Temperature detector and manufacturing method of temperature detector

Abstract

To provide a temperature detector capable of measuring a temperature of a coil in a rotary electric machine with high accuracy.SOLUTION: A temperature detector is a temperature detector provided to a rotary electric machine 1, that comprises: a stator core 10; and a coil 40 wound to the stator core 10. The temperature detector comprises: an insulator 20 which is arranged between the stator core 10 and the coil 40, and of which one side of a direction orthogonal to a winding shaft direction of the coil 40 is contacted to the stator core 10, and the other side includes a winding part 21 wound to the coil 40, and which electrically insulates a space between the stator core 10 and the coil 40; and a thermistor 50 that detects a temperature of the coil 40. The thermistor 50 is arranged to an inner part of the winding part 21. The front surface of the thermistor 50 is contacted to the winding part 21.SELECTED DRAWING: Figure 6

Description

[Technical field]

[0001] The present invention relates to a temperature detection device and a method for manufacturing a temperature detection device. [Background technology]

[0002] In recent years, efforts to realize a low-carbon or carbon-free society have been intensifying, and research and development of electrification technology has been conducted in vehicles to reduce CO2 emissions and improve energy efficiency. An electric vehicle includes a rotating electric machine as a prime mover. The rotating electric machine includes a stator around which a coil is wound, and a rotor that is rotatably provided relative to the stator. The stator includes a stator core around which a coil is wound. An insulator is attached to the stator core to electrically insulate the stator core from the coil. The stator may be provided with a temperature detection element that detects the temperature of the coil (see, for example, Patent Document 1). Patent Document 1 discloses an insulating bobbin that houses a stator core on its inner circumference and has a winding wound around its outer circumference in a layered manner, the insulating bobbin having a winding surface around which the winding is wound in a layered manner, and a temperature detection element fixing groove formed on the winding surface for fixing a temperature detection element that detects the temperature of the winding. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 5444770 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the field of motorization technology, rotating electric machines have the following problem. If the temperature detection element is exposed on the winding surface of the insulator, only a part of the temperature detection element contacts the coil and the other part contacts the air, so there is a possibility that the coil temperature cannot be measured accurately. Therefore, there is room for improvement in the arrangement of the temperature detection element in conventional rotating electric machines.

[0005] In order to solve the above problems, the present application has an object to provide a temperature detection device that can accurately measure the temperature of a coil in a rotating electrical machine and a manufacturing method thereof, which will ultimately contribute to improving energy efficiency. [Means for solving the problem]

[0006] The temperature detection device according to the first aspect of the present invention is a temperature detection device provided in a rotating electric machine (1) including an iron core (10) and a coil (40) wound around the iron core (10), and includes a winding portion (21) that is disposed between the iron core (10) and the coil (40) and has one side in a direction perpendicular to the winding axis direction of the coil (40) in contact with the iron core (10) and the other side in contact with the coil (40), an insulator (20) that electrically insulates between the iron core (10) and the coil (40), and a thermistor (50) that detects the temperature of the coil (40), the thermistor (50) is disposed inside the winding portion (21), and the surface of the thermistor (50) is in contact with the winding portion (21).

[0007] According to the first aspect, since there is no air layer around the thermistor, heat is easily conducted from the coil to the thermistor via the winding portion, and therefore the temperature of the coil can be measured with high accuracy.

[0008] A temperature detection device according to a second aspect of the present invention is the temperature detection device according to the first aspect, wherein the winding portion (21) has a winding surface (22) in contact with the coil (40), and the winding surface (22) is located on the opposite side of the thermistor (50) from the iron core (10), and may have a bulge (33) that bulges in a direction intersecting the winding axis direction.

[0009] According to the second aspect, the adhesion between the coil and the winding surface can be improved at the bulge, compared to a configuration in which the winding surface is formed flat, and heat is more easily conducted from the coil to the thermistor via the bulge, thereby making it possible to measure the temperature of the coil with high accuracy.

