Method for manufacturing rotating electrical machine

Abstract

Provided is a method for manufacturing a rotary electric machine, comprising: obtaining an annular motor member in which coils are formed on a plurality of teeth arranged in the circumferential direction of the motor; a pole insertion step of inserting a slot pole having a foamed insulating sheet adhered to only one end portion of the axial direction of the motor between a pair of adjacent coils in the circumferential direction of the motor; a heating step of heating the motor component in a first heating furnace having a foaming temperature lower than that of the foaming insulation sheet; a first dropping step of dropping varnish from the other side of the motor component in the motor axial direction to each coil; a first curing step of putting the motor component into the first heating furnace again to cure the varnish; a step of placing the motor component after the previous step into a second heating furnace having a temperature higher than that of the first heating furnace to foam the foamed insulating sheet; a second dropping step of dropping the varnish from the other side of the motor component in the motor axial direction after the previous step to the arrangement position of each slot pole; and a second curing step of putting the motor component after the previous step into the second heating furnace again to cure the varnish.

Description

Technical Field

[0001] The present invention relates to a method for manufacturing a rotating electrical machine.

[0002] This application claims priority based on Japanese Patent Application No. 2023-154143 filed in Japan on September 21, 2023, and the contents of which are incorporated herein by reference. Background Art

[0003] In recent years, efforts to realize a low-carbon society or a decarbonized society have become more active, and research and development related to electrification technology has also been carried out in order to reduce CO2 emissions and improve energy efficiency in vehicles.

[0004] For example, in rotating electrical machines such as vehicle drive motors, a winding excitation type is sometimes used instead of the mainstream embedded magnet type. In a winding excitation type motor, a coil is arranged on the rotor instead of a permanent magnet, and a current is passed through the coil to generate a magnetic flux in the rotor. The winding excitation type motor can adjust the magnetic flux of the rotor, so high-efficiency operation can be expected, and since permanent magnets are not used, there is no need to worry about the stable supply of rare earth elements.

[0005] That is, at least one of the stator and the rotor of the motor includes: an annular ring portion; a plurality of cores (teeth) radially protruding radially inward or outward of the annular portion; and a coil with a conducting wire wound around the outer circumference of each core.

[0006] For example, Japanese Patent Gazette No. 4593291 discloses the following situation: in a method for manufacturing a stator (motor component), after preheating the stator body, varnish is dripped onto the coil, so that the varnish, which is heated by contact with the coil and has a reduced viscosity, penetrates into the coil, thereby allowing the varnish to be applied to the entire coil with a smaller amount of dripping. Summary of the invention

[0007] However, a plate-shaped member (slot pole) is arranged between adjacent coils in the circumferential direction of the motor to insulate the coils and fix the coil positions. Between the slot pole and the coil, a gap of varying size is formed due to the unevenness of the outermost winding of the coil. Therefore, even if varnish is filled into the slot pole arrangement position, part of the varnish will flow out without being retained in the gap, and the varnish may be insufficiently filled.

[0008] On the other hand, it is also conceivable to insert a foamed insulating sheet together with the slot poles between the coils, first foam the foamed insulating sheet to fill the gap, and then fill it with varnish.

[0009] However, the foaming temperature of the foamed insulating sheet is higher than the curing temperature of the varnish, and after the foamed insulating sheet is foamed, the workpiece is temporarily cooled, and then the workpiece is heated again to a temperature suitable for the penetration of the varnish, thereby filling the varnish. Therefore, the energy required to complete the filling of the varnish increases, and improvement is desired.

[0010] An object of the present invention is to provide a method for manufacturing a rotating electrical machine that can prevent insufficient filling of varnish and reduce the energy required to complete filling of varnish, and further contribute to improvement of energy efficiency.

[0011] In order to achieve the above-mentioned object, a method for manufacturing a rotating electrical machine according to an aspect of the present invention adopts the following configuration.

