Motor

Abstract

To provide a technique of stably holding a temperature sensor to a bus bar.SOLUTION: A motor includes: a cylindrical stator core; a plurality of coils attached to the stator core; a bus bar electrically connected to at least one of the coils; and a temperature sensor attached to the bus bar. The bus bar has a plurality of passage units. At least a part of the temperature sensor passes through the passage units and is attached to the bus bar.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in this specification relates to motors.

Background Art

[0002] A stator, which is a component of a motor, includes a cylindrical stator core, a plurality of coils attached to the stator core, and a plurality of busbars. The plurality of coils include, for example, a U-phase coil, a V-phase coil, and a W-phase coil, and are wound around the inner peripheral surface of the stator core by distributed winding. The plurality of busbars include a neutral busbar and three lead-out busbars. The neutral busbar connects the U-phase coil, the V-phase coil, and the W-phase coil to each other to form the neutral point of the plurality of coils. Each of the three lead-out busbars is electrically connected to a corresponding one of the U-phase coil, the V-phase coil, and the W-phase coil.

[0003] Patent Document 1 discloses a motor in which a temperature sensor is attached to a neutral busbar. In this motor, the temperature sensor is press-fitted into a hole formed in the neutral busbar for attachment.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In this type of motor, a technology capable of stably holding a temperature sensor on a busbar is required.

Means for Solving the Problems

[0006] The motor disclosed in this specification may include a cylindrical stator core, a plurality of coils attached to the stator core, a bus bar electrically connected to at least one of the plurality of coils, and a temperature sensor attached to the bus bar. The bus bar may have a plurality of through portions. At least a part of the temperature sensor may be attached to the bus bar passing through each of the plurality of through portions.

[0007] At least a part of the temperature sensor is attached so as to be wound around the bus bar by passing through the plurality of through portions. Therefore, in the motor disclosed in this specification, the temperature sensor is stably held on the bus bar.

[0008] Details and further improvements of the motor disclosed in this specification will be described in the following "Mode for Carrying Out the Invention". will be described.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Embodiment for Carrying Out the Invention

[0010] In one embodiment of the motor disclosed in this specification, at least one of the plurality of passing portions may be a notch formed in at least one of a pair of side edges extending in the longitudinal direction of the bus bar. When the passing portion is constituted by a notch, the operation of passing the temperature sensor through the passing portion becomes easy. Therefore, the workability of attaching the temperature sensor to the bus bar is improved.

[0011] In one embodiment where the passing portion is constituted by a notch, the pair of side edges of the bus bar may have a proximal side edge located on the stator core side and a distal side edge located on the side opposite to the proximal side edge. Further, the notch may be formed in the distal side edge of the bus bar. When the notch is formed in the distal side edge of the bus bar, an operator attaching the temperature sensor to the bus bar can easily access the notch formed in the bus bar, so that the operation of passing the temperature sensor through the passing portion becomes easy. Therefore, the workability of attaching the temperature sensor to the bus bar is improved.

[0012] In one embodiment where the passing portion is constituted by a notch, the bus bar may have an adjacent portion adjacent to the notch in the short hand direction of the bus bar. The adjacent portion may include a side edge protruding portion protruding in the short hand direction of the bus bar from the side edge of the bus bar, a thick portion thicker than a portion adjacent to the adjacent portion in the longitudinal direction of the bus bar, or a combination thereof. When no countermeasure is taken, when a notch is formed in the bus bar, the cross-sectional area of the adjacent portion adjacent to the notch (that is, the cross-sectional area in a cross section orthogonal to the longitudinal direction of the bus bar) decreases, and the electrical resistance of the bus bar increases. In the above embodiment, since the adjacent portion is constituted by a side edge protruding portion, a thick portion, or a combination thereof, an increase in the electrical resistance of the adjacent portion can be suppressed.

[0013] In one embodiment where the through portion is constituted by a notch portion, the notch portion may have a first extending portion extending along the short side direction of the bus bar from the side edge of the bus bar, and a second extending portion extending along the long side direction of the bus bar from the first extending portion at a position away from the side edge of the bus bar. That is, at least a part of the notch portion may have an L-shaped portion. When at least a part of the notch portion has an L-shaped portion, the temperature sensor can be effectively prevented from falling out of the notch portion, so the temperature sensor is stably held on the bus bar.

