Rotating electric machine and method for manufacturing rotating electric machine

Abstract

The present invention is a rotating electric machine (1) comprising a stator (2) and a rotor (3) rotatably disposed to the inside of the stator (2), wherein: the stator (2) includes a stator core (221) and a plurality of stator coils (22) wound around the stator core (221); the plurality of stator coils (22) are formed by wires (5) in which the outer circumferences of conductors (51) are coated by insulating films (52); and terminal sections (221) of the wires (5) of the plurality of stator coils (22) are provided with joint sections (20) in which the conductors (51) are joined to each other by ultrasonic joining while the insulating films (52) are adhered.

Description

Rotating electric machine and method of manufacturing the same

[0001] The present disclosure relates to a rotating electric machine and a method for manufacturing the rotating electric machine.

[0002] When electrically joining the insulated conductor wires of the stator coil of a conventional rotating electric machine, a predetermined length of the insulating coating is stripped off from the portion to be joined to expose the conductor, and the exposed conductor is twisted together and ultrasonically joined to electrically connect the insulated conductor wires (see, for example, Patent Document 1).

[0003] International Publication No. 2012 / 005258 (paragraph "0019")

[0004] Conventional rotating electrical machines and methods for manufacturing rotating electrical machines have had the problem that a step of removing the insulating coating is required, which increases the number of steps and processing costs.

[0005] The present disclosure discloses a technique for solving the above-described problems, and aims to provide a rotating electric machine and a method for manufacturing a rotating electric machine that can reduce processing costs.

[0006] A rotating electric machine according to the present disclosure is a rotating electric machine including a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, wherein the plurality of stator coils are formed of conductor wires with an insulating coating on the outer periphery of the conductor, and terminal portions of the conductor wires of the plurality of stator coils are provided with joints where the conductors are joined by ultrasonic welding with the insulating coating still attached. Also, a rotating electric machine according to the present disclosure is a rotating electric machine including a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, wherein the plurality of stator coils are formed of conductor wires with an insulating coating on the outer periphery of the conductor, and terminal portions of the conductor wires of the plurality of stator coils are provided with joints where the conductors are joined by laser welding with the insulating coating still attached. The manufacturing method of the rotating electric machine of the present disclosure is the manufacturing method of the rotating electric machine described above, which includes applying vibrations to the terminal portions with ultrasonic waves, peeling off a part of the insulating coating by friction between the terminal portions, and joining the conductors to form the joint. The manufacturing method of the rotating electric machine of the present disclosure is the manufacturing method of the rotating electric machine described above, which includes melting a part of the insulating coating between the terminal portions with laser irradiation, and joining the conductors to form the joint.

[0007] According to the rotating electric machine and the manufacturing method of the rotating electric machine of the present disclosure, processing costs can be reduced.

[0008] 9A is a cross-sectional view showing the configuration of a rotating electric machine according to embodiment 1. FIG. 9B is a cross-sectional view showing the internal configuration of the rotating electric machine shown in FIG. 1. FIG. 11A is a plan view showing the configuration of a stator core of the rotating electric machine shown in FIG. 1. FIG. 12B is a schematic cross-sectional view showing the configuration of a distributed winding rotating electric machine according to embodiment 1. FIG. 9C is a perspective view showing the configuration of the stator of the rotating electric machine shown in FIG. 1. FIG. 9D is a plan view showing the configuration of the stator shown in FIG. 9E. FIG. 9F is a plan view showing the relationship between the U-phase, V-phase, and W-phase of the stator shown in FIG. 9F. FIG. 9G is a wiring diagram showing a three-phase coupling portion of the stator shown in FIG. 9G. FIG. 9H is a cross-sectional view showing a cross section taken along line H-H in FIG. 9A. FIG. 10A is a cross-sectional view showing a method of joining terminal portions shown in FIG. 9B. FIG. 10B is a cross-sectional view showing a state after joining of terminal portions shown in FIG. 10A. FIG. 11A is a cross-sectional view showing another method of joining terminal portions shown in FIG. 9B. FIG. 11B is a cross-sectional view showing a state after joining of terminal portions shown in FIG. 11A. 14A is a cross-sectional view showing another method of joining the terminal portions shown in FIG. 9B . FIG. 14A is a cross-sectional view showing a configuration before joining the terminal portions of a stator of a rotating electric machine according to embodiment 2. FIG. 14B is a cross-sectional view showing a state after joining the terminal portions shown in FIG. 14A . FIG. 15A is a cross-sectional view showing a method of joining the terminal portions shown in FIG. 14A . FIG. 15B is a cross-sectional view showing a state after joining the terminal portions shown in FIG. 15A . FIG. 16A is a cross-sectional view showing another method of joining the terminal portions shown in FIG. 14A . FIG. 16B is a cross-sectional view showing a state after joining the terminal portions shown in FIG. 16A . FIG. 14A is a cross-sectional view showing another method of joining the terminal portions shown in FIG. 14 ... perspective view showing a method of joining the terminal portions of a stator of a rotating electric machine according to embodiment 3. FIG. 14A is a perspective view showing another method of joining the terminal portions of a stator of a rotating electric machine according to embodiment 3. FIG. 14B is a plan view showing a method of joining the terminal portions of a stator of a rotating electric machine according to embodiment 4. Fig. 22A is a side view showing a method for joining terminal portions of the stator of the rotating electric machine shown in Fig. 21. Fig. 22B is a cross-sectional view showing the configuration of the joint portion between the terminal portions of the stator of the rotating electric machine in the cross section taken along line Y-Y in Fig. 22A. Fig. 23A is a partial plan view showing the wiring process of the stator shown in Fig. 5.FIG. 23B is a cross-sectional view showing a cross section taken along line H1-H1 in FIG. 23A. FIG. 24A is a cross-sectional view showing another method for joining the terminal portions shown in FIG. 9B. FIG. 24B is a cross-sectional view showing the state after the terminal portions shown in FIG. 24A have been joined. FIG. 25A is a cross-sectional view showing another method for joining the terminal portions shown in FIG. 9B. FIG. 25B is a cross-sectional view showing the state after the terminal portions shown in FIG. 25A have been joined. FIG. 26A is a cross-sectional view showing another method for joining the terminal portions shown in FIG. 9B. FIG. 26B is a cross-sectional view showing the state after the terminal portions shown in FIG. 26A have been joined. FIG. 27A is a cross-sectional view showing another method for joining the terminal portions shown in FIG. 9B. FIG. 27B is a cross-sectional view showing the state after the terminal portions shown in FIG. 27A have been joined. FIG. 28A is a plan view showing another configuration of the stator of the rotating electric machine shown in FIG. 1. FIG. 28B is a cross-sectional view showing the cross section taken along line H2-H2 in FIG. 28A. FIG. 29A is a cross-sectional view showing another method for joining the terminal portions shown in FIG. 9B. Fig. 29B is a cross-sectional view showing the state after the end portions shown in Fig. 29A have been joined together, and Fig. 29B is a cross-sectional view showing the relationship between the joint portion shown in Fig. 29B and the terminal.