[0012] (1) The present invention is a method for manufacturing a rotating electric machine, wherein windings are respectively wound on a plurality of teeth arranged in a circumferential direction of the motor to form a plurality of coils, and a plate-shaped slot pole is arranged between a pair of coils adjacent to each other in the circumferential direction of the motor to insulate the pair of coils, the method comprising: a motor component assembling step of obtaining an annular motor component having coils respectively formed on a plurality of teeth arranged in a circumferential direction of the motor; a pole inserting step of inserting a slot pole having a foamed insulating sheet attached to an end portion only on one side of the motor axial direction into a pair of coils adjacent to each other in the circumferential direction of the motor component; a first heating step of placing the motor component with the slot pole inserted in a first heating furnace at a temperature lower than the temperature at which the foamed insulating sheet is foamed to heat the motor component; A first varnish dripping process in which varnish is dripped from the other side of the motor shaft of the motor component after the first heating process toward each coil; a first varnish curing process in which the motor component after the first varnish dripping process is placed again in the first heating furnace to solidify the varnish dripped in the first varnish dripping process; a sheet foaming process in which the motor component after the first varnish curing process is placed in a second heating furnace at a temperature higher than the first heating furnace to foam the foamed insulating sheet; a second varnish dripping process in which varnish is dripped from the other side of the motor shaft of the motor component after the sheet foaming process toward the configuration position of each slot pole; and a second varnish curing process in which the motor component after the second varnish dripping process is placed again in the second heating furnace to solidify the varnish dripped in the second varnish dripping process.

[0013] According to the scheme (1) above, in a motor component having a plurality of teeth and coils arranged along the circumferential direction of the motor, a slot pole having a foamed insulating sheet attached to only the end on one side of the motor axial direction is inserted between a pair of coils adjacent to each other in the circumferential direction of the motor. After the motor component assembly process, the motor component is preheated in a relatively low-temperature first heating furnace, and then the varnish is dripped and penetrated into each coil, and then the motor component is placed in the first heating furnace again to solidify the varnish. In this way, the varnish is only applied to each coil, thereby reducing the amount of varnish used compared to a structure in which the motor component is immersed in an immersion tank to apply the varnish. In addition, by suppressing the application of varnish to the periphery of the coil, it becomes easier to press out and pull out the coil when the motor component is disassembled. Furthermore, in the early stage of the manufacturing process of the motor component, the relatively low-temperature first heating furnace is continuously used, thereby reducing the energy required from preheating of the motor component to solidification of the varnish.

[0014] After the varnish dripped onto the coil is solidified, the motor component is placed in a second heating furnace at a higher temperature than the first heating furnace to foam the foamed insulating sheet. As a result, the gap between the coil and the slot pole is closed around the end of the slot pole on one side of the motor axial direction. Then, the varnish is dripped from the other side of the motor axial direction to the configuration position of the slot pole, thereby filling the slot pole with varnish while preventing the dripped varnish from leaking from one side of the motor axial direction. The varnish filled around the slot pole is solidified by placing the motor component again in the second heating furnace. At this time, the residual heat of the second heating furnace can be used to solidify it.

[0015] Thus, the process of filling the rotating electrical machine with varnish is set in a temperature increasing order until the sheet foaming process, and after the sheet foaming process, in a temperature decreasing order, thereby preventing insufficient filling of varnish and reducing the energy required until the filling of varnish is completed.

[0016] According to the aspects of the present invention, it is possible to provide a method for manufacturing a rotating electrical machine which can prevent insufficient filling of the varnish and reduce the energy required to complete the filling of the varnish. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is an exploded perspective view of a motor in an embodiment of the present invention.

[0018] Figure 2 It is a plan view of a portion of the circumferential direction of the rotor of the above-mentioned motor as viewed from the axial direction, and includes a portion of the cross section.

[0019] Figure 3 It is a perspective view including a cross section along the axial direction of the above-mentioned rotor.

[0020] Figure 4 1 is a flow chart showing the manufacturing process of the above-mentioned rotor.

