Method of manufacturing rotor and jig for slot insulation

Abstract

To provide a method of manufacturing a rotor and a jig for slot insulation that can suppress decrease in productivity and increase in an amount of processing liquid to be used.SOLUTION: A method of manufacturing a rotor 1 includes a step of forming a rotor core 3 by stacking a plurality of core materials 2 on a core metal 12, a step of attaching an upper jig 20 to an upper end surface 3a of the rotor core 3, a step of attaching a lower jig 30 to a lower end surface 3b of the rotor core 3, a step of pressurizing the rotor core 3 in a stacking direction, a step of injecting processing liquid 10 in a pressurized state through the inside of the lower jig 30 to fill a slot 7, a step of discharging excess processing liquid 10 through the inside of the lower jig 30, and a step of forming an insulating coating 9 by drying the processing liquid 10, and a step of die-casting the rotor core 3 on which the insulating coating 9 is formed.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] Embodiments of the present invention relate to a method for manufacturing a rotor and a jig for slot insulation.

Background Art

[0002] The rotor of a rotating electrical machine such as a so-called cage-type induction motor is formed by die-casting a conductive material such as aluminum or copper into the slots of the rotor core. At this time, an insulating film may be formed on the inner surface of the slot in order to improve the efficiency of the rotating electrical machine (see, for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] This insulating film is formed by attaching a treatment liquid to the inner surface of the slot and then drying it. However, if the treatment liquid adheres to other parts when attaching it to the inner surface of the slot, it is necessary to wipe off the treatment liquid adhering to other parts or remove the insulating film, resulting in a decrease in productivity and an increase in the amount of treatment liquid used.

[0005] Therefore, a method for manufacturing a rotor and a jig for slot insulation that can suppress a decrease in productivity and an increase in the amount of treatment liquid used are provided.

Means for Solving the Problems

[0006] The method for manufacturing a rotor according to an embodiment includes a step of forming a rotor core by laminating a plurality of core materials using a mandrel for closing the shaft hole of the rotor core during die casting; a step of attaching an upper jig having an upper contact surface that at least contacts the outer and inner radial sides of the slots, an upper recess that forms a gap above each slot, at least one air hole connected to the upper recess, and a central through hole through which the end of the mandrel passes, to the upper end surface in a state where the axial direction of the rotor core is arranged along the vertical direction; a step of attaching a lower jig having a lower contact surface that at least contacts the outer and inner radial sides of the slots, a lower recess that forms a gap below each slot, at least one injection port connected to the lower recess, at least one discharge port connected to the lower gap, and a central insertion hole into which the end of the mandrel is inserted, to the lower end surface of the rotor core; a step of pressurizing the rotor core to which the upper and lower jigs are attached in the lamination direction; a step of injecting a treatment liquid for forming an insulating film from the injection port through the inside of the lower jig and filling the slots; a step of discharging the excess treatment liquid from the discharge port through the inside of the lower jig; a step of forming an insulating film by drying the treatment liquid by arranging the rotor core together with the mandrel in a drying furnace; and a step of performing die casting by arranging the rotor core together with the mandrel in a mold.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Figure 10

Figure 11

Embodiments for Carrying Out the Invention

[0008] Hereinafter, embodiments will be described with reference to the drawings. In this embodiment, a squirrel-cage induction motor is assumed as the rotating electrical machine. As shown in FIG. 1, the rotor 1 includes a rotor core 3 formed by laminating a plurality of core materials 2, a shaft member 6 inserted into a shaft hole 5 provided with a key groove 4, and conductors 8 filled in each slot 7 of the rotor core 3. Note that the shape, arrangement, and number of the slots 7 shown here are merely examples and are not limited thereto.

[0009] As is well known, the core material 2 is a thin plate formed by punching an electromagnetic steel sheet. Note that the core material 2 may be formed by punching a so-called self-fusing electromagnetic steel sheet coated with a fusion-type organic adhesive. The conductor 8 is formed integrally with short-circuit rings and cooling fins (not shown) on both axial end faces by melting and die-casting a metal material such as aluminum or copper.

[0010] As shown by partially enlarging the slot 7 of the rotor 1, an insulating film 9 is formed on the inner surface thereof. This insulating film 9 is formed by forming a film of a treatment liquid 10 (see FIG. 2) on the inner surface of the slot 7 and then drying it. As the treatment liquid 10, for example, although it is an example, a commercially available product obtained by diluting a titanium ceramics resin-based paint with a thinner can be appropriately selected and used. Note that the insulating film 9 is generally formed to have a thickness of about several μm.

