Stator manufacturing method and stator core

Abstract

The subject of the present invention is to suppress the varnish from flowing out from the lower part of the stator core by increasing the filling rate of the varnish in the groove. In the manufacturing method of the stator of the rotating electric machine of the present invention, the stator has a coil; and a stator core, the stator core is formed with a groove for accommodating the coil, and a resin member is filled into the groove from the injection side, the resin member has a lower viscosity at the first temperature and a higher viscosity at a second temperature higher than the first temperature, and the manufacturing method includes: a first step, in which a temperature difference is applied to the stator core so that the stator core has the first temperature on the injection side and the second temperature on the opposite side of the injection side; and a second step, in which the resin member is injected from the injection side while maintaining the temperature difference.

Description

Technical Field

[0001] The present invention provides a method for manufacturing a stator which constitutes a rotating electric machine and is wound with a coil. Background Art

[0002] As background technology in this technical field, there is the following prior art. In patent document 1 (Japanese Patent Laid-Open No. 2008-109732), in the first supply process after preheating, the stator core is held horizontally with the coil ends of the coil mounted on the stator core in an upper and lower position, and varnish is injected from the upper surface of the upper coil end protruding from the upper end face of the stator core in the coil, and the varnish is supplied while controlling the supply amount so that the varnish that is immersed and flows down from the upper part of the upper coil end is gelled before reaching the outside of the lower coil end protruding from the lower end face of the stator core in the coil. Then, in the reversal process, the stator core with the coil mounted is reversed at an interval longer than the time for the varnish last supplied in the first supply process to gel. In the second supply process after the reversal process, the varnish is supplied with a controlled supply amount so that gelation begins near the position where gelation begins in the first supply process. Then, the varnish impregnated in the coil is kept warm and cured. Prior art document

[0003] Patent Literature

[0004] Patent Document 1: Japanese Patent Application Publication No. 2008-109732 Summary of the invention

[0005] Technical problem to be solved by the invention

[0006] In order to fix the wound coil in the stator of the rotating electric machine, it is desired to increase the filling rate of the varnish in the slot. Therefore, although a large amount of varnish needs to be injected, if the varnish flows out from the lower side of the stator core, the filling rate will decrease. Therefore, for example, in the method described in Patent Document 1, the varnish is injected from different directions in the first supply process and the second supply process, but a reversing process is included between the first supply process and the second supply process, which makes the operation complicated.

[0007] Therefore, a method for manufacturing a stator in which the filling rate of varnish in the groove is high is required.

[0008] Technical solutions adopted to solve technical problems

[0009] As described below, a representative example of the invention disclosed in the present application is shown. That is, in a method for manufacturing a stator of a rotating electric machine, the stator has a coil; and a stator core, the stator core is formed with slots for accommodating the coil, and a resin member is filled into the slot from an injection side, the resin member has a lower viscosity at a first temperature and a higher viscosity at a second temperature higher than the first temperature, and the manufacturing method includes: a first step, in which a temperature difference is applied to the stator core so that the stator core has the first temperature on the injection side and the second temperature on the opposite side of the injection side; and a second step, in which the resin member is injected from the injection side while maintaining the temperature difference. Effect of the Invention

[0010] According to one aspect of the present invention, the filling rate of the varnish in the groove can be increased, and the varnish can be prevented from flowing downward from the lower side of the stator core. Other problems, structures and effects than those described above will be further clarified by the following description of the embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a diagram showing an outline of a stator manufacturing method according to an embodiment of the present invention.

[0012] Figure 2 It is a perspective view showing a stator core on which a coil is mounted.

[0013] Figure 3 This is a cross-sectional view of the stator core with the coil mounted thereon, viewed from the welding end side.

[0014] Figure 4 This is a perspective view of the stator core with the coil mounted thereon, viewed from the non-welding end side.

[0015] Figure 5 This is a diagram showing temperature changes during the manufacturing process of the stator.

[0016] Figure 6 This is a diagram showing the stator core when varnish is injected.

[0017] Figure 7 This is a diagram showing the stator core when varnish is injected. DETAILED DESCRIPTION

[0018] Figure 1 It is a diagram showing an outline of a stator manufacturing method according to an embodiment of the present invention.

[0019] In the manufacturing method of the stator of this embodiment, the stator core 305 is provided with a distributor from above ( Figure 3The varnish is injected into the stator core 305 (on the welding end side shown), the lower part of the stator core 305 is heated (or the upper part of the stator core 305 is cooled), and the varnish is injected from the low temperature side (upper part) in a state where there is a temperature difference between the upper part of the stator core 305 being low temperature (high-speed filling temperature region) and the lower part being high temperature (gelling temperature region). The varnish injected into the slot 310 of the stator core 305 is an example of an insulating resin member, and may be an insulating resin member of another name.