[0021] Figure 5 The figures are explanatory diagrams showing the temperature history of a heating furnace in the manufacturing process of the above-mentioned rotor, wherein (a) shows the temperature history of the embodiment, and (b) shows the temperature history of a comparative example.

[0022] Explanation of symbols:

[0023] 1 Motor (rotating motor)

[0024] 2 Rotor (motor parts)

[0025] 21 Rotation axis

[0026] 22 Rotor core

[0027] 32 Winding

[0028] 35 teeth

[0029] 36 slots

[0030] 37 Coil

[0031] 38 Insulator

[0032] 39 slot pole

[0033] 39a Foam insulation sheet

[0034] Da axial direction (motor axial direction)

[0035] Dc circumferential direction (motor circumferential direction)

[0036] Dr Radial (Motor Radial)

[0037] Dt1 tooth axial

[0038] Dt2 tooth radial

[0039] S1 Motor Components Assembly Process

[0040] S2 Pole Insertion Process

[0041] S3 First heating process

[0042] S4 First varnish dripping process

[0043] S5 The first varnish curing process

[0044] S6 sheet foaming process

[0045] S7 Second varnish dripping process

[0046] S8 Second clear coat curing process

[0047] W Varnish DETAILED DESCRIPTION

[0048] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0049] <Motor 1>

[0050] Figure 1 It is an exploded perspective view of a motor (rotating electric machine) 1 to which the embodiment of the present invention is applied.

[0051] like Figure 1 As shown, the motor 1 includes a rotor 2, a stator 3, and a case (not shown) covering the rotor 2 and the stator 3. In the present embodiment, the rotor 2 is arranged on the inner peripheral side with respect to the stator 3. That is, the motor 1 is an inner rotor type motor.

[0052] The motor 1 of the embodiment is a drive motor for an electric vehicle. In addition, the motor 1 of the embodiment is a winding excitation type motor, and has a rotor structure using an excitation winding (coil 37) instead of a permanent magnet. The motor 1 generates magnetic flux in the rotor 2 by passing a direct current from the outside to the excitation winding, and the excitation magnetic flux can be adjusted.

[0053] <Rotor 2>

[0054] The rotor 2 includes a rotating shaft 21 , a rotor core 22 , a plurality of magnetic pole portions 23 , and a commutator 24 .

[0055] The rotating shaft 21 extends in the axial direction (motor axial direction) Da. The rotating shaft 21 is supported by the housing via bearings (neither of which is shown). The rotating shaft 21 is supported to be rotatable in the circumferential direction (motor circumferential direction) Dc around the axis C extending in the axial direction Da.

[0056] The rotor core 22 is arranged outside (on the outer peripheral side) of the radial direction Dr (motor radial direction) centered on the axis C relative to the rotating shaft 21. The rotor core 22 is formed in a cylindrical shape with the axis C as the axis center. When viewed from the axial direction Da, a shaft insertion hole 22a for the rotating shaft 21 to pass through is formed in the center portion of the rotor core 22. The rotor core 22 can rotate integrally with the rotating shaft 21 in the circumferential direction Dc.

[0057] The plurality of magnetic pole portions 23 are arranged at equal intervals along the circumferential direction Dc at the outer periphery of the rotor core 22. Each magnetic pole portion 23 includes a coil 37. The coil 37 is formed by winding a winding 32 around the outer periphery of a tooth 35 formed on the rotor core 22 via an insulator 38. The details of the coil 37 and the insulator 38 will be described later.

[0058] The commutator 24 is coaxially provided at one end of the rotating shaft 21. The commutator 24 is rotatable in the circumferential direction Dc integrally with the rotating shaft 21. The brush 25 supported by the housing is in contact with the commutator 24 in the radial direction Dr so as to face the commutator 24.