[0011] Incidentally, in order to uniformly form the insulating film 9, it is necessary to uniformly adhere the treatment liquid 10 to the inner surface of the slot 7, that is, to uniformly form a film of the treatment liquid 10. However, if the treatment liquid 10 adheres to other parts than the inner surface of the slot 7 when filling the treatment liquid 10, operations such as wiping off the treatment liquid 10 and removing the cured insulating film 9 after drying are required, resulting in a decrease in work efficiency and an increase in the amount of the treatment liquid 10 used.

[0012] Therefore, in the present embodiment, in the manufacturing process of the rotor 1 shown in FIG. 2, the treatment liquid 10 is filled into the slot 7 using the treatment device 11 shown in FIG. 3. Note that FIG. 3 schematically shows a cross section of the rotor core 3 in the manufacturing process near the A-A line shown in FIG. 1 and the configuration of the treatment device 11 for injecting the treatment liquid 10. However, the configuration of the treatment device 11 is an example. Hereinafter, in FIG. 3, the stacking direction of the rotor core 3 in the vertical direction shown in the figure is referred to as the axial direction, and in a state where the rotor core 3 is arranged such that the axial direction is along the vertical direction, the upper end face is referred to as the upper end face 3a, and the lower end face is referred to as the lower end face 3b.

[0013] In this manufacturing process, first, the rotor core 3 is formed by laminating and fixing a predetermined number of core materials 2 to the mandrel 12 (S1). The mandrel 12 is a member for closing the shaft hole of the rotor core 3 during die casting, which will be described later. As shown in FIG. 4, the mandrel 12 is generally formed in a columnar shape as a whole, and a key 12a that protrudes outward and extends in the axial direction is provided on its outer peripheral surface. Therefore, in the process of forming the rotor core 3, a predetermined number of core materials 2 are laminated while aligning the key groove 4 of the core material 2 with the key 12a of the mandrel 12.

[0014] In the case of this embodiment, the key 12a of the core metal 12 is provided in a state where the circumferential position gradually shifts from one axial end side to the other end side. Therefore, when the core material 2 is laminated on the core metal 12, a rotor core 3 with so-called skew is formed. However, by using the core metal 12 provided with the key 12a in which the key 12a extends straight in the axial direction, a rotor core 3 without skew can also be formed. Therefore, in FIG. 3 and the like, since the manufacturing processes are common, a rotor core 3 without skew is shown.

[0015] Also, in the case of this embodiment, in the process of forming the rotor core 3, the core materials 2 that are about one to several sheets less than the standard number required to obtain the specified lamination thickness (H0) are laminated. That is, in this embodiment, the lamination thickness (H1) of the formed rotor core 3 is intentionally made shorter than the specified lamination thickness (H0). As a result, although details will be described later, the efficiency of the work of confirming and adjusting the lamination thickness after the formation of the insulating film 9 is improved.

[0016] After forming the rotor core 3, the upper jig 20 and the lower jig 30 are attached to the rotor core 3 (S2). As also shown in FIG. 5, the upper jig 20 is generally columnar with the same outer shape as the diameter of the rotor core 3, and the lower surface 21 on the rotor core 3 side is formed to be generally flat. The upper jig 20 is in a state of covering at least the outer side and the inner side in the radial direction of the slot 7, and is attached in a state where the lower surface 21 and the upper end surface 3a of the rotor core 3 are in close contact. The lower surface 21 of the upper jig 20 corresponds to the upper contact surface that contacts the upper end surface 3a of the rotor core 3.

[0017] Further, on the lower surface 21 of the upper jig 20, an upper groove portion 22 having the same width as the diameter of the slot 7 and recessed inward from the lower surface 21 is formed along the circumferential direction. When the upper jig 20 is attached to the rotor core 3, as shown in FIG. 3, this upper groove portion 22 forms a gap above the slot 7. Also, the upper groove portions 22 connect the gaps formed above the respective slots 7, and can store the surplus processing liquid 10 when the processing liquid 10 overflows from the slot 7. This upper groove portion 22 corresponds to the upper concave portion and the upper storage portion. Note that the width of the upper groove portion 22 may be appropriately set according to the shape and size of the slot 7.

[0018] Further, the upper jig 20 is provided with an air hole 24 that opens on the upper surface 23 on the side opposite to the contact surface of the rotor core 3 and penetrates the inside of the upper jig 20 and leads to the upper groove portion 22. This air hole 24 serves as a passage for air when filling the processing liquid 10 from the lower end side of the slot 7 as described later. Note that the number and arrangement of the air holes 24 are merely examples, and a plurality of air holes 24 may be provided, or air holes 24 that open at positions different from those in FIG. 5 may be provided. However, in the present embodiment, in order to reduce the possibility that the processing liquid 10 adheres to the side surface of the rotor core 3 or the like even if the processing liquid 10 leaks from the air hole 24, the air hole 24 that opens on the upper surface 23 is provided.

