Stator

Abstract

To simplify a manufacturing process of a stator having a neutral line comprising a plurality of segments.SOLUTION: A stator comprises: a stator core; a stator coil having 3 phase coils; a U-shaped segment which connects 2 phase coils out of 3 phase coils; an L-shaped segment 34 which connects remaining 1 phase coil and the U-shaped segment 32; and a temperature sensor 36. Each of both ends of the U-shaped segment and one end of the L-shaped segment is connected to a corresponding coil among 3 phase coils inside a plurality of slots of the stator core. The other end of the L-shaped segment is connected to a central section of the U-shaped segment outside the plurality of slots of the stator core. At a connection point between the U-shaped segment and the L-shaped segment, a concave section 32d and 34c to store the temperature sensor is installed at least either on the U-shaped segment or the L-shaped segment.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The technology disclosed in this specification relates to a stator of a motor.

Background Art

[0002] Patent Document 1 describes a stator of a motor. This stator includes a stator core, a plurality of slots, a stator coil disposed in the plurality of slots and having three-phase coils, a neutral line connecting the three-phase coils to each other, and a temperature sensor provided on the neutral line. The temperature sensor is provided on the neutral line by a joining member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the stator as described above, by disposing the joining portion between each phase coil and the neutral line inside the slot, the vibration durability of the neutral line can be enhanced. In this case, it is conceivable to adopt a neutral line having a Y-shaped configuration, but it is difficult to fabricate a neutral line having a Y-shaped configuration with a single segment (conductive wire). On the other hand, if a neutral line having a Y-shaped configuration is composed of, for example, two segments, a step of joining the two segments to each other is required, which complicates the manufacturing process of the stator.

[0005] This specification provides a technology capable of simplifying the manufacturing process of a stator while adopting a Y-shaped neutral line composed of two segments.

Means for Solving the Problems

[0006] The technology disclosed in this specification is embodied in a stator. The stator includes a stator core, a plurality of slots provided along the circumferential direction on the inner circumferential surface of the stator core, a stator coil disposed in the plurality of slots and having three-phase coils, a U-shaped segment connecting two of the three-phase coils to each other, an L-shaped segment connecting the remaining one of the three-phase coils and the U-shaped segment to each other, and a temperature sensor. Each of both ends of the U-shaped segment and one end of the L-shaped segment is joined to a corresponding one of the three-phase coils inside the plurality of slots of the stator core. The other end of the L-shaped segment is joined to the middle portion of the U-shaped segment outside the plurality of slots of the stator core. At the joint location of the U-shaped segment and the L-shaped segment, a recess for accommodating the temperature sensor is provided in at least one of the U-shaped segment and the L-shaped segment.

[0007] In the above-described stator, the U-shaped segment and the L-shaped segment are joined to each other to form a neutral line having a Y-shaped configuration. A recess is provided at the joint location of the U-shaped segment and the L-shaped segment, and the temperature sensor is accommodated in the recess. According to such a configuration, when the U-shaped segment and the L-shaped segment are joined to each other, it is possible to provide the temperature sensor on the neutral line. That is, the process of joining the U-shaped segment and the L-shaped segment to each other and the process of providing the temperature sensor on the neutral line can be simultaneously performed, and the manufacturing process of the stator can be simplified. Further, since the neutral line has a Y-shaped configuration, it is possible to join the neutral line and the three-phase coils inside the slots. Thereby, it is possible to avoid the entire neutral line being disposed outside the slots, and it is expected that the natural frequency of the neutral line will increase. Furthermore, by reducing the dimension of the neutral line in the axial direction of the stator, it is also possible to miniaturize the stator.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Mode for Carrying Out the Invention

[0009] In one embodiment of the present technology, each of the three-phase coils may have a plurality of first coil segments located on one axial side of the stator core and a plurality of second coil segments located on the other axial side of the stator core. In this case, the plurality of first coil segments and the plurality of second coil segments may be joined to each other inside the plurality of slots. According to such a configuration, inside the slots, in addition to the first coil segment and the second coil segment being joined to each other, the coil of each phase and the U-shaped segment or the L-shaped segment are joined to each other. From this, when joining the first coil segment and the second coil segment, it is possible to join the three-pronged neutral line and the coil of each phase together. That is, in one joining step, it is possible to perform the joining of the first coil segment and the second coil segment and the joining of the neutral line and the coil of each phase.