[0059] <Stator 3>

[0060] The stator 3 is disposed on the outer peripheral side of the rotor core 22 in the radial direction Dr with a gap (air gap) therebetween. The stator 3 is fixed to the inner peripheral side of the housing in the radial direction Dr. The stator 3 includes a stator core and a plurality of magnetic poles (neither of which are shown).

[0061] <Details of Rotor 2>

[0062] Hereinafter, the rotor 2 will be described in more detail.

[0063] like Figure 2 As shown, the rotor core 22 integrally includes an annular portion 34 and a plurality of teeth 35 .

[0064] The annular portion 34 is formed on the inner circumference side (rotation shaft 21 side) of the rotor core 22. The annular portion 34 extends in the circumferential direction Dc and is formed in an annular shape when viewed from the axial direction Da.

[0065] The plurality of teeth 35 are formed at regular intervals along the circumferential direction Dc. Each tooth 35 extends from the outer periphery of the annular portion 34 toward the outer periphery along the radial direction Dr. A slot 36 is formed between adjacent teeth 35 in the circumferential direction Dc. The slot 36 is formed by cutting out the outer periphery of the rotor core 22.

[0066] The slots 36 and the teeth 35 are formed in the same number (eight in the embodiment). The rotor core 22 may also be a structure that can be divided in the circumferential direction Dc according to a plurality of teeth 35. In the figure, the line Ct represents the center axis along the center axis of the tooth 35 (the protruding direction of the tooth 35 (motor radial direction Dr)). Hereinafter, the protruding direction of the tooth 35 is referred to as the tooth axial direction Dt1, and the direction orthogonal to the tooth axial direction Dt1 is referred to as the tooth radial direction Dt2.

[0067] The winding 32 is a conductive wire (e.g., a copper wire) and is held in the rotor core 22 in the form of a coil 37. The winding 32 is wound around the plurality of teeth 35 via an insulator 38 made of an insulating resin. When viewed from the tooth axial direction Dt1, the winding 32 is wound in a manner of stacking a plurality of layers on the outer periphery of the tooth 35. By winding the winding 32 around each tooth 35, a plurality of coils 37 arranged at intervals in the circumferential direction Dc are formed on the rotor 2. A slot pole (insulating plate) 39 made of an insulating resin such as PPS is inserted between a pair of coils 37 adjacent to each other in the circumferential direction Dc.

[0068] <Insulator 38>

[0069] like Figure 2As shown, the insulator 38 has: a flange-shaped outer peripheral piece 41 provided on one end side (motor outer peripheral side) in the tooth axial direction Dt1; a flange-shaped inner peripheral piece 42 provided on the other end side (motor inner peripheral side) in the tooth axial direction Dt1; and a cylindrical side wall portion (winding portion) 43 connecting the outer peripheral piece 41 and the inner peripheral piece 42 to each other. The internal space surrounded by the opposing surfaces of the outer peripheral piece 41 and the inner peripheral piece 42 and the outer side surface of the winding portion 43 on three sides becomes a storage portion 45, and the storage portion 45 stores the coil 37 of the stacked winding 32. The slot 36 is formed by a pair of adjacent storage portions 45 in the motor circumferential direction Dc. The winding 32 is densely arranged in the storage portion 45 by so-called stacking.

[0070] <Filling of varnish W>

[0071] like Figure 2 , Figure 3 As shown, the slot pole 39 is in the shape of a rectangular flat plate along the motor radial direction Dr and the motor axial direction Da. The slot pole 39 insulates a pair of coils 37 adjacent to each other in the motor circumferential direction Dc and fixes the position of each coil 37. In particular, unlike the stator 3 fixed to the housing, the winding excitation type rotor 2 rotates, so in order to prevent the winding from flying away due to centrifugal force, it is also necessary to fix the coil 37. Between the two side surfaces of the slot pole 39 in the motor circumferential direction Dc and the coil 37 adjacent to the slot pole 39, an uneven gap is formed due to the unevenness of the outermost layer of the coil 37. In order to fill the gap, varnish W is filled (at Figure 3 The dripping toward the rotor 2 is shown in FIG.