[0019] Also, a central through hole 25 for passing the core metal 12 is formed at the center of the upper jig 20 in the radial direction. Therefore, by applying pressure from the upper surface 23 side with the upper jig 20 attached to the rotor core 3, it becomes possible to apply pressure to the rotor core 3 in the axial direction.

[0020] On the other hand, as also shown in FIG. 6, the lower jig 30 has a substantially cylindrical shape with the same outer shape as the diameter of the rotor core 3, and the upper surface 31 on the rotor core 3 side is formed to be substantially flat. This lower jig 30 covers at least the outer side and the inner side in the radial direction of the slot 7, and is attached in a state where the upper surface 31 and the lower end surface 3b of the rotor core 3 are in close contact. The upper surface 31 of the lower jig 30 corresponds to the lower contact surface that contacts the lower end surface 3b of the rotor core 3.

[0021] On the upper surface 31 of the lower jig 30, a lower groove portion 32 having the same width as the diameter of the slot 7 and recessed inward from the upper surface 31 is formed along the circumferential direction. When the lower jig 30 is attached to the rotor core 3, this lower groove portion 32 forms a gap below the slot 7 as shown in FIG. 3. Further, the lower groove portions 32 connect the gaps formed below the respective slots 7, and can temporarily store the processing liquid 10 filled in the slots 7 and the processing liquid 10 discharged from the slots 7. This lower groove portion 32 corresponds to the lower concave portion and the lower storage portion. Also, by providing the lower groove portion 32, it becomes possible to evenly distribute the processing liquid 10 to each slot 7 during filling, and to prevent the processing liquid 10 from accumulating on the lower end side of the slot 7 during discharge. The width of the lower groove portion 32 may be appropriately set according to the shape and size of the slot 7 in the same manner as the upper groove portion 22.

[0022] Also, the lower jig 30 is provided with an injection port 34 and a discharge port 35 that open on the lower surface 33 on the side opposite to the contact surface of the rotor core 3, penetrate the inside of the lower jig 30, and lead to the lower groove portion 32. An injection pipe 40 shown in FIG. 3 is connected to this injection port 34, and a discharge pipe 41 is connected to the discharge port 35. Note that the number and arrangement of the injection port 34 and the discharge port 35 shown in FIG. 6 are merely examples, and a plurality of injection ports 34 or discharge ports 35 can be provided, or the number and size of the injection port 34 and the discharge port 35 can be made different, or the injection port 34 and the discharge port 35 can be provided at different positions. For example, by increasing the number of the discharge ports 35 compared to the injection port 34 or increasing the diameter of the discharge port 35 compared to the injection port 34, a configuration can be adopted in which the excess processing liquid 10 can be quickly discharged.

[0023] Further, in the lower jig 30, a central insertion hole 36 for inserting the core metal 12 is formed at the center of its upper surface 31. By inserting the lower end of the core metal 12 into this central insertion hole 36, the lower end surface 3b of the rotor core 3 and the upper surface 31 of the lower jig 30 are in contact with each other. Thereby, when the rotor core 3 is placed on the processing device 11, or when the rotor core 3 is pressed as described later, the rotor core 3 is supported by the lower jig 30.

[0024] Subsequently, as shown in FIG. 2, the rotor core 3 is placed on the processing device 11 (S3). As simply shown in FIG. 3, this processing device 11 includes a table 11a on which the lower jig 30 is placed, a pressing device 11b that presses the rotor core 3 in the axial direction together with the upper jig 20, and a support column 11c that connects them. A hole 11d for passing the injection pipe 40 and the discharge pipe 41 is formed in the table 11a, and the injection pipe 40 and the discharge pipe 41 connected to the lower jig 30 reach the tank 42 of the processing liquid 10 installed below the table 11a.

[0025] A pump 43 is provided in the injection pipe 40. By pumping up the processing liquid 10 in the tank 42 by this pump 43, it is possible to fill the processing liquid 10 into the slots 7 of the rotor core 3 via the inside of the lower jig 30 from the injection port 34. On the other hand, a valve 44 is provided in the discharge pipe 41. By closing the valve 44, it is possible to fill the processing liquid 10 into the slots 7, and by opening the valve 44, it is possible to discharge the excess processing liquid 10 and return it to the tank 42. Further, the stirrer 45 stirs the processing liquid 10 stored in the tank 42 so as to be in a state suitable for filling by rotationally driving the stirring blades located in the processing liquid 10.

