Stator

Abstract

To provide a stator capable of enhancing temperature detection accuracy of a temperature detection part while reducing manufacturing cost.SOLUTION: A stator comprises a stator core, an insulator 24, a coil, and a temperature detection part 25. The temperature detection part detects temperature of the coil. The insulator has a core back cover part 2411 and a teeth cover part 2412. The insulator has a groove 2415. The groove is recessed from one end surface in an axial direction of the insulator toward the axial direction, and positioned across the core back cover part and the teeth cover part and extends in a radial direction. The groove has one end in the radial direction opened, and accommodates the temperature detection part inside. A shortest distance in the axial direction of an inner wall 2415a of the groove formed on the teeth cover part from axial one end to the coil is shorter than an axial maximum depth of the groove formed on the teeth cover part.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present invention relates to a stator.

Background Art

[0002] A conventional 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 a plurality in the circumferential direction. The insulator covers the core back and the teeth. The coil is formed by a conducting wire wound around the teeth via the insulator. The temperature detection unit is arranged outside the coil in the axial direction and detects the temperature of the coil (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the conventional stator, the number of components may increase to fix the temperature detection unit, which may increase the manufacturing cost. In addition, the temperature detection unit is arranged away from the coil, and the temperature detection accuracy may decrease.

[0005] An object of the present invention is to provide a stator capable of improving the temperature detection accuracy of the temperature detection unit while reducing the manufacturing cost.

Means for Solving the Problems

[0006] An exemplary stator of the present invention 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 a plurality in the circumferential direction. The insulator covers the core back and the teeth. The coil is formed by a conductor wound around the teeth via 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 one end face of the core back in the axial direction. The tooth cover portion covers one end face of the teeth in the axial direction. The insulator has a groove portion. The groove portion is recessed axially from one end face of the insulator in the axial direction and extends radially across the core back cover portion and the tooth cover portion. One end in the radial direction of the groove portion is open and houses the temperature detection unit inside. The shortest axial distance from one end in the axial direction of the inner wall of the groove portion formed in the tooth cover portion to the coil is shorter than the maximum axial depth of the groove portion formed in the tooth cover portion.

Advantages of the Invention

[0007] According to an exemplary aspect of the present invention, it is possible to provide a stator capable of improving the temperature detection accuracy of the temperature detection unit while reducing the manufacturing cost.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Embodiments for Carrying Out the Invention

[0009] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the drawings. In this specification, the rotation axis of the motor 1 is referred to as the "central axis", and the direction parallel to the central axis C is referred to as the "axial direction". Also, the direction orthogonal to the central axis C of the motor 1 is referred to as the "radial direction", and the direction along the arc centered on the central axis C of the motor 1 is referred to as the "circumferential direction", respectively. Further, in the present application, the axial direction is the vertical direction, with the temperature detection unit 25 above the stator core 22, and the shape and positional relationship of each part will be described. Note that the vertical direction is merely a name used for explanation and does not limit the actual positional relationship and direction.

[0010] (1. Configuration of the Motor) The motor 1 according to an exemplary embodiment of the present invention will be described. FIG. 1 is a longitudinal cross-sectional view schematically showing the motor 1 according to an embodiment of the present invention. FIG. 2 is a perspective view of the stator 20, and FIG. 3 is an exploded perspective view of the stator 20. Note that in FIG. 1, the insulator 24 and the housing 21 are not shown. Also, in FIG. 3, the coil 23 and the housing 21 are not shown.

[0011] The motor 1 has a rotor 10 and a stator 20. The rotor 10 has a shaft 100, a rotor core 110, and a plurality of magnets 120. The shaft 100 is a columnar metal member extending along the central axis C extending vertically. The rotor core 110 is disposed on the outer side in the radial direction of the shaft 100 and extends along the axial direction. The rotor core 110 is formed in a cylindrical shape by laminating annular electromagnetic steel sheets in the axial direction.

[0012] 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.

[0013] Each magnet 120 is inserted into, for example, 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 with, for example, an adhesive. The plurality of magnets 120 are arranged in the circumferential direction such that the N poles and S poles are arranged alternately.

[0014] 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 houses the stator core 22. Specifically, the housing 21 covers the core back 221 from the radially outer side as will be described later. The housing 21 has a bottom plate portion 21a and a top plate portion 21b. The bottom plate portion 21a is disposed below (the other axial direction Z2) the stator core 22 and holds the lower bearing 27a. The top plate portion 21b is disposed above (one axial direction Z1) the stator core 22 and holds the upper bearing 27b.

