Electric rotary machine and manufacturing method for an electric rotary machine

Abstract

A manufacturing method for an electric rotary machine (100), comprising: a stator (40) having a stator core (41) comprising an outer core (41b) as a back yoke portion and an inner core (41a) in the form of a plurality of tooth portions (43, 243), and having a plurality of insulated and coated coils (20, 20U) each received in two slots (46) formed between the two tooth portions (43, 243) that are adjacent to each other, the coils (20, 20U) extending across the plurality of tooth portions (43, 243) of the stator core (41); and a rotor (30) rotatably supported on an inner side of the stator core (41), the manufacturing method comprising: - a winding step in which continuous intermediate coils (21), each including two slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) to be received in the slots (46) of the stator core (41), and two bridge portions (21c, 21d) by means of which both end portions of the slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) are connected, are formed in a flat plate shape from an insulated and coated conductor wire using a winding frame (60) having a winding core (61) and side plates (62a, 62b) sandwiching the winding core (61) from both surface sides thereof, and a projection (62at) defining the winding width of the bridge portions (21c, 21d) limited, is provided on the inner surfaces of the side plates (62a, 62b); - a coil forming step in which the two groove receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) of each intermediate coil (21) are twisted and each bridge portion (21c, 21d) is formed into a circular arc shape; - a temporary coil mounting step in which each coil (20, 20U) subjected to the coil forming step is temporarily mounted obliquely in the two grooves (46); - a coil insertion step in which the groove receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) of each coil (20, 20U) subjected to the temporary coil mounting step are pressed into the grooves (46) from an outer side to a radially inner side of the groove receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b); - a core assembling step in which the inner core (41a) on which each coil (20, 20U) is mounted is inserted into the outer core (41b); and - a final assembly step in which the rotor (30) is inserted into the stator (40) and the stator (40) and the rotor (30) are received in a frame (11).

Description

Technical area

[0001] The present invention relates to an electric rotary machine having excellent coil cooling capability and a manufacturing method for such an electric rotary machine. State of the art

[0002] Recently, rotating electrical machines, such as electric motors and electric generators, require small size, high output power, and high efficiency. To reduce the size and increase the output power of such rotating electrical machines, a rotating electrical machine with a concentrated winding stator with a relatively high coil space factor is used.

[0003] However, there is an increasing demand for a rotary electric machine having a stator using a coil having a distributed winding structure, which enables a further increase in output power (see, for example, Patent Document 1). While a concentrated winding coil is formed by winding a conductor wire on a single tooth, a distributed winding coil is formed by winding a conductor wire between slots spaced from each other by two slots or more.

[0004] Patent Document 2 discloses a motor including: a stator having a stator core, a plurality of slot portions, and a plurality of coils, the stator core including a plurality of stator core pieces, the stator core piece including a tooth portion having a distal end portion and two side portions, a yoke portion, and a claw portion formed at one of the two side portions and the distal end portion. The plurality of stator core pieces are connected such that a plurality of claw portions protrude in the same circumferential direction, thereby forming the stator core into a cylindrical shape. Each of the slot portions is formed between adjacent tooth portions and between the plurality of stator core pieces. The plurality of coils are inserted into the plurality of slot portions. The plurality of coils includes a first coil, a second coil, and a third coil.forming three phases, wherein the first coil, the second coil, and the third coil are bridged between two of the slot portions, the first coil including a first coil end portion protruding from an edge surface of the stator core in an axial direction and the third coil end portion intersecting each other; and a rotor disposed on an inner peripheral side of the stator and rotatably supported.

[0005] Patent Document 3 discloses a stator having main coils and an auxiliary coil. The auxiliary coil is formed in a predetermined shape by winding coil wires formed in a die having the predetermined shape. A stator core body is formed with a plurality of teeth protrudingly disposed on the outer periphery of a donut-shaped portion. A resin insulating layer is formed at least on the inner side and on both sides of the teeth of the stator core body. The main coils and the auxiliary coil are fitted from the outside into slots between the teeth of the stator core body, thereby fitting an annular yoke core into the outer periphery of the edge portions of the teeth of the stator core body.

[0006] Patent Document 4 discloses a dynamoelectric machine comprising a plurality of winding elements, each of which has a ring-wound winding portion and a sealing resin for sealing the winding portion, and which are ring-shaped as a whole in the circumferential direction of the winding portion and spirally arranged radially, and a core member having a plurality of teeth inserted such that a plurality of teeth are inserted into each of the plurality of winding elements, and which, together with the plurality of winding elements, forms an armature of a distribution winding. BibliographyPatent document Patent document 1: JP H10 - 117 452 A Patent document 2: US 2010 / 0 295 405 A1 Patent document 3: JP 2007 - 181 348 A Patent document 4: JP 2014 - 90 661 A Summary of the inventionProblems to be solved by the invention

[0007] To increase the output of a rotary electric machine, it is necessary to effectively dissipate the heat generated by the large current flowing through a coil. However, a conventional rotary electric machine disclosed in Patent Document 1 has a problem in that, since the coil is wound without gaps to improve the space factor, heat dissipation is deteriorated, thus preventing the output from being increased.

