Thermistor mounting structure and thermistor unit

Abstract

To suppress a load of a housing and improve measurement accuracy of a coil temperature in a thermistor mounting structure and a thermistor unit in which the housing incorporating a sensor part is wound in and fixed between layers of a coil.SOLUTION: In a thermistor mounting structure and a thermistor unit, a housing 51 of the thermistor unit is wound in and fixed between a pair of layers 32a in a coil 37. Coil contact parts 53 and 54 having abutment surfaces 53a and 54a in recessed shapes corresponding to an outer diameter of each winding 32 of the layer 32a in contact are formed on surfaces in contact with the pair of layers 32a in the housing 51. On a cross section along a motor radial direction Dr in the housing 51, centers 53c and 54c in the recessed shapes of the abutment surfaces 53a and 54a and a center 41c of a sensor part 41 are offset from each other in the motor radial direction Dr.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a thermistor mounting structure and a thermistor unit. [Background technology]

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have become more active, and research and development into electrification technologies is being conducted in vehicles to reduce CO2 emissions and improve energy efficiency. For example, it is known to attach a thermistor for measuring coil temperature to the coil of a motor (rotating electric machine) (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-202685 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the above-mentioned motorization technology, for example, in a motor manufactured using an automatic coil winding facility, a thermistor may be attached to the coil surface. In this case, the temperature is measured on one side of the thermistor, which poses a problem in terms of temperature measurement accuracy. For this reason, in order to measure the coil temperature with high accuracy, it is conceivable to insert a thermistor between the layers of the coils stacked on the outer periphery of the stator core. For example, the thermistor is held in a resin housing to form a unit, and this thermistor unit is placed on the coil surface during the automatic coil winding process, and the coil is further wound in this state to wrap and fix the thermistor unit between the layers of the coil. However, when winding a wire around the thermistor unit as described above, the load input from the winding can cause excessive stress on the housing of the thermistor unit, so a configuration that reduces the load on the housing is desired.

[0005] Therefore, the present invention aims to reduce the load on the housing and improve the measurement accuracy of the coil temperature in a thermistor mounting structure and thermistor unit in which a housing with a built-in sensor unit is wrapped and fixed between the layers of a coil, thereby contributing to improving energy efficiency. [Means for solving the problem]

[0006] As a means for solving the above problem, a first aspect of the present invention is a thermistor mounting structure including: a coil (37) having a winding (32) wound in a plurality of layers (32a) around an outer periphery of a tooth portion (35) protruding in a radial direction (Dr) of a motor; and a thermistor unit (40) having a sensor portion (41) inside a housing (51) for detecting a temperature of the coil (37), wherein the housing (51) of the thermistor unit (40) is wound between and fixed to the pair of layers (32a) of the coil (37), At least one of the surfaces of the body (51) that contact the pair of layers (32a) is formed with a coil contact portion (53, 54) having a concave abutment surface (53a, 54a) that corresponds to the outer diameter of each winding (32) of the contacting layer (32a), and in a cross section of the housing (51) along the motor radial direction (Dr), the concave centers (53c, 54c) of the abutment surfaces (53a, 54a) and the center (41c) of the sensor portion (41) are offset from each other in the motor radial direction (Dr). According to this configuration, in a configuration in which the housing of the thermistor unit is wound and fixed between multiple layers of the coil of the stator, a concave-shaped abutment surface is formed on the coil contact portion on the surface of the housing so as to align the individual windings, and the center of the concave shape of each abutment surface and the center of the sensor portion are offset from each other in a cross-sectional view of the housing, so that the sensor portion can be arranged in a thick portion of the housing having a corrugated coil contact portion. This makes it easier to ensure the thickness of the housing, especially around the sensor portion, even in a configuration in which the housing is curved to follow the winding wound around the teeth portion. Therefore, the rigidity of the housing around the sensor portion is ensured, and the increase in stress around the sensor portion when the winding is wound around the housing is suppressed. In other words, the overall rigidity of the housing can be increased, and the housing and therefore the thermistor unit can be made smaller and lighter.

[0007] A second aspect of the present invention is characterized in that, in the above-mentioned first aspect, the coil contact portions (53, 54) are formed on each surface of the housing (51) that contacts the pair of layers (32a), and in a cross section of the housing (51) along the motor radial direction (Dr), the centers (53c, 54c) of the concave shapes of each abutment surface (53a, 54a) of each coil contact portion (53, 54) and the center (41c) of the sensor portion (41) are offset from each other in the motor radial direction (Dr). With this configuration, in the coil contact portions on both sides of the housing, the center of the concave shape of each abutment surface is offset from the center of the sensor portion when viewed in cross section of the housing, so that the sensor portion can be reliably disposed in a thick portion even in a configuration having corrugated coil contact portions on both sides of the housing. This increases the overall rigidity of the housing, as described above, and makes it possible to reduce the size and weight of the housing and, in turn, the thermistor unit.