[0015] The lower bearing 27a and the upper bearing 27b rotatably support the shaft 100, which will be described later, with respect to the housing 21.

[0016] The stator core 22 is formed by laminating a plurality of annular electromagnetic steel sheets in the axial direction. The stator core 22 has a core back 221 and teeth 222 (see FIG. 3). The core back 221 is annular and is disposed radially outside the rotor 10 and surrounds the central axis C in the circumferential direction. The teeth 222 project radially inward from the core back 221 and a plurality of them are arranged in the circumferential direction.

[0017] The plurality of teeth 222 are arranged at equal intervals in the circumferential direction about the central axis C. In the present embodiment, 12 teeth 222 are arranged.

[0018] The teeth 222 have a base portion 222a and an umbrella portion 222b (see FIG. 3). The base portion 222a extends radially inward from the core back 221. The umbrella portion 222b protrudes from the radially inner end of the base portion 222a to both sides in the circumferential direction. The circumferential length of the umbrella portion 222b is larger than the circumferential length at the radially inner end of the base portion 222a.

[0019] The radially inner surface of the umbrella portion 222b is a curved surface along the circumferential direction. The radially inner surface of the umbrella portion 222b faces the outer peripheral surface of the rotor core 110 with a gap therebetween in the radial direction. The umbrella portions 222b adjacent to each other in the circumferential direction are arranged side by side via slots 223.

[0020] The coil 23 is formed by a conductor wire 23a wound around the teeth 222 via an insulator 24. Thereby, the coil 23 is inserted into each slot 223. The conductor wire 23a is covered with an insulating coating. The stator core 22 and the conductor wire 23a are insulated from each other via the insulator 24. The coils 23 are arranged in the circumferential direction in the order of, for example, phase U, phase V, and phase W.

[0021] The insulator 24 is made of an insulating resin molded product. The insulator 24 is divided into upper insulators 241 and 242 that sandwich the stator core 22 from above and below, and a lower insulator 243 (see FIG. 3). The upper insulators 241 and 242 and the lower insulator 243 are respectively arranged corresponding to each tooth 222.

[0022] One upper insulator 241 is provided on the upper surface of the stator core 22, and seven upper insulators 242 are provided. Eight lower insulators 243 are provided on the lower surface of the stator core 22. The upper insulator 241 and the upper insulator 242 have the same shape except that a groove portion 2415 is formed in the upper insulator 241.

[0023] The temperature detection unit 25 detects the temperature of the coil 23. The temperature detection unit 25 is disposed on the upper surface of the teeth 222 and is disposed inside the groove portion 2415 formed in the upper insulator 241. The temperature detection unit 25 is composed of, for example, a thermistor. Note that the temperature detection unit 25 may be composed of a thermistor and a resin molded product that holds the thermistor. The temperature detection unit 25 is connected to a circuit board (not shown) disposed above the coil 23 (in one axial direction Z1) via a connection wire 25a. The structure of the groove portion 2415 will be described in detail later.

[0024] In the motor 1 configured as described above, when a drive current is supplied to the coil 23, a magnetic flux is generated. Further, the magnetic flux flows through 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 act on each other, and a torque is generated in the circumferential direction of the rotor 10. Due to this torque, the rotor 10 rotates about the central axis C. At this time, the detection signal of the temperature detection unit 25 is transmitted to a circuit board (not shown) that controls the motor, and the states of the coils 23 corresponding to the U-phase, V-phase, and W-phase are controlled.

[0025] (2. Structure of the groove portion) FIG. 4 is a perspective view showing an enlarged part of the stator 20, FIG. 5 is a top view showing an enlarged part of the stator 20, FIG. 6 is a longitudinal cross-sectional perspective view showing an enlarged part of the stator 20, and FIG. 7 is a longitudinal cross-sectional view showing an enlarged part of the stator 20 and showing a cross-section orthogonal to the radial direction. Further, FIG. 8 is an exploded perspective view showing an enlarged part of the stator 20. Coils 23 are not shown in FIGS. 4, 5, and 7. Further, the temperature detection unit 25 is not shown in FIG. 7.