[0026] By arranging the tank 42 below the rotor core 3 in this way and enabling the injection and discharge of the processing liquid 10 via the lower jig 30, the rotor core 3 and the tank 42 are arranged at approximately the shortest distance, so that the piping routes of the injection pipe 40 and the discharge pipe 41 can be shortened and the piping routes can be simplified. That is, the positional relationship between the rotor core 3 and the tank 42 in the processing apparatus 11 is very significant as equipment.

[0027] When the rotor core 3 is arranged, as shown in FIG. 2, the rotor core 3 is pressurized in the axial direction (S4). As a result, the laminated core materials 2 are in a state of being in close contact with each other, and it is possible to suppress the intrusion of the processing liquid 10 between the core materials 2. Subsequently, the pump 43 is operated to inject the processing liquid 10 via the inside of the lower jig 30 and fill each slot 7 with the processing liquid 10 (S5). At this time, by controlling the operation time and the number of operations of the pump 43, the amount of the processing liquid 10 to be injected and the flow rate of the processing liquid 10, that is, the speed at which the processing liquid 10 is injected, are controlled to inject an amount of the processing liquid 10 that can fill the inside of all the slots 7.

[0028] The amount that can fill the inside of all the slots 7 is the total amount of the processing liquid 10 required to fill up to the upper ends of the slots 7 of the rotor core 3 arranged along the vertical and horizontal directions. This total amount can be obtained, for example, by calculating based on the sum of the volumes of each slot 7 and the volume of the space in which the processing liquid 10 is stored in the lower jig 30, or by actually testing using the rotor 1. Then, when injecting the processing liquid 10, by controlling the operation of the pump 43 so as to be approximately consistent with the total amount, it is possible to prevent the excess processing liquid 10 from overflowing from the air hole 24.

[0029] Also, if the injection speed of the treatment liquid 10 is too fast, there is a possibility that the treatment liquid 10 will overflow from the air holes 24 before all the slots 7 are filled. Therefore, in this embodiment, an appropriate injection speed of the treatment liquid 10 is obtained in advance by calculation or testing, and the operation of the pump 43 is controlled so that the treatment liquid 10 is injected at that injection speed. Although it is also assumed that the filling may be uneven and the treatment liquid 10 may exceed the upper end in some of the slots 7, since the upper jig 20 covers the inner and outer radial directions of the slot 7, and also because the upper groove portion 22 is provided to enable the storage of the treatment liquid 10, it is possible to suppress the treatment liquid 10 from overflowing to the outside and adhering to other parts other than the slots 7.

[0030] When the filling of the treatment liquid 10 is completed, as shown in FIG. 2, the treatment liquid 10 is discharged to the tank 42 via the inside of the lower jig 30 (S6). At this time, the treatment liquid 10 is discharged by natural flow from the inside of the rotor core 3 by opening the valve 44 and returned to the tank 42. As a result, by discharging the treatment liquid 10 without applying a force other than gravity, it is possible to obtain a state in which the treatment liquid 10 adheres uniformly to the inner surface of the slot 7, that is, a state in which a film of the treatment liquid 10 is uniformly formed on the inner surface of the slot 7. Note that, after the filling of the treatment liquid 10 is completed, it may be a procedure to wait for a predetermined waiting time and then discharge the treatment liquid 10.

[0031] When the discharge of the treatment liquid 10 is completed, the rotor core 3 is removed from the processing device 11 (S7), the upper jig 20 and the lower jig 30 are removed (S8), and an eye bolt 46 (see FIG. 7) as a transfer jig is attached to the mandrel 12 (S9). This eye bolt 46 is attached to the center of the upper end of the mandrel 12, and by hooking a belt or a fitting of a transfer device (not shown), the rotor core 3 can be easily transferred in an upright state. Note that, if there is no interference with the processing device 11, the eye bolt 46 may be attached to the mandrel 12 in advance before laminating the core material 2 in step S1. Also, if a relief hole into which the eye bolt 46 can be inserted is provided in the die-casting mold 60 (see FIG. 9), it is not always necessary to remove the eye bolt 46.

[0032] Subsequently, as shown in FIG. 2, the rotor core 3 is placed in a drying furnace 50 (S10), and the insulating film 9 is formed by baking and drying (S11). At this time, as shown in FIG. 7, the rotor core 3 is placed in the drying furnace 50 together with the shaft core 12 in an upright state. Therefore, a mounting insertion hole 52 for inserting the lower end of the shaft core 12 is provided in the mounting table 51 for mounting the rotor core 3 disposed inside the drying furnace 50. Note that the configurations of the drying furnace 50 and the mounting table 51 shown in FIG. 7 are merely examples, and the number of rotor cores 3 that can be dried at one time and their arrangements are not limited thereto.

