Stator

Abstract

A stator is provided with a stator core, an insulator, a coil, and a temperature detection unit. The stator core has an annular core back and teeth. The temperature detection unit detects the temperature of the coil. The insulator has a core back cover portion and a tooth cover portion. The core back cover part covers one axial end surface of the core back. The tooth cover part covers one axial end surface of the teeth. The insulator has a groove portion. The groove portion is recessed in the axial direction from one end surface of the insulator in the axial direction, and extends in the radial direction across the core back cover portion and the tooth cover portion. The groove portion opens one end portion in the radial direction and accommodates the temperature detection portion therein. The shortest distance in the axial direction of the coil from one end in the axial direction of the inner wall of the groove portion formed in the tooth cover portion is shorter than the maximum depth in the axial direction of the groove portion formed in the tooth cover portion.

Description

Technical Field

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

[0002] The existing stator includes a stator core, an insulator, a coil, and a temperature detection unit. The stator core has an annular core back and teeth. The core back surrounds the central axis in the circumferential direction. The teeth extend radially from the core back and are arranged in plurality in the circumferential direction. The insulator covers the core back and the teeth. The coil is formed by a conductive wire, which is wound around the teeth through the insulator. The temperature detection unit is arranged axially outside the coil and detects the temperature of the coil (for example, refer to patent document 1).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2015-226447 Summary of the invention

[0006] Problems to be solved by the invention

[0007] However, in the conventional stator, the number of parts may increase and the manufacturing cost may rise in order to fix the temperature detection part. In addition, the temperature detection part is arranged separately from the coil, and the temperature detection accuracy may decrease.

[0008] An object of the present invention is to provide a stator capable of improving the temperature detection accuracy of a temperature detection portion while reducing manufacturing costs.

[0009] Solutions to Solve Problems

[0010] An exemplary stator of the present invention comprises a stator core, an insulator, a coil and a temperature detection unit. The stator core has an annular core back and teeth. The core back surrounds the central axis in the circumferential direction. The teeth extend radially from the core back and are arranged in a plurality in the circumferential direction. The insulator covers the core back and the teeth. The coil is formed by a conductive wire, which is wound around the teeth through the insulator. The temperature detection unit detects the temperature of the coil. The insulator has a core back cover portion and a tooth cover portion. The core back cover portion covers the end face of the core back on one axial side. The tooth cover portion covers the end face of the tooth on one axial side. The insulator has a groove portion. The groove portion is axially recessed from the end face of the insulator on one axial side and extends radially across the core back cover portion and the tooth cover portion. The groove portion opens the end on one radial side and accommodates the temperature detection unit inside. The shortest distance from the end on one axial side of the inner wall of the groove portion formed in the tooth cover portion to the axial direction of the coil is shorter than the maximum axial depth of the groove portion formed in the tooth cover portion.

[0011] Effects of the Invention

[0012] According to the exemplary present invention, it is possible to provide a stator capable of improving the temperature detection accuracy of a temperature detection unit while reducing manufacturing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a longitudinal sectional view schematically showing a motor including a stator according to an embodiment of the present invention.

[0014] Figure 2 It is a perspective view of a stator according to an embodiment of the present invention.

[0015] Figure 3 It is an exploded perspective view of a stator according to an embodiment of the present invention.

[0016] Figure 4 This is a perspective view showing an enlarged portion of a stator according to an embodiment of the present invention.

[0017] Figure 5 This is a plan view showing a part of a stator in an enlarged manner according to an embodiment of the present invention.

[0018] Figure 6 This is a longitudinal sectional perspective view showing a part of a stator in an enlarged manner according to an embodiment of the present invention.

[0019] Figure 7 This is a longitudinal sectional view showing a part of a stator in an enlarged manner according to an embodiment of the present invention.

[0020] Figure 8 This is an exploded perspective view showing a part of a stator in an enlarged manner according to an embodiment of the present invention.