[0026] The upper insulators (insulators) 241 and 242 have an upper core back cover portion (core back cover portion) 2411, an upper teeth cover portion (teeth cover portion) 2412, and an upper protrusion 2413. Further, side cover portions 2414 that cover the outer peripheral surface of the umbrella portion 222b, both circumferential side surfaces of the base portion 222a, and the inner peripheral surface of the core back 221 are respectively provided on the upper insulator 241 and the lower insulator 243. The outer periphery of the slot 223 is surrounded by the side cover portion 2414.

[0027] The upper core back cover portion 2411 covers the upper surface (end face in the axial direction one Z1) of the core back 221. The upper teeth cover portion 2412 covers the upper surface (end face in the axial direction one Z1) of the teeth 33. The side cover portion 2414 covers the circumferential side surface of the teeth 33.

[0028] The lower insulator 243 has a lower core back cover portion 2431, a lower teeth cover portion 2432, and a lower protrusion 2433.

[0029] The lower core back cover portion 2431 covers the lower surface (end face in the axial direction the other Z2) of the core back 221. The lower teeth cover portion 2432 covers the lower surface (end face in the axial direction the other Z2) of the teeth 33.

[0030] The radially outer end portions (end portions in the radial direction one Y1) of the upper core back cover portion 2411 and the lower core back cover portion 2431 are located radially inward (radial direction the other Y2) than the radially outer end portion (end portion in the radial direction one Y1) of the core back 221.

[0031] The upper protrusion 2413 protrudes upward (axial direction one Z1) from the upper surface (end face in the axial direction one Z1) of the upper core back cover portion 2411. The upper protrusion 2413 has an upper notch portion 2413a. The upper notch portion 2413a is formed to be recessed axially from the upper surface (one end face in the axial direction) of the upper protrusion 2413. The upper notch portion 2413a is arranged in a pair on both circumferential sides with the groove portion 2415 interposed therebetween.

[0032] The lower protruding portion 2433 protrudes downward (in the other axial direction Z2) from the lower surface (the end surface in the other axial direction Z2) of the lower core back cover portion 2431. The lower protruding portion 2433 has a lower notch portion 2433a. The lower notch portion 2433a is formed to be recessed axially from the lower surface (one end surface in the axial direction) of the lower protruding portion 2433. A pair of the lower notch portions 2433a are arranged on both circumferential sides with the center in the circumferential direction of the lower core back cover portion 2431 interposed therebetween.

[0033] The conducting wire 23a constituting the coil 23 is connected to a jumper wire (not shown). The jumper wire is connected to a plurality of coils 23 of the same phase. The jumper wire extends circumferentially through the radially outer side of the upper protruding portion 2413 from the upper notch portion 2413a. Further, the jumper wire extends circumferentially through the radially outer side of the lower protruding portion 2413 from the lower notch portion 2433a. By providing the upper notch portion 2413a and the lower notch portion 2433a, it is possible to prevent the jumper wire from bulging radially outside the radially outer edge of the stator core 22 and contacting other members or the like.

[0034] In the present embodiment, the groove portion 2415 is formed only in the upper insulator 241. The groove portion 2415 is recessed axially from the upper surface (the end surface in one axial direction Z1) of the upper insulator (insulator) 241 and extends radially across the upper core back cover portion (core back cover portion) 2411 and the upper teeth cover portion (teeth cover portion) 2412. Further, the radially outer end portion (the end portion in one radial direction Y1) of the groove portion 2415 is open to accommodate the temperature detection portion 25 therein.

[0035] In this embodiment, it is disposed 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. Further, the shortest axial distance D1 from the upper end (the end in the axial direction Z1) of the inner wall 2415a of the groove portion 2415 formed in the upper tooth cover portion (tooth cover portion) 2412 to the coil 23 is shorter than the maximum axial depth D2 of the groove portion 2415 formed in the upper tooth cover portion (tooth cover portion) 2412 (see FIG. 7). The maximum axial depth D2 of the groove portion 2415 is the axial distance from the upper end (the end in the axial direction Z1) of the inner wall 2415a of the groove portion 2415 to the lower end (the end in the other axial direction Z2) of the inner wall 2415a.

[0036] Further, the upper end (the end in the axial direction Z1) of the inner wall 2415a 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.

[0037] Further, the groove portion 2415 has an open lower end portion (the end portion in the other axial direction Z2) and the stator core 22 is exposed.