[0009] Embodiment 1. Fig. 1 is a cross-sectional view showing the configuration of a rotating electric machine according to embodiment 1. Fig. 2 is a cross-sectional view showing the internal configuration of the rotating electric machine shown in Fig. 1. Fig. 3 is a plan view showing the configuration of a stator core of the rotating electric machine shown in Fig. 1. Fig. 4 is a schematic cross-sectional view showing the configuration of a distributed winding rotating electric machine according to embodiment 1. Fig. 5 is a perspective view showing the configuration of the stator of the rotating electric machine shown in Fig. 1. Fig. 6 is a plan view showing the configuration of the stator shown in Fig. 5. Fig. 7 is a plan view showing the relationship between the U-phase, V-phase, and W-phase of the stator shown in Fig. 5. Fig. 8 is a wiring diagram showing the three-phase coupling portion of the stator shown in Fig. 5.

[0010] Fig. 9A is a partial plan view showing the wire connection process of the stator shown in Fig. 5. Fig. 9B is a cross-sectional view showing the cross section taken along line H-H in Fig. 9A. Fig. 10A is a cross-sectional view showing a method for joining terminal portions shown in Fig. 9B. Fig. 10B is a cross-sectional view showing the state after the terminal portions shown in Fig. 10A have been joined. Fig. 11A is a cross-sectional view showing another method for joining terminal portions shown in Fig. 9B. Fig. 11B is a cross-sectional view showing the state after the terminal portions shown in Fig. 11A have been joined. Figs. 12 and 13 are cross-sectional views showing another method for joining terminal portions shown in Fig. 9B.

[0011] 1 and 2 , a rotating electric machine 1 includes a stator 2 and a rotor 3 rotatably disposed inside the stator 2 across a gap. The stator 2 includes a stator core 21 and a plurality of stator coils 22 wound around the stator core 21. As shown in FIG. 9B , the plurality of stator coils 22 are formed of conductors 51 each having a conductor wire 5 covered on its outer periphery with an insulating coating 52. As will be described in detail later, terminal portions 221 of the conductor wires 5 of the plurality of stator coils 22 include joints 20 where the conductors 51 are joined together with the insulating coating 52 still attached.

[0012] The rotor 3 has a rotor core 31 that is fixed by press fitting, shrink fitting, or the like to a rotating shaft 4 that rotates around the center Q of the rotating electric machine 1. This rotor 3 has an IPM (Interior Permanent Magnet) motor structure, and a magnet 32 ​​is disposed inside the rotor core 31. Note that the present disclosure is similarly applicable to an SPM (Surface Permanent Magnet) motor structure.

[0013] As shown in Fig. 3, the stator core 21 is configured by circumferentially dividing a plurality of core segments 24 into an annular arrangement. Each core segment 24 is covered with an insulator (not shown), such as resin. The core segments 24 are made by stacking a plurality of electromagnetic steel sheets or thin plates in the axial direction. Each core segment 24 has a back yoke portion 25 extending in the circumferential direction and teeth portions 26 protruding from the radially inner side of the back yoke portion 25 toward the center Q.

[0014] 1, the stator coil 22 is wound around each tooth 26 and is in contact with the inner end surface of the back yoke 25. The stator coil 22 is housed in a slot 27 defined between circumferentially adjacent teeth 26. Here, the stator coil 22 is arranged in this slot 27 with concentrated winding around the teeth 26.

[0015] As shown in Figure 3, an example has been shown in which the stator core 21 is composed of multiple split cores 24, but this is not limited to this, and various shapes of the stator core 21 are possible, such as when the stator core 21 is not split, or when the circumferential ends of the back yoke portion are connected together with a thin wall.

