Rotary electric machine and manufacturing method thereof

It is realized that a shape of a bus ring is simplified, and a rotary electric machine is downsized. A coil connecting portion, which is protruded from bus ring maintaining portions to a shaft direction, is provided at a bus ring, and coil terminals are arranged in such a way that the coil terminals are protruded toward an outer side in a diameter direction with respect to the coil connecting portion, and the coil terminals and the coil connecting portion are connected by performing a resistance welding process. Thereby, it is not required that a slit and a bent portion or the like are formed at a tip of the bus ring, and a shape of the bus ring is simplified. Moreover, a welding board for a welding process and a chuck board for a connecting portion are not required, so that a rotary electric machine can be downsized.

BACKGROUND OF THE INVENTION

Field of the Invention

The present invention relates to a rotary electric machine such as a generator, an electric motor, and an electric generator, and relates to a manufacturing method of the rotary electric machine.

Description of the Related Art

As a connection method of a bus ring and a coil in a conventional rotary electric machine, there is a method in which a slit, by which a tip portion of the bus ring is longitudinally divided, is formed, and a coil terminal is arranged in the slit so as to be connected by using a TIG welding method. The TIG welding method is used as a welding method in which an electric current is flowed, in an inert gas, to a tungsten electrode, which is a non-consumable electrode, and a high temperature arc is caused between a welding material and the tungsten electrode, whereby the welding material is welded. For example in Patent Document 1, protruding flakes at both sides, by which the slit of the bus ring is sandwiched, are formed in a tapered shape, whereby the protruding flakes are easily welded.

In a connection method which is disclosed in Patent Document 1, a slit and a bent portion are formed at a tip of a bus ring, so that there is a problem in which a shape of the bus ring is complicated. Moreover, a welding board for a TIG welding method and a chuck board for a connecting portion are required, so that a height of a welding portion is enhanced, and it is prevented that a rotary electric machine is downsized.

SUMMARY OF THE INVENTION

The present invention has been made to disclose a technology by which the above-described problems are solved, and an object of the invention is to simplify a shape of a bus ring, and to downsize a rotary electric machine.

A rotary electric machine, which is disclosed in the present invention, includes a stator which includes a stator core which includes teeth which are protruded from inner circumference wall surfaces of core back portions having an arc shape, bobbins which are made of a resin and are respectively arranged on end surfaces in a shaft direction at both sides of the stator core, and coils which are wound around the teeth via the bobbins; and a rotor which is rotatably arranged at an inner circumference side of the stator; wherein the bobbins, which are arranged on at least one of the end surfaces in a shaft direction of the stator core, include coil winding portions, which are arranged at end surfaces in a shaft direction of the teeth, on which the coils are wound; and flange portions, which are arranged at end surfaces in a shaft direction of the core back portions, at which a plurality of bus ring maintaining portions are formed, and a plurality of bus rings, which are made of a plane sheet having a band shape, are concentrically arranged in a state where the bus rings are inserted to the bus ring maintaining portions, and each of the bus rings includes coil connecting portions which are protruded from the bus ring maintaining portions to a shaft direction, and terminals of the coils are arranged in such a way that the terminals of the coils are protruded toward an outer side in a diameter direction with respect to the coil connecting portions, and the terminals of the coils are connected to plane tip portions of the coil connecting portions.

A manufacturing method of a rotary electric machine, which is disclosed in the present invention, includes a first step in which a plurality of bus rings, which are made of a plane sheet having a band shape, are inserted to bus ring maintaining portions having a ditch shape, which are formed at bobbins which are arranged on at least one of end surfaces in a shaft direction of a stator core; a second step in which terminals of the coils, which are connection objects, are arranged at coil connecting portions, which are protruded from the bus ring maintaining portions to a shaft direction, of each of the bus rings; and a third step in which electrodes are respectively arranged at the terminals of the coils which are arranged at the adjacent coil connecting portions, and the electrodes are energized while the electrodes are pressed in a direction of the coil connecting portions, and resistance welding processes of the terminals of the coils are concurrently performed to the coil connecting portions at two positions.