[0008] The present invention was conceived to solve the above-described problem. Therefore, it is an object of the present invention to provide a rotary electric machine having improved coil cooling efficiency and small dimensions, high output power, and high efficiency, as well as a manufacturing method for such a rotary electric machine. Solving the problems

[0009] The object underlying the invention is achieved by a manufacturing method for an electric rotary machine having the features of independent patent claim 1. Advantageous developments of the manufacturing method according to the invention are specified in dependent claims 2 to 5. Effect of the invention

[0010] In the electric rotary machine according to the present invention, the following applies: Since bridge portions of the coils form coil end portions of the stator at both ends in the axial direction and are configured coaxially with an axis of the stator, wherein at least one bridge portion of the bridge portions of each coil is located at both ends in the axial direction outside an inner peripheral surface of the stator, and If there is a gap between an end face of the stator core in the axial direction and each bridge portion, it is possible to ensure a flow path for passing a coolant such as air or cooling oil to improve the cooling performance, thus preventing interference from another coil.

[0011] In addition, the manufacturing method for an electric rotary machine according to the present invention has the following: a winding step in which intermediate coils, each having two slot receiving portions to be received in the slots of the stator core and two bridge portions by means of which both end portions of the slot receiving portions are connected, are continuously formed in a flat plate shape from an insulated and coated conductor wire using a winding frame; a coil forming step in which the two groove receiving portions of each intermediate coil are twisted and each bridge portion is formed into a circular arc shape; a temporary coil mounting step in which each coil subjected to the coil forming step is temporarily mounted obliquely in the two grooves; a coil insertion step in which the groove receiving portions of each coil subjected to the temporary coil mounting step are pressed into the grooves from an outer side to a radially inner side of the groove receiving portions; a core assembling step in which the inner core on which each coil is mounted is inserted into the outer core; and a final assembly step in which the rotor is inserted into the stator and the stator and rotor are accommodated in a frame.

[0012] Therefore, it is possible to form a gap between the end face of the inner core in the axial direction and each bridge portion, so that it is possible to ensure a flow path for passing a coolant such as air or cooling oil to improve the cooling performance, thus preventing interference from another coil. Short description of the drawings Fig. 1 is a one-sided schematic front cross-sectional diagram of an electric rotary machine according to Embodiment 1 of the present invention. Fig. 2 is a perspective view of an electric rotary machine (only a stator and a rotor) according to Embodiment 1 of the present invention. Fig. 3 is a perspective view of the stator according to Embodiment 1 of the present invention. Fig. 4 is a perspective view of an inner core of the stator according to Embodiment 1 of the present invention. Fig. 5 is a perspective view of an outer core of the stator according to Embodiment 1 of the present invention. Fig. 6 is a perspective view of a coil used in the stator according to Embodiment 1 of the present invention. Fig. 7 is a front view of the coil used in the stator according to Embodiment 1 of the present invention. Fig. 8 is a plan view of the coil used in the stator according to Embodiment 1 of the present invention. Fig. 9 is a flowchart showing a manufacturing method of a rotary electric machine according to Embodiment 1 of the present invention. Fig. 10 is a perspective view of a winding frame used in a winding step according to Embodiment 1 of the present invention. Fig. 11 is a diagram showing the winding step according to Embodiment 1 of the present invention. Fig. 12 is a front view of an intermediate coil taken out from the winding frame after the end of the winding step according to Embodiment 1 of the present invention. Fig. 13 is a cross-sectional view taken along a line AA shown in Fig. 12. is shown. Fig. 14 is a front view of a twisted intermediate coil according to Embodiment 1 of the present invention. Fig. 15 is a perspective view showing a state in which the twisted intermediate coil is arranged on a bridge portion forming die according to Embodiment 1 of the present invention. Fig. 16 is a diagram showing the states before and after a bridge portion of the twisted intermediate coil is formed by the bridge portion forming die according to Embodiment 1 of the present invention. Fig. 17 is a perspective view of the inner core and U-phase coils in a temporary coil mounting step according to Embodiment 1 of the present invention. Fig. 18 is a perspective view of the inner core and the U-phase coils in the temporary coil mounting step according to Embodiment 1 of the present invention. Fig. 19 is a perspective view showing a state of the inner core and the U-phase coils after the end of the coil insertion step for the U-phase according to Embodiment 1 of the present invention. Fig. 20 is a diagram showing a coil insertion method using a jig according to Embodiment 1 of the present invention. Fig. 21 is a diagram showing a coil insertion method using a jig according to Embodiment 1 of the present invention. Fig. 22 is a diagram showing a coil insertion method using a jig according to Embodiment 1 of the present invention. Fig. 23 is a diagram showing a diameter-reduced state of groove receiving portions of the coil before and after the coil insertion step according to Embodiment 1 of the present invention. Fig. 24 is a diagram showing a state of a rising state of a bridge portion on an open side before and after the coil insertion step according to Embodiment 1 of the present invention. Fig. Figure 25 is a diagram showing the relationship between R1, R2 and T in the case where a coil with a peak in a bridge region is used. Fig. 26 is a diagram showing the temporary coil mounting step for the V phase according to Embodiment 1 of the present invention. Fig. 27 is a diagram showing the temporary coil mounting step for the V phase according to Embodiment 1 of the present invention. Fig. 28 is a diagram showing a state in which the coil insertion step for the V phase according to Embodiment 1 of the present invention has been completed. Fig. 29 is a diagram showing the temporary coil mounting step for the W phase according to Embodiment 1 of the present invention. Fig. 30 is a diagram showing the temporary coil mounting step for the W phase according to Embodiment 1 of the present invention. Fig. 31 is a diagram showing a state in which the coil insertion step for the W phase according to Embodiment 1 of the present invention has been completed. Fig. 32 is a perspective view showing a state immediately before the inner core on which all the coils for three phases according to Embodiment 1 of the present invention are mounted is joined to the outer core. Fig. 33 is a perspective view of the stator which has been completed. Fig. 34 is a diagram showing a final assembly step according to Embodiment 1 of the present invention. Fig. 35 is a diagram showing various groove shapes according to Embodiment 1 of the present invention. Fig. 36 is a perspective view of a stator according to Embodiment 2 of the present invention. Fig. 37 is a perspective view of a tooth portion according to Embodiment 2 of the present invention. Fig. 38 is a perspective view of an outer core of a stator core according to Embodiment 2 of the present invention. Fig. 39 is a flowchart showing a manufacturing method of a rotary electric machine according to Embodiment 2 of the present invention. Fig. 40 is a diagram showing a temporary coil mounting step for the U phase according to Embodiment 2 of the present invention. Fig. 41 is a diagram showing a state of a coil after the end of a coil insertion step for the U phase according to Embodiment 2 of the present invention. Fig. 42 is a cross-sectional view showing the tooth portions and the coils after the end of the coil insertion step for all three phases according to Embodiment 2 of the present invention. Fig. 43 is a cross-sectional view of a stator assembled in a core assembling step according to Embodiment 2 of the present invention. Fig. 44 is a cross-sectional view of a stator assembled in the core assembling step according to Embodiment 2 of the present invention. Fig. 45 is a diagram showing a final assembly step according to Embodiment 2 of the present invention. Description of the embodimentsEmbodiment 1

