JPS58112442A - Manufacture of rotor - Google Patents

Abstract

PURPOSE:To prevent the slot of a rotor core from displacing due to its skew by caulking both axial ends of the skewed and laminated core. CONSTITUTION:A rotor core 1 is set to a skew forming unit, and is skewed. The parts which correspond to projections to be caulked on the upper and lower axial surfaces of the core 1 are caulked, thereby forming caulked recesses 8 and 9. Thereafter, a conductor 10 and end rings 11, 12 are cast at the core 1, and after the casting, the outer periphery of the core 1 is finished by cutting, thereby completing the manufacture of an aluminum cast rotor 14. Since the casting is performed after this caulking, the slot 2 is prevented from being skewed.

Description

TECHNICAL FIELD OF THE INVENTION The present invention relates to a method of manufacturing a rotor having slots for forming a skew.

TECHNICAL BACKGROUND OF THE INVENTION Conventionally, when manufacturing, for example, a cast aluminum rotor for an induction motor (1), a rotor core is constructed by laminating a large number of silicon steel plates, and a slot pitch of one slot is formed in the rotor core. After unskewing by twisting the rotor core, the low rotation shaft is press-fitted into the shaft hole in the center of the rotor core, and the rotor core is set in a casting mold to form the slots of the rotor core and the rotor. A conductor and an end ring are each cast from aluminum on both axial end faces of the iron core, and the low rotation shaft is removed from the shaft hole of the rotor core after casting, and the original rotation shaft is press-fitted into the shaft hole.
After that, finishing cutting is performed on the outer peripheral portion of the rotor core.

Problems in the technical background The low rotation shaft inserted into the shaft hole of the rotor core is used for handling purposes such as transferring the rotor core to the conveyor and setting it in the casting mold, and is pulled out from the shaft hole after casting. Therefore, it is temporarily press-fitted into the shaft hole of the rotor core, which is different from the strong press-fitted track like the original rotating shaft. If some kind of impact is applied, the silicon steel plates, especially near both ends, tend to shift relative to the low-rotation shaft, which may cause a shift in the skew of the slot. There was a problem that warping occurred in the slot portion of the silicon steel plate that was misaligned when finishing cutting was performed, resulting in a defective product.

Purpose of the Invention The present invention has been made in view of the above circumstances, and its purpose is to provide a rotor manufacturing method that can reliably prevent skew deviation of slots in a rotor core and eliminate the occurrence of defective products. It is in.

Summary of the Invention The present invention constructs a rotor core by laminating a large number of steel plates so as to form slots for forming skew, and caulks both axial end faces of the rotor core. The caulking recess prevents the system slot from becoming skewed.

Embodiment of the Invention An embodiment of the invention will be described below with reference to FIGS. 1 to 5.

Reference numeral 1 denotes a rotor core, which is constructed by laminating a large number of silicon steel plates with a thickness of 0, s s m, and has a large number of closed slots 2 formed in the outer periphery so as to extend in the axial direction. Moreover, some of these slots 2 are formed in an open shape to serve as slots 2a for forming a skew. Then, this rotor core 1 is set in a skew forming device (not shown), and the skew is removed by twisting the slot 2a by one slot pitch so that the skew forming slot 2a is not parallel to the axial direction. skew will be applied. Thereafter, a low rotation shaft 6 is press-fitted into the shaft hole 1a at the center of the rotor core 1. 4 is a lower jig for caulking, which has a short cylindrical shape with a bottom, and has an insertion hole 4a formed in the center of the bottom wall, and holes equally spaced around the soil surface of the bottom wall. A plurality of, for example, three caulking protrusions 5 are provided to protrude upward. Reference numeral 6 denotes an upper jig for caulking, which is disk-shaped and has an insertion hole 6a formed in its center, and a fitting wall 6b protruding downward around the lower surface. There is. Furthermore, a plurality of, for example, three, caulking protrusions 7 are provided on the periphery of the lower surface of the upper caulking jig 6 at equal intervals so as to protrude downward. Then, the rotor core 1 is fitted into the lower caulking jig 4 while inserting the lower end of the low rotation shaft 3 into the insertion hole 4a thereof, and the lower surface of the rotor core 1 is placed on the caulking protrusion 5. After that, the insertion hole 6a of the upper caulking jig 6 is fitted to the upper end of the low rotation shaft 3, and the fitting wall 6) is inserted into the rotor core 1.
When the upper caulking jig 6 is lowered under a predetermined pressure, the portions of the lower and upper surfaces of the rotor core 1 corresponding to the caulking protrusions 5 and 7, respectively, are fitted onto the outer circumference of the rotor core 1 and then lowered with a predetermined pressure. The four caulking parts 8 and 9 having a depth of about 1M, for example, are formed in the respective portions.