[0014] In one embodiment of the motor disclosed in this specification, each of the plurality of coils may have a coil protruding portion protruding from the stator core on one side in the axial direction of the stator core. In this case, the bus bar may be arranged adjacent to the coil protruding portion in the axial direction of the stator core and may extend in the circumferential direction of the stator core. Instead of this embodiment, the bus bar may be arranged around the stator core in the radial direction of the stator core and may extend along the circumferential direction of the stator core.

[0015] In one embodiment where the bus bar extends along the circumferential direction of the stator core, the plurality of through portions may be arranged along the circumferential direction of the stator core. Since the temperature sensor is attached along the longitudinal direction of the bus bar, a long range of the temperature sensor is stably held on the bus bar.

[0016] In one embodiment where the bus bar extends along the circumferential direction of the stator core, each of the plurality of through portions may penetrate the bus bar along the radial direction of the stator core. In this embodiment, the temperature sensor may pass through the bus bar from the inside to the outside (or from the outside to the inside) in the radial direction of the stator core, for example, and then pass through the bus bar from the outside to the inside (or from the inside to the outside) in the radial direction of the stator core and be attached to the bus bar.

[0017] In one embodiment of the motor disclosed in this specification, the temperature sensor may include a thermistor temperature measurement unit and a cable unit connected to the thermistor temperature measurement unit. In this case, the thermistor temperature measurement unit may pass through at least one of the passing portions and be attached to the bus bar. When the thermistor temperature measurement unit passes through the passing portion, the thermistor temperature measurement unit is attached close to the bus bar, so that the sensitivity and response speed of the temperature sensor are improved.

[0018] In one embodiment where the thermistor temperature measurement unit passes through the passing portion, the bus bar and the thermistor temperature measurement unit may be integrally coated with resin. Since the thermistor temperature measurement unit is attached to the bus bar in close contact by the resin, the sensitivity and response speed of the temperature sensor are improved.

[0019] In one embodiment of the motor disclosed in this specification, the plurality of coils may include a U-phase coil, a V-phase coil, and a W-phase coil. In this case, the bus bar may be a neutral line bus bar that electrically connects the U-phase coil, the V-phase coil, and the W-phase coil to form a neutral point of the plurality of coils. Instead of this embodiment, the bus bar may be any one of the three lead-out bus bars provided corresponding to the U-phase coil, the V-phase coil, and the W-phase coil.

Example

[0020] Hereinafter, with reference to the drawings, the stator, which is a component of the motor, will be described. For the purpose of clarity of illustration, the shapes of the common components may be changed between different drawings, but the components with the same reference numerals indicate the same components. The motor disclosed in this specification is not particularly limited, but may be mounted on, for example, an electric vehicle. The "electric vehicle" in this specification includes battery electric vehicles (BEV), hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), fuel cell electric vehicles (FCEV), and the like.

[0021] As shown in FIG. 1, the stator 1 includes a stator core 10, a plurality of segment coils 20, a bus bar 30, and a temperature sensor 40.

[0022] Here, with reference to the cylindrical stator core 10, a cylindrical coordinate system composed of an axial direction, a radial direction, and a circumferential direction is defined. The z-axis shown in the figure is located on the central axis of the stator core 10 and indicates the axial direction of the stator core 10. In this specification, the positive direction of the z-axis is referred to as one side of the axial direction, and the negative direction of the z-axis is referred to as the other side of the axial direction. The r-axis shown in the figure is orthogonal to the z-axis and indicates the radial direction of the stator core 10. In this specification, the positive direction of the r-axis is referred to as the outside of the radial direction, and the negative direction of the r-axis is referred to as the inside of the radial direction. The θ-axis shown in the figure is orthogonal to the z-axis and the r-axis and indicates the circumferential direction of the stator core 10. In this specification, the positive direction of the θ-axis is referred to as one side of the circumferential direction, and the negative direction of the θ-axis is referred to as the other side of the circumferential direction.