Examples

[0010] With reference to the drawings, the stator 20 of this embodiment and the motor 10 in which it is adopted will be described. The motor 10 is a radial gap type electric motor and includes a rotor 12 and a stator 20. Although it is an example, the motor 10 can be used as a driving motor for driving an electric vehicle. In this specification, the axial direction, the circumferential direction, and the radial direction of the motor 10 may be simply referred to as the axial direction, the circumferential direction, and the radial direction, respectively.

[0011] As shown in FIG. 1, the rotor 12 includes a rotor core 14, a rotor shaft 16, and a plurality of permanent magnets 18. The rotor core 14 has a cylindrical shape extending in the axial direction. The rotor core 14 is made of electromagnetic steel, and specifically, has a structure in which a plurality of electromagnetic steel plates are laminated in the axial direction. In the rotor core 14, a through hole 14a extending in the axial direction is provided at the central portion in the radial direction. The rotor shaft 16 is disposed in the through hole 14a. Thereby, the rotor core 14 is rotatably supported by the rotor shaft 16. The plurality of permanent magnets 18 are respectively accommodated in a plurality of magnet holes 18a provided in the rotor core 14. The plurality of magnet holes 18a are through holes extending along the axial direction respectively, and are arranged along the circumferential direction of the rotor core 14. Note that the specific number of the plurality of permanent magnets 18 is not particularly limited.

[0012] As shown in FIGS. 1 and 2, the stator 20 includes a stator core 22. The stator core 22 has a cylindrical shape extending in the axial direction. The stator core 22 is made of electromagnetic steel, and specifically, has a structure in which a plurality of electromagnetic steel plates are laminated in the axial direction. In the stator core 22, a through hole 22a extending in the axial direction is provided at the central portion in the radial direction. The rotor 12 is disposed in the through hole 22a. The stator core 22 includes a plurality of teeth 24 and a plurality of slots 26. Each tooth 24 protrudes radially inward from the inner peripheral surface of the stator core 22, and the plurality of teeth 24 are provided along the circumferential direction at a predetermined interval on the inner peripheral surface of the stator core 22. One slot 26 is formed between each adjacent pair of teeth 24. Therefore, each slot 26 opens into the through hole 22a of the stator core 22. The plurality of slots 26 are provided along the circumferential direction at a predetermined interval on the inner peripheral surface of the stator core 22. Note that the specific numbers of the plurality of teeth 24 and the plurality of slots 26 are not particularly limited.

[0013] As shown in FIGS. 1 and 2, the stator 20 further includes a stator coil 28. The stator coil 28 has three-phase coils 28U, 28V, 28W (that is, the U-phase coil 28U, the V-phase coil 28V, and the W-phase coil 28W). Each of the three-phase coils 28U, 28V, 28W is composed of a plurality of coil segments 30. The plurality of coil segments 30 includes a plurality of first coil segments 30a located on the upper side in the axial direction of the stator core 22 and a plurality of second coil segments 30b located on the lower side in the axial direction of the stator core 22. Each of the coil segments 30a, 30b is a conductive wire (so-called flat wire) having a rectangular cross section, is formed in a substantially U shape, and is inserted into the slot 26 of the stator core 22 from the upper side or the lower side in the axial direction.

[0014] As shown in the enlarged view in FIG. 2, in each of the three-phase coils 28U, 28V, 28W, a plurality of first coil segments 30a and a plurality of second coil segments 30b are joined to each other inside the slot 26, thereby forming a series of coils. For example, in the U-phase coil 28U, one end of the first coil segment 30a is joined to one end of the second coil segment 30b inside the slot 26. Also, the other end of the second coil segment 30b is joined to one end of another first coil segment 30a inside another slot 26. The same applies to the V-phase coil 28V and the W-phase coil 28W. Thus, in each of the three-phase coils 28U, 28V, 28W, a series of coils are formed by connecting a plurality of coil segments 30 in series. Note that the specific number and configuration of the plurality of coil segments 30 are not particularly limited and can be appropriately changed according to the output required for the motor 10 and the like. Also, the plurality of coil segments 30 can be joined to each other by welding, ultrasonic bonding, press-fitting bonding, etc., but the specific bonding method is not particularly limited.