[0021] In the figure:

[0022] 1—motor, 10—rotor, 20—stator, 21—housing, 21a—bottom plate, 21b—top plate, 22—stator core, 23—coil, 23a—conducting wire, 24—insulator, 25—temperature detection part, 25a—connecting wire, 27a—lower bearing, 27b—upper bearing, 33—tooth, 100—shaft, 110—rotor core, 111—shaft hole, 112—magnet hole, 120—magnet, 221—core back, 222—tooth, 222a—base, 222b—umbrella-shaped part, 223—slot, 241, 242—upper insulator, 243—lower insulator, 241 1—upper core back cover portion (core back cover portion), 2412—upper tooth cover portion (tooth cover portion), 2413—upper protrusion, 2413a, 2433a—cutout portion, 2414—side cover portion, 2415—groove portion, 2415a—inner wall, 2431—lower core back cover portion, 2432—lower tooth cover portion, 2433—lower protrusion, C—center axis, D1, D3—shortest distance, D2—maximum depth, L1—length, L2—length, Y1—one radial side (radial outer side), Y2—the other radial side (radial inner side), Z1—one axial side (upper side), Z2—the other axial side (lower side). DETAILED DESCRIPTION

[0023] Hereinafter, an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification, the rotating shaft of the motor 1 is referred to as the "center axis", and the direction parallel to the center axis C is referred to as the "axial direction". In addition, the direction orthogonal to the center axis C of the motor 1 is referred to as the "radial direction", and the direction along the arc centered on the center axis C of the motor 1 is referred to as the "circumferential direction". In addition, in this application, the axial direction is referred to as the up-down direction, and the temperature detection part 25 is referred to as the top relative to the stator core 22, and the shape and positional relationship of each part are described. In addition, the up-down direction is only a name used for explanation, and does not limit the actual positional relationship and direction.

[0024] (1. Motor structure)

[0025] A motor 1 according to an exemplary embodiment of the present invention will be described. Figure 1 It is a longitudinal sectional view schematically showing the motor 1 according to the embodiment of the present invention. Figure 2 is a three-dimensional diagram of the stator 20, Figure 3 2 is an exploded perspective view of the stator 20. Figure 1 The insulator 24 and the housing 21 are not shown. Figure 3 The coil 23 and the housing 21 are not shown.

[0026] The motor 1 includes a rotor 10 and a stator 20. The rotor 10 includes a shaft 100, a rotor core 110, and a plurality of magnets 120. The shaft 100 is a columnar metal component extending along a central axis C extending vertically. The rotor core 110 is arranged radially outside the shaft 100 and extends axially. The rotor core 110 is formed into a cylindrical shape by stacking annular electromagnetic steel sheets in the axial direction.

[0027] The rotor core 110 has a shaft hole 111 extending in the axial direction and a magnet hole 112. The shaft 100 is press-fitted into the shaft hole 111 and fixed to the rotor core 110.

[0028] Each magnet 120 is inserted into the magnet hole 112 and fixed to the rotor core 110. The magnet 120 may be fixed to the outer peripheral surface of the rotor core 110 by, for example, an adhesive. The plurality of magnets 120 are arranged in the circumferential direction so that N poles and S poles are alternately arranged.

[0029] The stator 20 includes a housing 21, a stator core 22, a coil 23, an insulator 24, and a temperature detection unit 25. The housing 21 is formed in a cylindrical shape and accommodates the stator core 22. Specifically, the housing 21 covers the core back 221 described later from the radially outer side. The housing 21 has a bottom plate portion 21a and a top plate portion 21b. The bottom plate portion 21a is arranged on the lower side (the other axial direction Z2) of the stator core 22 and holds the lower bearing 27a. The top plate portion 21b is arranged on the upper side (the axial direction Z1) of the stator core 22 and holds the upper bearing 27b.

[0030] The lower bearing 27 a and the upper bearing 27 b support a shaft 100 to be described later so as to be rotatable relative to the housing 21 .

[0031] The stator core 22 is formed by stacking a plurality of annular electromagnetic steel sheets in the axial direction. The stator core 22 includes a core back 221 and teeth 222 (see Figure 3 The core back 221 is annular, arranged radially outside the rotor 10, and circumferentially surrounds the central axis C. The teeth 222 protrude radially inward from the core back 221, and a plurality of teeth 222 are arranged circumferentially.