[0013] Hereinafter, a rotating electric machine and a manufacturing method of a rotating electric machine according to Embodiment 1 of the present invention will be described with reference to the drawings. In the description, the terms "circumferential direction", "radial direction", "axial direction", "inner", and "outer" refer to the "circumferential direction", "radial direction", and "axial direction" of a stator of a rotating electric machine, the "inner side", "outer side", "outer periphery", and the "inner periphery" of the stator, and the like.

[0014] Fig. 1 is a one-sided schematic front cross-sectional diagram of an electric rotary machine 100 according to Embodiment 1 of the present invention.

[0015] Fig. 2 is a perspective view of the rotary electric machine 100 (only a stator 40 and a rotor 30).

[0016] The rotary electric machine 100 includes: a housing 1 having a frame 11 having a cylindrical shape with a bottom surface and an end plate 12 closing the opening of the frame 11; the stator 40 fixedly attached to the cylindrical portion of the frame 11 in an internally fitted state; and the rotor 30 rotatably supported on the bottom surface of the frame 11 and the end plate 12 by means of a bearing 2, and disposed on the inner peripheral side of the stator 40.

[0017] The rotor 30 is a permanent magnet rotor comprising: a rotor core 32 fixedly attached to a rotating shaft 31; and permanent magnets 33 embedded on the outer peripheral surface side of the rotor core 32 and at a predetermined pitch in the circumferential direction, forming the magnetic poles.

[0018] The rotor 30 is not limited to a permanent magnet rotor, and the following may also be used: a cage-type rotor having a non-insulated rotor conductor accommodated in a slot of a rotor core and short-circuited at both sides thereof by a short-circuit ring; or a winding-type rotor having an insulated conductor wire mounted in a slot of a rotor core.

[0019] The configuration of the stator 40 will be described below with reference to the drawings. Fig. 3 is a perspective view of the stator 40. Fig. 4 is a perspective view of an inner core 41a of the stator 40. Fig. 5 is a perspective view of an outer core 41b of the stator 40.

[0020] As shown in the respective drawings, the stator 40 includes a stator core 41, coils 20 mounted on the stator core 41, and slot cells 42a that electrically insulate the coils 20 and the stator core 41 from each other. For convenience of explanation, the number of poles of the rotor 30 is four, the number of slots 46 of the stator core 41 is twenty-four, and the coils 20 are three-phase windings. That is, the slots 46 are formed in the stator core 41 at a ratio of two slots per pole.

[0021] The stator core 41 has the inner core 41a and the outer core 41b. As shown in Fig. As shown in Fig. 4, in the inner core 41a, a plurality of tooth portions 43 forming magnetic poles are formed in a circular ring shape such that their ends on the inner peripheral side are connected to each other by a thin portion 44. The groove 46 is formed between the tooth portions 43 adjacent to each other.