[0010] A temperature detection device according to a third aspect of the present invention is the temperature detection device according to the first or second aspect, further comprising a terminal (60) connected to the thermistor (50) and drawn out to the outside of the insulator (20), and the insulator (20) may be filled around the connection portion between the thermistor (50) and the terminal (60).

[0011] According to the third aspect, the thermistor and the terminals are joined together in advance, and the insulator can be molded integrally with the thermistor and the terminals. This makes it easier to mold the insulator incorporating the thermistor and the terminals. In addition, it is possible to prevent the thermistor from shifting position during molding of the insulator, thereby improving the positional accuracy of the thermistor.

[0012] A manufacturing method for a temperature detection device according to a fourth aspect of the present invention is a manufacturing method for a temperature detection device provided in a rotating electric machine (1) including an iron core (10) and a coil (40) wound around the iron core (10), wherein the temperature detection device is arranged between the iron core (10) and the coil (40), and has a winding portion (21) having one side in a direction perpendicular to the winding axis direction of the coil (40) in contact with the iron core (10) and the other side in contact with the coil (40), and comprises an insulator (20) that electrically insulates between the iron core (10) and the coil (40), and a thermistor (50) that detects the temperature of the coil (40), and the insulator (20) is formed by insert molding together with the thermistor (50) such that the thermistor (50) is arranged inside the winding portion (21) and the surface of the thermistor (50) is in contact with the winding portion (21).

[0013] According to the fourth aspect, since there is no air layer around the thermistor, heat is easily conducted from the coil to the thermistor via the winding portion, and therefore a temperature detection device capable of measuring the temperature of the coil with high accuracy can be manufactured. Effect of the Invention

[0014] According to the present invention, it is possible to provide a temperature detection device capable of measuring the temperature of a coil in a rotating electrical machine with high accuracy, and a manufacturing method thereof. [Brief description of the drawings]

[0015] [Figure 1] FIG. 2 is a perspective view of a portion of a stator according to an embodiment. [Diagram 2] 2 is a view of a part of the stator shown in FIG. 1 as viewed from the axial direction. [Diagram 3] FIG. 4 is a view showing a part of the insulator according to the embodiment as viewed from a radial direction. [Figure 4] FIG. 2 is a perspective view of a first insulator according to the embodiment. [Diagram 5] FIG. 2 is a perspective view of a thermistor and a terminal. [Figure 6] FIG. 3 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] 7 is a cross-sectional view taken along a line VII-VII in FIG. 6. [Figure 8] 8 is a cross-sectional view taken along a line VIII-VIII in FIG. 7. [Figure 9] 7 is a cross-sectional view of a stator according to a first modified example of the embodiment, which corresponds to the cross section IV-IV in FIG. 6. FIG. [Figure 10] 7 is a cross-sectional view of a stator according to a second modified example of the embodiment, which corresponds to the cross section shown in FIG. 6. [Figure 11] 7 is a cross-sectional view of a stator according to a third modified example of the embodiment, which corresponds to the cross section shown in FIG. 6. FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the following description, components having the same or similar functions are denoted by the same reference numerals. In addition, duplicate descriptions of those components may be omitted.

[0017] The rotating electric machine 1 of this embodiment is an inner rotor type three-phase permanent magnet synchronous motor. The rotating electric machine 1 is a driving motor mounted on a vehicle such as an electric two-wheeler. The rotating electric machine 1 includes a rotor that rotates integrally with a rotating shaft, and a stator 3 that surrounds the rotor. The rotor and the stator 3 are arranged coaxially. In the following description, the direction in which the common axis of the rotor and the stator 3 extends is referred to as the axial direction, the direction perpendicular to the common axis is referred to as the radial direction, and the direction revolving around the common axis is referred to as the circumferential direction. In addition, in the drawings used in the following description, the arrow A indicates the axial direction, the arrow R indicates the radial direction, and the arrow P indicates the circumferential direction, respectively.

[0018] Fig. 1 is a perspective view of a portion of a stator according to an embodiment of the present invention, Fig. 2 is a view of the portion of the stator shown in Fig. 1 as seen from the axial direction. 1 and 2, the stator 3 includes a stator core 10 (iron core), an insulator 20, and a coil 40. In this embodiment, the winding axis direction of the coil 40 coincides with the radial direction.