[0032] The plurality of teeth 222 are arranged at equal intervals in the circumferential direction around the central axis C. In the present embodiment, twelve teeth 222 are arranged.

[0033] The tooth 222 has a base portion 222a and an umbrella-shaped portion 222b (see Figure 3 ). The base 222a extends radially inward from the core back 221. The umbrella-shaped portion 222b protrudes from the radial inner end of the base 222a to both sides in the circumferential direction. The circumferential length of the umbrella-shaped portion 222b is longer than the circumferential length of the radial inner end of the base 222a.

[0034] The radially inner surface of the umbrella-shaped portion 222b is a curved surface along the circumferential direction. The radially inner surface of the umbrella-shaped portion 222b faces the outer circumferential surface of the rotor core 110 with a gap therebetween in the radial direction. The umbrella-shaped portions 222b adjacent to each other in the circumferential direction are arranged side by side with the slots 223 therebetween.

[0035] The coil 23 is formed of a conductive wire 23a, and the conductive wire 23a is wound around the teeth 222 via an insulator 24. Thus, the coil 23 is inserted into each slot 223. The conductive wire 23a is covered with an insulating film. The stator core 22 and the conductive wire 23a are insulated via an insulator 24. The coil 23 is arranged in the circumferential direction in the order of, for example, U phase, V phase, and W phase.

[0036] The insulator 24 is made of an insulating resin molded product. The insulator 24 is divided into upper insulators 241 and 242 and a lower insulator 243 that sandwich the stator core 22 from top to bottom (see Figure 3 The upper insulators 241 and 242 and the lower insulator 243 are arranged corresponding to the teeth 222 .

[0037] One upper insulator 241 and seven upper insulators 242 are provided on the upper surface of the stator core 22. Eight lower insulators 243 are provided on the lower surface of the stator core 22. The upper insulators 241 and 242 have the same shape except that a groove 2415 is formed in the upper insulator 241.

[0038] The temperature detection unit 25 detects the temperature of the coil 23. The temperature detection unit 25 is arranged on the upper surface of the tooth 222 and is arranged inside the groove 2415 formed in the upper insulator 241. The temperature detection unit 25 is composed of, for example, a thermistor. In addition, the temperature detection unit 25 can also be composed of a thermistor and a resin molded product that holds the thermistor. The temperature detection unit 25 is connected to a circuit substrate (not shown) arranged on the upper side (axial direction Z1) of the coil 23 via a connecting wire 25a. The structure of the groove 2415 will be described in detail later.

[0039] In the motor 1 of the above structure, when a driving current is supplied to the coil 23, a magnetic flux is generated. In addition, a magnetic flux flows in the stator core 22. The magnetic field generated by the magnetic flux of the stator core 22 and the magnetic field generated by the magnetic flux of the magnet 120 interact with each other, and a torque is generated in the circumferential direction of the rotor 10. The rotor 10 rotates around the central axis C by this torque. At this time, the detection signal of the temperature detection unit 25 is sent to the circuit board (not shown) for controlling the motor, and the state of the coil 23 corresponding to the U phase, V phase, and W phase is controlled.

[0040] (2. Structure of the groove)

[0041] Figure 4 is a perspective view showing a part of the stator 20 in an enlarged manner. Figure 5It is a plan view showing a part of the stator 20 in an enlarged manner. Figure 6 It is a longitudinal sectional perspective view showing a part of the stator 20 in an enlarged manner. Figure 7 2 is a longitudinal sectional view showing a part of the stator 20 in an enlarged manner, and shows a cross section perpendicular to the radial direction. Figure 8 It is an exploded perspective view showing a part of the stator 20 in an enlarged manner. Figure 4 , Figure 5 as well as Figure 7 The coil 23 is not shown. Figure 7 The temperature detection unit 25 is not shown.

[0042] The upper insulator (insulator) 241, 242 has an upper core back cover (core back cover) 2411, an upper tooth cover (tooth cover) 2412, and an upper protrusion 2413. In addition, the upper insulator 241 and the lower insulator 243 are respectively provided with a side cover 2414 that covers the outer peripheral surface of the umbrella-shaped portion 222b, the circumferential sides of the base 222a, and the inner peripheral surface of the core back 221. The outer periphery of the slot 223 is surrounded by the side cover 2414.