[0008] A third aspect of the present invention is characterized in that, in the above-mentioned second aspect, a pair of layers (32a) sandwiching the housing (51) are stacked in a stacking direction perpendicular to the motor radial direction (Dr), and in a cross section of the housing (51) along the motor radial direction (Dr), each coil contact portion (53, 54) has a center (53c, 54c) in each of the concave shapes of a plurality of abutment surfaces (53a, 54a), and when imaginary straight lines (t1) along the stacking direction are extended from the center (53c, 54c) of each of the concave shapes on one side of each coil contact portion (53, 54), the sensor portion (41) is arranged between a pair of adjacent imaginary straight lines (t1) in the motor radial direction (Dr). With this configuration, the sensor unit can be disposed between the center positions (diameter of the motor) of the concave shapes of the contact surfaces in the cross-sectional view of the housing, in the coil contact portions on both sides of the housing. This increases the overall rigidity of the housing, as described above, and makes it possible to reduce the size and weight of the housing and the thermistor unit.

[0009] A fourth aspect of the present invention is characterized in that, in the above-mentioned first or second aspect, of the coil contact portions (53, 54), at least the first coil contact portion (53) farthest from the tooth portion (35) is formed in a convex curved shape away from the tooth portion (35) when viewed from the motor radial direction (Dr), and the second coil contact portion (54) of the coil contact portions (53, 54) closer to the tooth portion (35) is formed in a curved shape having a smaller curvature than the first coil contact portion (53) or in a straight shape when viewed from the motor radial direction (Dr). According to this configuration, of the coil contact parts on both sides of the housing, the first coil contact part on the outer periphery, passing through the tooth part, is curved in the stacking direction of the winding layers so as to follow the winding that winds around the tooth part. This allows the winding that wraps around the housing to fit comfortably against the surface of the housing, increasing the contact area with the housing, improving the temperature measurement accuracy of the coil and reducing (distributing) the load applied to the housing from the winding. Of the coil contact parts on both sides of the housing, the second coil contact part on the inner side closer to the teeth can be curved with a smaller curvature than the first coil contact part on the outer side, or made straight, so that the thickness of the housing in the stacking direction can be reduced toward the curved end of the first coil contact part. This makes it easier for the winding that winds around the housing to come into contact (join) with the layer on the inner side after passing the curved end of the first coil contact part, reducing the load on the housing caused by winding the winding, optimizing the rigidity of the housing, and making it smaller and lighter. By curving the second coil contact portion on the inside near the teeth portion of the housing, the inner surface of the housing fits comfortably into the winding, increasing the contact area with the winding, and further improving the accuracy of measuring the coil temperature.

[0010] A fifth aspect of the present invention is a thermistor unit (40) including: a sensor section (41) for detecting a temperature of a coil (37) having a winding (32) wound in a plurality of layers (32a) around an outer periphery of a tooth section (35) protruding in a radial direction (Dr) of a motor; and a housing (51) incorporating the sensor section (41), the housing (51) being wound and fixed between a pair of layers (32a) in the coil (37), a coil contact portion (53, 54) having a concave-shaped abutment surface (53a, 54a) corresponding to an outer diameter of each winding (32) of the layer (32a) with which it comes into contact is formed on at least one of the surfaces of the housing (51), and in a cross section of the housing (51) taken along the motor radial direction (Dr), a center (53c, 54c) of the concave shape of each abutment surface (53a, 54a) and a center (41c) of the sensor portion (41) are offset from each other in the motor radial direction (Dr). Effect of the Invention

[0011] According to the present invention, in a thermistor mounting structure and a thermistor unit in which a housing containing a sensor portion is wrapped and fixed between layers of a coil, the load on the housing can be reduced and the measurement accuracy of the coil temperature can be improved. [Brief description of the drawings]