[0072] For example, if the winding of the coil 37 is wound along the tooth axial direction Dt1 , a method of inserting a wedge-shaped member into the space between the coils 37 and filling the minute gap between the member and the coil 37 with varnish W, mold resin, or the like may be considered.

[0073] On the other hand, if the conical winding is adopted in which the number of turns of the coil 37 increases toward the outer side in the motor radial direction Dr as in the embodiment, the concavity and convexity of the outermost layer of the coil 37 becomes uneven, and the gap between the slot pole 39 and the coil 37 becomes larger. Therefore, even if the varnish W is filled in the arrangement position of the slot pole 39, part of it will leak to the outside of the rotor 2, and there is a possibility that the filling of the varnish W is insufficient. In addition, the filling by molding requires the addition of a process and a sealing structure, which increases the cost.

[0074] In the embodiment, in order to reliably fill the varnish W even if the gap between the slot pole 39 and the coil 37 is large, a foamed insulating sheet (e.g., foamed insulating paper, such as a structure having a PEN (polyethylene naphthalate) film as a base material and a foamed adhesive layer on both sides thereof) 39a is effectively utilized.

[0075] like Figure 3As shown, the foamed insulating sheet 39a is disposed only at the end portion of the slot pole 39 on the motor axial direction Da side. The foamed insulating sheet 39a is disposed on both surfaces of the slot pole 39 in the motor circumferential direction Dc. The foamed insulating sheet 39a is previously attached to the slot pole 39 by epoxy resin or the like, and is inserted between a pair of coils 37 adjacent in the motor circumferential direction Dc from the outside toward the inside in the motor radial direction Dr in the motor component assembly step S1 described later.

[0076] Then, in the sheet foaming step S6 described later, the foamed insulating sheet 39a is foamed on both sides of the end of the slot pole 39 on the motor axial direction Da side. As a result, the gap between the slot pole 39 and the coil 37 can be filled at the end of the slot pole 39 on the motor axial direction Da side. At the end of the slot pole 39 on the other side of the motor axial direction Da, the gap between the slot pole 39 and the coil 37 is open, so the varnish W can be filled from the other side of the motor axial direction Da to the arrangement position of the slot pole 39. At this time, the varnish W is stopped by the foamed insulating sheet 39a on the motor axial direction Da side of the arrangement position of the slot pole 39, and the filled varnish W is prevented from leaking from the motor axial direction Da side.

[0077] <Method for Manufacturing Rotor 2>

[0078] like Figure 4 As shown, the manufacturing method of the rotor 2 of the embodiment includes a motor component assembling step S1, a pole inserting step S2, a first heating step S3, a first varnish dropping step S4, a first varnish curing step S5, a sheet foaming step S6, a second varnish dropping step S7, and a second varnish curing step S8.

[0079] In the motor component assembly step S1, the annular rotor 2 is obtained in which the coils 37 are formed on each of the plurality of teeth 35 arranged along the motor circumferential direction Dc. The motor component assembly step S1 includes a shaft pressing step S1a of pressing the rotating shaft 21 into the rotor core, an insulator mounting step S1b of mounting the insulator 38 on each of the teeth 35 of the rotor core, and a winding step S1c of winding a winding on the winding portion 43 of the insulator 38 to form the coil 37.

[0080] In the pole insertion step S2, the slot pole 39 is inserted between a pair of coils 37 adjacent to each other in the motor circumferential direction Dc in the rotor 2. The slot pole 39 has a band-shaped foamed insulating sheet 39a cut to a predetermined width previously attached to both surfaces of the end portion on the motor axial direction Da side in a state where the slot pole 39 is assembled to the rotor 2 by epoxy adhesive or the like.