[0016] 4, the present disclosure is also applicable to a rotating electric machine 1 in which the stator coil 22 is wound across a plurality of slots, a winding method known as distributed winding. The rotating electric machine 1 described above is an example, and the number of poles and the number of slots are not limited to these.

[0017] As described above, the present disclosure is applicable to either a concentrated winding rotating electric machine 1 or a distributed winding rotating electric machine 1, as long as terminal portions 221 (described later) drawn out from a stator coil 22 wound around a stator core 21 are electrically connected to each other, and a magnetic field is generated by the stator coil 22 by passing current between the terminal portions 221, thereby rotating the rotor 3.

[0018] 5 and 6, terminal portions 221 of each stator coil 22 of the stator core 21 are engaged in grooves formed in insulators 28, which are insulating members attached to the stator core 21. Each terminal portion 221 has a winding start wire X1 (see FIG. 6) side that is introduced into the groove of the insulator 28 when winding of the stator coil 22 begins, and a winding end wire X2 (see FIG. 6) side that is led out of the groove of the insulator 28 when winding of the stator coil 22 is completed.

[0019] As shown in Fig. 7 , the stator coils 22 include three-phase stator coils 22 for U, V, and W phases, i.e., a U-phase stator coil 22, a V-phase stator coil 22, and a W-phase stator coil 22. Furthermore, as shown in Fig. 8 , the terminal portions 221 of the stator coils 22 of each phase may be connected by a Y connection. Furthermore, the terminal portions 221 of the stator coils 22 of each phase are connected such that the winding start wires are connected to each other, or the winding end wires are connected to each other, or the winding start wires and the winding end wires are connected to each other, and the configuration depends on the type of connection method of the rotating electric machine 1.

[0020] Although these connection states are described as examples in this disclosure, the contents of this disclosure are applicable regardless of the connection state, and are effective for various connection methods, such as when multiple phase stator coils 22 are connected in parallel, when a delta connection is used, or when a configuration is used in which a wye connection and a delta connection are switched.

[0021] Next, a method for manufacturing the joints 20 of the terminal portions 221 of the stator coils 22 of the stator 2 of the rotating electric machine 1 according to the first embodiment configured as described above will be described. First, as shown in Fig. 9 , in order to bring the terminal portions 221 of the stator coils 22 into contact with each other, the terminal portions 221 wound around the stator core 21 and drawn out from the stator coils 22 are placed adjacent to each other so that their longitudinal side surfaces are in contact with each other. Here, because the cross-sectional shape of each of the terminal portions 221 of the adjacent stator coils 22 is round, the two terminal portions 221 make line contact with each other.

[0022] 10A , each terminal 221 is fixed by a fixture 6 with all of the insulating coating 52 still present. Laser irradiation 7 is then performed on the areas where the terminals 221 are in line contact with each other. As a result, as shown in FIG. 10B , a portion of the insulating coating 52 on the terminals 221 melts and peels off, exposing the conductors 51. The conductors 51 of the terminals 221 are laser-melted and joined to each other, forming joints 20 with the insulating coating 52 still attached (with a portion remaining). That is, in a cross section taken perpendicular to the longitudinal direction of the conductor 5 at a portion including the joints 20 at the terminals 221 of the conductors 5 of the multiple stator coils 22, there are areas where the insulating coating 52 remains (hereinafter, these areas may be referred to simply as "areas where the insulating coating 52 remains"; further, only in FIG. 10B , the areas corresponding to the "areas where the insulating coating 52 remains" are indicated by hatching).

[0023] In another manufacturing method, as shown in FIG. 11A , each terminal 221 is fixed by a fixture 6 with the insulating coating 52 fully present. The terminals 221 are in line contact with each other. A horn 8 is connected to one of the fixtures 6, and the other fixture 6 is fixed and immobile. Ultrasonic waves are then generated from the horn 8. The ultrasonic waves are transmitted to the terminals 221 via the fixture 6, and friction between the terminals 221 causes a portion of the insulating coating 52 to peel off. The conductors 51 of the terminals 221 are ultrasonically bonded to each other, with the insulating coating 52 still attached (with a portion remaining). That is, as in the above case, in a cross section of the terminals 221 of the conductors 5 of the multiple stator coils 22, including the joints 20, taken perpendicular to the longitudinal direction of the conductors 5, there are portions where the insulating coating 52 remains except for the joints 20.

[0024] The remaining portion of the insulating coating 52 includes the portion where the fixing device 6 contacts the terminal portion 221 and is located on the outer periphery of the terminal portion 221. Therefore, electrical insulation is ensured in the remaining portion of the insulating coating 52, and a creepage distance can be secured from the joint 20 to an external conductive material, such as a conductive terminal, that contacts the portion where the insulating coating 52 remains. As a specific example, FIG. 23 shows the relationship between the terminal portion 221 and the conductive terminal 10. FIG. 23A is a partial plan view showing the wiring process of the stator shown in FIG. 5. FIG. 23B is a cross-sectional view taken along line H1-H1 in FIG. 23A. As shown in FIG. 23, when the conductive terminal 10 is attached, leaving the remaining portion of the insulating coating 52 ensures a creepage distance, preventing current from flowing to the terminal 10.