[0033] By drying the rotor core 3 in an upright state in this way, it is possible to suppress the occurrence of unevenness in the thickness of the film of the treatment liquid 10 during drying, and the insulation film 9 can be made uniform. In this embodiment, so-called baking and drying is performed, and the formation of the insulating film 9 and the annealing of the rotor core 3 are performed simultaneously. Also, preliminary drying can be performed before so-called main drying.

[0034] When the insulating film 9 is formed, the lamination thickness of the rotor core 3 is confirmed and adjusted as shown in FIG. 2 (S12). As described above, the rotor core 3 is formed by laminating the core materials 2 in a number that is about one to several less than the standard number for obtaining the specified lamination thickness (H0). The specified lamination thickness (H0) is a value determined to obtain a desired core density, and is the lamination thickness required for die casting.

[0035] This is because if the lamination thickness exceeds the specified lamination thickness (H0) after the insulating film 9 is formed, it is necessary to remove the core material 2. However, since the insulating film 9 is formed by curing the treatment liquid 10, the operation of removing the core material 2 after the formation of the insulating film 9 is very laborious. In other words, in this embodiment, in order to simplify the operations performed after the formation of the insulating film 9, the rotor core 3 is formed by laminating the core materials 2 in a number less than the standard number.

[0036] However, it is assumed that the laminated thickness (H10) of the rotor core 3 formed in this way is insufficient for the specified laminated thickness (H0) after the insulating film 9 is formed as shown in FIG. 8. Therefore, when the laminated thickness (H10) of the rotor core 3 is confirmed and found to be insufficient for the specified laminated thickness (H0), an iron core material 2 without the insulating film 9 is added and laminated so as to obtain the specified laminated thickness (H0).

[0037] In this case, since the iron core material 2 without the insulating film 9 is very small when viewed from the entire rotor core 3, it is considered that it will not have a great influence on the performance of the rotating electrical machine. In addition, the operation of adding and laminating the iron core material 2 can greatly improve the working efficiency because it is significantly easier than the operation of removing the iron core material 2 after the formation of the insulating film 9.

[0038] Note that an insulating film 9 can be formed on a single iron core material 2, and when the laminated thickness is insufficient, the iron core material 2 with the insulating film 9 formed thereon can be laminated. However, in the present embodiment, as a result of examining the performance difference between the case where the iron core material 2 provided with the insulating film 9 is added and the case where the iron core material 2 not provided with the insulating film 9 is added, and the amount of work for individually forming the insulating film 9 on the additional iron core material 2, the procedure of adding the iron core material 2 not provided with the insulating film 9 is adopted.

[0039] When the confirmation and adjustment of the laminated thickness are completed, the eye bolt 46 is removed as shown in FIG. 2 (S13), and the rotor core 3 together with the core bar 12 is placed in the die-casting mold 60 (S14). As shown in FIG. 9, the mold 60 has a space for accommodating the rotor core 3 inside, and is provided with a plate 61 that opens on the axial side of the rotor core 3. Hereinafter, for convenience, the left side in the drawing is referred to as the plate 61A, and the right side in the drawing is referred to as the plate 61B.

[0040] The plate 61A is provided with a cavity 62A which is a cavity for forming a short - circuit ring and cooling fins, a runner 63A which serves as a flow path for sending the melted conductor 8 into the cavity 62A, and a housing hole portion 64A for housing the left - hand end side (as shown in the figure) of the mandrel 12. Further, the plate 61A is provided with a partition wall 65A which contacts the lower end surface 3b of the rotor core 3 and partitions between the cavity 62A and the housing hole portion 64A.

[0041] On the other hand, the plate 61B is provided with a cavity 62B and a runner 63B having a symmetrical shape to the plate 61A, a housing hole portion 64B for housing the right - hand end side (as shown in the figure) of the mandrel 12, and a partition wall 65B which contacts the upper end surface 3a of the rotor core 3 and partitions between the cavity 62B and the housing hole portion 64B. Note that the configuration of the mold 60 shown in FIG. 9 is an example and is not limited thereto. For example, a configuration in which either one of the runner 63A or the runner 63B is provided may be used.

[0042] When the rotor core 3 is arranged in the mold 60, die - casting is performed as shown in FIG. 2 (S15). As a result, the conductor 8 is filled in the slot 7 to form a so - called conductor bar, and a short - circuit ring and cooling fins are integrally formed with the conductor bar at the axial end portions of the rotor core 3. Through such a process, the rotor 1 is manufactured.