[0019] The stator core 10 is formed by arranging a plurality of split cores 11 in an annular shape along the circumferential direction. For example, the split cores 11 are formed by stacking a plurality of T-shaped electromagnetic steel sheets punched by a press. The split cores 11 include back yoke pieces 12 extending along the circumferential direction and teeth 13 extending radially inward from the back yoke pieces 12. The back yoke pieces 12 form an annular back yoke of the stator core 10 by connecting the split cores 11 in the circumferential direction. The teeth 13 form slots 14 between adjacent teeth 13 by connecting the split cores 11 in the circumferential direction. The radially inner ends of the teeth 13 face the magnetic pole portions of the rotor.

[0020] The insulators 20 are attached to each of the split cores 11 so as to surround the teeth 13. The insulators 20 are made of an electrically insulating material such as resin. For example, the insulators 20 are made of polyphenylene sulfide. The insulators 20 include a winding portion 21 that is arranged along the outer peripheral surface of the teeth 13, an inner flange 24 that protrudes from a radially inner edge of the winding portion 21, and an outer flange 25 that protrudes from a radially outer edge of the winding portion 21. The winding portion 21 is disposed between the teeth 13 and the coil 40, and one side of the winding portion 21 in a direction perpendicular to the winding axis direction of the coil 40 contacts the stator core 10, and the other side contacts the coil 40. The winding portion 21 has a winding surface 22 that contacts the coil 40 from its inner peripheral side (see FIG. 4).

[0021] The winding portion 21 includes a first end surface covering portion 21a covering a first end surface of the tooth 13 facing a first axial direction, a second end surface covering portion (not shown) covering a second end surface of the tooth 13 facing a second axial direction, and a pair of side surface covering portions 21c covering a pair of side surfaces facing the circumferential direction (see also FIG. 4). For example, the thickness of the first end surface covering portion 21a and the second end surface covering portion is greater than the thickness of the side surface covering portion 21c. The inner flange 24 and the outer flange 25 extend so as to surround the entire circumference of the tooth 13. The outer flange 25 is aligned along the inner peripheral surface of the back yoke piece 12. A winding groove 28 is formed between the inner flange 24 and the outer flange 25, in which the coil 40 wound around the winding portion 21 is disposed. The outer flange 25 has a protruding portion 26 located in the first direction of the back yoke piece 12 of the split core 11 when viewed from the radial direction.

[0022] Fig. 3 is a view showing a part of the insulator according to the embodiment as viewed from a radial direction. In Fig. 3, teeth 13 located on the inner side of insulator 20 are shown by imaginary lines. As shown in FIG. 3, a recess 31 recessed in the axial direction is formed at a corner of the inner peripheral surface of the insulator 20. The recess 31 faces a side of the tooth 13 extending in the radial direction. The recess 31 is formed at a location facing an end face of the tooth 13 facing the axial direction. That is, the recess 31 is formed in the first end surface covering portion 21a and the second end surface covering portion of the winding portion 21. It is preferable that the recess 31 faces the side of the tooth 13 extending in the radial direction over its entire length. In this embodiment, the recess 31 extends along the radial direction over the entire length of the inner peripheral surface of the insulator 20. The recess 31 may be formed on both sides in the axial direction, or may be formed on only one side in the axial direction. That is, in this embodiment, the recess 31 is formed in both the first end surface covering portion 21a and the second end surface covering portion, but it may be formed in only one of the first end surface covering portion 21a and the second end surface covering portion.

[0023] FIG. 4 is a perspective view of the first insulator according to the embodiment. As shown in FIG. 1 and FIG. 4, the insulator 20 is divided into two parts, a first insulator 201 and a second insulator 202. The division positions of the first insulator 201 and the second insulator 202 are located at positions corresponding to the axial middle parts of the teeth 13. The middle parts may be located between one end and the other end of the teeth 13 in the axial direction. The insulator 20 is divided in the axial direction so that the division positions of the first insulator 201 and the second insulator 202 are located at each side surface covering portion 21c. That is, the first insulator 201 has the entire first end surface covering portion 21a. The first insulator 201 and the second insulator 202 are each a single member formed of a single material.