[0020] Therefore, the high temperature area at the lower part of the stator core 305 is set to a temperature at which the varnish gels and the viscosity increases, thereby forming a varnish stop range in which the injected varnish does not flow out from the lower part of the stator core 305. On the other hand, since the temperature from the low temperature area at the upper part of the stator core 305 to the medium temperature area at the central part is set to a temperature at which the viscosity of the varnish is relatively low, the injected varnish stays on the upper side of the varnish stop range, and the varnish is injected at a higher filling rate. Therefore, in the high filling range, the bubbles between the stator core 305 and the coil are reduced, the heat generated in the coil is easily released, the vibration of the coil can be suppressed, and the characteristics of the rotating motor are stable.

[0021] Next, the structure of the stator core 305 according to the embodiment of the present invention will be described.

[0022] Figure 2 is a perspective view showing a stator core 305 on which a coil is mounted. Figure 3 is a cross-sectional view of the stator core 305 with the coil installed thereon as viewed from the welding end side. Figure 4 This is a perspective view of the stator core 305 to which the coil is mounted, as viewed from the non-welding end side.

[0023] The stator 300 of the rotary electric machine 200 includes a cylindrical stator core 305 , a stator coil 510 inserted into the stator core 305 , and a slot liner 520 .

[0024] The stator core 305 is supported inside the housing 205, and a rotor embedded with a permanent magnet is rotatably supported on the inner circumference of the stator core 305 through a gap. The stator core 305 is formed by stacking a plurality of magnetic bodies (e.g., a plurality of electromagnetic steel sheets) in the axial direction, and a plurality of teeth 307 and slots 310 are formed at equal intervals in the circumferential direction, and each tooth 307 is integrated with the back of the annular core. Figure 3 In the figure, not all teeth are labeled, but only a part of the tooth core 307 is labeled as a representative. A plurality of slots 310 are formed on the rotor side between adjacent tooth cores 307 and are continuous in the circumferential direction. Slot insulators (not shown) of slot liners 520 are provided in the slots 310, and multi-phase coils such as U-phase, V-phase, and W-phase constituting the stator 300 are installed in the slots 310.

[0025] like Figure 2 As shown, the stator coil 510 is received in the slot 310 of the stator core 305. Figure 2 In the example shown, the slot 310 is an open slot, and the opening is formed on the inner peripheral side of the stator core 305. Figure 3 As shown, the circumferential width of the opening formed on the innermost circumference of the slot 310 is almost equal to or slightly smaller than the coil mounting portion of each slot 310 where the stator coil 510 is mounted.

[0026] The slot liner 520 is disposed in each slot 310. The slot liner 520 is, for example, an insulating sheet made of a heat-resistant resin and has a thickness of about 0.1 to 0.5 mm. By disposing the slot liner 520 in the slot 310, the insulation withstand voltage between the coils inserted through the slot 310 and between the coil and the inner surface of the slot 310 is improved, and even if the insulation film of the coil is deteriorated or damaged, the necessary insulation withstand voltage is maintained.

[0027] In order to improve the insertability of the coil, the gap between the coil in the slot 310 and the stator core 305 is different in the circumferential and radial directions of the stator core 305, and one gap is larger than the other gap. There is a trade-off relationship between the coil insertability determined by the gap size and the coil volume occupancy rate. In addition, in the present embodiment, the varnish injected into the slot 310 is retained by the slot liner 520. That is, the slot liner 520 serves as a varnish retaining member. The insulation between the coils and the insulation between the coil and the stator core 305 are enhanced by the varnish, and the stator coil 510 is fixed in the slot 310, thereby suppressing the movement of the stator coil 510 in the slot 310 caused by the vibration applied to the rotating electric machine 200 and the electromagnetic vibration of the stator coil 510.

[0028] like Figure 2 As shown, in the stator core 305 of this embodiment, a plurality of segmented coils 512 whose outer circumference is covered with an insulating film and formed into a U-shape are accommodated in two separate slots 310, so that the ends of the segmented coils 512 are exposed from the slots 310 (i.e., the stator core 305), one end is adjacent to another segmented coil 512, and the other end is adjacent to yet another segmented coil 512. The segmented coils 512 are arranged in each slot 310, for example, the rectangular cross-section of the coil is longer in the circumferential direction of the stator core 305 and shorter in the radial direction. The ends of the segmented coils 512 are on the welding end side ( Figure 2 The right inner side of the stator core 305 is connected to each other to form a stator coil 510 of distributed winding wound on the stator core 305.