[0023] The stator core 10 is formed by laminating a plurality of laminated steel sheets made of, for example, a magnetic material in the axial direction. The stator core 10 has a cylindrical yoke portion 12 and a plurality of teeth 14 extending radially inward from the inner peripheral surface of the yoke portion 12. A rotor (not shown) is inserted into the central hole of the yoke portion 12. Each of the plurality of teeth 14 extends along the axial direction from one opening edge portion of the yoke portion 12 to the other opening edge portion and is arranged at intervals from adjacent teeth 14 along the circumferential direction. The space between adjacent teeth 14 is called a slot 16.

[0024] Each of the plurality of segment coils 20 is inserted into two corresponding slots 16 out of the plurality of slots 16 of the stator core 10. Each of the plurality of segment coils 20 is a rectangular wire formed by coating an insulator on the surface of a conductor (for example, copper). Each of the plurality of segment coils 20 has a first coil protrusion 22 and a second coil protrusion 24 that protrude axially from the slot 16 of the stator core 10. The first coil protrusion 22 is a portion of the segment coil 20 that protrudes from the slot 16 of the stator core 10 on one side in the axial direction. The second coil protrusion 24 is a portion of the segment coil 20 that protrudes from the slot 16 of the stator core 10 on the other side in the axial direction. Each of the plurality of segment coils 20 is formed by being bent into a substantially U shape and then inserted into the slot 16 of the stator core 10 along the axial direction, and then bending the first coil protrusion 22 of the segment coil 20. The tip of the first coil protrusion 22 of the bent segment coil 20 (corresponding to the peeled portion where the insulator is peeled off and the conductor is exposed) is welded to the tip of the first coil protrusion 22 of the other bent segment coil 20. The plurality of segment coils 20 connected by welding constitute one coil. Thereby, a U-phase coil, a V-phase coil, and a W-phase coil are wound around the inner peripheral surface of the stator core 10 by distributed winding.

[0025] The bus bar 30 is arranged adjacent to the first coil protrusion 22 in the axial direction. Specifically, the bus bar 30 is located at a position slightly separated from the first coil protrusion 22 in the axial direction and is arranged within the range where the first coil protrusion 22 exists when viewed from the axial direction. The bus bar 30 has a shape in which a rectangular conductive plate is curved in the longitudinal direction and extends along the circumferential direction. In this example, the bus bar 30 extends only over a partial range of the entire circumference of the stator core 10. Instead of this example, the bus bar 30 may extend over the entire circumference of the stator core 10.

[0026] The bus bar 30 has an inner main surface 32 and an outer main surface 34. The inner main surface 32 and the outer main surface 34 extend along the longitudinal direction of the bus bar 30 while facing each other in the radial direction. The bus bar 30 further has a pair of proximal edges 36 and distal edges 38. The pair of proximal edges 36 and distal edges 38 extend in the longitudinal direction of the bus bar 30 while facing each other in the axial direction. The proximal edge 36 is located closer to the stator core 10 than the distal edge 38.

[0027] As shown in FIGS. 1 and 2, the tip 28 of the segment coil 20, which is one end of each of the U-phase coil, V-phase coil, and W-phase coil, is joined to the bus bar 30. Specifically, each tip 28 is welded to the outer main surface 34 of the bus bar 30. Note that the position where each tip 28 is joined to the bus bar 30 and the joining manner thereof are not particularly limited. In this way, the bus bar 30 is a neutral line bus bar that electrically connects the U-phase coil, V-phase coil, and W-phase coil to form the neutral point of these coils. Note that although not particularly limited, when the motor has a neutral point terminal (not shown), the neutral line bus bar is electrically connected to the neutral point terminal. Such a neutral point terminal can be used for so-called neutral point charging and is electrically connected to an external DC power source when charging the battery connected to the motor.

[0028] The tip (not shown) of the segment coil 20, which is the other end of each of the U-phase coil, V-phase coil, and W-phase coil, is electrically connected to a corresponding one of the three lead-out bus bars (not shown). Such three lead-out bus bars may extend along the circumferential direction, for example, on the outer side in the radial direction with respect to the stator core 10. Also, although not shown, the three lead-out bus bars are electrically connected to the U-phase terminal, V-phase terminal, and W-phase terminal of the motor, respectively.