[0022] The outer core 41b, which is located in Fig. 5 is a back yoke portion that magnetically connects each of the tooth portions 43 to the inner core 41a. The inner core 41a is fitted to the inner side of the outer core 41b so that the outer peripheral surfaces 45a of the inner core 41a and the inner peripheral surface 45b of the outer core 41b are magnetically connected to each other.

[0023] Fig. 6 is a perspective view of the coil 20 used in the stator 40. Fig. 7 is a front view of the coil 20. Fig. 8 is a plan view of the coil 20.

[0024] As in the Fig. 6 to 8, the coil 20 includes a first slot receiving portion 20a and a second slot receiving portion 20b (hereinafter simply referred to as slot receiving portions 20a and 20b) to be inserted into the slots 46 of the stator core 41; and an open-side bridge portion 20c and a closed-side bridge portion 20d, which respectively connect ends of the slot receiving portion 20a and the slot receiving portion 20b to each other, and which extend across the plurality of tooth portions 43. The "open-side" refers to a side on which the frame 11 is opened, and the "closed-side" refers to a side opposite to the open-side.

[0025] The coil 20 is formed by winding, a plurality of times, for example, a conductor wire made of copper or aluminum, which is insulated and coated with an enamel resin and is continuously formed without any connection.

[0026] The bridge portions 20c and 20d are formed smaller in thickness in the radial direction than the groove receiving portions 20a and 20b in order to avoid interference at a coil end portion from the coil 20 forming a different phase.

[0027] As in Fig. As shown in Figure 8, the closed-side bridge portion 20d is located radially inward of the open-side bridge portion 20c. When the coil 20 is inserted into the slots 46, the closed-side bridge portion 20d is located inward of the thin portion 44 of the inner core 41a.

[0028] A manufacturing method for an electric rotary machine 100 is described below.

[0029] Fig. 9 is a flowchart showing a manufacturing process for an electric rotary machine 100.

[0030] As shown in the drawing, the rotary electric machine 100 is completed through: a winding step ST100, a coil forming step ST110, a temporary coil assembling step ST120, a coil inserting step ST130, a core assembling step ST140, and a final assembling step ST150.

[0031] First, the winding step ST100 is described.

[0032] Fig. 10(a) is an exploded perspective view of a winding frame 60 used in the winding step ST100.

[0033] Fig. 10(b) is a perspective view after assembly of the winding frame 60 used in the winding step ST100.

[0034] Fig. 11 is a diagram showing the winding step ST100.

[0035] Fig. 12 is a front view of a hollow plate-shaped intermediate coil 21 taken out from the winding frame 60 after the end of the winding step ST100.

[0036] Fig. 13 is a cross-sectional view taken along a line AA shown in Fig. 12. is shown.

[0037] The intermediate coil 21 is a coil before slot receiving portions 20a and 20b and the bridge portions 20c and 20d of the coil 20 are formed. The winding frame 60 includes a winding core 61 having an outer periphery on which the intermediate coil 21 is to be wound; and side plates 62a and 62b sandwiching the winding core 61 from both side surfaces thereof. These parts can be disassembled so that the wound intermediate coil 21 can be removed. The bridge portions 20c and 20d of the coil 20 must be formed to be thinner in the radial direction than the slot receiving portions 20a and 20b. Therefore, a protrusion 62at, which restricts the winding width, is provided on the inner surface 62a1 of the side plate 62a.

[0038] Although in Fig. 10, the lower half of the side plate 62b also has the same shape as that of the side plate 62a. A conductor wire 7 is inserted into the winding frame 60 through an insertion portion 62b3 provided in the center of an upper portion of the side plate 62b, as shown in Fig. 11, and it is wound in the direction of an arrow, which is shown in Fig. 11 to perform winding of the intermediate coil 21. As shown in Fig. 13, by using the winding frame 60, the conductor wire 7 constituting the intermediate coil 21 can be wound so as to be regularly aligned.

[0039] Hereinafter, the coil forming step ST110 will be described with reference to Fig. 12 to 16 described.

[0040] Fig. 14 is a front view of a twisted intermediate coil 22.

[0041] First, groove receiving areas 21a and 21b of the intermediate coil 21, which are in Fig. 12, in the directions of the arrows in Fig. 12 to obtain the wound intermediate coil 22, which in Fig. 14 is shown.

[0042] Fig. 15 is a perspective view showing a state in which the twisted intermediate coil 22 is arranged on a bridge portion forming die 80.

[0043] Fig. 16 is a front view of a state in which the twisted intermediate coil 22 is arranged on the bridge portion forming die 80.

[0044] Fig. 16(b) is a front view of a state in which a bridge portion 22c of the twisted intermediate coil 22 is formed by the bridge portion forming die 80.

[0045] The bridge portion forming die 80 has a convex shape 80a and a concave shape 80b. The bridge portions 22c and 22d of the twisted intermediate coil 22 are formed by the convex shape 80a and the concave shape 80b to have a circular arc shape, with the center of curvature located on the axis of the stator 40.