[0043] The upper core back cover 2411 covers the upper surface (the end surface in the axial direction Z1 ) of the core back 221 . The upper tooth cover 2412 covers the upper surface (the end surface in the axial direction Z1 ) of the tooth 33 . The side cover 2414 covers the circumferential side surface of the tooth 33 .

[0044] The lower insulator 243 has a lower core back cover portion 2431 , a lower tooth cover portion 2432 , and a lower protruding portion 2433 .

[0045] The lower core back cover portion 2431 covers the lower surface (the end surface in the other axial direction Z2 ) of the core back 221 . The lower tooth cover portion 2432 covers the lower surface (the end surface in the other axial direction Z2 ) of the tooth 33 .

[0046] The radially outer ends (ends on one radial direction Y1 ) of the upper core back cover portion 2411 and the lower core back cover portion 2431 are located radially inward (on the other radial direction Y2 ) of the radially outer end (end on one radial direction Y1 ) of the core back 221 .

[0047] The upper protrusion 2413 protrudes upward (in the axial direction Z1) from the upper surface (the end surface in the axial direction Z1) of the upper core back cover 2411. The upper protrusion 2413 has an upper cutout 2413a. The upper cutout 2413a is formed by being recessed in the axial direction from the upper surface (the end surface in the axial direction) of the upper protrusion 2413. A pair of upper cutouts 2413a are arranged on both sides of the groove 2415 in the circumferential direction.

[0048] The lower protrusion 2433 protrudes from the lower surface (the end surface of the other axial direction Z2) of the lower core back cover 2431 to the lower side (the other axial direction Z2). The lower protrusion 2433 has a lower cutout 2433a. The lower cutout 2433a is formed by being recessed along the axial direction from the lower surface (one axial end surface) of the lower protrusion 2433. A pair of lower cutouts 2433a are arranged on both sides of the circumferential center of the lower core back cover 2431.

[0049] The conductor 23a constituting the coil 23 is connected to a lap wire (not shown). The lap wire is connected to a plurality of coils 23 of the same phase. The lap wire extends circumferentially from the upper cutout portion 2413a through the radially outer side of the upper protrusion 2413. In addition, the lap wire extends circumferentially from the lower cutout portion 2433a through the radially outer side of the lower protrusion 2433. By providing the upper cutout portion 2413a and the lower cutout portion 2433a, it is possible to prevent the lap wire from bulging radially outward from the radially outer edge of the stator core 22 and contacting other components.

[0050] In this embodiment, the groove 2415 is formed only in the upper insulator 241. The groove 2415 is recessed in the axial direction from the upper surface (end surface of the axial direction Z1) of the upper insulator (insulator) 241, and extends in the radial direction across the upper core back cover (core back cover) 2411 and the upper tooth cover (tooth cover) 2412. In addition, the groove 2415 opens the radial outer end (end of the radial direction Y1) and accommodates the temperature detection unit 25 inside.

[0051] In the present embodiment, the groove 2415 is arranged at the circumferential center of the upper core back cover portion (core back cover portion) 2411 and the upper tooth cover portion (tooth cover portion) 2412. In addition, the shortest distance D1 from the upper end (the end on the axial direction Z1) of the inner wall 2415a of the groove 2415 formed in the upper tooth cover portion (tooth cover portion) 2412 to the axial direction of the coil 23 is shorter than the maximum depth D2 of the groove 2415 formed in the upper tooth cover portion (tooth cover portion) 2412 (refer to Figure 7 ). In addition, the maximum axial depth D2 of the groove portion 2415 is the axial distance from the upper end of the inner wall 2415a of the groove portion 2415 (the end on one axial side Z1) to the lower end of the inner wall 2415a (the end on the other axial side Z2).

[0052] In addition, the upper end (the end in the axial direction Z1 ) of the inner wall 2415 a of the groove portion 2415 is located above (in the axial direction Z1 ) the upper end (the end in the axial direction Z1 ) of the temperature detection portion 25 .