[0025] Because the joint 20 is configured as described above, there is no need to connect the terminal portions 221 of each stator coil 22 with a separate member such as a bus bar. This reduces the material costs of separate members such as bus bars. Furthermore, there is no need to remove the insulating coating 52 beforehand, reducing processing costs. Furthermore, by physically connecting the winding start wire X1 and winding end wire X2, which serve as the terminal portions 221 extending from the stator coil 22, electricity can be applied, generating a magnetic field in the stator coil 22 wound around the stator core 21.

[0026] 12 and 13 , in another manufacturing method, a fixing surface 61 conforming to the outer shape of the terminal portion 221 is formed on the fixing device 6, and the terminal portion 221 is positioned and fixed so as to fit along the fixing surface 61, and the joining process is performed in the same manner as in the case described above. By gripping and fixing the terminal portion 221 with the arc-shaped fixing surface 61 of the fixing device 6 conforming to the outer shape of the terminal portion 221 in this way, it is possible to stably join the terminal portion 221 without misalignment, and the conductors 51 of the terminal portions 221 can be joined together while the insulating coating 52 is removed stably at the targeted position by applying laser irradiation 7 and ultrasonic waves, and the joint 20 can be formed with the insulating coating 52 still attached.

[0027] Furthermore, in the first embodiment, an example has been shown in which the bonded portion 20 is formed using the laser irradiation 7 or the horn 8, but it is also possible to add a heating portion for heating the fixing device 6. Specific examples are shown in Figures 24 and 25. Figure 24A is a cross-sectional view showing another method for joining the terminal portions shown in Figure 9B. Figure 24B is a cross-sectional view showing the state after the terminal portions shown in Figure 24A have been joined. Figure 25A is a cross-sectional view showing another method for joining the terminal portions shown in Figure 9B. Figure 25B is a cross-sectional view showing the state after the terminal portions shown in Figure 25A have been joined.

[0028] 24 and 25 , a heating unit 9 is added to heat the fixing device 6. The heating unit 9 can apply electricity to the fixing device 6 to heat it. That is, by heating the fixing device 6, the terminal portion 221 is heated. By controlling the amount of electricity applied to the fixing device 6 by the heating unit 9, it is possible to adjust the heating temperature of the fixing device 6.

[0029] If the insulating coating 52 of the conductor 5 is heat-resistant, the fixing device 6 is heated using the heating unit 9 to heat the insulating coating 52, thereby increasing its melting property and peelability, in order to facilitate the removal of the insulating coating 52 from the conductor 5. In this case, as in the first embodiment, the terminals 221 are joined together to form the joint 20 by irradiating the laser 7 shown in FIG. 24 or vibrating the horn 8 used for ultrasonic welding shown in FIG. 23 , and the insulating coating 52 remains in the area other than the joint 20. In other words, the heating of the fixing device 6 easily melts the insulating coating 52 in the area that will become the joint 20, increasing its peelability, and thus facilitating the formation of the joint 20. Similarly to the above-described case, if the configuration shown in FIG. 23 is adopted for the area where the insulating coating 52 remains, a creepage distance to the terminal 10 can be ensured.

[0030] Furthermore, in the above-mentioned embodiment 1, an example is shown in which the insulating coating 52 remains in a portion other than the joint 20, but this is not limited to this. It is also possible to configure the structure so that in a cross section of the portion including the joint 20 at the terminal portion 221 of the conductor 5 of multiple stator coils, cut perpendicular to the longitudinal direction of the conductor 5, there is a trace 50 where the insulating coating 52 has melted and the conductor 51 is exposed at a portion on the opposite side of the joint 20 at the terminal portion 221 of the conductor 5.

[0031] Specific examples are shown in Figures 26 and 27. Figure 26A is a cross-sectional view showing another method for joining the terminal portions shown in Figure 9B. Figure 26B is a cross-sectional view showing the state after the terminal portions shown in Figure 26A have been joined. Figure 27A is a cross-sectional view showing another method for joining the terminal portions shown in Figure 9B. Figure 27B is a cross-sectional view showing the state after the terminal portions shown in Figure 27A have been joined.

[0032] 26 and 27 , similarly to the first embodiment, the removal of insulating coating 52 is facilitated by vibrating laser irradiation 7 in FIG. 26 or horn 8 used for ultrasonic welding in FIG. 27 , and further heating fixture 6. In this manner, insulating coating 52 is removed not only at joint 20 but also at the contact points between heated fixture 6 and conductor 5, exposing conductor 51. As a result, insulating coating 52 of conductor 5 is removed at joint 20 and the contact points with fixture 6.

[0033] That is, in a cross section including the joints 20 at the terminals 221 of the conductor wires 5 of the multiple stator coils 22, a mark 50 is formed where the insulating coating 52 is melted and the conductor 51 is exposed at the portion of the terminals 221 of the conductor wires 5 opposite the joints 20, which is in contact with the fixing device 6. (Hereinafter, this portion may be simply referred to as the "mark 50 where the insulating coating 52 is melted and the conductor 51 is exposed.") The rotating electric machine 1 must be electrically connected to the stator 2 via a wire connection, but by removing the insulating coating 52 at a location other than the joints 20, it is not necessary to consider the insulating coating 52 when attaching the power line, making it easier to supply power. This makes it possible to reduce the processing time for wire connection and the processing costs for assembling the power line.