[0012] [Figure 1] 1 is a plan view of a motor according to an embodiment of the present invention, viewed from an axial direction. [Diagram 2] 4 is a plan view of a coil to which a thermistor unit is attached in the motor as viewed from the axial direction. FIG. [Diagram 3] FIG. 3 is a cross-sectional view taken along line III-III of FIG. [Figure 4] FIG. 4 is an enlarged view of a main part of FIG. [Diagram 5] FIG. 2 is a perspective view of a thermistor unit. [Figure 6A] 6 is a cross-sectional view taken along line VI-VI of FIG. [Figure 6B] FIG. 6B is a cross-sectional view showing a modified example of the housing shown in FIG. 6A. [Figure 7] 5 is a cross-sectional view corresponding to FIG. 4 and showing details of a sensor unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows a part of a rotating electrical machine to which an embodiment of the present invention is applied. <Motor> As shown in Fig. 1, the rotating electric machine 1A includes a rotor 2, a stator 3A, and a casing 4 that covers the rotor 2 and the stator 3A. In this embodiment, the rotating electric machine 1A is a motor. In this embodiment, the rotor 2 is disposed on the inner peripheral side of the stator 3A. In other words, the rotating electric machine 1A is an inner rotor type motor.

[0014] <Rotor> The rotor 2 has a rotating shaft 21, a rotor core 22, and a plurality of magnetic pole portions . The rotating shaft 21 extends in an axial direction (a direction perpendicular to the plane of the paper in FIG. 1) and is supported via bearings (not shown) so as to be rotatable in a circumferential direction (motor circumferential direction) Dc about an axis C that extends in the axial direction.

[0015] The rotor core 22 is provided on the outer periphery of the rotating shaft 21 in a radial direction (motor radial direction) Dr centered on the axis C. The rotor core 22 is formed in a circular disk shape when viewed from the axial direction. When viewed from the axial direction, a shaft insertion hole 22h through which the rotating shaft 21 is inserted is formed in the center of the rotor core 22. The rotor core 22 is rotatable integrally with the rotating shaft 21 in the circumferential direction Dc.

[0016] The multiple magnetic pole portions 23 are disposed at equal intervals in the circumferential direction Dc on the outer periphery of the rotor core 22. Each magnetic pole portion 23 includes multiple permanent magnets 25. The multiple permanent magnets 25 are embedded in each of the multiple magnet insertion holes 24 formed in the rotor core 22. For example, the permanent magnets 25 are permanent magnets such as neodymium magnets. The number, arrangement, and shape of the permanent magnets 25 constituting the magnetic pole portion 23 can be changed as appropriate.

[0017] <Stator> The stator 3A is disposed on the outer circumferential side in the radial direction Dr with a gap (air gap) therebetween with respect to the rotor core 22. The stator 3A is fixed to the inner circumferential side in the radial direction Dr of the casing 4. The stator 3A has a stator core 31 and a winding 32.

[0018] The stator core 31 integrally includes an annular portion 34 and a plurality of teeth portions 35 . The annular portion 34 is formed on the outer periphery of the stator core 31. The annular portion 34 extends in the circumferential direction Dc and is formed in a circular ring shape when viewed from the axial direction. The annular portion 34, and therefore the stator core 31, are configured by integrating unit parts, which are divided in the circumferential direction Dc for each of a plurality of teeth portions 35, into a ring shape (see FIG. 2).

[0019] The teeth 35 are formed at equal intervals in the circumferential direction Dc. Each tooth 35 extends from the inner periphery of the annular portion 34 toward the inner periphery along the radial direction Dr. A slot 36 is formed between adjacent teeth 35 in the circumferential direction Dc. The slot 36 is formed by cutting out the inner periphery of the stator core 31. The slots 36 are formed in the same number as the teeth 35.

[0020] The winding 32 is a conductive wire (e.g., copper wire) and is held by the stator core 31. The winding 32 is wound around each of the multiple teeth 35 via an insulator 38 made of insulating resin. The winding 32 is wound so that multiple layers 32a are stacked around the outer periphery of the teeth 35 when viewed from the protruding direction of the teeth 35 (the motor radial direction Dr). By winding the winding 32 around each tooth 35, the stator 3A is formed with multiple coils 37 arranged at intervals in the circumferential direction Dc.

[0021] <Thermistor unit> 2 and 3, a thermistor unit 40 that measures the temperature of coil 37 is attached to rotating electric machine 1A. Thermistor unit 40 is attached to one of the multiple coils 37. The thermistor unit 40 is fixed in a state where a housing 51 incorporating a sensor unit 41 is inserted between layers 32a of winding 32 of coil 37.