[0038] The temperature detection portion 25 is inserted from the radially outer end portion (the end portion in the radial direction Y1) of the groove portion 2415 radially inward (in the radial direction Y2) with the conductor 23a wound around the teeth 222. For this reason, the temperature detection portion 25 can be easily positioned with respect to the coil 23 without increasing the number of parts. Thereby, the manufacturing cost of the stator 20 can be reduced.

[0039] By accommodating the temperature detection unit 25 in the groove portion 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 with respect to the coil 23 can be improved. Further, the conducting wire 23a wound around the teeth 222 may bulge upward (in the axial direction Z1) from the upper end (the end in the axial direction Z1) of the upper teeth cover portion (teeth cover portion) 2412 (see FIG. 7). At this time, the shortest axial distance D1 from the inner wall 2415a of the groove portion 2415 to the coil 23 is shorter than the maximum axial depth D2 of the groove portion 2415. Thereby, the temperature detection unit 25 can be arranged close to the coil 23, and the temperature detection accuracy of the temperature detection unit 25 with respect to the coil 23 can be further improved.

[0040] Also, the shortest axial distance D3 from the upper end (the end in the axial direction Z1) of the temperature detection unit 25 to the upper end (the end in the axial direction Z1) of the inner wall 2415a of the groove portion 2415 formed in the upper teeth cover portion (teeth cover portion) 2412 is shorter than the shortest distance D1. Thereby, the temperature detection unit 25 can be arranged close to the coil 23, and the temperature detection accuracy of the temperature detection unit 25 with respect to the coil 23 can be further improved.

[0041] Also, the upper end of the inner wall 2415a of the groove portion 2415 is located above the upper end of the temperature detection unit 25, and the conducting wire 23a wound around the periphery of the teeth 222 is located above the inner wall 2415a of the groove portion 2415. Thereby, when the temperature detection unit 25 is inserted into the groove portion 2415, it is difficult for the temperature detection unit 25 to contact the coil 23. Therefore, the assembly workability of the stator 20 is improved. Also, by accommodating the temperature detection unit 25 in the groove portion 2415, the temperature detection unit 25 can be arranged close to the coil 23. Thereby, the temperature detection accuracy of the temperature detection unit 25 with respect to the coil 23 can be improved.

[0042] Further, the groove portion 2415 has its lower end portion (the other end portion in the axial direction) open, and the stator core 22 is exposed. As a result, the temperature detection portion 25 contacts the upper surface (the end surface in one axial direction Z1) of the stator core 22. Therefore, while suppressing the axial thickness of the upper tooth cover portion (tooth cover portion) 2412 to be small, the axial height within the groove portion 2415 can be ensured. Accordingly, the stator 20 can be miniaturized in the axial direction.

[0043] Further, the circumferential width of the groove portion 2415 becomes narrower as it goes from the open radially outer end portion (the end portion in one radial direction Y1) toward the radially inner side (the other radial direction Y2) (see FIG. 5). As a result, the temperature detection portion 25 can be easily inserted into the groove portion 2415 from the radially outer end portion. Accordingly, the assembly workability of the stator 20 is further improved. In the present embodiment, the inner wall 2415a of the groove portion 2415 is recessed in the circumferential direction at the radially outer end portion to form a step. Note that, when viewed from the axial direction, the inner wall 2415a may be inclined from the radially outer end portion toward the radially inner side.

[0044] Further, 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 entire 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 radially inner end portion (the end portion in the other radial direction Y2) of the upper tooth cover portion (tooth cover portion) 2412. For this reason, the temperature detection portion 25 can widely detect the temperature of the coil 23 in the radial direction. Accordingly, the temperature detection accuracy of the temperature detection portion 25 can be further improved.

[0045] Further, after the temperature detection unit 25 is inserted into the groove portion 2415, a heat-conductive grease (heat-conductive member) 28 is filled into the groove portion 2415 from a gap at the radially outer end portion (the end portion on one side Y1 in the radial direction) of the groove portion 2415 (see FIG. 6). Thereby, in the groove portion 2415, the heat-conductive grease (heat-conductive member) 28 is disposed in the axial gap between the temperature detection unit 25 and the conducting wire 23a. Therefore, the temperature detection accuracy of the temperature detection unit 25 with respect to the coil 23 can be further improved. Further, since the heat-conductive grease is a viscous liquid, it can be easily interposed between the temperature detection unit 25 and the conducting wire 23a.