[0029] As shown in FIGS. 1 and 3, the bus bar 30 has a first notch 31 and a second notch 33. Both the first notch 31 and the second notch 33 are formed at the distal edge 38 of the bus bar 30 and penetrate between the inner main surface 32 and the outer main surface 34 of the bus bar 30 along the radial direction. The first notch 31 and the second notch 33 are arranged apart from each other along the circumferential direction. In this example, only two notches 31 and 33 are shown, but three or more notches may be formed in the bus bar 30.

[0030] The temperature sensor 40 has a thermistor temperature measuring section 42 and a cable section 44 connected to the thermistor temperature measuring section 42. The thermistor temperature measuring section 42 is not particularly limited, but is, for example, an electronic component having a temperature measuring resistor at its tip. The thermistor temperature measuring section 42 has a structure in which two lead wires extending from the temperature measuring resistor are covered with a resin tube, and most of it except the temperature measuring resistor is flexible and long. The cable section 44 also has a structure in which two conducting wires are covered with a resin tube, and most of it is flexible and long. The two conducting wires of the cable section 44 are electrically connected to the corresponding lead wire among the two lead wires constituting the thermistor temperature measuring section 42. A connector (not shown) is connected to the end of the cable section 44 opposite to the end connected to the thermistor temperature measuring section 42.

[0031] As shown in Fig. 1, the thermistor temperature measurement unit 42 is attached to the bus bar 30 passing through each of the first notch 31 and the second notch 33. Note that the cable portion 44 may be attached to the bus bar 30 passing through at least one of the first notch 31 and the second notch 33. In this example, when observing from the cable portion 44 toward the tip of the thermistor temperature measurement unit 42, the thermistor temperature measurement unit 42 passes through the first notch 31 from the inner main surface 32 to the outer main surface 34 of the bus bar 30, and then passes through the second notch 33 from the outer main surface 34 to the inner main surface 32 of the bus bar 30 and is attached to the bus bar 30. The thermistor temperature measurement unit 42 is attached so as to wrap around the bus bar 30 by reciprocating between the inner main surface 32 and the outer main surface 34 of the bus bar 30. Thereby, the temperature sensor 40 is stably held on the bus bar 30. Further, since the first notch 31 and the second notch 33 are arranged apart from each other along the longitudinal direction of the bus bar 30, a long range of the thermistor temperature measurement unit 42 is stably held on the bus bar 30.

[0032] The first notch 31 and the second notch 33 formed at the distal edge 38 of the bus bar 30 are arranged to be exposed outward from the stator core 10, so they are arranged at positions that can be easily accessed by the operator attaching the temperature sensor 40 to the bus bar 30. For this reason, the operation of passing the temperature sensor 40 through the first notch 31 and the second notch 33 becomes easy, so the workability of attaching the temperature sensor 40 to the bus bar 30 is improved.

[0033] In this example, since the thermistor temperature measurement unit 42 passes through the first notch 31 and the second notch 33 and is attached to the bus bar 30, the thermistor temperature measurement unit 42 is attached close to the bus bar 30. For this reason, the heat generated in the bus bar 30 is efficiently transferred to the thermistor temperature measurement unit 42, so the sensitivity and response speed of the temperature sensor 40 are improved.

[0034] As shown in FIG. 3, the bus bar 30 and the thermistor temperature measurement unit 42 are integrally covered with a resin 50. In FIGS. 1 and 2, for clarity of illustration, the resin 50 is removed and shown. The resin 50 is not particularly limited. For example, the bus bar 30 and the thermistor temperature measurement unit 42 may be formed to be integrally covered by applying a powder resin to the bus bar 30 and the thermistor temperature measurement unit 42, or the bus bar 30 and the thermistor temperature measurement unit 42 may be formed to be integrally covered by immersing them in a molten resin. The resin 50 may be formed to integrally cover the welded joint at the tip of the first coil protrusion 22. Since the thermistor temperature measurement unit 42 is attached to the bus bar 30 in close contact by the resin 50, the sensitivity and response speed of the temperature sensor 40 are improved. Also, since the heat generated in the bus bar 30 can be transferred to the thermistor temperature measurement unit 42 through the resin 50, the sensitivity and response speed of the temperature sensor 40 are improved in this regard as well.