[0022] Referring also to Figure 5, the thermistor unit 40 of the embodiment comprises a sensor portion 41 which is the thermistor main body, a pair of lead wires (electric wires) 43 extending from the sensor portion 41, a pair of external terminals 45 connected to each lead wire 43, and a housing 51 which is molded by inserting the sensor portion 41, the lead wires 43 and the external terminals 45.

[0023] 7, the sensor unit 41 is an assembled part in which a thermistor body 41a (e.g., semiconductor ceramics) is sealed in a glass tube 41b, and further resin-molded with a protective layer 41d such as epoxy resin. The protective layer 41d of the sensor unit 41 prevents the glass tube 41b from cracking when a housing 51 incorporating the sensor unit 41 is insert-molded. Also, when the housing 51 is wound with the winding 32 of the coil 37, the glass tube 41b is prevented from cracking due to an external force applied to the housing 51 from the winding 32.

[0024] 2, 3 and 5, the sensor unit 41 has a cylindrical shape, and is disposed so that the sensor axis direction is aligned with the motor circumferential direction Dc (tangential direction) when viewed from the motor axial direction Da (axial direction of the rotating shaft 21) in a state where it is attached to the coil 37. The motor circumferential direction Dc is also the width direction of the teeth 35, the motor radial direction Dr is also the protruding direction of the teeth 35 from the annular portion 34, and the motor axial direction Da is also the thickness direction of the teeth 35 and the housing 51.

[0025] In the motor radial direction Dr, the right side in the figure is the outer circumferential side, and the left side in the figure is the inner circumferential side. For convenience of explanation, the upper side in the motor axial direction Da in the figure is referred to as "upper" and the lower side in the figure is referred to as "lower". The thermistor unit 40 is disposed on the upper surface side of the coil 37 in the motor axial direction Da. In the location where the thermistor unit 40 is disposed in this embodiment, the motor axial direction Da corresponds to the stacking direction of the multiple layers 32a of the coil 37.

[0026] Lead wires 43 are led out from both axial ends of the sensor unit 41. Each lead wire 43 extends in the motor circumferential direction Dc and then bends and extends toward the outer periphery in the motor radial direction Dr. A tip end of each lead wire 43 is electrically connected to a base end 47 of a corresponding external terminal 45. For example, the tip end of each lead wire 43 and the base end 47 of the corresponding external terminal 45 may be connected by solder or the like before being inserted into the housing 51.

[0027] Each external terminal 45 is formed by bending one end of a metal plate (conductor plate) that is long in one direction at a right angle to the remaining portion. When attached to the coil 37, each external terminal 45 is disposed such that one end side beyond the bent portion 46 is aligned along the motor circumferential direction Dc, and the other end side beyond the bent portion 46 is aligned along the motor axial direction Da.

[0028] Each external terminal 45 is integrated by inserting the base end portion 47 on the one end side into the housing 51. One end side of each external terminal 45 is arranged such that the plate thickness direction faces the motor axial direction Da. The base end portions 47 of each external terminal 45 have their tips facing each other in the motor circumferential direction Dc and spaced apart from each other. The base end portions 47 of each external terminal 45 are arranged so as to be located on the same plane as each other.

[0029] The other end of each external terminal 45 is disposed such that the plate thickness direction faces the motor circumferential direction Dc. The lower side of the other end of each external terminal 45 is a narrow portion 48 having a relatively narrow width in the motor radial direction Dr, and the upper side of the other end of each external terminal 45 is a terminal body 49 having a relatively wide width in the motor radial direction Dr. A locking hole 48a for locking a locking claw 38b, which will be described later, is formed at the upper end of the narrow portion 48. A widened portion 49a having a wider width in the motor radial direction Dr is formed at the lower end of the terminal body 49. For example, wiring extending from a motor control device can be connected to each terminal body 49.

[0030] 5, the housing 51 has a flat shape with a reduced thickness in the motor axial direction Da. The housing 51 has a substantially rectangular shape when viewed from the motor axial direction Da. The housing 51 has an inner peripheral portion in the motor radial direction Dr as an insertion portion 52 to be inserted between the layers 32a of the coil 37, and an outer peripheral portion in the motor radial direction Dr as an external extension portion 55 disposed outside the coil 37. The housing 51 is formed of a heat-resistant resin such as polyphenylene sulfide resin (PPS resin).