Thereafter, the rotor core 1 is set in a casting mold (not shown), molten aluminum is injected, and the conductors 10 are cast into the slots 2゜2a, as well as around the lower and upper surfaces of both axial ends of the rotor core 1. End rings 11 and 12 that short-circuit both ends of the conductor 10 are cast. In this case, the caulking recesses 8 and (5) 9 are positioned so that they are formed at the positions where the end rings 11 and 12 on the lower and upper surfaces of the rotor core 1 are cast, respectively. These caulking recesses 8 and 9 are hidden by end rings 11 and 12. Thereafter, the rotor core 1 is taken out from the casting mold, the low rotation shaft 5 is pulled out from the shaft hole 1a, and the original rotation shaft 13 is press-fitted into the shaft hole 1a, and then the outer peripheral portion of the rotor core 1 is is subjected to finishing cutting, thereby completing the manufacture of the cast aluminum rotor 14. In this case, all of the slots 2 of the rotor core 1 have the closed base portions of their outer peripheries removed by the above-mentioned finishing cutting process, so that they become open like the slots 2a.

According to this embodiment, caulking is performed on the lower and upper surfaces of the skewed and stacked rotor core 1 to form the four caulked parts 8 and 9, and after the machining, the rotor cores 1 are cast in a casting mold. Therefore, after press-fitting the low-rotation shaft 5 into the rotor core 1 and until the setting of the rotor core 1 into the casting mold is completed, it is possible that the slots 2 will be skewed (A"+) especially in the vicinity of both ends in the axial direction. Therefore, when finishing cutting is performed on the outer circumference of the rotor core 1 after casting, the silicon steel plate does not warp, which prevents the production of defective products and improves yield. , it is also possible to reduce costs.

Further, according to this embodiment, since the caulking position of the rotor core 1 is set at the casting position of the end ring 11, 12, the caulking recess 8, formed by the caulking process,
9 is hidden by the end rings 11 and 12, so that the appearance of the cast aluminum rotor 14 is not impaired.

In the above embodiment, the caulking position of the rotor core 1 is set at the casting position of the end ring 11, 12, but if there is no need to place particular importance on the appearance, for example, the caulking position of the rotor core 1 as shown in FIG. 6 may be used. As in other embodiments of the invention, the caulking recesses 15 may be formed by temporarily rotating both end faces of the rotor core 1 in the axial direction. It may be set at any position, and the number of caulking locations can be set as appropriate.

In addition, the present invention is not limited only to the embodiments described above and shown in the drawings, and it goes without saying that the present invention can be implemented with appropriate modifications within the scope of the invention.

Effects of the Invention As explained above, in the present invention, since the skewed and laminated rotor core is caulked on both end faces in the axial direction and then cast, it is possible to reliably prevent the slots from being skewed. This has excellent effects such as eliminating the occurrence of defective products, simplifying the inspection for warpage of steel plates due to skew deviation, improving yields, and reducing costs.

[Brief explanation of drawings]

1 to 5 show an embodiment of the present invention, FIG. 1 is a perspective view of the rotor core before skewing, and FIG. 2 is a perspective view of the rotor core after skewing. Figure 6 is a vertical cross-sectional view of the spool for explaining the caulking process, and Figure 4 is an enlarged vertical cross-sectional view of the caulking recessed portion. FIG. 5 is a longitudinal sectional view of the cast aluminum rotor after manufacturing is completed, and FIG. 6 is a view corresponding to FIG. 2 showing another embodiment of the present invention. In the drawing, -1 is the rotor core, 2 and 2a are the slots, and 4
Lower jig for caulking, 5 is protrusion for caulking, 6 is upper jig for caulking, 7 is protrusion for caulking, 8 and 9 are caulking recesses, 10
11 and 12 are end rings, 14 is a cast aluminum rotor, and 15 is a caulking four parts. Applicant Tokyo Shibaura Electric Co., Ltd. Figure 1

Claims (1)

[Claims] 1. After skewing and stacking a large number of steel plates to form a rotor core, caulking both axial end faces of the rotor core, conductors and A method for manufacturing a rotor, comprising the steps of: casting an end ring; and finishing cutting the outer periphery of the rotor core after casting. 2. The method for manufacturing a rotor according to claim 1, wherein caulking is performed at the end ring casting position in the rotor core.