surface corner portion satisfies the condition "B / 8<H<B / 2" using the pole tooth portion width (B).

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