According to the rotary electric machine which is disclosed in the present invention, the coil connecting portions, which are protruded from the bus ring maintaining portions to a shaft direction, are provided at the each of the bus rings, and the terminals of the coils are connected to the tip portions, which have a plane shape, of the coil connecting portions, so that it is not required that a slit and a bent portion are formed, like a conventional rotary electric machine, at a tip of a bus ring, and a shape of the bus rings is simplified, and it can be realized that the rotary electric machine is downsized. Moreover, the terminals of the coils are arranged in such a way that the terminals of the coils are protruded toward an outer side in a diameter direction, so that the fillets are formed between the end surfaces of the coil connecting portions and the protruding portions of the terminals of the coils, so that a high connection strength is obtained.

According to the manufacturing method of the rotary electric machine, which is disclosed in the present invention, the resistance welding processes of the terminals of the coils are concurrently performed to the coil connecting portions at two positions, so that a productivity is improved in comparison with a case in which the terminals of the coils are welded at every one position. Moreover, the electrodes are arranged at the coil terminals which are arranged at the adjacent coil connecting portions, and the electrodes are energized, so that the energization passage can be shortened, and the damage, which is caused by heat, to the coils and the bobbin can be inhibited. Moreover, the terminals of the coils are welded while the terminals of the coils are pressed in a direction of the coil connecting portions, so that it can be prevented that the positions of the terminals of the coils are deviated, and a stable welding process, of which reliability is high, can be performed. Moreover, a welding board for a welding process and a chuck board for a connecting portion are not required so that it can be realized that the rotary electric machine is downsized.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Hereinafter, a rotary electric machine according to Embodiment 1 and a manufacturing method of the rotary electric machine will be explained in accordance with the drawings.FIG. 1is a one-side cross-sectional view which indicates a rotary electric machine according to Embodiment 1.FIG. 2is an oblique perspective view in which a stator of the rotary electric machine according to Embodiment 1 is viewed from one end side in a shaft direction.FIG. 3is a plane view in which the stator of the rotary electric machine according to Embodiment 1 is viewed from one end side in a shaft direction.FIG. 4is a cross-sectional view which indicates the stator of the rotary electric machine according to Embodiment 1.FIG. 5is an oblique perspective view in which the stator of the rotary electric machine according to Embodiment 1 is viewed from the other end side in a shaft direction. In addition, in each of the drawings, the same symbols are given to the same or equivalent parts. Moreover, inFIG. 1, an arrow “Z” indicates a shaft direction of a rotary electric machine100.

The rotary electric machine100according to Embodiment 1 is applied to an electric motor such as a motor which is mounted in a household electric appliance, or a motor which is mounted in an industrial machine, and as indicated inFIG. 1, the rotary electric machine100includes a rotor5and a stator10, which are installed in the inside of a housing1. The housing1includes a frame2, which is configured in a cylinder shape having a bottom and includes a cylinder portion2aand a bottom portion2b, and an end plate3by which an aperture of the flame2is closed. An aluminum material or the like is used for a material of the flame2. The stator10is inserted into the cylinder portion2aof the frame2so as to be fixed. The rotor5is rotatably arranged at an inner circumference side of the stator10.

The rotor5is a permanent magnet-type rotor which includes a rotary shaft6, a rotor core7, and permanent magnets8. The rotary shaft6is supported to the bottom portion2bof the frame2and the end plate3via a bearing4, and is inserted at a position of a shaft center. The rotor core7is fixed to the rotary shaft6. The permanent magnets8are buried at an outer circumference surface side of the rotor core7and are arranged, in a circumference direction, with a predetermined pitch, whereby the permanent magnets8compose a magnetic pole. In addition, the rotor5is not limited to a permanent magnet-type rotor, and it is suitable that a squirrel-cage type rotor, in which a rotor conductor, which is not insulated, is installed in a slot of a rotor core and both sides are shorted by using a short circle, is used, or a winding-type rotor or the like, in which a conductive wire, which is insulated, is mounted at a slot of a rotor core, is used.