[0034] An example of a connection portion is shown in Figure 28. Figure 28A is a plan view showing another configuration of the stator of the rotating electric machine shown in Figure 1. Figure 28B is a cross-sectional view showing a cross section taken along line H2-H2 in Figure 28A. As shown in Figure 28B, it is possible to pass a current through a mark 50, which is a location different from the joint 20, where the insulating coating 52 has melted and the conductor 51 is exposed, via an electrically connected terminal 10, and it is possible to generate a rotating magnetic field in the stator 2 of the rotating electric machine 1.

[0035] Another example is shown in Fig. 29. Fig. 29A is a cross-sectional view showing another method for joining the terminal portions shown in Fig. 9B. Fig. 29B is a cross-sectional view showing the state after the terminal portions shown in Fig. 29A have been joined. As shown in Fig. 29B, it is also possible to heat one fixing tool 6 (on the right side of the drawing) to a lower temperature or not to heat it at all, and heat the "portion where the insulating coating 52 remains" by heating the other fixing tool 6 (on the left side of the drawing) to a higher temperature than the heating temperature of the one fixing tool 6, thereby forming a mark 50 where the insulating coating 52 has melted and the conductor 51 is exposed.

[0036] In this case, when the terminal 10 is installed as shown in Figure 30, the insulating coating 52 melts at the portion of the terminal 221 of the conductor 5 opposite the joint 20 where the fixture 6 comes into contact, forming a trace 50 where the conductor 51 is exposed and connected to the power source. Therefore, the point where electricity flows is limited to one point, and the current flow state can be stabilized.

[0037] Note that the method of heating the fixture 6 does not have to be a method using current through the heating unit 9; as long as the fixture 6 is heatable and the heating temperature is adjustable, other methods can be used and can be performed in the same way. Furthermore, since the provision of the heating unit 9, the formation of the "portion where the insulating coating 52 remains," and the formation of the "mark 50 where the insulating coating 52 is melted and the conductor 51 is exposed" can be performed and formed in the same way in the following embodiments, explanations thereof will be omitted as appropriate.

[0038] In the above-described first embodiment, the connection of two terminal wires is shown as an example, but the present invention is not limited thereto. For example, the same can be done in the case of joining three or more terminal wires of a plurality of stator coils 22 at a neutral point or the like as shown in Fig. 8. Furthermore, in the above-described first embodiment, an example is shown in which a joint is formed while the insulating coating remains attached to both of the two terminal portions, but the present invention is not limited thereto. The insulating coating of one terminal portion may be removed and the joint may be formed while the insulating coating of the other terminal portion remains. The above also applies to the following embodiments, so description thereof will be omitted as appropriate.

[0039] According to the rotating electric machine of embodiment 1 configured as described above, the rotating electric machine includes a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, wherein the plurality of stator coils are formed of conductor wires with an insulating coating on the outer periphery of the conductor, and the terminal ends of the conductor wires of the plurality of stator coils are provided with joints where the conductors are joined together by ultrasonic welding with the insulating coating still attached, thereby making it possible to form joints by joining the terminal ends together without removing the insulating coating, thereby reducing processing costs.

[0040] According to the rotating electric machine of embodiment 1 configured as described above, the rotating electric machine includes a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, wherein the plurality of stator coils are formed of conductor wires with an insulating coating on the outer periphery of the conductor, and the terminal ends of the conductor wires of the plurality of stator coils are provided with joints where the conductors are joined by laser melt joining with the insulating coating still attached, thereby making it possible to form joints by joining the terminal ends without removing the insulating coating, thereby reducing processing costs.

[0041] Furthermore, according to the manufacturing method for the rotating electric machine of embodiment 1 configured as described above, the manufacturing method for the rotating electric machine described above involves applying vibrations to the terminal portions using ultrasonic waves, causing friction between the terminal portions to peel off part of the insulating coating, and joining the conductors to form the joint.This means that the step of peeling off the insulating coating can be omitted, reducing processing costs, and it is possible to reliably and easily form a joint that joins the terminal portions to each other while keeping the insulating coating attached.

[0042] Furthermore, according to the manufacturing method for the rotating electric machine of embodiment 1 configured as described above, the manufacturing method for the rotating electric machine described above involves melting a portion of the insulating coating between the terminal portions by laser irradiation to join the conductors together and form the joint, so that the step of peeling off the insulating coating can be omitted, reducing processing costs, and a joint that joins the terminal portions together without peeling off the insulating coating can be reliably and easily formed.

[0043] Furthermore, according to the manufacturing method for the rotating electric machine of embodiment 1 configured as described above, the outer periphery of the terminal portion is fixed using a fixing device that fixes the outer periphery of the terminal portion, and the joint is then joined, so that the joint that joins the terminal portions together can be stably formed without peeling off the insulating coating.

[0044] Furthermore, according to the rotating electric machine of embodiment 1 configured as described above, in a cross section obtained by cutting a portion including the joint at the end portion of the conductor of each of the plurality of stator coils perpendicular to the longitudinal direction of the conductor, there are portions where the insulating coating remains other than the joint, so that a creepage distance can be secured between the insulating coating and external conductive materials.