[0024] 4, a thermistor 50 and terminals 60 are incorporated in the insulator 20. The peripheral structure of the thermistor 50 and terminals 60 will be described later.

[0025] 1 and 2, coils 40 are formed by winding wire around teeth 13 via insulators 20. Stator 3 is provided with a U-phase coil, a V-phase coil, and a W-phase coil. One of coils 40, the U-phase coil, the V-phase coil, and the W-phase coil, is wound around each split core 11. Coils 40 are wound around teeth 13 via insulators 20 by concentrated winding.

[0026] The following describes the peripheral structure of the thermistor 50 and terminal 60. The thermistor 50 is an example of a temperature detection element. FIG. 5 is a perspective view of the thermistor and terminals. As shown in Figures 4 and 5, the thermistor 50 includes an element body 51 and a pair of lead wires 52 extending from the element body 51. The element body 51 includes a resistor 51a and a glass portion 51b covering the resistor 51a (see Figure 8). The pair of lead wires 52 are electrically connected to the resistor 51a. The pair of terminals 60 are made of a metal material. The pair of terminals 60 are electrically connected to the pair of lead wires 52 of the thermistor 50 in a one-to-one relationship.

[0027] Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 2. Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. As shown in FIG. 6 and FIG. 7, the thermistor 50 is disposed inside the winding portion 21 in the first insulator 201. More specifically, the winding portion 21 is filled around at least the element body 51 of the thermistor 50, and the surface of the element body 51 is in contact with the winding portion 21. In other words, the entire element body 51 is covered with the material forming the first insulator 201. As a result, the material forming the winding surface 22 of the insulator 20 is continuous up to the surface in contact with the element body 51. Furthermore, the first insulator 201 is also filled around the entire lead wire 52 of the thermistor 50. Therefore, the first insulator 201 is filled around the entire thermistor 50.

[0028] The element body 51 of the thermistor 50 is located between the winding surface 22 and the teeth 13 in the axial direction so as to overlap the teeth 13 and the coil 40 when viewed in the axial direction. The element body 51 has the insulators 20 interposed between the coil 40 and the teeth 13. As a result, the element body 51 is not in contact with the coil 40 and the stator core 10, and does not directly face the coil 40 and the stator core 10. The element body 51 overlaps the circumferential center position of the first end face of the teeth 13. The element body 51 is located in the central region when the formation range of the winding groove 28 is divided into thirds in the radial direction.

[0029] The pair of lead wires 52 extend radially outward from the element body 51. Each lead wire 52 has a base end 52a connected to the element body 51 and extending radially, and a tip end 52b bent from the end of the base end 52a opposite the element body 51 and extending in the circumferential direction. The tip ends 52b of the pair of lead wires 52 extend in the circumferential direction so as to be separated from each other.

[0030] A pair of terminals 60 are arranged at intervals in the circumferential direction. Each terminal 60 is connected to the thermistor 50 inside the insulator 20 and is drawn out to the outside of the insulator 20. Each terminal 60 includes a covering portion 61 covered by the insulator 20 and an outer extension portion 62 extending from the insulator 20 and exposed to the outside of the insulator 20. The covering portion 61 is arranged inside the first insulator 201. The covering portion 61 has a connection portion 63 connected to the lead wire 52. The first insulator 201 is filled around the connection portion 63. The covering portion 61 extends from the connection portion 63 inside the protruding portion 26 in a first axial direction. The outer extension portion 62 protrudes in the first direction from an end face of the protruding portion 26 in the first direction.

[0031] For example, the lead wire 52 of the thermistor 50 and the terminal 60 are joined together by ultrasonic welding, spot welding, soldering, or the like. The first insulator 201 is insert molded together with the joined thermistor 50 and terminal 60, and is filled around the thermistor 50 and terminal 60. The first insulator 201 incorporating the thermistor 50 and terminal 60 is combined with the second insulator 202 and attached to the split core 11, and the coil 40 is wound around the winding portion 21 of the insulator 20 consisting of the first insulator 201 and the second insulator 202, thereby completing a part of the stator 3 shown in FIG.