[0031] Upper and lower coil contact portions 53, 54 that come into contact with the pair of layers 32a of the coil 37 that sandwich the housing 51 therebetween are formed on the upper and lower surfaces of the insertion portion 52 in the motor axial direction Da. 6A, an upper coil contact portion (first coil contact portion) 53 on the upper surface side (opposite the teeth 35) of the insertion portion 52 is formed in a convex arc shape on the side away from the teeth 35 (opposite the teeth 35 in the motor axial direction Da, upward in the figure) when viewed from the motor radial direction Dr. For example, a lower coil contact portion (second coil contact portion) 54 on the lower surface side (toward the teeth 35) of the insertion portion 52 is formed in a straight line perpendicular to the motor axial direction Da when viewed from the motor radial direction Dr.

[0032] As a result, the insertion portion 52 is formed such that its vertical thickness in the motor axial direction Da decreases from the center to the end in the motor circumferential direction Dc when viewed from the motor radial direction Dr. Similarly to the insertion portion 52, the external extension portion 55 is also formed such that its upper surface side is formed in an upwardly convex arc shape and its lower surface side is formed in a straight line perpendicular to the motor axial direction Da when viewed from the motor radial direction Dr, and its vertical thickness decreases from the center to the end in the motor circumferential direction Dc.

[0033] 6B, the lower coil contact portion 54 on the lower surface side of the insertion portion 52 may be a lower coil contact portion 54' formed in a convex arc shape on the side (upward) away from the teeth portion 35 when viewed from the motor radial direction Dr. The curvature of the lower coil contact portion 54' when viewed from the motor radial direction Dr is smaller than the curvature of the upper coil contact portion 53 when viewed from the motor radial direction Dr. This maintains an aspect in which the vertical thickness of the insertion portion 52 in the motor axial direction Da decreases from the center to the end portions in the motor circumferential direction Dc when viewed from the motor radial direction Dr.

[0034] 4 and 5, each coil contact portion 53, 54 is formed with a plurality of concave abutment surfaces 53a, 54a corresponding to (matching the outer peripheral shape of) the outer diameter of each winding 32 of the layer 32a with which each coil contact portion 53, 54 contacts in the coil 37. The plurality of abutment surfaces 53a, 54a are arranged in parallel adjacent to each other in the motor radial direction Dr. Each coil contact portion 53, 54 has a wavy shape with a plurality of concave shapes arranged.

[0035] Referring to Figure 4, in a cross section along the motor radial direction Dr of the housing 51, the centers 53c, 54c (corresponding to the axis of the winding 32) of the concave shapes of the contact surfaces 53a, 54a of the coil contact portions 53, 54 and the center 41c of the sensor portion 41 are offset from each other in the motor radial direction Dr.

[0036] In detail, in a cross section along the motor radial direction Dr of the housing 51, when a virtual straight line t1 is extended along the stacking direction (motor axial direction Da) from the center 53c or 54c of the concave shape of each abutment surface 53a or 54a on one side of each coil contact portion 53, 54, the center 54c or 53c of the concave shape of each abutment surface 54a or 53a on the other side of each coil contact portion 53, 54 is located on each virtual straight line t1.

[0037] That is, in a section along the motor radial direction Dr, in a portion where the housing 51 is wound around the coil 37, a pair of layers 32a on both sides of the housing 51 make the motor radial direction positions of the concave shapes of the multiple abutment surfaces 53a, 54a coincide with each other. The entire sensor unit 41 is disposed between a pair of imaginary straight lines t1 adjacent to each other in the motor radial direction Dr. In a section along the motor radial direction Dr, the sensor unit 41 and the winding 32 have roughly the same diameter, and in a section where the sensor unit 41 is disposed, the winding 32 and the sensor unit 41 of the pair of layers 32a on the upper and lower sides of the housing 51 overlap with each other with their motor radial direction positions shifted by a radius, so that the sensor unit 41 can be disposed easily and the thickness of the housing 51 can be easily ensured around the sensor unit 41.

[0038] Here, the thermistor unit 40 is attached to the coil 37 by temporarily stopping the automatic coil winding process during which the coil 37 is manufactured, placing the thermistor unit 40 on the surface of the inner layer 32a, and then restarting the automatic winding process to wind the thermistor unit 40 into the coil 37.

[0039] The winding 32 of the coil 37 is wound so as to wind around the outer periphery of the teeth 35 when viewed from the protruding direction of the teeth 35 (the motor radial direction Dr). The winding 32 is wound so as to stack a plurality of layers 32a around the outer periphery of the teeth 35 when viewed from the protruding direction of the teeth 35. At the location where the thermistor unit 40 is arranged, a housing 51 of the thermistor unit 40 is wrapped and fixed between a pair of layers 32a adjacent to each other in the stacking direction (the motor axial direction Da) among the plurality of layers 32a.