[0045] Furthermore, according to the rotating electric machine of embodiment 1 configured as described above, in a cross section obtained by cutting a portion including the joint at the end portions of the conductors of the multiple stator coils perpendicular to the longitudinal direction of the conductors, at least one end portion of the conductor has a mark on the side opposite the joint where the insulating coating has melted and the conductor has been exposed.Therefore, a rotating electric machine can be obtained in which electrical continuity can be easily ensured by bringing an external conductive material into contact with the mark where the insulating coating has melted and the conductor has been exposed.

[0046] Furthermore, according to the manufacturing method of the rotating electric machine of embodiment 1 configured as described above, in a cross section obtained by cutting the portion including the joint at the end portion of the conductor of the plurality of stator coils perpendicular to the longitudinal direction of the conductor, the insulating coating remains in a portion other than the joint, so that a rotating electric machine can be obtained that ensures a creepage distance from external conductive materials.

[0047] Furthermore, according to the manufacturing method of the rotating electric machine of embodiment 1 configured as described above, in a cross section obtained by cutting a portion including the joint at the end portions of the conductors of the multiple stator coils perpendicular to the longitudinal direction of the conductors, the insulating coating is melted to form a mark exposing the conductor at a location opposite the joint at the end portion of at least one of the conductors.Therefore, it is possible to obtain a rotating electric machine in which electrical continuity can be easily ensured by bringing an external conductive material into contact with the conductor at the mark where the insulating coating is melted and the conductor is exposed.

[0048] Furthermore, according to the manufacturing method for the rotating electric machine of the first embodiment configured as described above, the fixing tool heats the terminal portion, so that the insulating coating of the conductor wire can be easily melted.

[0049] Embodiment 2. Fig. 14A is a cross-sectional view showing the configuration of a stator of a rotating electric machine according to embodiment 2 before terminal portions thereof are joined together. Fig. 14B is a cross-sectional view showing the configuration after the terminal portions shown in Fig. 14A have been joined together. Fig. 15A is a cross-sectional view showing a method of joining the terminal portions shown in Fig. 14A. Fig. 15B is a cross-sectional view showing the state after the terminal portions shown in Fig. 15A have been joined together. Fig. 16A is a cross-sectional view showing another method of joining the terminal portions shown in Fig. 14A. Fig. 16B is a cross-sectional view showing the state after the terminal portions shown in Fig. 16A have been joined together. Figs. 17 and 18 are cross-sectional views showing another method of joining the terminal portions shown in Fig. 14A. In the figures, parts similar to those in embodiment 1 above are omitted and are designated by the same reference numerals.

[0050] In the first embodiment, the conductor wire 5 of the stator coil 22 has a round cross section. Therefore, when connecting the terminal portions 221 of the stator coil 22, the joints between the terminal portions 221 are in point contact or line contact. Therefore, when joining the terminal portions 221, the positions may not be stable, and for example, the penetration of the joint 20 may be shallow. Therefore, in the second embodiment, the joint 20 of the terminal portion 221 of the stator coil 22 using the conductor wire 5 having the flat portion 55 will be described.

[0051] As shown in FIG. 14 , in the second embodiment, the conductor 5 forming the terminal portion 221 of the stator coil 22 has a flat portion 55 on the outer periphery. Then, as shown in FIG. 14A , the flat portions 55 of the terminal portions 221 are brought into contact with each other. Then, as shown in FIG. 14B , the conductors 51 are joined to each other with the insulating coating 52 still attached, forming a joint 20. Because the joint 20 is formed with the flat portions 55 of the conductor 5 in contact, the joint 20 of the terminal portions 221 is in surface contact over a wide area. This also prevents misalignment of the terminal portions 221 of the stator coil 22. Therefore, by preventing misalignment of the joint 20 and increasing the joint area, stable joining of the stator coils 22 to each other is possible.

[0052] Next, a method for manufacturing the joint 20 of the terminal portions 221 of the stator coil 22 of the stator 2 of the rotating electric machine 1 according to the second embodiment configured as described above will be described. First, as shown in Fig. 15A , the terminal portions 221 of the stator coil 22 are fixed together using fasteners 6 so that the flat portions 55 of the terminal portions 221 are in contact with each other, with the insulating coating 52 remaining entirely. Then, laser irradiation 7 is performed on the areas where the flat portions 55 of the terminal portions 221 are in surface contact with each other. As a result, as shown in Fig. 15B , the insulating coating 52 on the flat portions 55 of the terminal portions 221 is entirely melted, exposing the conductors 51. The conductors 51 on the flat portions 55 of the terminal portions 221 are joined together by laser melt joining, and the joint 20 is formed with the insulating coating 52 remaining attached to the other portions.

[0053] 16A , for example, terminal portions 221 of the stator coil 22 are fixed together by fixtures 6 so that the flat portions 55 of the terminal portions 221 are in contact with each other, with all of the insulating coating 52 still present. A horn 8 is then connected to one of the fixtures 6, and the other fixture 6 is fixed and immovable. Ultrasonic waves are then generated from the horn 8. The ultrasonic waves are transmitted to the terminal portions 221 via the fixtures 6, and the friction between the flat portions 55 of the terminal portions 221 melts all of the insulating coating 52 on the flat portions 55, joining the conductors 51 of the terminal portions 221 together by ultrasonic welding, forming a joint 20 with the insulating coating 52 remaining attached.