[0081] In the first heating step S3, the rotor 2 into which the slot poles 39 are inserted after the pole insertion step S2 is placed in a first heating furnace at a temperature (e.g., 120°C±10°C) lower than the temperature (e.g., 180°C±10°C) at which the foamed insulating sheet 39a is foamed, and is heated. The set temperature of the first heating furnace is set to a temperature at which the viscosity of the varnish W is reduced and the varnish W can easily penetrate into the coil 37.

[0082] In the first varnish dripping step S4, the varnish W is dripped from the other side of the motor axial direction Da of the rotor 2 after the first heating step S3 to each coil 37. The dripping amount of the varnish W can be set in advance to an amount that can penetrate the entire coil 37. By making the varnish W penetrate into each coil 37, the windings 32 and the transition part are fixed. The varnish W dripped into each coil 37 penetrates and is retained in each coil 37, so that leakage to the outside of the rotor 2 can be suppressed.

[0083] In the first varnish curing step S5, the rotor 2 after the first varnish dripping step S4 is put into the first heating furnace again to cure the varnish W dripped in the first varnish dripping step. Curing of the varnish W requires heating for 60 to 70 minutes at 120°C ± 10°C, for example. From the first heating step S3 to the first varnish curing step S5, the first heating furnace can be maintained at a constant temperature of 120°C ± 10°C, which can suppress energy consumption using the heating furnace.

[0084] In the sheet foaming step S6, the rotor 2 after the first varnish curing step S5 is placed in a second heating furnace with a temperature higher than that of the first heating furnace (for example, 180°C ± 10°C), so that the foamed insulating sheet 39a is foamed. The second heating furnace is a structure in which the set temperature is changed using the same equipment as the first heating furnace, but it can also be a structure in which a different equipment from the first heating furnace is used. The foaming of the foamed insulating sheet 39a requires heating for 10 minutes to 20 minutes at 180°C ± 10°C, for example. The foamed insulating sheet 39a is foamed on both sides of the end of the slot pole 39 on the motor axial direction Da side, thereby filling the gap between the slot pole 39 and the coil 37. The foamed insulating sheet 39a is not provided in the area of ​​the slot pole 39 other than the end on the motor axial direction Da side, and the varnish W can be filled into the area from the other side of the motor axial direction Da.

[0085] In the second varnish dripping step S7, the varnish W is dripped from the other side of the rotor 2 in the motor axial direction Da after the sheet foaming step S6 to the arrangement position of each slot pole 39. The dripping amount of the varnish W can be set in advance to an amount that can fill the gap around each slot pole 39. The end of the slot pole 39 on the motor axial direction Da side is provided with a foamed insulating sheet 39a, thereby preventing the varnish W dripped to the arrangement position of each slot pole 39 from leaking from the motor axial direction Da side of the rotor 2.

[0086] In the second varnish curing step S8, the rotor 2 after the second varnish dropping step S7 is put into the second heating furnace again to cure the varnish W dropped in the second varnish dropping step S7. The second heating furnace is used by lowering the set temperature to 120°C±10°C, which is the same as that of the first heating furnace, after the second varnish dropping step S7. In the second varnish curing step S8, the first heating furnace may be used instead of the second heating furnace.

[0087] <Temperature History of the Manufacturing Process of the Rotor 2>

[0088] Figure 5 (a) shows the temperature history of the entire process of filling the rotor 2 with varnish W in the manufacturing process of the rotor 2 according to the embodiment. In this example, the first heating furnace and the second heating furnace are configured by using the same heating furnace but setting different temperatures.

[0089] In the figure, range A represents the range for heating the first heating furnace, range B represents the range for maintaining the first heating furnace at a specified temperature (120°C±10°C), range C represents the range for heating the second heating furnace, range D represents the range for maintaining the second heating furnace at a specified temperature (180°C±10°C), and range E represents the range for cooling the second heating furnace (natural heat dissipation).

[0090] The temperature of the entire process in the embodiment shifts in order of increasing temperature to the sheet foaming step S6 (range D), and shifts in order of decreasing temperature after the sheet foaming step S6.