[0046] Although not specifically shown, by using different bridge portion forming dies for the bridge portion 22c and the bridge portion 22d, the twisted intermediate coil 22 is formed such that the bridge portion 20d of the completed coil 20 is located radially inward of the bridge portion 20c of the completed coil 20, as shown in Fig. 8 shown.

[0047] Hereinafter, the temporary coil mounting step ST120 and the coil insertion step ST130 are described with reference to the Fig. 17 to 31 described.

[0048] Fig. 17 and Fig. 18 are perspective views of the inner core 41a and the coils 20U in the temporary coil mounting step ST120.

[0049] Fig. 19 is a perspective view showing a state of the inner core 41a and the U-phase coils 20U after the end of the coil insertion step ST130 for the U-phase.

[0050] In the temporary coil assembling step ST120, the slot cells 42a, which insulate the respective tooth portions 43 and the coils 20 (coils 20U, 20V and 20W) from each other, are assembled along inner wall surfaces of the slots 46 of the inner core 41a, and first, the coils 20U constituting the U-phase are obliquely inserted into the corresponding slots 46 so that their bridge portions 20Uc on the opened side initially enter therein, as shown in Fig. 17, and they are temporarily mounted on the inner core 41a to maintain the state according to Fig. 18 to receive.

[0051] As in Fig. 19, next, in the coil insertion step ST130, the bridge portions 20Uc on the opened side are closed so that their diameter is reduced, so that slot receiving portions 20Ua and 20Ub of each coil 20U are fully inserted into the slots 46.

[0052] Fig. 20(a) and Fig. 20(b) are diagrams showing a method of inserting the coil 20U using a rotary plate jig 71.

[0053] Fig. 20(a) shows a state of the coil 20U after the end of the temporary coil mounting step ST120, and Fig. Figure 20(b) shows a state of the coil 20U after the end of the coil insertion step ST130. Each drawing is a schematic cross-sectional diagram centered on the axis of the inner core 41a. The rotation plate jig 71 has a rotation center 71a on the radially outer side of each of the closed-side ends of the groove receiving portions 20Ua and 20Ub.

[0054] In the coil insertion step ST130, a pressing portion 71b of the rotating plate jig 71 presses each of the groove receiving portions 20Ua and 20Ub of the coil 20U temporarily obliquely mounted in the grooves 46 into the grooves 46 from the outer peripheral side while rotating around the rotation center 71a, so that the groove receiving portions 20Ua and 20Ub gradually become parallel to the axial direction.

[0055] Fig. 21(a) and Fig. 21(b) are diagrams showing a method of inserting the spool 20U using a roller jig 72 different from the rotating plate jig 71.

[0056] Fig. 21(a) shows a state of the coil 20U after the end of the temporary coil mounting step ST120, and Fig. Figure 21(b) shows a state of the coil 20U after the end of the coil insertion step ST130. Each drawing is a schematic cross-sectional diagram centered on the axis of the inner core 41a.

[0057] As in Fig. 21, in the coil insertion step ST130, the groove receiving portions 20Ua and 20Ub of the coil 20U temporarily mounted in the grooves 46 may be pressed from both closed-side ends thereof toward the open-side ends thereof by using rollers 72b of the roller jig 72.

[0058] Fig. 22(a) and Fig. 22(b) are diagrams showing a method of inserting the spool 20U using a slide jig 73 different from the rotating plate jig 71 and the roller jig 72.

[0059] Fig. 22(a) shows a state of the coil 20U after the end of the temporary coil mounting step ST120, and Fig. Figure 22(b) shows a state of the coil 20U after the end of the coil insertion step ST130. Each drawing is a schematic cross-sectional diagram centered on the axis of the inner core 41a.

[0060] The slide jig 73 has a cylindrical shape with an inner diameter substantially equal to the outer diameter of the inner core 41a. The inner core 41a, which undergoes the temporary coil assembly step ST120, is fully inserted into the slide jig 73 while sliding on the inner side of the slide jig 73 from the closed end side. The upper edge of the inner peripheral surface of the slide jig 73 is provided with a chamfered portion 73a for easy insertion of the inner core 41a.

[0061] Fig. 23 is a diagram showing a diameter-reduced state of the groove receiving portions 20Ua and 20Ub of the coil 20U before and after the coil insertion step ST130.

[0062] Fig. 24 is a diagram showing a rising state of the bridge portion 20Uc on the opened side before and after the coil insertion step ST130. The bridge portion 20Uc has a substantially rectangular shape when viewed from the axis of the stator. When the slot receiving portions 20Ua and 20Ub of the coil 20U are completely received in the slots 46 by using any of the jigs, the positions of the two slot receiving portions 20a and 20b move to the inner peripheral side, which is indicated by arrows B1 and B2 in Fig. 23, so that the length of a circular arc connecting the ends 20Uai and 20Ubi on the inner peripheral side of the groove receiving portions 20Ua and 20Ub and having its center on an axis O decreases from R1 to R2.

[0063] Here, the length R1 of the circular arc is also the length of a circular arc whose center lies on the axis O of the stator 40, which lies between the straight lines passing through the centers of the two slots 46 into which the coil 20U is inserted, and has a radius at the outermost position of the tooth portion 43.