[0054] In this way, by providing the flat surfaces 55 of the terminal portions 221, the flat surfaces 55 of the terminal portions 221 come into contact with each other, stabilizing the position for forming the joint 20. Furthermore, since the contact area between the flat surfaces 55 of the terminal portions 221 is increased, friction due to ultrasonic waves is strengthened, and the removal and joining of the insulating coating 52 can be performed with small vibrations.

[0055] 17 and 18 , in another manufacturing method, a fixing surface 62 conforming to the outer shape of the terminal portion 221 is formed on the fixing device 6, and the terminal portion 221 is positioned and fixed so as to fit along the fixing surface 62, in the same manner as described above. By gripping and fixing the terminal portion 221 to the fixing device 6 with the arc-shaped fixing surface 61 conforming to the outer shape in this way, the terminal portion 221 can be stably joined without shifting in position, and positional shifting of the terminal portion 221 during joining can be suppressed. The terminal portions 221 can be joined together while the insulating coating 52 is removed stably at the targeted position by laser irradiation 7 and application of ultrasonic waves, and the joint 20 can be formed while the insulating coating 52 of the remaining portions remains attached.

[0056] According to the manufacturing method of the rotating electric machine of the second embodiment configured as described above, the same effects as those of the first embodiment can be achieved, and the conductor has a flat portion on the outer periphery of the terminal portion, and the joint is formed by joining the flat portions of the terminal portions together, so that the joint is formed on the flat portion of the terminal portion, making it possible to achieve a stable joint.

[0057] Embodiment 3. Fig. 19 is a perspective view showing a method for joining terminal portions of a stator of a rotating electric machine according to embodiment 3. Fig. 20 is a perspective view showing another method for joining terminal portions of a stator of a rotating electric machine according to embodiment 3. In the figure, parts that are the same as those in the above embodiments are given the same reference numerals and are omitted.

[0058] In each of the above-described embodiments, examples have been shown in which the terminal portions 221 are brought into line contact or surface contact with each other to form a joint. However, there is a possibility that the terminal portions 221 may become misaligned during joining. Therefore, in this third embodiment, the terminal portions 221 are made to cross each other and come into contact with each other. For example, the terminal portions 221 are made to cross each other as shown in FIG. 19 , or the flat portions 55 of the terminal portions 221 are made to cross each other as shown in FIG. 20 . Then, as in the above-described embodiments, the terminal portions 221 are fixed, and the conductors 51 of the terminal portions 221 of the stator coil 22 are joined together by laser irradiation or vibrating the horn 8, thereby forming the joint 20 with the insulating coating 52 still attached.

[0059] The rotating electric machine of embodiment 3 configured as described above has the same effects as the above embodiments, and in addition, since the joints are joined by crossing the terminal portions with each other, this cross-joining structure can suppress positional deviation compared to when fixed by line contact, making it easier to achieve a joint with stable position.

[0060] Embodiment 4. Fig. 21 is a plan view showing a method for joining terminal portions of a stator of a rotating electric machine according to embodiment 4. Fig. 22A is a side view showing a method for joining terminal portions of a stator of a rotating electric machine shown in Fig. 21. Fig. 22B is a cross-sectional view showing the configuration of a joint between terminal portions of a stator of a rotating electric machine taken along line Y-Y in Fig. 22A. In the figure, parts similar to those in the above embodiments are omitted and are designated by the same reference numerals.

[0061] In the fourth embodiment, in order to join the terminal portions 221 of the stator coil 22 together, the terminal portions 221 are twisted together as shown in FIG. 21 . In this state, the terminal portions 221 come into contact with each other at some point. Then, as shown in FIG. 22A , they are fixed with a fixture 6. A horn 8 is connected to one of the fixtures 6, and the other fixture 6 is fixed and immovable. Ultrasonic waves are then generated from the horn 8. The ultrasonic waves are transmitted to the terminal portions 221 via the fixture 6, and as shown in FIG. 22B , the insulating coating 52 between the terminal portions 221 melts, and the conductors 51 of the terminal portions 221 are ultrasonically joined to each other, forming a joint 20 with the insulating coating 52 still attached (with a portion remaining).

[0062] In this way, multiple terminal portions 221 are bundled together in a twisted structure, and ultrasonic vibration is applied to any of the points where the terminal portions 221 are twisted, removing the insulating coating 52 while joining the terminal portions 221 to form a joint 20, so that the terminal portions 221 can be reliably joined to each other.

[0063] The rotating electric machine of embodiment 4 configured as described above has the same effects as the above embodiments, and the joint is formed by twisting two or more of the terminal portions together, so that the terminal portions are twisted together to form the joint, thereby ensuring the formation of the joint.

[0064] Although various exemplary embodiments and examples are described in this disclosure, the various features, aspects, and functions described in one or more embodiments are not limited to the application of a particular embodiment, but may be applied to the embodiments alone or in various combinations. Therefore, countless variations not illustrated are anticipated within the scope of the technology disclosed in this specification. For example, this includes cases where at least one component is modified, added, or omitted, or where at least one component is extracted and combined with components of another embodiment.

[0065] Various aspects of the present disclosure are summarized below as appendices.