[0043] According to the embodiment described above, the following effects can be obtained. The manufacturing method of the rotor 1 includes a step of laminating a plurality of core materials 2 using a mandrel 12 for closing the shaft hole of the rotor core 3 during die casting to form the rotor core 3; a step of attaching an upper jig 20 to the upper end surface 3a in a state where the axial direction of the rotor core 3 is arranged along the vertical direction; a step of attaching a lower jig 30 to the lower end surface 3b of the rotor core 3; a step of pressurizing the rotor core 3 to which the upper jig 20 and the lower jig 30 are attached in the lamination direction; a step of injecting a treatment liquid 10 for forming an insulating film 9 from an injection port 34 through the inside of the lower jig 30 and filling the slot 7; a step of discharging the excess treatment liquid 10 from a discharge port 35 through the inside of the lower jig 30; a step of arranging the rotor core 3 together with the mandrel 12 in a drying furnace 50 and drying the treatment liquid 10 to form the insulating film 9; and a step of arranging the rotor core 3 together with the mandrel 12 in a mold 60 and performing die casting.

[0044] By filling the treatment liquid 10 into the slot 7 through the inside of the lower jig 30 in this way, and also discharging the excess treatment liquid 10 through the inside of the lower jig 30, it is possible to reduce the risk of the treatment liquid 10 adhering to other parts than the inner surface of the slot 7. As a result, almost no treatment liquid 10 is wasted, and the operations of wiping off the treatment liquid 10 adhering to other parts or removing the dried and cured insulating film 9 together with the core material 2 are unnecessary or simplified.

[0045] Also, since the treatment liquid 10 can be discharged by natural flow while the rotor core 3 is arranged, a uniform film of the treatment liquid 10 can be formed as compared with the case where the rotor core 3 is tilted and discharged. Further, in the step of filling the treatment liquid 10, by filling the treatment liquid 10 while pressurizing the rotor core 3 in the lamination direction, it is possible to prevent the treatment liquid 10 from excessively entering the gaps between the core materials 2.

[0046] Therefore, the processing liquid 10 can be uniformly adhered to the inner surface of the slot 7, and it is possible to suppress a decrease in productivity and an increase in the amount of the processing liquid 10 used. Further, by returning the discharged processing liquid 10 to the tank 42 as it is, it is possible to prevent the equipment from being contaminated and simplify the cleaning work, and thus it has effective practicality in terms other than productivity.

[0047] In the method for manufacturing the rotor 1, in the step of forming the rotor core 3, the core materials 2 are laminated in a number smaller than the standard number for obtaining a specified lamination thickness, and the method further includes a step of adjusting the lamination thickness of the rotor core 3 after the step of forming the insulating film 9. It is difficult to remove the insulating film 9 with a thickness of about one layer from the rotor core 3 on which the insulating film 9 is formed, and there is also a risk of damaging the core material 2 to be left during the removal operation. On the other hand, by laminating a small number of core materials 2 in advance to form the rotor core 3, the removal operation can be eliminated or simplified, so that it is possible to suppress a decrease in productivity and easily adjust the lamination thickness of the rotor core 3.

[0048] In the method for manufacturing the rotor 1, in the step of adjusting the lamination thickness of the rotor core 3, when the lamination thickness has not reached the specified value, the core material 2 on which the insulation treatment is not formed is added to the slot 7 to adjust the lamination thickness. Since the number of core materials 2 to be additionally laminated is about one to several, it is very small when viewed from the entire rotor core 3 and does not significantly affect the performance of the rotating electrical machine. Further, the operation of adding the core material 2 is overwhelmingly easier than the operation of removing the insulating film 9 as described above, so that the lamination thickness of the rotor core 3 can be easily adjusted.

[0049] In the method for manufacturing the rotor 1, in the step of injecting the processing liquid 10, the processing liquid 10 in an amount capable of filling the inside of all the slots 7 is injected. Thereby, the possibility that the processing liquid 10 adheres to the upper end surface 3a of the rotor core 3 can be reduced, and the wiping operation or the like can be eliminated or simplified, so that a decrease in productivity can be suppressed.

[0050] In the method for manufacturing the rotor 1, the method further includes a step of attaching a transfer jig such as an eye bolt 46 to the core metal 12, and a step of removing the transfer jig before the die-casting step. In this case, the transfer jig can be attached at any time as long as it is before the die-casting step. Thereby, the transfer of the rotor core 3 to each work location can be facilitated.