[0032] As described above, the rotating electric machine 1 of this embodiment has a temperature detection device including the insulator 20 having the winding portion 21 arranged between the stator core 10 and the coil 40, and the thermistor 50 that detects the temperature of the coil 40. The thermistor 50 is arranged inside the winding portion 21. The insulator 20 is formed by insert molding together with the thermistor 50 so that the surface of the thermistor 50 is in contact with the winding portion 21. With this configuration, since there is no air layer around the thermistor 50, heat is easily conducted from the coil 40 to thermistor 50 via the winding portion 21. Therefore, the temperature of the coil 40 can be measured with high accuracy.

[0033] The insulator 20 is filled around the connection between the lead wire 52 of the thermistor 50 and the terminal 60. With this configuration, the thermistor 50 and the terminal 60 are joined together in advance, and the insulator 20 can be molded integrally with the thermistor 50 and the terminal 60. This makes it easy to mold the insulator 20 incorporating the thermistor 50 and the terminal 60. Furthermore, it is possible to prevent the thermistor 50 from shifting out of position during molding of the insulator 20, improving the positional accuracy of the thermistor 50.

[0034] Axial recesses 31 are formed in the corners of the inner peripheral surface of the insulator 20. The recesses 31 face radially extending sides of the teeth 13. This configuration can prevent the sides of the teeth 13 from digging into the insulator 20 and damaging the insulator 20.

[0035] The element body 51 of thermistor 50 is disposed in a central region when the formation range of winding groove 28 is divided into thirds in the radial direction. With this configuration, the temperature of the radial central portion of coil 40, which is more likely to become hot, can be measured by thermistor 50. Therefore, the temperature of coil 40 can be measured with high accuracy.

[0036] As shown in FIG. 9, the winding surface 22 of the insulator 20 may have a bulge 33 that bulges in a direction intersecting the winding axis direction of the coil 40. The bulge 33 is located on the opposite side of the teeth 13 across the element body 51 of the thermistor 50. That is, the bulge 33 is formed on the first end surface covering portion 21a of the winding portion 21. The bulge 33 bulges in the first direction as viewed from the radial direction so as to be located closest to the first axial direction at the same position as the element body 51 of the thermistor 50 in the circumferential direction. The bulge 33 is curved in a convex curved shape as viewed from the radial direction. The bulge 33 extends in the radial direction over the entire length of the winding portion 21.

[0037] According to this configuration, it is easier to improve the adhesion between the coil 40 and the winding surface 22 at the bulge 33 compared to a configuration in which the winding surface is formed in a flat shape, so that heat is more easily conducted from the coil 40 to the thermistor 50 via the bulge 33. Therefore, the temperature of the coil 40 can be measured with high accuracy. In addition, since the winding portion 21 can be made thick around the element body 51, when the coil 40 is wound around the winding portion 21, it is possible to prevent the tension of the coil 40 from being transmitted to the element body 51 and excessive stress being applied to the thermistor 50.

[0038] As shown in FIG. 10, a peak 35 protruding outward (in a first axial direction) as viewed from the circumferential direction may be formed on the winding surface 22 at a location on the opposite side of the teeth 13 across the thermistor 50. The peak 35 may be formed on the above-mentioned bulging portion 33, or on a flat portion perpendicular to the axial direction. For example, the peak 35 extends along the circumferential direction and is provided in a plurality of locations at approximately equal intervals in the radial direction. In this case, the valley 36 between a pair of adjacent peaks 35 may position the winding located on the innermost circumference of the coil 40. By disposing the element body 51 of the thermistor 50 between the peak 35 and the teeth 13, the portion of the insulator 20 located between the element body 51 of the thermistor 50 and the coil 40 can be made thick. Therefore, when the coil 40 is wound around the winding portion 21, the tension of the coil 40 is transmitted to the element body 51, and excessive stress is prevented from being applied to the thermistor 50.