[0066] (Supplementary Note 1) A rotating electric machine comprising a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, wherein the plurality of stator coils are formed of conductor wires with an insulating coating applied to the outer periphery of the conductor, and wherein terminal portions of the conductor wires of the plurality of stator coils are provided with joints where the conductors are joined by ultrasonic welding with the insulating coating still attached. (Supplementary Note 2) A rotating electric machine comprising a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, wherein the plurality of stator coils are formed of conductor wires with an insulating coating applied to the outer periphery of the conductor, and wherein terminal portions of the conductor wires of the plurality of stator coils are provided with joints where the conductors are joined by laser welding with the insulating coating still attached. (Supplementary Note 3) The rotating electric machine according to Supplementary Note 1 or Supplementary Note 2, wherein the joint is formed by joining the terminal portions by crossing each other. (Supplementary Note 4) The rotating electric machine according to any one of Supplementary Note 1 to Supplementary Note 3, wherein the conductor wire has a flat portion on the outer periphery of the terminal portion, and the joint is formed by joining the flat portions of the terminal portions together. (Supplementary Note 5) The rotating electric machine according to Supplementary Note 1, wherein the joint is formed by twisting two or more terminal portions together. (Supplementary Note 6) A method for manufacturing a rotating electric machine according to Supplementary Note 1, wherein the method vibrates the terminal portions with ultrasonic waves, peels off part of the insulating coating by friction between the terminal portions, and joins the conductors together to form the joint. (Supplementary Note 7) A method for manufacturing a rotating electric machine according to Supplementary Note 2, wherein the method melts part of the insulating coating on the terminal portions with laser irradiation, and joins the conductors together to form the joint. (Supplementary Note 8) The method for manufacturing a rotating electric machine according to Supplementary Note 6 or Supplementary Note 7, wherein the outer periphery of the terminal portion is fixed by a fixture for fixing the outer periphery of the terminal portion, and the joint portion is joined.

[0067] REFERENCE SIGNS LIST 1 Rotating electric machine, 10 Terminal, 2 Stator, 20 Joint, 21 Stator core, 22 Stator coil, 221 Terminal portion, 24 Segment core, 25 Back yoke portion, 26 Teeth portion, 27 Slot portion, 28 Insulator, 3 Rotor, 31 Rotor core, 32 Magnet, 4 Rotating shaft, 5 Conductor, 50 Mark, 51 Conductor, 52 Insulating coating, 55 Flat portion, 6 Fixing tool, 61 Fixing surface, 62 Fixing surface, 7 Laser irradiation, 8 Horn, 9 Heating portion, X1 Winding start wire, X2 Winding end wire, Q Center.

Claims

1. A rotating electric machine comprising a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, wherein the plurality of stator coils are formed from conductors with an insulating coating on the outer periphery of the conductors, and wherein terminal portions of the conductors of the plurality of stator coils are provided with joints where the conductors are joined together by ultrasonic welding while the insulating coating remains attached.

2. A rotating electric machine comprising a stator and a rotor rotatably arranged inside the stator, wherein the stator has a stator core and a plurality of stator coils wound around the stator core, the plurality of stator coils being formed from conductors with an insulating coating on the outer periphery of the conductors, and the terminal ends of the conductors of the plurality of stator coils are provided with joints where the conductors are joined together by laser melt welding while the insulating coating remains attached.

3. A rotating electric machine according to claim 1 or claim 2, wherein in a cross section taken perpendicular to the longitudinal direction of the conductor at a portion including the joint at the end portion of the conductor of a plurality of the stator coils, there are portions where the insulating coating remains other than at the joint.

4. A rotating electric machine as claimed in claim 1 or claim 2, wherein in a cross section taken perpendicular to the longitudinal direction of the conductors of a plurality of the stator coils, at a portion including the joint at the end portions of the conductors, at least one of the end portions of the conductors has a trace where the insulating coating has melted and the conductor is exposed, at a location opposite the joint.

5. A rotating electric machine according to any one of claims 1 to 4, wherein the terminal portions of the joint are joined by crossing each other.

6. A rotating electric machine according to any one of claims 1 to 5, wherein the conductor has a flat portion on the outer periphery of the terminal portion, and the joint is formed by joining the flat portions of the terminal portions together.

7. A rotating electric machine according to any one of claims 1 to 6, wherein the joint is formed by twisting two or more of the terminal portions together.

8. A method for manufacturing a rotating electric machine as described in claim 1, wherein the terminal portions are vibrated by ultrasonic waves, and friction between the terminal portions causes a portion of the insulating coating to peel off, joining the conductors together to form the joint.

9. A method for manufacturing a rotating electric machine according to claim 2, wherein a part of the insulating coating between the terminal portions is melted by laser irradiation to join the conductors together and form the joint.

10. A method for manufacturing a rotating electric machine as described in claim 8 or claim 9, wherein in a cross section obtained by cutting a portion including the joint at the end portion of the conductor of a plurality of the stator coils perpendicular to the longitudinal direction of the conductor, the insulating coating remains in a portion other than the joint.

11. A method for manufacturing a rotating electric machine as described in claim 8 or claim 9, wherein in a cross section of a portion including the joint at the end portion of the conductor of a plurality of the stator coils cut perpendicular to the longitudinal direction of the conductor, the insulating coating is melted to form a mark exposing the conductor at a location opposite the joint at the end portion of at least one of the conductors.

12. A method of manufacturing a rotating electric machine according to any one of claims 8 to 11, wherein the outer periphery of the terminal portion is fixed with a fixture for fixing the outer periphery of the terminal portion, and the joint portion is joined.

13. A method for manufacturing a rotating electric machine according to claim 12, wherein the fixing tool heats the terminal portion.

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