[0029] like Figure 4As shown, the connection terminal 340 and the thermistor 350 are provided on the non-welding end side of the stator 300. The connection terminal 340 is provided at the end of the multi-phase coil such as the U phase, the V phase, and the W phase, and is connected to the driver of the control circuit (not shown). The thermistor 350 measures the temperature of the coil. The temperature of the coil measured by the thermistor 350 is input to the control circuit.

[0030] Figure 5 3 is a graph showing temperature changes during the manufacturing process of the stator 300 of the present embodiment, wherein the vertical axis represents temperature and the horizontal axis represents elapsed time.

[0031] In addition, in the present embodiment, since the varnish is injected from the welding end side of the stator core 305, the welding end side becomes the upper part and the non-welding end side becomes the lower part.

[0032] First, the entire stator core 305 is heated from room temperature to a high-speed filling temperature region. The high-speed filling temperature region depends on the material of the varnish, and in this embodiment is 65° C. to 130° C. For example, since the stator core 305 is formed of an iron plate, it can be heated by an IH heater having an electrode inserted into a cavity (a portion into which the rotor is inserted) within the stator core 305.

[0033] Then, the lower part (non-welding end side) of the stator core 305 is locally heated to the gelation temperature region. In the present embodiment, the gelation temperature region is above 130°C. For example, heating can be performed by an IH heater having an electrode close to the lower part of the stator core 305. By this local heating, the temperature of the lower part of the stator core 305 becomes higher than the upper part (welding end side) from the middle part of the stator core 305, and a temperature difference is generated on the stator core 305. Therefore, a varnish stop range is formed in the lower part of the stator core 305, and a high filling range is formed from the middle part to the upper part of the stator core 305 (above, the first process).

[0034] In addition, in the method of generating a temperature difference, instead of locally heating the lower portion of the stator core 305, the stator core 305 is temporarily heated to a gelation temperature region, and then the upper portion is cooled starting from the middle portion of the stator core 305 (for example, by a point cooler), and a temperature difference can be applied to the stator core 305 so that the temperature from the middle portion to the upper portion of the stator core 305 is lower than the temperature of the lower portion of the stator core 305 (high-speed filling temperature region).

[0035] While maintaining a specified temperature difference (the lower part of the stator core 305 is in the gelation temperature zone, and the middle to upper part are in the high-speed filling temperature zone), the varnish is injected into the slot 310 from the upper part of the stator core 305. When the varnish flowing downward in the slot 310 of the stator core 305 reaches the lower part of the stator core 305 (the varnish stop range as the gelation temperature zone), the varnish gels and stops without flowing out from the lower end of the stator core 305, and the filling rate of the varnish in this area decreases. Thereafter, the varnish is continuously injected and the varnish is injected into the upper end of the stator core 305 (the above, the second process). Since the middle to upper part of the stator core 305 is the high-speed filling temperature zone, the fluidity of the injected varnish is high, and a sufficient amount of varnish can be filled between the coil and the inner wall of the slot 310, so that the filling rate of the varnish becomes high.

[0036] When injecting varnish, such as Figure 6 As shown, the axis of the stator core 305 can be changed from vertical to inclined. By tilting the stator core 305 and injecting the varnish, the inflow speed of the varnish can be controlled.

[0037] In addition, if Figure 6 and Figure 7 As shown, the varnish can be injected while the stator core 305 is rotated, turned or shaken. By injecting the varnish while the stator core 305 is rotated or turned, the relative position of the stator core 305 and the dispenser is changed, and the varnish can be injected uniformly in the circumferential direction. In particular, when the stator core 305 is tilted and the varnish is injected, the varnish can be filled uniformly. In addition, the varnish is injected while the stator core 305 is moved by rotating, turning or shaking, thereby suppressing the residue of bubbles and enabling the varnish to be filled with a high filling rate. In addition, the stator core 305 can be rotated or turned, but the dispenser can also be moved when the varnish is injected with the axis of the stator core 305 in a vertical state.

[0038] After the filling of the prescribed amount of varnish is completed, the entire stator core 305 is heated to the curing temperature region. For example, since the stator core 305 is formed of an iron plate, it is heated by an IH heater having an electrode inserted into a cavity (a portion into which the rotor is inserted) in the stator core 305. The curing temperature region also depends on the material of the varnish, but is 130° C. or more in this embodiment. By keeping the stator core 305 in the curing temperature region for a long time, the varnish is further hardened and cured from the gel state (the third step above).

[0039] Then, the stator core 305 after the varnish is cured is cooled to room temperature (or lower than the electrical test temperature) (the above, the fourth step).

[0040] In this embodiment, the varnish is gelled in the varnish stop range at the lower part of the stator core 305 and stops at the lower part of the stator core 305, so the varnish does not flow out from the lower end of the stator core 305. Therefore, the filling rate of the varnish in the high filling range from the middle to the upper part of the stator core 305 can be improved.