[0015] As shown in FIGS. 3 and 4, the stator 20 further includes a neutral line 31. The neutral line 31 is a member that electrically connects the three-phase coils 28U, 28V, and 28W to each other. The neutral line 31 has a Y-shaped form with three ends, and the three ends are respectively connected to one ends of the three-phase coils 28U, 28V, and 28W.

[0016] Although not shown in the figure, the other ends of the coils 28U, 28V, and 28W of each phase are connected to an external power source. When the motor 10 functions as a driver, currents corresponding to the coils 28U, 28V, and 28W of each phase are input from the external power source. When an alternating current of three phases flows through the stator coil 28, a rotating magnetic field is generated between the stator 20 and the rotor 12, and the rotor 12 rotates. On the other hand, when the motor 10 functions as a generator, power for rotating the rotor 12 externally is applied. When the rotor 12 rotates, currents are generated in the coils 28U, 28V, and 28W of each phase, and the currents are supplied to the external power source.

[0017] As shown in FIGS. 3 and 4, the neutral line 31 includes a U-shaped segment 32 and an L-shaped segment 34. The U-shaped segment 32 has a rectangular cross-section (flat wire) and is formed in a substantially U shape. The L-shaped segment 34 has a rectangular cross-section (flat wire) and is formed in a substantially L shape. One end 32a of the U-shaped segment is joined to the U-phase coil 28U inside one of the plurality of slots 26. The other end 32b of the U-shaped segment is joined to the V-phase coil 28V inside another one of the plurality of slots 26. Thus, the U-shaped segment 32 joins the U-phase coil 28U and the V-phase coil 28V to each other. One end 34a of the L-shaped segment is joined to the W-phase coil 28W inside yet another one of the plurality of slots 26. The other end 34b of the L-shaped segment is joined to the middle portion 32c of the U-shaped segment 32 outside the plurality of slots 26. Thus, the L-shaped segment 34 connects the W-phase coil 28W and the U-shaped segment 32 to each other. From the above configuration, the U-shaped segment 32 and the L-shaped segment 34 are joined to each other to form the neutral line 31 having a Y shape. Note that the joining of the U-shaped segment 32 and the L-shaped segment 34, and the joining of each phase's coils 28U, 28V, 28W and the U-shaped segment 32 or the L-shaped segment 34 can be joined to each other by welding, ultrasonic joining, press fitting, etc., but the specific joining method is not particularly limited.

[0018] However, for the two-phase coils connected to each other by the U-shaped segment 32 and the one-phase coil connected to the L-shaped segment 34, the specific phases are not particularly limited. That is, as another embodiment, the U-shaped segment 32 may join the V-phase coil 28V and the W-phase coil 28W to each other, and the L-shaped segment 34 may connect the U-phase coil 28U and the U-shaped segment 32 to each other. As yet another embodiment, the U-shaped segment 32 may join the W-phase coil 28W and the U-phase coil 28U to each other, and the L-shaped segment 34 may connect the V-phase coil 28V and the U-shaped segment 32 to each other.

[0019] In addition to the above, at the joint between the U-shaped segment 32 and the L-shaped segment 34, a concave portion 32d is provided in the U-shaped segment 32, and a concave portion 34c is provided in the L-shaped segment 34. The concave portion 32d of the U-shaped segment 32 and the concave portion 34c of the L-shaped segment 34 are arranged to face each other in the radial direction. Note that at the joint between the U-shaped segment 32 and the L-shaped segment 34, it is not necessary for both the U-shaped segment 32 and the L-shaped segment 34 to be provided with the concave portions 32d and 34c. It is sufficient that at least one of the U-shaped segment 32 and the L-shaped segment 34 is provided with the concave portions 32d and 34c. Also, the concave portion 32d of the U-shaped segment 32 and the concave portion 34c of the L-shaped segment 34 do not necessarily have to be arranged to face each other in the radial direction. As another embodiment, these concave portions 32d and 34c may be arranged to face each other in the axial direction or the circumferential direction.