As indicated inFIG. 2throughFIG. 5, the stator10includes a stator core11; a bobbin14and a bobbin15, which are made of a resin and are respectively arranged at both end surfaces in a shaft direction of the stator core11; and coils16which are wound around teeth12bvia the bobbin14and the bobbin15. The stator core11is configured in such a way that separated cores12, of which number is 18, are arranged in an annular shape. The separated cores12are formed in such a way that a predetermined number of electromagnetic steel sheets are laminated and integrated. Each of the separated cores12includes core back portions12ahaving an arc shape, and teeth12bwhich are protruded from inner circumference wall surfaces of the core back portions12ato an inner side in a diameter direction of the core back portions12a.

Any of a U-phase coil16, a V-phase coil16, and a W-phase coil16is wound around each of the separated cores12via the bobbin14and the bobbin14. Moreover, the U-phase coil16, the V-phase coil16, and the W-phase coil16are respectively connected to a U-phase bus ring25, a V-phase bus ring26, and a W-phase bus ring27. Thereby, at the stator10, three-phase AC windings, of which number is 6, in which the U-phase coil16, the V-phase coil16, and W-phase coil16are respectively formed in a Y connection state, are configured. In the rotary electric machine100, an AC electric current is supplied to the U-phase bus ring25, the V-phase bus ring26, and the W-phase bus ring27via an inverter at the outside, whereby a rotary magnetic field is generated at the stator10. The rotor5is rotated and driven in accordance with a suction force or a repulsion force, which is caused by the rotary magnetic field.

As indicated inFIG. 6, the bobbin14, which is arranged at one end surface in a shaft direction (at an upper side inFIG. 4) of the separated cores12, includes a coil winding portion14a, which is arranged at an end surface in a shaft direction of the teeth12b, on which the coil16is wound; and a flange portion14b, which is arranged at an end surface in a shaft direction of the core back portions12a, on which a plurality of a bus ring maintaining portion20, a bus ring maintaining portion21, and a bus ring maintaining portion22are formed. The U-phase bus ring25, the V-phase bus ring26, and the W-phase bus ring27are respectively maintained at the bus ring maintaining portion20, the bus ring maintaining portion21, and the bus ring maintaining portion22, which have a ditch shape.

Moreover, as indicated inFIG. 5, the bobbin15, which is arranged at the other end surface in a shaft direction (at a lower side inFIG. 4) of the separated cores12, includes a coil winding portion15a, which is arranged at the end surface in a shaft direction of the teeth12b, on which the coil16is wound. In addition, the bobbin14and the bobbin15are made of a resin material such as a polybutylene terephthalate resin (PBT) or a polyphenylene sulfide resin (PPS). In addition, it is suitable that the bobbin14and the bobbin15are fixed to the separated cores12from a viewpoint of an easy winding operation of the coils16. In this case, it can be performed that the bobbin14and the bobbin15are fixed to the separated cores12by using a fitting operation, or the bobbin14and the bobbin15are fixed to the separated cores12by using an adhesive material. In the other case, it is suitable that the bobbin14and the bobbin15are integrally molded and formed with the separated cores12.

As indicated inFIG. 7, the coils16are configured in such a way that a conductive wire, which is composed of a round copper wire on which an insulating film is coated, is wound, with a predetermined number, around the teeth12bof the separated cores12, and the coil winding portion14aand the coil winding portion15aof the bobbin14and the bobbin15, which are arranged at the end surface in a shaft direction of the teeth12b. In addition, insulators (not illustrated) are arranged at both side surfaces of the teeth12bin a circumference direction, whereby an insulation capability between the coils16and the separated cores12is maintained.

As described above, as indicated inFIG. 2throughFIG. 5, the separated cores12, of which number is 18, on which the coils16are wound, are inserted and fixed, by using a press-inserting method, a burn-fitting method or the like, to the inside of a yoke13having a cylinder shape, in a state where the teeth12bare faced toward an inner side in a diameter direction, and side surfaces of the core back portions12ain a circumference direction are faced to each other so as to be arranged in an annular shape. The yoke13is formed by shaving and processing or by squeezing and processing a single metal material such as an iron, or is formed by laminating and integrating a steel sheet such as an electromagnetic steel sheet.

The coils16, which are wound around the separated cores12so as to be arranged in an annular shape, are repeated and arranged, in a sequence of the U-phase coil16, the V-phase coil16, and the W-phase coil16, in a circumference direction. As indicated inFIG. 2, one terminal16aof each of the coils16is led, toward the bobbin14side, in a shaft direction, and is led toward an outer side in a diameter direction in a state where the terminal16ais bent, at a right angle, between the coil winding portion14aand the flange portion14bof the bobbin14.