[0035] As described above, in the example where the bus bar 30 and the thermistor temperature measurement unit 42 are integrally covered with the resin 50, it is necessary to position the thermistor temperature measurement unit 42 with respect to the bus bar 30 prior to coating the resin 50. Also, it is necessary to hold the thermistor temperature measurement unit 42 in close contact with the bus bar 30 during the process of coating the resin 50. By passing the thermistor temperature measurement unit 42 through the first notch 31 and the second notch 33 at specific positions of the thermistor temperature measurement unit 42, the thermistor temperature measurement unit 42 is accurately positioned with respect to the bus bar 30. Also, the thermistor temperature measurement unit 42 that has passed through the first notch 31 and the second notch 33 is held in close contact with the bus bar 30. Thus, the technique of forming the first notch 31 and the second notch 33 in the bus bar 30 is particularly useful when the bus bar 30 and the thermistor temperature measurement unit 42 are integrally covered with the resin 50.

[0036] Hereinafter, modified examples of the bus bar 30 will be listed. Note that parts that exhibit the same effects as those of the bus bar 30 are given the same reference numerals, and their descriptions are omitted.

[0037] The bus bar 130 shown in FIG. 4 is an example having a plurality of through holes 131 and 133. The temperature sensor 40 is attached to the bus bar 130 by passing through each of the plurality of through holes 131 and 133. Although the workability of passing the temperature sensor 40 through the plurality of through holes 131 and 133 is reduced, it is possible to prevent the temperature sensor 40 from falling off.

[0038] The bus bar 230 shown in FIG. 5 is an example in which a plurality of engaging portions 231 and 233 are formed by a plurality of protrusions protruding from the side edges of the bus bar 230. The plurality of protrusions are arranged at intervals along the longitudinal direction of the bus bar 230. The plurality of engaging portions 231 and 233 are defined by adjacent protrusions, and the distance between adjacent protrusions is adjusted so that the temperature sensor 40 can be held. The temperature sensor 40 is attached to the bus bar 230 by passing through each of the plurality of engaging portions 231 and 233.

[0039] As shown in the modified examples of FIGS. 4 and 5, as a structure for stably holding the temperature sensor 40, various geometric shapes can be adopted that penetrate the bus bar in a direction connecting a pair of main surfaces of the bus bar and allow the flexible elongated temperature sensor 40 to pass through. In this specification, a portion of the bus bar having various geometric shapes through which the temperature sensor 40 can pass is referred to as a passing portion. The plurality of passing portions formed in the bus bar may be formed by a combination of a single type of passing portion (for example, a combination of only notch portions), or a combination of different types of passing portions (for example, any combination of notch portions, through holes, and engaging portions).

[0040] The bus bar 330 shown in FIG. 6 is an example in which a first notch portion 31 is formed on one side edge of the bus bar 330 and a second notch portion 33 is formed on the other side edge of the bus bar 330. The position within the bus bar 330 where the plurality of notch portions 31 and 33 are formed may be appropriately adjusted according to the position and orientation where the bus bar 330 is arranged.

[0041] The bus bar 430 shown in FIG. 7 is an example in which the first notch 31 has a first extending portion 31a extending along the short side direction of the bus bar 330 from the side edge of the bus bar 430, and a second extending portion 31b extending along the long side direction of the bus bar 430 from the first extending portion 31a at a position away from the side edge of the bus bar 430. The same applies to the second notch 33. In this way, both the first notch 31 and the second notch 33 are configured in an L shape. When the first notch 31 and the second notch 33 are configured in an L shape, the temperature sensor 40 can be effectively prevented from falling out from the first notch 31 and the second notch 33, so the temperature sensor 40 is stably held on the bus bar 430.

[0042] The bus bar 530 shown in FIG. 8 is an example having a first adjacent portion 35 adjacent to the first notch 31 in the short side direction of the bus bar 530, and a second adjacent portion 37 adjacent to the second notch 33 in the short side direction of the bus bar 530. Both the first adjacent portion 35 and the second adjacent portion 37 have a side edge protruding portion 39 protruding in the short side direction of the bus bar 530 from the side edge of the bus bar 530. If the first adjacent portion 35 and the second adjacent portion 37 do not have the side edge protruding portion 39, when the first notch 31 and the second notch 33 are formed in the bus bar 530, the cross-sectional areas of the first adjacent portion 35 and the second adjacent portion 37 (that is, the areas of the cross-sections perpendicular to the long side direction of the bus bar 530) decrease, and the electrical resistance of the bus bar 530 increases. In this example, since each of the first adjacent portion 35 and the second adjacent portion 37 has the side edge protruding portion 39, an increase in the electrical resistance of the first adjacent portion 35 and the second adjacent portion 37 is suppressed.