[0020] As shown in FIGS. 3 and 4, the stator 20 further includes a temperature sensor 36. The temperature sensor 36 incorporates, for example, a thermistor and has a structure in which the thermistor is sealed in an insulator package such as resin. The temperature sensor 36 is provided at the joint between the U-shaped segment 32 and the L-shaped segment 34. As described above, the concave portion 32d of the U-shaped segment 32 and the concave portion 34c of the L-shaped segment 34 are provided at the joint, and the temperature sensor 36 is accommodated in the two concave portions 32d and 34c. Note that the shape of the temperature sensor 36 is not particularly limited as long as the temperature sensor 36 can be accommodated in the concave portions 32d and 34c of the neutral line 31. Also, the temperature sensor 36 may be joined to the two concave portions 32d and 34c by press fitting or the like, or may be fixed to the two concave portions 32d and 34c via an adhesive or the like. The specific fixing method of the temperature sensor 36 is not particularly limited.

[0021] In the above-described motor 10, the U-shaped segment 32 and the L-shaped segment 34 are joined to each other to form a neutral line 31 having a bifurcated shape. Recesses 32d and 34c are provided at the joint between the U-shaped segment 32 and the L-shaped segment 34, and a temperature sensor 36 is accommodated in the recesses 32d and 34c. According to such a configuration, when the U-shaped segment 32 and the L-shaped segment 34 are joined to each other, the temperature sensor 36 can be provided on the neutral line 31 at the same time. That is, the process of joining the U-shaped segment 32 and the L-shaped segment 34 to each other and the process of providing the temperature sensor 36 on the neutral line 31 can be carried out simultaneously, and the manufacturing process of the stator 20 can be simplified. Further, since the neutral line 31 has a bifurcated shape, it is possible to join the neutral line 31 and the three-phase coils 28U, 28V, and 28W inside the slot 26. As a result, it is possible to avoid the entire neutral line 31 being disposed outside the slot 26, and it is expected that the natural frequency of the neutral line 31 will increase. Furthermore, since the dimension of the neutral line 31 in the axial direction of the stator 20 is reduced, the stator 20 can also be miniaturized.

[0022] As described above, several specific examples have been described in detail, but these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above. The technical elements described in this specification or the drawings exhibit technical usefulness alone or in combination.

Explanation of Reference Numerals

[0023] 10: Motor 12: Rotor 14: Rotor Core 14a: Through Hole 16: Rotor Shaft 18: Permanent Magnet 18a: Magnet Hole 20: Stator 22: Stator Core 22a: Through Hole 24: Teeth 26: Slot 28: Stator coil 28U: Coil 28V: Coil 28W: Coil 30: Coil segment 30a: First coil segment 30b: Second coil segment 31: Neutral line 32: U-shaped segment 32a: One end 32b: The other end 32c: Middle part 32d: Concave part 34: L-shaped segment 34a: One end 34b: The other end 34c: Concave part 36: Temperature sensor

Claims

【Claim 1】 A stator core, a plurality of slots provided along the circumferential direction on the inner peripheral surface of the stator core, a stator coil arranged in the plurality of slots and having three-phase coils, a U-shaped segment connecting two of the three-phase coils to each other, an L-shaped segment connecting the remaining one of the three-phase coils and the U-shaped segment to each other, a temperature sensor, and comprising: each of both ends of the U-shaped segment and one end of the L-shaped segment is joined to a corresponding one of the three-phase coils inside the plurality of slots of the stator core, the other end of the L-shaped segment is joined to an intermediate portion of the U-shaped segment outside the plurality of slots of the stator core, at a joint portion between the U-shaped segment and the L-shaped segment, the temperature sensor is housed in a recess provided in at least one of the surface of the U-shaped segment and the surface of the L-shaped segment facing each other through the temperature sensor, the temperature sensor is surrounded in the recess by the U-shaped segment and the L-shaped segment from four directions, a stator.

Images