As indicated inFIG. 5, the other coil terminal16bof each of the coils16is led toward the bobbin15side in a shaft direction. The U-phase coil terminal16b, the V-phase coil terminal16b, and the W-phase coil terminal16b, at a common side, which are led toward the bobbin15side, are integrated, and are electrically connected by using a TIG welding method, a laser welding method or the like. A connecting portion at a common side of each of the coils16is coated by using an insulating tube17. In addition, it is suitable that the connecting portion is coated by using a resin mold, an insulating tape or the like.

The U-phase bus ring25, the V-phase bus ring26, and the W-phase bus ring27are configured in such a way that a plane sheet having a band shape, which is composed of an oxygen free copper, a deoxidized copper, a tough pitch copper or the like, is bent and formed in a ring shape. As indicated inFIG. 2throughFIG. 4, the bus ring25, the bus ring26, and the bus ring27are respectively fitted to the bus ring maintaining portion20, the bus ring maintaining portion21, and the bus ring maintaining portion22, which are formed at the bobbin14and have a ditch shape, and are fixed by using an adhesive material or the like in accordance with a requirement. The bus ring25, the bus ring26, and the bus ring27are concentrically arranged in a state where the bus ring25, the bus ring26, and the bus ring27are inserted to the bus ring maintaining portion20, the bus ring maintaining portion21, and the bus ring maintaining portion22. Moreover, each of the bus ring25, the bus ring26, and the bus ring27includes a coil connecting portion25a, a coil connecting portion26a, and a coil connecting portion27a, which are protruded from the bus ring maintaining portion20, the bus ring maintaining portion21, and the bus ring maintaining portion22to a shaft direction.

The connecting portions for the coil terminals16aand the bus ring25, the bus ring26, and the bus ring27will be minutely explained by usingFIG. 8andFIG. 9. As described above, the U-phase coil terminal16a, the V-phase coil terminal16a, and the W-phase coil terminal16aare led toward the bobbin14side in a shaft direction, and are led toward an outer side in a diameter direction in a state where each of the coil terminals16ais bent at a right angle. Moreover, as indicated inFIG. 8, each of the coil terminals16ais connected to the coil connecting portion25aof the bus ring25, the coil connecting portion26aof the bus ring26, and the coil connecting portion27aof the bus ring27, which are connection objects.

In other words, the U-phase coil terminal16ais connected to the coil connecting portion25aof the U-phase bus ring25, and the V-phase coil terminal16ais connected to the coil connecting portion26aof the V-phase bus ring26, and the W-phase coil terminal16ais connected to the coil connecting portion27aof the W-phase bus ring27. Each of the coil terminals16ais connected, by performing a resistance welding process, to a tip portion251, a tip portion261, and a tip portion271, which have a plane shape, of the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a. The resistance welding process is performed in such a way that an electric current is passed between metals, which are welded, while a pressure is applied, and the both metals are welded by using heat which is caused in accordance with a resistance of a metal in itself and a resistance of a contacting portion.

Moreover, as indicated inFIG. 9, the coil terminals16aare arranged in such a way that the coil terminals16aare protruded toward an outer side in a diameter direction with respect to the coil connecting portion26aof the bus ring26. Thereby, the coil terminals16ainclude protruding portions16cwhich are protruded toward an outer side in a diameter direction with respect to the coil connecting portion26aof the bus ring26. In addition, inFIG. 9, although a connecting portion for the coil connecting portion26aof the V-phase bus ring26and the coil terminals16ais indicated as an example, a connecting portion for a U-phase and a connecting portion for a W-phase are similarly indicated.

As described above, the coil terminals16ainclude the protruding portions16c, whereby fillets18are formed between the coil terminals16aand the tip portion261, and between the coil terminals16aand a side surface at an inner side in a diameter direction of the coil connecting portion26a, and moreover between the protruding portions16cand a side surface at an outer side in a diameter direction of the coil connecting portion26a, so that a connection strength is improved in comparison with a case in which the protruding portions16care not included.