[0064] In addition, R2 is also the length of a circular arc whose center lies on the axis O of the stator 40, which lies between the straight lines passing through the centers of the two slots 46 into which the coil 20U is inserted, and which has a radius at the innermost position of the tooth portion 43. In Fig. 24 and the later described Fig. 25 R1 and R2 indicate the lengths of the circular arcs.

[0065] When the slot receiving portions 20Ua and 20Ub of the coil 20U are fully inserted into the slots 46, the bridge portion 20Uc on the opened side rises simultaneously, as shown in Fig. 24, so that a gap S can be formed between an axial direction end surface 41T of the inner core 41a and the bridge portion 20Uc. The gap S ensures a space to avoid interference from the bridge portion of another coil and serves as a flow path for a coolant to contribute to improving the cooling performance of the rotary electric machine 100.

[0066] The dimension of the height T of the gap S at this time is (R1-R2) / 2. The formation of the gap S allows the coil insertion step ST130 to be performed smoothly. In order to actually arrange the coils 20U around the inner core 41a, each coil 20U is located slightly outside the position of R1 in Fig. 23. Consequently, the relation T ≥ (R1-R2) / 2 is satisfied.

[0067] However, if the value of T is excessively increased, the peripheral length of the coil will increase by 20U. This will result in an increase in the resistance value and an increase in the overall size of the motor. Therefore, the dimension is set within a range of up to approximately 5%, and it is desirable to satisfy the relationship T < ((R1-R2) / 2) × 1.05.

[0068] Fig. Figure 25 is a diagram showing the relationship between R1, R2, and T when using a 20U coil with a 20Uct apex in a 20Uc bridge portion. The 20Uc bridge portion has a substantially triangular shape when viewed from the stator axis. In the case of the 20U coil in which a central portion of the 20Uc bridge portion protrudes circumferentially in the axial direction, T can be defined as the "height" of a pseudo-isosceles triangle, and it can be calculated according to the Pythagorean theorem based on a right-angled triangle, which is half of the isosceles triangle.

[0069] That is, since the bridge area 20Uc rises with 1 / 2 of R1 so that it forms the hypotenuse, has the base 1 / 2 of R2 and the height is T, T = √(R1 2 -R2 2 ) / 2 is fulfilled, based on T 2 = (R1 / 2) 2 - (R2 / 2) 2. If the above requirement is taken into account, T ≥ √(R1 2 - R2 2 ) / 2 and T < (√(R1 2 - R2 2 ) / 2) × 1.05 is met. Even with such a coil, the coil insertion step ST130 can be performed smoothly.

[0070] Fig. 26 and Fig. 27 are diagrams showing the temporary coil mounting step ST120 for the V phase.

[0071] Fig. 28 is a diagram showing a state after the end of the temporary coil mounting step ST120 for the V phase.

[0072] As in Fig. 26 to 28, all the coils 20V constituting the V phase are mounted on the inner core 41a on which the coils 20U are mounted, similarly to the coils 20U described above.

[0073] Fig. 29 and Fig. 30 are diagrams showing the temporary coil mounting step ST120 for the W phase.

[0074] Fig. 31 is a diagram showing a state after the end of the coil insertion step ST130 for the W phase.

[0075] As in Fig. As shown in Figures 29 to 31, all the coils 20W constituting the W phase are mounted on the inner core 41a on which the coils 20V are mounted, similarly to the coils 20U and 20V described above. The temporary coil mounting step ST120 and the coil insertion step ST130 are completed by repeating the sequence of operations described above. The bridge portions 20Uc, 20Vc, and 20Wc form a coil end portion Kc on the open side, and the bridge portions 20Ud, 20Vd, and 20Wd form a coil end portion Kd on the closed side.

[0076] Fig. 32 is a perspective view showing a state immediately before the inner core 41a, on which all the coils 20 (20U, 20V and 20W) for three phases are mounted, is joined to the outer core 41b.

[0077] Fig. 33 is a perspective view of the stator 40 which has been completed.

[0078] Fig. 34 is a diagram showing a final assembly step for inserting the rotor 30 into the stator 40.

[0079] After all the coils 20 have been completely assembled to the inner core 41a, slot cells 42b that insulate the outer core 41b and the respective coils 20 from each other are assembled on the outer peripheral surface sides of the slot receiving portions 20a and 20b of the coils 20, and the outer core 41b is built into the inner core 41a from the bridge portion 20d side on the closed side to complete the core assembling step ST140 and obtain the stator 40.

[0080] Finally, the rotor 30 is inserted into the stator 40 from the coil end portion where the bridge portions 20c are formed on the open side. Here, these components are housed in the housing 1, which is Fig. 1 to complete the final assembly step ST150 so that the rotary electric machine 100 can be obtained.

[0081] Fig. 35 is a diagram showing various groove shapes, and each part is a plan view of a main portion of the inner core.