[0046] Also, the temperature detection unit 25 is held in the groove portion 2415 via the heat-conductive grease. Thereby, the temperature detection unit 25 can be suppressed from vibrating. Note that the heat-conductive grease may have adhesiveness. Thereby, the temperature detection unit 25 is fixed in the groove portion 2415 via the heat-conductive grease. Note that before inserting the temperature detection unit 25 into the groove portion 2415, the groove portion 2415 may be filled with the heat-conductive grease (heat-conductive member) 28 in advance.

[0047] Also, a connection wire 25a connected to the temperature detection unit 25 is drawn out upward (on one side in the axial direction) from a groove portion 2415 formed in the upper core back cover portion (core back cover portion) 2411. Thereby, the connection wire 25a can be easily drawn out axially along the inner peripheral surface of the housing 21. Therefore, the assembly workability of the stator 20 is further improved.

[0048] <3. Others> As described above, the embodiments of the present invention have been described. Note that the scope of the present invention is not limited to the above-described embodiments. The present invention can be implemented with various modifications without departing from the gist of the invention. Further, the above-described embodiments can be arbitrarily combined as appropriate.

[0049] In this embodiment, the inner rotor type motor 1 has been described. However, the technology of the present disclosure is also applicable to an outer rotor type motor. At this time, the teeth 222 project radially outward from the core back 221 and are arranged in plurality in the circumferential direction. Further, the groove portion 2415 has an open radially inner end and houses the temperature detection portion 25 therein. Further, the temperature detection portion 25 is inserted radially outward from the radially inner end of the groove portion 2415 with the conducting wire 23a wound around the teeth 222.

[0050] Further, in this embodiment, the groove portion 2415 is formed in the upper insulator 241, but it may be formed in the lower insulator 243. At this time, the groove portion 2415 is recessed axially from the lower surface (end face in the other axial direction Z2) of the lower insulator (insulator) 243 and extends radially across the lower core back cover portion (core back cover portion) 2431 and the lower tooth cover portion (tooth cover portion) 2432.

[0051] Further, in this embodiment, only one upper insulator 241 in which the groove portion 2415 is formed is provided, but two or more upper insulators 241 in which the groove portion 2415 is formed may be provided. Further, the temperature detection portions 25 may be respectively arranged in the groove portion 2415 formed in the upper insulator 241 and the groove portion formed in the lower insulator 243. By arranging a plurality of temperature detection portions 25, the temperature detection accuracy of the coil 23 of the temperature detection portion 25 can be further improved.

[0052] Further, in this embodiment, the upper end (end in one axial direction Z1) of the inner wall 2415a of the groove portion 2415 is located above (in one axial direction Z1) the upper end (end in one axial direction Z1) of the temperature detection portion 25. However, the upper end (end in one axial direction Z1) of the temperature detection portion 25 may be located above (in one axial direction Z1) the upper end (end in one axial direction Z1) of the inner wall 2415a of the groove portion 2415. At this time, if the conducting wire 23a wound around the teeth 222 bulges above (in one axial direction Z1) the upper end (end in one axial direction Z1) of the upper tooth cover portion (tooth cover portion) 2412, the temperature detection portion 25 can be easily inserted into the groove portion 2415.

[0053] <4. Supplementary Note> As described above, the stator (20) according to one aspect of the present disclosure includes a stator core (22) having an annular core back (221) that circumferentially surrounds a central axis (C) and a plurality of teeth (222) that project radially from the core back and are arranged in the circumferential direction, an insulator (24) that covers the core back and the teeth, a coil (23) formed by a conductor (23a) wound around the teeth via the insulator, and a temperature detection unit (25) that detects the temperature of the coil. The insulator has a core back cover portion (2411) that covers an end face on one axial side (Z1) of the core back and a tooth cover portion (2422) that covers an end face on one axial side of the teeth. The insulator has a groove portion (2415) that is recessed axially from an end face on one axial side and extends radially across the core back cover portion and the tooth cover portion. The groove portion has an end on one radial side (Y1) that is open and houses the temperature detection unit therein. The shortest axial distance (D1) from an end on one axial side of the inner wall (2415) of the groove portion formed in the tooth cover portion to the coil is shorter than the maximum axial depth (D2) of the groove portion formed in the tooth cover portion (first configuration).