In addition, in Embodiment 1, although an example, in which the bobbin14, which is arranged at one end surface in a shaft direction of the stator core11, includes the bus ring maintaining portion20, the bus ring maintaining portion21, and the bus ring maintaining portion22, is explained, it is suitable that the bobbin14and the bobbin15, which are arranged at the end surfaces in a shaft direction at both sides of the stator core11, include the bus ring maintaining portions. In this case, the bobbin15, which is arranged at the other end surface in a shaft direction of the stator core11, includes the bus ring maintaining portion by which the bus ring for a common is maintained, and the U-phase coil terminal16b, the V-phase coil terminal16b, and the W-phase coil terminal16b, at a common side, are connected to the coil connecting portions of the bus rings.

As described above, in the rotary electric machine100according to Embodiment 1, the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, which are protruded from the bus ring maintaining portion20, the bus ring maintaining portion21, and the bus ring maintaining portion22to a shaft direction, are provided at the each of the bus ring25, the bus ring26, and the bus ring27, and the coil terminals16aare arranged in such a way that the coil terminals16aare protruded toward an outer side in a diameter direction with respect to the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, and the coil terminals16aare connected to the tip portion251, the tip portion261, and the tip portion271, which have a plane shape, of the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, so that it is not required that a slit and a bent portion or the like are formed, like a conventional rotary electric machine, at a tip of a bus ring, and shapes of the bus ring25, the bus ring26, and the bus ring27are simplified, whereby the rotary electric machine100is easily manufactured.

Moreover, the coil terminals16aare connected by performing a resistance welding process in a state where the coil terminals16aare arranged at the tip portion251, the tip portion261, and a tip portion271, which have a plane shape, of the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, so that a welding board for a welding process and a chuck board for a connecting portion are not required, whereby the rotary electric machine100can be downsized. Moreover, the coil terminals16aare arranged in such a way that the coil terminals16aare protruded toward an outer side in a diameter direction with respect to the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, so that the fillets18are formed between the protruding portions16cand the end surfaces of the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, whereby a high connection strength is obtained.

Moreover, the coil terminals16aare welded to the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, whereby a required amount of heat is reduced, when a welding process is performed, in comparison with a case in which the coil terminals16aare directly welded to the end surfaces in a shaft direction of the bus ring25, the bus ring26, and the bus ring27, and damage to the films of the coils16and to the bobbin14can be inhibited. Moreover, when a welding process is performed, interference between the bobbin14and a tool of a connection facility or the like is inhibited, so that an assembly capability of the stator10is improved. Moreover, contact areas of the coil terminals16aand the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27aare limited in accordance with a thickness size of the bus ring25, the bus ring26, and the bus ring27, so that a contact resistance is increased, and a resistance welding process is favorably performed.

FIG. 10A,FIG. 10B, andFIG. 11are views which indicate a connecting portion for a bus ring and a coil terminal, at a rotary electric machine according to Embodiment 2. In addition, an overall configuration of the rotary electric machine according to Embodiment 2 is similar to an overall configuration of the rotary electric machine according to Embodiment 1 which is described above, so that an explanation is omitted. In Embodiment 2, a suitable condition of a size of each of elements at a connecting portion of a coil terminal.16aand a coil connecting portion25aof a bus ring25will be explained.

As indicated inFIG. 10AandFIG. 10B, when a thickness size of the bus ring25is set as “T”, and a contact width of the coil terminal.16aand the coil connecting portion25aof the bus ring25is se as “W3”, and a contact area of the coil terminal.16aand the bus ring25, after a welding process is performed, is set as “A2”, the contact area “A2” is calculated by the following formula.
A2=W3×T

When a cross-sectional area of the coil terminal.16ais set as “A1”, it is desirable that the following formula is realized.
A1<A2
Thereby, an electric current density of the connecting portion of the coil connecting portion25aand the coil terminal.16ais smaller than an electric current density of a coil16, and heat generation at the connecting portion can be inhibited.