[0053] In addition, the lower end portion (the end portion in the other axial direction Z2 ) of the groove portion 2415 is open to expose the stator core 22 .

[0054] The temperature detection unit 25 is inserted from the radially outer end (the end on one radial direction Y1) of the groove 2415 to the radially inner side (the other radial direction Y2) in a state where the conductive wire 23a is wound around the teeth 222. Therefore, the temperature detection unit 25 can be easily positioned relative to the coil 23 without increasing the number of components. As a result, the manufacturing cost of the stator 20 can be reduced.

[0055] By accommodating the temperature detection unit 25 in the groove 2415, the temperature detection unit 25 can be arranged close to the coil 23. Therefore, the temperature detection accuracy of the temperature detection unit 25 for the coil 23 can be improved. In addition, the conductive wire 23a wound around the tooth 222 may bulge upward (in the axial direction Z1) from the upper end (end in the axial direction Z1) of the upper tooth cover portion (tooth cover portion) 2412 (refer to Figure 7 ). At this time, the shortest axial distance D1 from the inner wall 2415a of the groove 2415 to the coil 23 is shorter than the maximum axial depth D2 of the groove 2415. Thus, the temperature detection unit 25 can be arranged close to the coil 23, further improving the temperature detection accuracy of the temperature detection unit 25 for the coil 23.

[0056] In addition, the shortest axial distance D3 from the upper end (the end in one axial direction Z1) of the temperature detection unit 25 to the upper end (the end in one axial direction Z1) of the inner wall 2415a of the groove 2415 formed in the upper tooth cover portion (tooth cover portion) 2412 is shorter than the shortest distance D1. Thus, the temperature detection unit 25 can be arranged close to the coil 23, and the temperature detection accuracy of the temperature detection unit 25 for the coil 23 can be further improved.

[0057] In addition, the upper end of the inner wall 2415a of the groove 2415 is located above the upper end of the temperature detection part 25, and the wire 23a wound around the tooth 222 is located above the inner wall 2415a of the groove 2415. As a result, when the temperature detection part 25 is inserted into the groove 2415, it is difficult for the temperature detection part 25 to contact the coil 23. Therefore, the assembly workability of the stator 20 is improved. In addition, by accommodating the temperature detection part 25 in the groove 2415, the temperature detection part 25 can be arranged close to the coil 23. As a result, the temperature detection accuracy of the temperature detection part 25 on the coil 23 can be improved.

[0058] In addition, the lower end portion (the end portion on the other axial side) of the groove portion 2415 is open to expose the stator core 22. As a result, the temperature detection portion 25 contacts the upper surface (the end surface on one axial side Z1) of the stator core 22. Therefore, the axial thickness of the upper tooth cover portion (tooth cover portion) 2412 can be suppressed to be small while ensuring the axial height in the groove portion 2415. Therefore, the stator 20 can be miniaturized in the axial direction.

[0059] The circumferential width of the groove 2415 becomes narrower as it moves from the open radially outer end (the end on one radial direction Y1) toward the radially inner side (the end on the other radial direction Y2) (see Figure 5 ). Thus, the temperature detection unit 25 can be easily inserted into the groove 2415 from the radial outer end. Therefore, the assembly workability of the stator 20 is further improved. In the present embodiment, the inner wall 2415a of the groove 2415 is recessed along the circumferential direction at the radial outer end to form a step. In addition, when viewed from the axial direction, the inner wall 2415a can also be inclined from the radial outer end toward the radial inner side.

[0060] In addition, the radial length L1 of the groove portion 2415 formed in the upper tooth cover portion (tooth cover portion) 2412 is longer than half of the radial length L2 of the upper tooth cover portion (tooth cover portion) 2412. As a result, the temperature detection portion 25 can be arranged close to the radial inner end portion (the end portion of the other radial direction Y2) of the upper tooth cover portion (tooth cover portion) 2412. Therefore, the temperature detection portion 25 can detect the temperature of the coil 23 over a wide range in the radial direction. Therefore, the temperature detection accuracy of the temperature detection portion 25 can be further improved.