[0091] Figure 5 (b) shows the temperature history of the rotor manufacturing process of the comparative example. In this comparative example, after the pole insertion process, the sheet foaming process is performed without dripping the varnish W, and the foamed insulating sheet 39a is first foamed to fill the gap around the slot pole 39, and then the varnish W is filled (the process of permeating the coil 37).

[0092] In the process of the comparative example, the foaming temperature of the foamed insulating sheet 39a is higher than the curing temperature of the varnish W, so the rotor 2 is cooled once after the foamed insulating sheet 39a is foamed. Then, the rotor 2 is heated again to a temperature suitable for the penetration of the varnish W, and then the varnish W is filled into the appropriate position. Therefore, the energy required to complete the filling of the varnish W is increased by the temperature difference T when the rotor 2 is heated again to a temperature suitable for the penetration of the varnish W after the rotor 2 is cooled.

[0093] In contrast, in the embodiment, before the sheet foaming step S6 with the highest set temperature, the step of impregnating the varnish W into each coil 37 is performed while gradually raising the temperature of the rotor 2 and the device, and after the sheet foaming step S6, the step of filling the varnish W into the arrangement position of the slot pole 39 is performed while gradually lowering the temperature of the rotor 2 and the device. Thus, there is no loss such as raising the temperature again after a temporary decrease as in the comparative example, and the energy required until the filling of the varnish W is completed can be reduced.

[0094] As described above, the manufacturing method of the rotating electric machine in the above-mentioned embodiment is a manufacturing method of the motor 1 (rotor 2), wherein the motor 1 is formed by winding windings on a plurality of teeth 35 arranged along the motor circumferential direction Dc to form a plurality of coils 37, and a plate-shaped slot pole 39 is arranged between a pair of coils 37 adjacent to each other in the motor circumferential direction Dc, and the manufacturing method of the motor 1 (rotor 2) includes: a motor component assembling step S1 of obtaining a ring-shaped rotor 2 in which the coils 37 are respectively formed on a plurality of teeth 35 arranged along the motor circumferential direction Dc; a pole inserting step S2 of inserting the slot pole 39 having the foamed insulating sheet 39a attached only to the end portion on one side of the motor axial direction Da into the rotor 2 between the pair of coils 37 adjacent to each other in the motor circumferential direction Dc; and placing the rotor 2 with the slot pole 39 inserted into a first heating furnace at a temperature lower than the foaming temperature of the foamed insulating sheet 39a. A first heating step S3 for heating; a first varnish dripping step S4 for dripping the varnish W from the other side of the motor axial direction Da of the rotor 2 after the first heating step S3 toward each coil 37; a first varnish curing step S5 for placing the rotor 2 after the first varnish dripping step S4 into the first heating furnace again to solidify the varnish W dripped in the first varnish dripping step S4; a sheet foaming step S6 for placing the rotor 2 after the first varnish curing step S5 into a second heating furnace at a temperature higher than that of the first heating furnace to foam the foamed insulating sheet 39a; a second varnish dripping step S7 for dripping the varnish W from the other side of the motor axial direction Da of the rotor 2 after the sheet foaming step S6 toward the configuration position of each slot pole 39; and a second varnish curing step S8 for placing the rotor 2 after the second varnish dripping step S7 into the second heating furnace again to solidify the varnish W dripped in the second varnish dripping step S7.

[0095] According to this structure, in the rotor 2 having a plurality of teeth 35 and coils 37 arranged in the motor circumferential direction Dc, a slot pole 39 having a foamed insulating sheet 39a attached only to the end on one side of the motor axial direction Da is inserted between a pair of coils 37 adjacent in the motor circumferential direction Dc. After the rotor 2 is preheated in the first heating furnace at a relatively low temperature after the motor component assembly step S1, the varnish W is dripped and permeated into each coil 37, and then the rotor 2 is put into the first heating furnace again to solidify the varnish W. In this way, the varnish W is applied only to each coil 37, thereby reducing the amount of varnish W used compared to the structure in which the rotor 2 is immersed in the dipping tank to apply the varnish W. In addition, by suppressing the application of the varnish W to the periphery of the coil 37, it becomes easy to press out and pull out the coil 37 when the rotor 2 is disassembled. In addition, in the early stage of the manufacturing process of the rotor 2, the first heating furnace at a relatively low temperature is continuously used, thereby reducing the energy required from the preheating of the rotor 2 to the solidification of the varnish W.

