JPS5826549A - Manufacture of rotor used on motor - Google Patents

Abstract

PURPOSE:To form the protrusion of the rotor shaft on the titled rotor into uniform length by a method wherein, when the main body of the rotor and one end of the rotor shaft are coupled using a die-casting molding method, an inclined surface is formed at one end of the rotor shaft, and an extrusion force is utilized when the molding is performed. CONSTITUTION:When a rotor core and the rotor shaft 8 are coupled in one body together with the rotor main body by performing die-casting molding, an inclined surface 16 facing toward the direction of axial center is formed at one end of the rotor shaft. As a result, extruding force works on the rotor shaft 8 in the direction as shown by the arrow C when the die-casting molding is performed, and this allows the other end 8b of the rotor shaft 8 to be tightly fixed to the bottom face of an inserting hole 15a, thereby enabling to form the protrusion of the rotor shaft 8 after molding into uniform length.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a motor rotor in which one end of the rotor shaft is integrally connected to a rotor body manufactured by die-casting. An object of the present invention is to provide a method for manufacturing a rotor of a motor, which allows the protrusion amount of the other end of the rotor shaft to be manufactured without variation.

An embodiment of the present invention will be described below with reference to FIGS. 1 and 2. Reference numeral 1 denotes a sheet metal frame that holds a stator core 2 on its inner periphery and has a shaft cylindrical portion 3 formed in its center. An annular oil wick 5 is disposed in contact with the outer periphery.

Reference numeral 6 denotes a rotor body formed by aluminum die-casting as described later, in which the rotor, iron core 7, and one end portion 8a of the rotor shaft 8 are integrally held. The rotor main body 6 has the other end 8b of the rotor shaft 8 rotatably supported by the bearing member 4, and is supported in a manner that prevents it from coming off by a washer 9 and a stop ring 10 fitted in the annular groove 80. ing. Reference numeral 11 denotes a cover plate fixedly fixed to the center of the frame 1 via an O-ring 12, and a cover plate 11a attached to the center of the inner surface of the cover plate 11 is attached to the end surface of the rotor shaft 8 on the other end 8b side. They are in contact with each other to absorb the thrust load of the rotor shaft 8.

Now, FIG. 2 shows a mold for molding the rotor main body 6, and 13 and 14 are a pair of molds, with insertion holes 15 and 15 in the mold 14.
A temporary shaft 15 having a diameter of 1.a is fitted, and the rotor shaft 8 is held in the mold 14 by inserting the other end 8b into the insertion hole 15a in advance during molding.

On the other hand, reference numeral 16 denotes a hemispherical surface portion as an inclined surface formed at one end of the rotor shaft 8, which exhibits an inclined state with respect to the fineness of the rotor shaft 8.

When the rotor core 7 and the rotor shaft 8 are held in the molds 13 and 14 in advance and molten aluminum material is pumped through the sprue 17, molds 13 and 14 are formed as shown by arrow A in FIG. flow inside.

At this time, the rotor shaft 8 receives a pressing force shown by the arrow B due to the pouring metal flow flowing in the direction of the arrow along the surface of the hemispherical part 16, and part of this pressing force B is directed toward the other end 8b of the rotor shaft 8. Receives an extrusion force by component force C, which causes rotor shaft 8
The other end 8b is in close contact with the bottom surface of the insertion hole 15a. Therefore, the protrusion length D of the rotor shaft 8 from the rotor body 6 does not vary (is constant), and manufacturing errors are minimized.

By the way, since one end of the rotor shaft 8 conventionally had a planar shape without the hemispherical surface portion 16, the rotor shaft 8 received a pushing force toward the other end 8b due to the pouring metal flow flowing in the direction of the arrow. This may cause the protruding length D of the rotor shaft 8 to vary, causing the center positions of the rotor core 7 and stator core 2 to shift, resulting in increased operating noise or the rotor body 6 hitting the frame 1. However, according to the present invention, as described above, the protruding length of the rotor shaft can be manufactured to a constant value without variation, so that operational noise can be reduced and assembly can be easily performed.

Incidentally, even if a conical inclined surface 18 as shown in FIG. 3 is provided at one end of the rotor shaft 8 instead of the hemispherical surface portion 16, a pushing force acts on the rotor shaft 8 in the same manner as described above. The protrusion length becomes constant without variation.

[Brief explanation of the drawing]

1 and 2 show one embodiment of the present invention, FIG. 1 is a longitudinal cross-sectional view, FIG. 2 is a longitudinal cross-sectional view showing a rotor mold, and FIG. 3 is a cross-sectional view of the rotor mold. FIG. 3 is a vertical cross-sectional view of the main part of another embodiment of the invention. In the drawing, 1 is a frame, 6 is a rotor body, 7 is a rotor core, 8 is a rotor shaft, 13, 14 is a mold, and 16 is a hemispherical part (
18 is an inclined surface. Applicant: Tokyo Shibaura Electric Co., Ltd. 5- Figure 1

Claims (1)

[Claims] 1. In order to integrally connect the iron core and one end of the rotor shaft to the rotor body by die-casting, the pouring metal flow during die-casting is applied to the inclined surface to form other parts on the rotor shaft. A method for manufacturing a rotor of a motor, characterized in that an extrusion force is applied in the direction of an end.