[0061] After the temperature detection unit 25 is inserted into the groove 2415, the heat conductive grease (heat conductive member) 28 is filled into the groove 2415 from the gap at the radial outer end (the end on the radial direction Y1) of the groove 2415 (see Figure 6 ). Thus, in the groove 2415, a thermally conductive grease (thermal conductive member) 28 is arranged in the axial gap between the temperature detection unit 25 and the lead wire 23a. Therefore, the temperature detection accuracy of the temperature detection unit 25 for the coil 23 can be further improved. In addition, since the thermally conductive grease is a viscous liquid, it can be easily inserted between the temperature detection unit 25 and the lead wire 23a.

[0062] In addition, the temperature detection part 25 is held in the groove part 2415 via the thermally conductive grease. Thus, the vibration of the temperature detection part 25 can be suppressed. In addition, the thermally conductive grease may have adhesiveness. Thus, the temperature detection part 25 is fixed in the groove part 2415 via the thermally conductive grease. In addition, before the temperature detection part 25 is inserted into the groove part 2415, the thermally conductive grease (thermal conductive member) 28 may be filled in the groove part 2415 in advance.

[0063] In addition, the connection wire 25a connected to the temperature detection part 25 is led out to the upper side (one side in the axial direction) from the groove part 2415 formed in the upper core back cover part (core back cover part) 2411. Thus, the connection wire 25a can be easily led out in the axial direction along the inner peripheral surface of the housing 21. Therefore, the assembly workability of the stator 20 is further improved.

[0064] <3. Others>

[0065] The embodiments of the present invention have been described above. In addition, the scope of the present invention is not limited to the above-mentioned embodiments. The present invention can be implemented by adding various changes within the scope of the gist of the invention. In addition, the above-mentioned embodiments can be appropriately combined arbitrarily.

[0066] In this embodiment, the inner rotor type motor 1 is described, but the technology of the present invention can also be applied to an outer rotor type motor. At this time, the teeth 222 protrude radially outward from the core back 221, and a plurality of teeth are arranged in the circumferential direction. In addition, the groove 2415 opens the radial inner end and accommodates the temperature detection unit 25 inside. In addition, the temperature detection unit 25 is inserted from the radial inner end of the groove 2415 to the radial outer side in a state where the wire 23a is wound around the teeth 222.

[0067] In addition, in the present embodiment, the groove 2415 is formed in the upper insulator 241, but it may be formed in the lower insulator 243. In this case, the groove 2415 is recessed in the axial direction from the lower surface (end surface of the other axial direction Z2) of the lower insulator (insulator) 243, and extends in the radial direction across the lower core back cover (core back cover) 2431 and the lower tooth cover (tooth cover) 2432.

[0068] In addition, in the present embodiment, only one upper insulator 241 having the groove 2415 is provided, but two or more upper insulators 241 having the groove 2415 may be provided. In addition, the temperature detection unit 25 may be provided in the groove 2415 formed in the upper insulator 241 and the groove formed in the lower insulator 243. By providing a plurality of temperature detection units 25, the temperature detection accuracy of the coil 23 by the temperature detection unit 25 can be further improved.

[0069] In addition, in the present embodiment, the upper end (the end in one axial direction Z1) of the inner wall 2415a of the groove 2415 is located on the upper side (the end in one axial direction Z1) than the upper end (the end in one axial direction Z1) of the temperature detection unit 25, but the upper end (the end in one axial direction Z1) of the temperature detection unit 25 may be located on the upper side (the end in one axial direction Z1) than the upper end (the end in one axial direction Z1) of the inner wall 2415a of the groove 2415. In this case, if the conductive wire 23a wound around the tooth 222 bulges on the upper side (the end in one axial direction Z1) than the upper end (the end in one axial direction Z1) of the upper tooth cover portion (tooth cover portion) 2412, it is easy to insert the temperature detection unit 25 into the groove 2415.