[0041] In addition, the stator 300 has a portion to prevent varnish from adhering. According to the manufacturing method of the stator of this embodiment, since the varnish can be prevented from flowing out from the lower end of the stator core 305, it is possible to suppress the varnish from adhering to the varnish adhesion prohibited area. Figure 4 As shown, varnish is prohibited from adhering to the connection terminal 340 and the thermistor 350 provided on the non-welding end side (the lower side when the varnish is injected) of the stator 300. Since the connection terminal 340 connects the coil to the control circuit, the varnish adhering to its surface is insulated. By preventing the varnish from adhering to the connection terminal 340, poor conduction between the rotating motor and the control circuit can be suppressed. In addition, in order to measure the temperature of the coil, the thermistor 350 needs to be in close contact with the coil, but since the varnish is sandwiched between the thermistor 350 and the coil, the thermal coupling between the thermistor 350 and the coil will become sparse. By preventing the varnish from adhering to the thermistor 350, the thermal coupling between the thermistor 350 and the coil becomes tight, and the thermistor 350 can measure the correct temperature of the coil.

[0042] As described above, the manufacturing method of the stator 300 of the present embodiment includes: a first step in which the stator core 305 has a temperature difference so that the stator core 305 has a first temperature (gelling temperature region) on the injection side (the upper welding end side) and a second temperature (high-speed filling temperature region) on the side opposite to the injection side (the lower non-welding end side); and a second step in which the resin member (varnish) is injected from the injection side while maintaining the temperature difference, thereby increasing the filling rate of the varnish in the groove 310. In addition, the varnish can be prevented from flowing out from the lower side of the stator core 305, and the varnish can be suppressed from adhering to the varnish adhesion prohibited portion (connection terminal 340, thermistor 350, etc.).

[0043] Furthermore, in the second step, since the resin member is injected in a state where the axis of the stator core 305 is changed from vertical to inclined, the inflow speed of the resin material can be controlled.

[0044] In the second step, the resin member is injected while the stator core 305 is rotated, turned or shaken about the axis, so that the varnish can be injected uniformly in the circumferential direction. In addition, the remaining bubbles are suppressed and the varnish can be injected at a high filling rate.

[0045] Furthermore, in the stator core 305 manufactured by the manufacturing method of this embodiment, a region (high filling range) with a high filling rate of the resin member is formed on the injection side (from the upper part to the middle part) in the slot 310, and a region (varnish stop range) with a low filling rate is formed on the opposite side (lower part) of the injection side. In the high filling range, there are fewer bubbles between the stator core 305 and the coil, so the heat generated in the coil is easily released, the vibration of the coil can be suppressed, and the characteristics of the rotating electric machine are stabilized.

[0046] In addition, the present invention is not limited to the above-mentioned embodiments, but includes various modifications and equivalent structures within the subject matter of the attached claims. For example, the embodiments are detailed descriptions for the purpose of facilitating the understanding of the present invention, and are not limited to having all the structures described. In addition, a part of the structure of a certain embodiment may be replaced with the structure of another embodiment. In addition, the structure of another embodiment may be added to the structure of a certain embodiment. In addition, for a part of the structure of each embodiment, other structures may be added, deleted, or replaced. Explanation of reference numerals

[0047] 200 Rotating motor.

[0048] 205 Housing

[0049] 300 Stator

[0050] 305 stator coil

[0051] 307 teeth

[0052] 307 tooth core

[0053] 310 slots

[0054] 340 Connection Terminals

[0055] 350 Thermistor

[0056] 510 stator coil

[0057] 510 Segment Coil

[0058] 520 Trough Liner.

Claims

1. A manufacturing method, the manufacturing method being a manufacturing method of a stator of a rotating electrical machine, The stator has a coil; and a stator core formed with slots for accommodating the coils, A resin member is filled into the groove from the injection side, and the resin member has a low viscosity at a first temperature and a high viscosity at a second temperature higher than the first temperature, characterized in that: The manufacturing method comprises: A first step of applying a temperature difference to the stator core so that the stator core has the first temperature on an injection side which is a welding end side of the coil and has the second temperature on a side opposite to the injection side which is a non-welding end side of the coil; as well as and a second step of injecting the resin member from the injection side while maintaining the temperature difference.

2. The manufacturing method according to claim 1, characterized in that In the second step, the resin member is injected in a state where the axis of the stator core is tilted from vertical.

3. The manufacturing method according to claim 1, characterized in that: In the second step, the resin member is injected while the stator core is rotated, turned, or shaken about an axis.

4. A stator core, characterized in that: The stator core is manufactured by the manufacturing method according to any one of claims 1 to 3, In the groove, a region having a high filling rate of the resin member is formed on the injection side, and a region having a low filling rate is formed on the opposite side to the injection side.

Images