[0043] The bus bar 630 shown in Fig. 9 is an example in which a first adjacent portion 35 adjacent to the first notch portion 31 in the short side direction of the bus bar 630 has a thick portion 52 that is thicker than a portion adjacent to the first adjacent portion 35 in the longitudinal direction of the bus bar 630. The same applies to the second adjacent portion 37 adjacent to the second notch portion 33. Also in this example, even if the first notch portion 31 and the second notch portion 33 are formed, a decrease in the cross-sectional area of the first adjacent portion 35 and the second adjacent portion 37 is suppressed, and an increase in the electrical resistance of the first adjacent portion 35 and the second adjacent portion 37 is suppressed. Note that the first adjacent portion 35 and the second adjacent portion 37 may simultaneously have a side edge protruding portion 39 (see Fig. 8) and a thick portion (see Fig. 9).

Description of Signs

[0044] 1: Stator, 10: Stator core, 12: Yoke portion, 14: Teeth, 16: Slots, 20: Segment coil, 22: First coil protruding portion, 24: Second coil protruding portion, 28: Tip portion, 30: Bus bar, 31: First notch portion, 33: Second notch portion, 40: Temperature sensor, 42: Thermistor temperature measurement portion, 44: Cable portion

Claims

1. A cylindrical stator core; a plurality of coils attached to the stator core; a bus bar electrically connected to at least one of the plurality of coils; a temperature sensor attached to the bus bar, the bus bar has a plurality of passing portions, At least a portion of the temperature sensor passes through each of the plurality of passing portions and is attached to the bus bar.

2. The motor according to claim 1 , wherein at least one of the plurality of passing portions is a notch formed in at least one of a pair of side edges extending in the longitudinal direction of the bus bar.

3. the pair of side edges of the bus bar include a proximal edge located on the stator core side and a distal edge located opposite the proximal edge, The motor of claim 2 , wherein the notch is formed in the distal edge of the bus bar.

4. the bus bar has an adjacent portion adjacent to the notch portion in a short direction of the bus bar, 3. The motor according to claim 2, wherein the adjacent portion includes a side edge protruding portion protruding from the side edge of the bus bar in a short direction of the bus bar, a thick portion that is thicker than a portion of the bus bar adjacent to the adjacent portion in the long direction of the bus bar, or a combination thereof.

5. 3. The motor according to claim 2, wherein the cutout portion includes a first extending portion cut out from the side edge of the bus bar along a short direction of the bus bar, and a second extending portion cut out from the first extending portion along a longitudinal direction of the bus bar at a position away from the side edge of the bus bar.

6. Each of the plurality of coils has a coil protrusion that protrudes from the stator core on one side in the axial direction of the stator core, The motor according to claim 1 , wherein the bus bar is disposed adjacent to the coil protrusion in the axial direction of the stator core and extends in the circumferential direction of the stator core.

7. The motor according to claim 6 , wherein the plurality of passing portions are arranged along a circumferential direction of the stator core.

8. The motor according to claim 6 , wherein each of the plurality of passing portions penetrates the bus bar along a radial direction of the stator core.

9. The temperature sensor a thermistor temperature measuring unit; a cable portion connected to the thermistor temperature measuring portion, The motor according to claim 1 , wherein the thermistor temperature measuring portion passes through at least one of the plurality of passing portions and is attached to the bus bar.

10. The motor according to claim 9 , wherein the bus bar and the thermistor temperature measuring portion are integrally covered with a resin.

11. the plurality of coils include a U-phase coil, a V-phase coil, and a W-phase coil, The motor according to any one of claims 1 to 10, wherein the bus bar is a neutral bus bar that electrically connects the U-phase coil, the V-phase coil, and the W-phase coil to each other and forms a neutral point of the plurality of coils.

Images