[0039] 11, the element body 51 of thermistor 50 may be disposed between the valley portion 36 and the teeth 13. This configuration allows the portion of the insulator 20 located between the element body 51 of thermistor 50 and the coil 40 to be thin. This facilitates heat conduction from the coil 40 to the element body 51 of thermistor 50, allowing the temperature of the coil 40 to be measured with high accuracy.

[0040] The thermistor may also have a protective layer that covers the glass portion. For example, the protective layer is an epoxy resin. With this configuration, the protective layer can prevent the tension of the coil 40 that is transmitted to the element body 51 when the coil 40 is wound, and the vibration during operation of the rotating electric machine 1, from being transmitted to the glass portion. Therefore, it is possible to prevent excessive stress from being applied to the glass portion of the element body.

[0041] The present invention is not limited to the above-described embodiment explained with reference to the drawings, and various modifications are possible within the technical scope of the present invention. For example, in the above embodiment, the coil 40 is wound around the teeth 13 by concentrated winding, but the coil may be wound around the teeth by distributed winding.

[0042] In the above embodiment, the teeth 13 extend in the axial direction, but the teeth may extend in a direction inclined relative to the axial direction, and the stator core may be skewed.

[0043] In the above embodiment, the present invention is applied to a radial gap type rotating electric machine in which the stator and the rotor have a magnetic gap in the radial direction. However, the present invention may also be applied to an axial gap type rotating electric machine in which the stator and the rotor have a magnetic gap in the axial direction.

[0044] In the above embodiment, the insulator 20 is divided into the first insulator 201 and the second insulator 202, but the insulator does not have to be divided. The thermistor may be embedded at any position in the winding part of the insulator. That is, the thermistor may be located between the winding surface and the stator core in a direction intersecting the winding axis direction of the coil.

[0045] In addition, within the scope of the spirit of the present invention, it is possible to replace the components in the above-described embodiments with well-known components as appropriate, and the above-described embodiments and each modified example may be combined as appropriate. [Explanation of symbols]

[0046] Reference Signs List 1... rotating electric machine 10... stator core (iron core) 20... insulator 21... winding portion 22... winding surface 33... bulge portion 40... coil 50... thermistor 60... terminal

Claims

1. A temperature detection device provided in a rotating electric machine (1) including an iron core (10) and a coil (40) wound around the iron core (10), an insulator (20) that is disposed between the iron core (10) and the coil (40), has a winding portion (21) that is in contact with the iron core (10) on one side in a direction perpendicular to the winding axis direction of the coil (40) and is in contact with the coil (40) on the other side, and electrically insulates the iron core (10) from the coil (40); A thermistor (50) for detecting the temperature of the coil (40); Equipped with The thermistor (50) is disposed inside the winding portion (21); The surface of the thermistor (50) is in contact with the winding portion (21). Temperature detection device.

2. The winding portion (21) has a winding surface (22) in contact with the coil (40), The winding surface (22) is located on the opposite side of the thermistor (50) from the iron core (10), and has a bulge (33) that bulges in a direction intersecting the winding axis direction. The temperature detection device according to claim 1 .

3. The insulator further includes a terminal (60) connected to the thermistor (50) and extending to the outside of the insulator (20), The insulator (20) is filled around the connection portion between the thermistor (50) and the terminal (60). The temperature detection device according to claim 1 or 2.

4. A method for manufacturing a temperature detection device provided in a rotating electric machine (1) including an iron core (10) and a coil (40) wound around the iron core (10), comprising: The temperature detection device is an insulator (20) that is disposed between the iron core (10) and the coil (40), has a winding portion (21) that is in contact with the iron core (10) on one side in a direction perpendicular to the winding axis direction of the coil (40) and is in contact with the coil (40) on the other side, and electrically insulates the iron core (10) from the coil (40); A thermistor (50) for detecting the temperature of the coil (40); Equipped with The insulator (20) is formed by insert molding together with the thermistor (50) so that the thermistor (50) is disposed inside the winding portion (21) and a surface of the thermistor (50) is in contact with the winding portion (21). A method for manufacturing a temperature detection device.

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