[0096] After the varnish W dripped onto the coil 37 is solidified, the rotor 2 is placed in a second heating furnace at a higher temperature than the first heating furnace to foam the foamed insulating sheet 39a. As a result, the gap between the coil 37 and the slot pole 39 is closed around the end of the slot pole 39 on the motor axial direction Da side. Then, the varnish W is dripped from the other side of the motor axial direction Da to the arrangement position of the slot pole 39, thereby preventing the dripped varnish W from leaking from the motor axial direction Da side, and filling the slot pole 39 with the varnish W. The varnish W filled around the slot pole 39 is solidified by placing the rotor 2 again in the second heating furnace. At this time, it can be solidified by the residual heat of the second heating furnace.

[0097] In this way, the process of filling the varnish W into the rotating electrical machine is set in a temperature rising order until the sheet foaming step S6, and after the sheet foaming step S6, it is set in a temperature falling order, thereby preventing insufficient filling of the varnish W and reducing the energy required until the filling of the varnish W is completed.

[0098] The present invention is not limited to the above-mentioned embodiments. For example, the manufacturing method of the rotating electric machine of the embodiment can be applied to rotating electric machines other than vehicle drive motors. For example, the rotating electric machine illustrated in the embodiment is an inner rotor type motor, but it is not limited to this structure. For example, the rotating electric machine can also be an outer rotor type in which the rotor is arranged on the outer peripheral side relative to the stator. In addition, the rotating electric machine is not limited to a motor, and can also be a generator. In order to heat and foam the foamed insulating paper, electric heating of the winding 32 of the rotor 2 can also be used. In this case, large equipment such as a heating furnace is not required.

[0099] Furthermore, the configuration in the above-described embodiment is an example of the present invention, and the components of the embodiment may be replaced with well-known components, and various changes may be made without departing from the gist of the present invention.

Claims

1. A method for manufacturing a rotating electric machine, wherein a plurality of coils are formed by winding windings around a plurality of teeth arranged in a circumferential direction of a motor, and a plate-shaped slot pole is arranged between a pair of coils adjacent to each other in the circumferential direction of the motor to insulate the pair of coils, wherein the method for manufacturing a rotating electric machine is characterized in that: The manufacturing method of the rotating electrical machine comprises: A motor component assembling step of obtaining an annular motor component in which the coils are respectively formed on a plurality of the teeth arranged along the circumferential direction of the motor; A pole insertion step of inserting the slot pole having a foamed insulating sheet attached to only one end portion on one side of the motor axial direction into a pair of coils adjacent to each other in the motor circumferential direction in the motor component; A first heating step of placing the motor component with the slot pole inserted thereinto into a first heating furnace at a temperature lower than the foaming temperature of the foamed insulating sheet to heat the motor component; a first varnish dripping step of causing varnish to drip from the other side of the motor shaft of the motor component after the first heating step toward each coil; a first varnish curing step of placing the motor component after the first varnish dripping step again into the first heating furnace to cure the varnish dripped in the first varnish dripping step; A sheet foaming step of placing the motor component after the first varnish curing step into a second heating furnace at a temperature higher than that of the first heating furnace to foam the foamed insulating sheet; A second varnish dripping step of dripping the varnish from the other side of the motor shaft of the motor component after the sheet foaming step toward the arrangement position of each slot pole; and A second varnish curing step of placing the motor component after the second varnish dropping step again in the second heating furnace to cure the varnish dropped in the second varnish dropping step.

Images