[0054] Further, in the first configuration, an end on one axial side of the inner wall of the groove portion formed in the tooth cover portion is located on one axial side relative to an end on one axial side of the temperature detection unit (second configuration).

[0055] Further, in the first or second configuration, the radial length (L1) of the groove portion formed in the tooth cover portion may be longer than half of the overall radial length (L2) of the tooth cover portion (third configuration).

[0056] Further, in any of the first to third configurations, the groove portion may have an end on the other axial side that is open and the stator core may be exposed (fourth configuration).

[0057] Further, in any one of the first to fourth configurations described above, a heat conductive member (28) may be arranged in the axial gap between the temperature detection unit and the conducting wire (fifth configuration).

[0058] Further, in any one of the first to fifth configurations described above, a cylindrical housing (21) that covers the core back from the radially outer side is further provided, the teeth extend radially inward from the core back, and the connection wire (25a) connected to the temperature detection unit may be drawn out axially in one direction from the groove formed in the core back cover portion (sixth configuration).

[0059] Further, in any one of the first to sixth configurations described above, the circumferential width of the groove portion may be configured to become narrower as it goes from the end portion on the open radially one side (Y1) toward the radially other side (Y2) (seventh configuration).

Industrial Applicability

[0060] The present invention can be used, for example, in electric devices equipped with motors, automobiles, ships, airplanes, trains, electric assist bicycles, wind turbines, and the like.

Explanation of Signs

[0061] 1 Motor 10 Rotor 20 Stator 21 Housing 21a Bottom plate portion 21b Top plate portion 22 Stator core 23 Coil 23a Conducting wire 24 Insulator 25 Temperature detection unit 25a Connection wire 27a Lower bearing 27b Upper bearing 33 Teeth 100 Shaft 110 Rotor core 111 Shaft hole 112 Magnet hole 120 magnets 221 core back 222 teeth 222a base 222b umbrella part 223 slot 241, 242 upper insulator 243 lower insulator 2411 upper core back cover part (core back cover part) 2412 upper teeth cover part (teeth cover part) 2413 upper protrusion 2413a, 2433a notch 2414 side cover part 2415 groove part 2415a inner wall 2431 lower core back cover part 2432 lower teeth cover part 2433 lower protrusion C central axis D1, D3 shortest distance D2 maximum depth L1 length L2 length Y1 one direction in the radial direction (outer side in the radial direction) Y2 the other direction in the radial direction (inner side in the radial direction) Z1 one direction in the axial direction (upper side) Z2 the other direction in the axial direction (lower side)

Claims

1. a stator core having an annular core back that circumferentially surrounds a central axis, and a plurality of teeth that protrude radially from the core back and are arranged in the circumferential direction; an insulator covering the core back and the teeth; a coil formed by a conducting wire wound around the tooth via the insulator; A stator including a temperature detection unit that detects a temperature of the coil, The insulator comprises: a core back cover portion covering one axial end face of the core back; a teeth cover portion covering one axial end face of the teeth, The insulator comprises: A groove portion is provided which is recessed in the axial direction from one axial end face and extends in the radial direction across the core back cover portion and the teeth cover portion, The groove portion has one radial end open and accommodates the temperature detection portion therein, A stator, wherein the shortest axial distance from one axial end of the inner wall of the groove formed in the teeth cover portion to the coil is shorter than the maximum axial depth of the groove formed in the teeth cover portion.

2. The stator according to claim 1 , wherein one axial end of an inner wall of the groove portion formed in the teeth cover portion is positioned axially further to one axial end of the temperature detection portion.

3. 3. The stator according to claim 1, wherein a radial length of the groove formed in the tooth cover portion is longer than half of an entire radial length of the tooth cover portion.

4. 3. The stator according to claim 1, wherein the groove has another axial end open to expose the stator core.

5. 3. The stator according to claim 1, further comprising a thermally conductive member disposed in an axial gap between the temperature detector and the conducting wire.

6. A cylindrical housing is further provided to cover the core back from a radially outer side. The teeth extend radially inward from the core back, 3. The stator according to claim 1, wherein a connection wire connected to the temperature detector is drawn out in one axial direction from the groove formed in the core back cover portion.

7. 3. The stator according to claim 1, wherein a circumferential width of the groove portion narrows from one open radial end toward the other radial end.

Images