Moreover, as indicated inFIG. 11, when a diameter of the coil terminal.16ais set as “D”, a width of a tip portion251of the coil connecting portion25ain a circumference direction is set as “W4”, it is desirable that the following formula is realized.
D<W4
Thereby, a shape of a fillet at the connecting portion of the coil terminal.16aand the coil connecting portion25ais stabilized. In the rotary electric machine according to Embodiment 2, it is realized that an effect, which is similar to the above-described effect according to Embodiment 1, is obtained, and moreover, it is realized that a connection strength and quality are improved.

FIG. 12A,FIG. 12B, andFIG. 12Care views which indicate connecting portions for a bus ring and a coil terminal, at a rotary electric machine according to Embodiment 3. In Embodiment 3, a deformation example of the coil connecting portion25aaccording to Embodiment 1, which is described above, will be explained. In addition, an overall configuration of the rotary electric machine according to Embodiment 3 is similar to an overall configuration of the rotary electric machine according to Embodiment 1, which is described above, so that an explanation is omitted.

As indicated inFIG. 12AthroughFIG. 12C, each of a coil connecting portion25b, a coil connecting portion25c, and a coil connecting portion25, according to Embodiment 3, is formed in such a way that widths “W1” of tip portions251in a circumference direction are narrower than widths “W2” of bases in a circumference direction. At the coil connecting portion25bwhich is indicated inFIG. 12A, side surfaces are formed as inclined surfaces having a predetermined angle. At the coil connecting portion25cwhich is indicated inFIG. 12B, side surfaces are formed as curved surfaces having a fillet shape. Moreover, at the coil connecting portion25dwhich is indicated inFIG. 12C, the coil connecting portion25dhas a chamfered shape in which portions of side surfaces are formed as inclined surfaces.

In the rotary electric machine according to Embodiment 3, it is realized that an effect, which is similar to the above-described effect according to Embodiment 1, is obtained, and the coil connecting portion25b, the coil connecting portion25c, and the coil connecting portion25dare formed in such a way that the widths “W2” of the bases of the coil connecting portion25b, the coil connecting portion25c, and the coil connecting portion25dare wider than the widths “W11” of the tip portions251, so that it is realized that a strength is improved while thermal diffusion of the coil connecting portion25b, the coil connecting portion25c, and the coil connecting portion25dis prevented.

FIG. 13is a view which indicates a connecting portion for a bus ring and a coil terminal, at a rotary electric machine according to Embodiment 4. In Embodiment 4, a deformation example of the coil connecting portion25aaccording to Embodiment 1, which is described above, will be explained. In addition, an overall configuration of the rotary electric machine according to Embodiment 4 is similar to an overall configuration of the rotary electric machine according to Embodiment 1, which is described above, so that an explanation is omitted.

In the rotary electric machine according to Embodiment 4, a wax material29is arranged between a coil terminal16aand a coil connecting portion25aof a bus ring25. A flux, by which an oxide film is removed, is not required, so that it is suitable that a phosphorus copper wax is used as the wax material29. The wax material29is arranged, whereby a weld temperature can be lowered in comparison with a case in which coils16and the coil connecting portion25aare directly welded.

In the rotary electric machine according to Embodiment 4, it is realized that an effect, which is similar to the above-described effect according to Embodiment 1, is obtained, and moreover, the wax material29is arranged between the coil terminal16aand the coil connecting portion25a, whereby a required amount of heat is reduced, when a welding process is performed, in comparison with a case in which the wax material29is not arranged, so that damage to the films of the coils16and to a bobbin14can be inhibited. Moreover, a phosphorus copper wax is used as the wax material29, whereby the flux is not required, so that a welding process can be performed by using a simple facility.

FIG. 14is a view which explains a manufacturing method of a rotary electric machine according to Embodiment 5. In addition, an overall configuration of the rotary electric machine, which is manufactured in accordance with Embodiment 5, is similar to an overall configuration of the rotary electric machine100according to Embodiment 1, which is described above, so thatFIG. 8andFIG. 9are diverted, and an explanation for each of configuration elements is omitted.

The manufacturing method of the rotary electric machine according to Embodiment 5 will be explained by usingFIG. 8,FIG. 9, andFIG. 14. Firstly, as a first step, a plurality of a bus ring25, a bus ring26, and a bus ring27, which are made of a plane sheet having a band shape, are inserted to a bus ring maintaining portion20, a bus ring maintaining portion21, and a bus ring maintaining portion22, which have a ditch shape, which are formed at a bobbin (a bobbin14inFIG. 8andFIG. 9) which is arranged on at least one of end surfaces in a shaft direction of a stator core11.