[0040] The configuration for positioning and temporarily fixing the thermistor unit 40 to the coil 37 (workpiece) in the middle of manufacture will be described below. The positioning of the thermistor unit 40 to the workpiece is mainly performed by the external extension 55 of the housing 51 and the pair of external terminals 45. The thermistor unit 40 is placed (temporarily fixed) on the surface of the coil 37 during the automatic coil winding process, and in this state, the winding 32 is further wound, whereby the housing 51 is wrapped between the layers 32a of the winding 32 of the coil 37 and fixed.

[0041] 2, 3, and 6A, a pair of standing walls 38a standing upward in the motor axial direction Da are formed on the outer circumferential side of the insulator 38 in the motor radial direction Dr. The pair of standing walls 38a are spaced apart from each other in the motor circumferential direction Dc, and the external extension 55 of the housing 51 and the pair of external terminals 45 are disposed within the space. A locking claw 38b corresponding to the locking hole 48a of each external terminal 45 is protruded from each of the standing walls 38a.

[0042] The thermistor unit 40 approaches the workpiece from above in the motor axial direction Da, and inserts the external extension 55 of the housing 51 and the pair of external terminals 45 between the pair of standing wall portions 38a. The pair of external terminals 45 are inserted between the pair of standing wall portions 38a so that the outer surfaces on the outer side in the motor circumferential direction are in sliding contact with the inner surfaces on the inner side in the motor circumferential direction of the pair of standing wall portions 38a. This positions the thermistor unit 40 in the motor circumferential direction Dc.

[0043] The pair of external terminals 45 have the motor radially inner edge 48b of each narrow portion 48 abut against the abutment portions 38c formed on the inner surfaces of the pair of standing wall portions 38a. This positions the thermistor unit 40 in the motor radial direction Dr. In this positioning, the thermistor unit 40 is displaceable toward the motor radially outer periphery, and priority can be given to matching the abutment surfaces 53a, 54a of the insertion portion 52 of the housing 51 with the windings 32 of the coil 37.

[0044] The pair of external terminals 45 are restricted from disengaging upward in the motor axial direction Da by the locking claws 38b of the standing wall portion 38a being inserted (engaged) into the respective locking holes 48a, thereby positioning the pair of external terminals 45 in the motor axial direction Da. For example, by setting a prescribed play in the engagement between the locking holes 48a and the locking claws 38b, the thermistor unit 40 can be displaced by a prescribed amount in the motor axial direction Da, and it is possible to prioritize the insertion portion 52 of the housing 51 being sandwiched between the pair of layers 32a of the coil 37 without load.

[0045] As described above, the thermistor mounting structure in the above embodiment includes a coil 37 having a winding 32 wound in a plurality of layers 32a around a tooth portion 35 protruding in the motor radial direction Dr, and a thermistor unit 40 having a sensor portion 41 inside a housing 51 for detecting the temperature of the coil 37, in which the housing 51 of the thermistor unit 40 is wound between a pair of layers 32a of the coil 37 and fixed, and coil contact portions 53, 54 having a plurality of concave abutment surfaces 53a, 54a corresponding to the outer diameter of each winding 32 of the contacting layer 32a are formed on each surface of the housing 51 that contacts the pair of layers 32a, and in a cross section of the housing 51 along the motor radial direction Dr, the concave centers 53c, 54c of the concave shapes of the abutment surfaces 53a, 54a and the center 41c of the sensor portion 41 are offset from each other in the motor radial direction Dr.

[0046] That is, the thermistor unit 40 in the above embodiment has a sensor section 41 that detects the temperature of a coil 37 having a winding 32 wound to form multiple layers 32a around a tooth portion 35 protruding in the motor radial direction Dr, and a housing 51 that incorporates the sensor section 41, and the housing 51 is fixed by being wound between a pair of layers 32a of the coil 37, and coil contact sections 53, 54 having a plurality of concave abutment surfaces 53a, 54a that correspond to the outer diameter of each winding 32 of the contacting layer 32a are formed on each surface of the housing 51 that contacts the pair of layers 32a, and in a cross section of the housing 51 along the motor radial direction Dr, centers 53c, 54c of the concave shapes of each abutment surface 53a, 54a and the center 41c of the sensor section 41 are offset from each other in the motor radial direction Dr.