[0070] <4. Notes>

[0071] As described above, the stator 20 of one embodiment of the present invention comprises: a stator core 22, which has an annular core back 221 surrounding the central axis C in the circumferential direction and a plurality of teeth 222 protruding radially from the core back and arranged in the circumferential direction; an insulator 24, which covers the core back and the teeth; a coil 23, which is formed by a conductive wire 23a wound around the teeth through the insulator; and a temperature detection unit 25, which detects the temperature of the coil, wherein the insulator has: a core back cover 2411, which covers the end of the core back on one axial side Z1 surface; and a tooth cover portion 2422, which covers the end face of the above-mentioned tooth on one axial side, the above-mentioned insulator has a groove portion 2415 which is axially recessed from the end face on one axial side and extends radially across the above-mentioned core back cover portion and the above-mentioned tooth cover portion, the above-mentioned groove portion opens the end portion on the radial side Y1 and accommodates the above-mentioned temperature detection portion inside, and the axial shortest distance D1 from the end portion on one axial side of the inner wall 2415a of the above-mentioned groove portion formed in the above-mentioned tooth cover portion to the above-mentioned coil is shorter than the axial maximum depth D2 of the above-mentioned groove portion formed in the above-mentioned tooth cover portion (first structure).

[0072] In the first configuration, one axial end of the inner wall of the groove portion formed in the tooth cover portion is located closer to one axial end than one axial end of the temperature detection portion (second configuration).

[0073] In the first or second configuration, a radial length L1 of the groove formed in the tooth cover portion may be longer than half a radial length L2 of the entire tooth cover portion (third configuration).

[0074] In any one of the first to third structures, the groove portion may be configured such that the other end portion in the axial direction is open to expose the stator core (fourth structure).

[0075] In any one of the first to fourth structures, a thermally conductive member 28 may be disposed in a gap in the axial direction between the temperature detection portion and the lead wire (fifth structure).

[0076] In addition, in any one of the first to fifth structures mentioned above, it can also be constructed as a cylindrical shell 21 that also covers the core back from the radial outside, the teeth extend radially inside from the core back, and the connecting wire 25a connected to the temperature detection part is led out to one side axially from the groove formed in the core back cover part (sixth structure).

[0077] In any of the first to sixth structures, the circumferential width of the groove portion may be narrowed from the open end portion in one radial direction Y1 toward the other radial direction Y2 (seventh structure).

[0078] Availability in production

[0079] The present invention can be used, for example, in electric equipment, automobiles, ships, aircraft, trains, electric-assisted bicycles, wind power generators, and the like equipped with motors.

Claims

1. A stator, comprising: A stator core having an annular core back surrounding a central axis in a circumferential direction and a plurality of teeth protruding in a radial direction from the core back and arranged in a circumferential direction; an insulator covering the core back and the teeth; a coil formed by a conductive wire wound around the tooth via the insulator; and a temperature detection unit for detecting the temperature of the coil, The stator is characterized in that The insulator has: a core back cover portion covering an end surface of the core back in one axial direction; and a tooth cover portion covering an end surface of one axial direction of the tooth, The insulator has a groove portion that is recessed in the axial direction from one end surface in the axial direction and extends in the radial direction across the core back cover portion and the tooth cover portion. The groove portion has one radial end portion open and contains the temperature detection portion therein. The shortest distance from one axial end of the inner wall of the groove formed in the tooth cover portion to the coil in the axial direction is shorter than the maximum axial depth of the groove formed in the tooth cover portion.

2. The stator according to claim 1, characterized in that: One axial end of the inner wall of the groove portion formed in the gear cover portion is located closer to one axial side than one axial end of the temperature detection portion.

3. The stator according to claim 1 or 2, characterized in that: The radial length of the groove portion formed in the tooth cover portion is longer than half of the entire radial length of the tooth cover portion.

4. The stator according to claim 1 or 2, characterized in that: The groove portion has the other axial end portion opened to expose the stator core.

5. The stator according to claim 1 or 2, characterized in that: A thermally conductive member is disposed in an axial gap between the temperature detection portion and the lead wire.

6. The stator according to claim 1 or 2, characterized in that: It also includes a cylindrical housing covering the core back from the radial outside, The teeth extend radially inwardly from the core, A connection line connected to the temperature detection portion is led out from the groove portion formed in the core back cover portion in one direction in the axial direction.

7. The stator according to claim 1 or 2, characterized in that: The circumferential width of the groove portion narrows from one open end portion in the radial direction toward the other end portion in the radial direction.

Images