The U-phase bus ring25, the V-phase bus ring26, and the W-phase bus ring27are bent in a ring shape so as to be formed, and the U-phase bus ring25, the V-phase bus ring26, and the W-phase bus ring27are respectively fitted to a bus ring maintaining portion20, a bus ring maintaining portion21, and a bus ring maintaining portion22, and are fixed by using an adhesive material or the like in accordance with a requirement. In addition, it is suitable that the bus ring maintaining portions are formed at a bobbin15which is arranged at the other end surface in a shaft direction of the stator core11.

In a next process as a second step, coil terminals16a, which are connection objects, are arranged at each of a coil connecting portion25aof the bus ring25, a coil connecting portion26aof the bus ring26, and a coil connecting portion27aof the bus ring27, which are protruded from the bus ring maintaining portion20, the bus ring maintaining portion21, and the bus ring maintaining portion22to a shaft direction. As indicated inFIG. 9, the coil terminals16aare bent, at right angles, between a coil winding portion14aand a flange portion14bof the bobbin14, and are led toward an outer side in a diameter direction. Moreover, the coil terminals16aare arranged in such a way that the coil terminals16aare protruded toward an outer side in a diameter direction with respect to the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a.

In a next process as a third step, as indicated inFIG. 14, a plus electrode30aand a minus electrode30bof an AC power supply are respectively arranged at the coil terminals16awhich are arranged at the adjacent coil connecting portion25aand the coil connecting portion26a, and the electrode30aand the electrode30bare energized while the plus electrode30aand the minus electrode30bare pressed in a direction of the coil connecting portion25aand the coil connecting portion26a, and resistance welding processes of the coil terminals16aare concurrently performed to the coil connecting portion25aand the coil connecting portion26aat two positions. In addition, although a DC power supply can be used for a power supply by which the electrode30aand the electrode30bare energized, the AC power supply is used, whereby a deviation of a welding state, which is caused by the Peltier effect, can be prevented.

In the manufacturing method of the rotary electric machine according to Embodiment 5, the coil terminals16acan be concurrently welded to the coil connecting portion25aand the coil connecting portion26aat two positions, so that productivity is improved in comparison with a case in which the coil terminals16aare welded at every one position. Moreover, the electrode30aand the electrode30bare arranged at the coil terminals16awhich are arranged at the adjacent coil connecting portion25aand the coil connecting portion26a, and the electrode30aand the electrode30bare energized, so that an energization passage can be shortened, and damage, which is caused by heat, to coils16and the bobbin14can be inhibited.

The coil terminals16aare arranged at a tip portion251and a tip portion261, which have a flat shape, of the coil connecting portion25aand the coil connecting portion26a, and the coil terminals16aare welded while the coil terminals16aare pressed, so that it can be prevented that positions of the coil terminals16aare deviated, and a stable welding process, of which reliability is high, can be performed. Moreover, the coil terminals16aare arranged in such a way that the coil terminals16aare protruded toward an outer side in a diameter direction with respect to the coil connecting portion25a, the coil connecting portion26a, and the coil connecting portion27a, so that fillets18are formed between the side surfaces, of the coil connecting portion25aand the coil connecting portion26a, and protruding portions16cof the coil terminals16a, whereby a high connection strength is obtained. Moreover, a welding board for a welding process and a chuck board for a connecting portion are not required, so that it can be realized that the rotary electric machine is downsized.

In the disclosed present invention, although various and exemplary embodiments are described, various characteristics, modes, and functions, which are described in one or a plurality of embodiments, are not limited to an applicability of a specific embodiment, and can be applied to the embodiments in a single state or in various combination states. Therefore, countless deformation examples, which are not exemplified, are assumed in a field of a technology which is disclosed in the specification of the present invention. For example, it is assumed that a case in which at least one of components is deformed, and a case in which at least one of components is added, or a case in which at least one of components is omitted, and moreover, a case in which at least one of components is extracted and combined to a component of the other embodiment, are included.