[0047] According to this configuration, in a configuration in which the housing 51 of the thermistor unit 40 is wound and fixed between a plurality of layers 32a of the coil 37 of the stator 3A, a plurality of concave abutment surfaces 53a, 54a are formed on the coil contact portions 53, 54 on the surface of the housing 51 so as to align the individual windings 32, and the centers 53c, 54c of the concave shapes of the abutment surfaces 53a, 54a and the center 41c of the sensor portion 41 are offset from each other in a cross-sectional view of the housing 51, so that the sensor portion 41 can be disposed in a thick portion of the housing 51 having the corrugated coil contact portions 53, 54. This makes it easier to ensure the thickness of the housing 51, especially around the sensor portion 41, even in a configuration in which the housing 51 is curved so as to follow the winding 32 wound around the teeth portion 35. This makes it easier to ensure the rigidity of the housing 51 around the sensor portion 41, and suppresses an increase in stress around the sensor portion 41 when the winding 32 is wound around the housing 51. That is, the overall rigidity of the housing 51 can be increased, and the housing 51, and therefore the thermistor unit 40, can be made smaller and lighter.

[0048] In the above thermistor mounting structure (and thermistor unit 40), the pair of layers 32a sandwiching the housing 51 are stacked in a stacking direction (motor axial direction Da) perpendicular to the motor radial direction Dr, and in a cross section of the housing 51 along the motor radial direction Dr, each coil contact portion 53, 54 has a center 53c, 54c in each of the concave shapes of the multiple abutment surfaces 53a, 54a, and when an imaginary straight line t1 extending along the stacking direction is extended from the center 53c, 54c of each of the concave shapes on one side of each of the coil contact portions 53, 54, the center 53c, 54c of each of the concave shapes on the other side of each of the coil contact portions 53, 54 is disposed on each imaginary straight line t1, The sensor unit 41 is disposed between a pair of imaginary straight lines t1 adjacent to each other in the motor radial direction Dr. According to this configuration, in the coil contact portions 53, 54 on both sides of the housing 51, the central positions (motor radial position) of the concave shapes of the contact surfaces 53a, 54a are aligned on both sides of the housing 51 in a cross-sectional view of the housing 51, so that the sensor portion 41 can be disposed in a portion with a certain thickness between adjacent concave shapes in the motor radial direction Dr. As a result, as in the above, the overall rigidity of the housing 51 can be increased, and the housing 51, and in turn, the thermistor unit 40, can be made smaller and lighter.

[0049] In the above thermistor mounting structure (and thermistor unit 40), of the coil contact portions 53, 54, at least the first coil contact portion 53 farthest from the tooth portion 35 is formed in a convex curved shape away from the tooth portion 35 when viewed in the motor radial direction Dr, and of the coil contact portions 53, 54, the second coil contact portion 54 closer to the tooth portion 35 is formed in a curved shape having a smaller curvature than the first coil contact portion 53 or in a straight line when viewed in the motor radial direction Dr. According to this configuration, of the coil contact portions 53, 54 on both sides of the housing 51, the first coil contact portion 53 on the outside, passing through the tooth portion 35, is curved in the stacking direction of the layers 32a of the winding 32 so as to follow the winding 32 wound around the tooth portion 35, so that the winding 32 that winds around the housing 51 is wound so as to fit closely to the surface of the housing 51, thereby increasing the contact area with the housing 51, improving the temperature measurement accuracy of the coil 37 and reducing (distributing) the load applied to the housing 51 from the winding 32.

[0050] Of the coil contact portions 53, 54 on both sides of the housing 51, the second coil contact portion 54 on the inner periphery side closer to the teeth portion 35 is curved with a smaller curvature than the first coil contact portion 53 on the outer periphery side, or is straight, so that the thickness of the housing 51 in the stacking direction can be reduced toward the curved end of the first coil contact portion 53. This makes it easier for the winding 32 wound around the housing 51 to come into contact (join) with the layer 32a on the inner periphery side after passing the curved end of the first coil contact portion 53, reducing the load on the housing 51 caused by winding the winding 32 and optimizing the rigidity of the housing 51 to achieve a smaller and lighter body. By curving the inner second coil contact portion 54 near the tooth portion 35 of the housing 51, the inner surface of the housing 51 comes into contact with the winding 32 in a conformal manner, thereby increasing the contact area with the winding 32 and further improving the temperature measurement accuracy of the coil 37.