[0051] The jig for slot insulation is attached to the upper end surface 3a of the rotor core 3 in a state where the axial direction of the rotor core 3 is arranged along the vertical direction. The upper jig 20 has an upper contact surface that at least contacts the outer and inner radial sides of the slot 7, an upper recess that forms a gap above each slot 7, at least one air hole 24 connected to the upper recess, and a central through hole 25 through which the end of the core metal 12 passes. The lower jig 30 is attached to the lower end surface 3b of the rotor core 3 and has a lower contact surface that at least contacts the outer and inner radial sides of the slot 7, a lower recess that forms a gap below each slot 7, at least one injection port 34 connected to the lower recess, at least one discharge port 35 connected to the lower gap, and a central insertion hole 36 into which the end of the core metal 12 is inserted.

[0052] By using such a jig for slot insulation, it becomes possible to fill the inside of the slot 7 with the treatment liquid 10 via the inside of the lower jig 30 and to discharge the excess treatment liquid 10 via the inside of the lower jig 30. It is possible to reduce the risk of the treatment liquid 10 adhering to other parts than the inner surface of the slot 7, and the same effect as the above-described manufacturing method can be obtained.

[0053] The jig for slot insulation further has an upper storage portion in which the upper jig 20 is formed above each slot 7, is connected to the upper recess, and can store the treatment liquid 10, and the air hole 24 is connected to the upper storage portion. Thereby, even when the treatment liquid 10 overflows from the slot 7, the risk of scattering from the air hole 24 can be reduced.

[0054] The jig for slot insulation further has a lower storage part where the lower jigs 30 are connected to their respective lower gaps and can store the processing liquid 10, and the injection port 34 and the discharge port 35 are connected to the lower storage part. Thus, by providing one injection port 34 and one discharge port 35, it is possible to fill and discharge the processing liquid 10 for all the slots 7.

[0055] By the way, as the jig for slot insulation, for example, as shown in FIG. 10, an upper jig 120 having a structure different from that of the embodiment can be used. This upper jig 120 is provided with a plurality of upper through holes 123 that have the same shape as each slot 7 when viewed from the axial direction and penetrate from the lower surface 121 to the upper surface 122 at positions corresponding to the slots 7 of the rotor core 3 around the central through hole 25. Although not shown, when attached to the upper end surface 3a of the rotor core 3, the upper through hole 123 functions as an upper recess that forms a gap above each slot 7 and an upper storage part that can store the excess processing liquid 10, and also functions as an air hole for discharging air.

[0056] By using such an upper jig 120, on the upper end surface 3a of the rotor core 3, since other parts other than the slots 7 are covered by contacting the upper jig 120, it is possible to prevent the processing liquid 10 from adhering to other parts. Therefore, the operation of wiping off the processing liquid 10 adhering to the upper end surface 3a is unnecessary or simplified, and it is possible to suppress a decrease in productivity.

[0057] Also, although not shown, a groove part connecting the respective upper through holes 123 can be provided on the upper surface side or inside of the upper jig 120. Also, it is possible to adopt a shape in which the diameter on the upper surface side is relatively small instead of a simple through hole. Even with such a configuration, it is possible to prevent the processing liquid 10 from adhering to other parts other than the slots 7 on the upper end surface 3a of the rotor core 3.

[0058] Alternatively, as a jig for slot insulation, for example, a lower jig 130 having a structure different from that of the embodiment can be used as shown in FIG. 11. On the upper surface 131 of the lower jig 130, at positions corresponding to the respective slots 7 of the rotor core 3, a plurality of lower communication holes 133 are formed which have the same shape as the respective slots 7 when viewed from the axial direction and communicate with an internal storage portion 132 formed inside the lower jig 130. Although not shown, the lower communication hole 133 corresponds to a lower recess that forms a gap above each slot 7 when attached to the lower end surface 3b of the rotor core 3, and the internal storage portion 132 corresponds to a lower storage portion capable of storing the processing liquid 10.

[0059] Further, an injection port 34 and a discharge port 35 connected to the internal storage portion 132 are provided on the lower surface 134 of the lower jig 130. By using such a lower jig 130, since other parts other than the slots 7 are covered in contact with the lower jig 130 on the lower end surface 3b of the rotor core 3, it is possible to prevent the processing liquid 10 from adhering to other parts. Note that the lower jig 130 may be integrally molded, or may have a structure that can be divided, for example, vertically as shown in the figure, in order to facilitate the formation of the internal storage portion 132.

[0060] In the embodiment, the configuration in which the upper jig 20 and the lower jig 30 are attached and then arranged in the processing apparatus 11 is illustrated, but the attachment of the upper jig 20, the attachment of the lower jig 30, and the arrangement in the processing apparatus 11 can be performed in any order. For example, the lower jig 30 can be fixed in advance at a predetermined position on the table 11a of the processing apparatus 11, and the core metal 12 of the rotor core 3 can be inserted into the central insertion hole 36 of the lower jig 30, so that the attachment of the lower jig 30 and the arrangement in the processing apparatus 11 can be performed simultaneously. In that case, the upper jig 20 may be attached after the rotor core 3 is arranged in the processing apparatus 11, or the rotor core 3 with the upper jig 20 attached may be arranged in the processing apparatus 11.