[0082] In the above description, in each groove 46, a cross section perpendicular to the axial direction has a rectangular shape except for its innermost peripheral portion, as shown in Fig. 35(a). However, the cross section may also have a conical shape that widens outwardly so that the relationship between a width dimension w1 in the circumferential direction of a depth portion of a groove 46b and a width dimension w2 of a groove opening between the end portions on the outer peripheral side of the tooth portions 43b satisfies the relation w2 > w1, as shown in Fig. 35(b), or it may have a shape which has a change point 46c1 at which the gradient of a conical shape changes, as in Fig. 35(c).

[0083] If the relationship between the width dimension w1 in the circumferential direction of the depth portion of the slot 46, 46b or 46c and the width dimension w2 of the slot opening between the end portions 43x, 43bx or 43cx on the outer peripheral side of the tooth portions 43, 43b or 43c satisfies the relation w2 ≥ w1, then the evenly aligned coils 20 can be smoothly inserted into the slots 46, so that the assemblability of the stator 40 improves.

[0084] In the above embodiment, the case where at least one bridge portion among the bridge portions of each coil at both ends in the axial direction is located outside the inner peripheral surface of the stator is described. However, the present invention is not limited to this, and both bridge portions may also be located outside the inner peripheral surface of the stator.

[0085] In the rotary electric machine and the manufacturing method of the rotary electric machine according to Embodiment 1 of the present invention, since the gap can be provided between the bridge portion of each coil and the end face of the stator core in the axial direction, it is possible to achieve a rotary electric machine that ensures a flow path for passing a coolant such as air or cooling oil to improve coil cooling efficiency while preventing interference of coils constituting each phase with coils constituting another phase, and that has a small size, high output, and high efficiency; and a manufacturing method of such a rotary electric machine.

[0086] In addition, since the stator core is divided into the inner core (the tooth portions) and the outer core (the back yoke portion), and the ends of the respective tooth portions are connected to each other in the circumferential direction by means of the thin portion, the evenly aligned coils can be inserted into the slots, so that an improvement in the space factor of the coil becomes possible.

[0087] In addition, since the coil end portions of the coils constituting the respective phases are arranged to be coaxially superimposed with respect to the axis of the stator, the assembly of the stator from one direction (from the outer side) can be enabled.

[0088] Furthermore, since at least one bridge portion among the bridge portions of each coil at both ends in the axial direction is located outside the inner peripheral surface of the stator, the rotor can be inserted into the stator having the coils mounted thereon, so that the performance of the rotary electric machine is improved. Embodiment 2

[0089] Hereinafter, a rotary electric machine and a manufacturing method of a rotary electric machine according to Embodiment 2 of the present invention will be described, mainly considering parts different from those in Embodiment 1.

[0090] Fig. 36 is a perspective view of a stator 240 according to Embodiment 2.

[0091] As shown in the drawing, the stator 240 has a stator core 241 and coils 20U, 20V and 20W mounted on the stator core 241.

[0092] Fig. 37 is a perspective view of a tooth portion 243 of the stator core 241.

[0093] Fig. 38 is a perspective view of an outer core 241b of the stator core 241.

[0094] The stator core 241 has: tooth portions 243 which form magnetic poles, as shown in Fig. 37; and an outer core 241b, which is an annular back yoke region, as shown in Fig. 38. Each tooth portion 243 has flange portions 243a at its end, which project circumferentially on both sides.

[0095] Fitting portions 243b and 243c are provided in predetermined areas of base portions of the two surfaces of each tooth portion 243 in the circumferential direction, and they are fitted to the wall surfaces 5b and 5c of the corresponding notches 5 provided on the inner peripheral surface of the outer core 241b and at regular intervals in the axial direction.

[0096] The manufacturing method for an electric rotary machine according to the present embodiment will be described with reference to Fig. 39 to 45. A winding step ST100 and a coil forming step ST110 are the same as those according to Embodiment 1, and thus, their description will be omitted. Fig. 39 is a flowchart showing a manufacturing method of the rotary electric machine according to the present embodiment.

[0097] Fig. 40 is a diagram showing a temporary coil mounting step ST120, and it shows a state in which the coil 20U is temporarily mounted in the grooves 246 between the tooth portions 243 fixed by a tooth holder 9.

[0098] Fig. 41 is a diagram showing a state of the coil 20U after the end of a coil insertion step ST130.

[0099] Fig. 40 and Fig. 41 are schematic cross-sectional diagrams centered on the axis of the tooth holding device 9.

[0100] The tooth portions 243 according to the present embodiment are formed separately from each other, and they are not connected at their ends on the inner peripheral side by means of a thin portion like the tooth portions 43 according to Embodiment 1. However, all the tooth portions correspond to the inner core according to Embodiment 1.

[0101] Therefore, all tooth portions 243 must be radially arranged beforehand, and a tooth fixing step ST115 for fixing by means of the tooth holding device 9 as shown in Fig. 40 must be performed before the temporary coil mounting step ST120. Then, in the temporary coil mounting step ST120, the U-phase coils 20U are temporarily mounted into the slots 246 each formed between the fixed tooth portions 243 adjacent to each other, similarly to Embodiment 1. Thereafter, the coil insertion step ST130 shown in Fig. 41 is performed in a similar manner to Embodiment 1.