[0051] The present invention is not limited to the above-described embodiments explained with reference to the drawings, and various modifications are possible within the technical scope of the present invention. For example, the rotating electric machine 1A is an inner rotor type motor, but is not limited to this configuration. For example, the rotating electric machine may be an outer rotor type in which the rotor is disposed on the outer periphery side of the stator. Furthermore, the rotating electric machine is not limited to a motor, and may be a generator. The housing of the thermistor unit may be configured such that the corrugated coil contact portion corresponding to each winding of the contacting layer is formed on only one of the upper and lower surfaces of the housing. The number of concave abutment surfaces formed on the coil contact portion is not limited to two or more, and may be one. The configurations in the above-described embodiments are merely examples of the present invention, and various modifications are possible without departing from the gist of the present invention, such as replacing the components of the embodiments with well-known components. [Explanation of symbols]

[0052] 1A Rotating Electric Machine, Motor 3A Stator 31 Stator core 32 windings 32a layer 35 Teeth 37 Coil 40 Thermistor unit 41 Sensor section 41c center 51 Case 53 Upper coil contact portion (first coil contact portion) 53a Contact surface 53c center 54 Lower coil contact portion (second coil contact portion) 54a Contact surface 54c center t1 Virtual line Dr Motor radial direction Da Motor axial direction Dc Motor circumferential direction

Claims

1. a coil (37) in which a winding (32) is wound in a plurality of layers (32a) around an outer periphery of a tooth portion (35) protruding in a radial direction (Dr) of the motor; a thermistor unit (40) having a sensor portion (41) for detecting the temperature of the coil (37) inside a housing (51); A thermistor mounting structure in which a housing (51) of the thermistor unit (40) is wound between a pair of layers (32a) of the coil (37) and fixed thereto, a coil contact portion (53, 54) having a concave contact surface (53a, 54a) corresponding to an outer diameter of each winding (32) of the contacting layer (32a) is formed on at least one of the surfaces of the housing (51) that contacts the pair of layers (32a); a thermistor mounting structure characterized in that, in a cross section of the housing (51) along the motor radial direction (Dr), the center (53c, 54c) of the concave shape of each abutment surface (53a, 54a) and the center (41c) of the sensor portion (41) are offset from each other in the motor radial direction (Dr).

2. The coil contact portions (53, 54) are formed on the surfaces of the housing (51) that contact the pair of layers (32a), 2. The thermistor mounting structure according to claim 1, characterized in that, in a cross section of the housing (51) along the motor radial direction (Dr), the center (53c, 54c) of the concave shape of each abutment surface (53a, 54a) of each coil contact portion (53, 54) and the center (41c) of the sensor portion (41) are offset from each other in the motor radial direction (Dr).

3. A pair of layers (32a) sandwiching the housing (51) are laminated in a lamination direction perpendicular to the motor radial direction (Dr), In a cross section of the housing (51) along the motor radial direction (Dr), each coil contact portion (53, 54) has a center (53c, 54c) in each of the concave shapes of a plurality of contact surfaces (53a, 54a), 3. The thermistor mounting structure according to claim 2, characterized in that when imaginary straight lines (t1) are extended along the stacking direction from the center (53c, 54c) of each concave shape of one of the coil contact portions (53, 54), the sensor portion (41) is disposed between a pair of adjacent imaginary straight lines (t1) in the motor radial direction (Dr).

4. Among the coil contact portions (53, 54), at least a first coil contact portion (53) farther from the teeth portion (35) is formed in a curved shape that is convex toward a side away from the teeth portion (35) when viewed in the motor radial direction (Dr), 3. The thermistor mounting structure according to claim 1, wherein, of the coil contact portions (53, 54), a second coil contact portion (54) closer to the teeth portion (35) is formed in a curved shape having a smaller curvature than the first coil contact portion (53) or in a straight shape when viewed in the motor radial direction (Dr).

5. a sensor unit (41) for detecting the temperature of a coil (37) having a winding (32) wound in a plurality of layers (32a) around an outer periphery of a tooth portion (35) protruding in a radial direction (Dr) of the motor; A housing (51) incorporating the sensor unit (41), The thermistor unit (40) is configured such that the housing (51) is wound between a pair of layers (32a) of the coil (37) and fixed thereto, a coil contact portion (53, 54) having a concave contact surface (53a, 54a) corresponding to an outer diameter of each winding (32) of the contacting layer (32a) is formed on at least one of the surfaces of the housing (51) that contacts the pair of layers (32a); A thermistor unit characterized in that, in a cross section of the housing (51) along the motor radial direction (Dr), the center (53c, 54c) of the concave shape of each abutment surface (53a, 54a) and the center (41c) of the sensor portion (41) are offset from each other in the motor radial direction (Dr).

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