[0061] In the embodiment, an example was shown in which the core material 2 less than the standard number is laminated in order to make the lamination thickness (H1) of the rotor core 3 shorter than the specified lamination thickness (H0), but it is also possible to laminate the core material 2 of the standard number to form the rotor core 3. Although some embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

Explanation of Reference Numerals

[0062] In the drawings, 1 is a rotor, 2 is a core material, 3 is a rotor core, 3a is an upper end face, 3b is a lower end face, 5 is a shaft hole, 7 is a slot, 8 is a conductor, 9 is an insulating film, 10 is a treatment liquid, 11 is a treatment device, 12 is a core bar, 20 and 120 are upper jigs, 22 is an upper groove portion, 24 is an air hole, 25 is a central through hole, 30 and 130 are lower jigs, 32 is a lower groove portion, 34 is an injection port, 35 is a discharge port, 36 is a central insertion hole, 46 is an eyebolt, 60 is a mold, 123 is an upper through hole, 132 is an internal storage portion, and 133 is a lower communication hole.

Claims

1. A method for manufacturing a rotor in which an insulating film is formed on an inner surface of a slot of a rotor core, comprising: a step of laminating a plurality of core materials using a mandrel for closing an axial hole of the rotor core during die casting to form the rotor core; a step of attaching an upper jig having an upper contact surface that at least contacts the outer and inner radial sides of the slot, an upper recess that forms a gap above each of the slots, at least one air hole connected to the upper recess, and a central through hole through which an end portion of the mandrel penetrates, to an upper end surface in a state where the axial direction of the rotor core is arranged along the vertical direction; a step of attaching a lower jig having a lower contact surface that at least contacts the outer and inner radial sides of the slot, a lower recess that forms a gap below each of the slots, at least one injection port connected to the lower recess, at least one discharge port connected to the lower gap, and a central insertion hole into which an end portion of the mandrel is inserted, to a lower end surface of the rotor core; a step of pressurizing the rotor core to which the upper jig and the lower jig are attached in the stacking direction; a step of injecting a treatment liquid for forming the insulating film from the injection port through the inside of the lower jig and filling the slot; a step of discharging excess treatment liquid from the discharge port through the inside of the lower jig; a step of arranging the rotor core together with the mandrel in a drying furnace and forming the insulating film by drying the treatment liquid; a step of arranging the rotor core together with the mandrel in a mold and performing die casting; A method for manufacturing a rotor including the above steps.

2. In the step of forming the rotor core, the core materials are laminated in a number less than a standard number for obtaining a specified lamination thickness, The method for manufacturing a rotor according to claim 1, further comprising a step of adjusting a lamination thickness of the rotor core after the step of forming the insulating film.

3. In the step of adjusting the lamination thickness of the rotor core, when the specified lamination thickness has not been reached, the core material in which the insulating treatment has not been formed in the slot is added to adjust the lamination thickness. The method for manufacturing a rotor according to claim 2.

4. In the step of filling the treatment liquid, an amount of the treatment liquid capable of filling the inside of all the slots is injected. The method for manufacturing a rotor according to claim 1.

5. A step of attaching a transfer jig to the mandrel A step of removing the transfer jig before the die-casting step, The method for manufacturing a rotor according to claim 1, further comprising

6. A jig for slot insulation that forms an insulating film on the inner surface of the slots of the rotor core, It is attached to the upper end surface of the rotor core in a state where the axial direction of the rotor core is arranged along the vertical direction, and has an upper contact surface that contacts at least the radially outer and inner sides of the slot, an upper recess that forms a gap above each of the slots, at least one air hole connected to the upper recess, and a central through hole through which the end of the core metal passes, an upper jig having It is attached to the lower end surface of the rotor core, and has a lower contact surface that contacts at least the radially outer and inner sides of the slot, a lower recess that forms a gap below each of the slots, at least one injection port connected to the lower recess, at least one discharge port connected to the lower gap, and a central insertion hole into which the end of the core metal is inserted, a lower jig having A jig for slot insulation comprising

7. The upper jig further has an upper storage portion that is formed above each of the slots, is connected to the upper recess, and can store the treatment liquid, The air hole is connected to the upper storage portion. The jig for slot insulation according to claim 6.

8. The lower jig further has a lower storage portion that is connected to each of the lower gaps and can store the treatment liquid, The injection port and the discharge port are connected to the lower storage portion. The jig for slot insulation according to claim 6 or 7.

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