[0102] Fig. Figure 42 is a cross-sectional view showing the tooth portions 243 and the coils 20 after the coil insertion step for all three phases is completed. Bridge portions 20Uc, 20Vc, and 20Wc form a coil end portion Kc on the open side, and bridge portions 20Ud, 20Vd, and 20Wd form a coil end portion Kd on the closed side.

[0103] Fig. 43 and Fig. 44 are cross-sectional views of the stator 240 being assembled in a core assembly step ST140. After all coils 20U, 20V and 20W have been fully inserted as in Fig. 42, the fitting portions 243b and 243c of all tooth portions 243 are fitted into the notches 5 of the outer core 241b, as shown in Fig. 43 and Fig. 44 to obtain the stator 240. After the outer core 241b and all tooth portions 243 have been fitted and secured, the tooth retainer 9 is released.

[0104] Fig.45 is a diagram showing a final assembly step for inserting the rotor 30 into the stator 240.

[0105] Finally, the rotor 30 is inserted into the stator 240 from the coil end portion KC where the bridge portions 20c are formed on the open side. Here, these components are housed in a casing (not shown) to complete the final assembly step ST150, so that the rotary electric machine can be obtained.

[0106] In the rotary electric machine and the manufacturing method of a rotary electric machine according to Embodiment 2 of the present invention, the same advantageous effects as those in Embodiment 1 are obtained. In addition, since the ends of the tooth portions 243 on the inner peripheral side are not connected to each other by a thin portion and the flange portions 243a projecting on both sides in the circumferential direction are formed so that the magnetic connection is interrupted, the leakage flux of the stator 240 can be reduced, so that the torque of the rotary electric machine can be increased.

[0107] Furthermore, since it is not necessary to pass each coil 20 through a narrow opening between the flange portions 243a adjacent to each other, the restrictions on the width of the opening between the flange portions are reduced, thus improving the flexibility of stator design. Consequently, a rotary electric machine with a high coil space factor and less torque ripple can be obtained.

[0108] It should be noted that, within the scope of the present invention, the above embodiments may be freely combined with each other, or each of the above embodiments may be appropriately modified and features may be omitted.

Claims

[1] A manufacturing method for an electric rotary machine (100) comprising: a stator (40) having a stator core (41) comprising an outer core (41b) as a back yoke portion and an inner core (41a) in the form of a plurality of tooth portions (43, 243), and having a plurality of insulated and coated coils (20, 20U) each received in two slots (46) formed between the two tooth portions (43, 243) adjacent to each other, the coils (20, 20U) extending across the plurality of tooth portions (43, 243) of the stator core (41); and a rotor (30) rotatably supported on an inner side of the stator core (41), the manufacturing method comprising: - a winding step in which continuous intermediate coils (21), each including two slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) to be received in the slots (46) of the stator core (41), and two bridge portions (21c, 21d) by means of which both end portions of the slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) are connected, are formed in a flat plate shape from an insulated and coated conductor wire using a winding frame (60) having a winding core (61) and side plates (62a, 62b) sandwiching the winding core (61) from both surface sides thereof, and a projection (62at) defining the winding width of the bridge portions (21c, 21d) limited, is provided on the inner surfaces of the side plates (62a, 62b); - a coil forming step in which the two groove receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) of each intermediate coil (21) are twisted and each bridge portion (21c, 21d) is formed into a circular arc shape; - a temporary coil mounting step in which each coil (20, 20U) subjected to the coil forming step is temporarily mounted obliquely in the two grooves (46); - a coil insertion step in which the groove receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) of each coil (20, 20U) subjected to the temporary coil mounting step are pressed into the grooves (46) from an outer side to a radially inner side of the groove receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b); - a core assembling step in which the inner core (41a) on which each coil (20, 20U) is mounted is inserted into the outer core (41b); and - a final assembly step in which the rotor (30) is inserted into the stator (40) and the stator (40) and the rotor (30) are received in a frame (11). [2] The manufacturing method according to claim 1, further comprising a tooth fixing process for radially fixing the plurality of independent tooth portions (43, 243) before the temporary coil mounting step. [3] The manufacturing method according to claim 1 or 2, wherein the coil insertion step comprises pushing in the entireties of outer peripheral surfaces of the slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) of the coil (20, 20U) temporarily mounted obliquely in the slots (46) by means of a rotary plate jig (71) rotating around a point to insert the slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b). [4] The manufacturing method according to claim 1 or 2, wherein the coil insertion step comprises pushing in the outer peripheral surfaces of the slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) of the coil (20, 20U) temporarily mounted obliquely in the slots (46) from the one end side toward the other end side in the axial direction by means of a roller jig (72) to insert the slot receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b). [5] The manufacturing method according to claim 1 or 2, wherein the coil insertion step comprises inserting the inner core (41a) into a cylindrical slide jig (73) to insert the groove receiving portions (20a, 20b, 20Ua, 20Ub, 21a, 21b) of the coil (20, 20U) temporarily mounted obliquely in the grooves (46) into the grooves (46).

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