JPS6041541B2 - Manufacturing method of commutator for rotating electrical machines - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method of manufacturing a commutator for a rotating electric machine.

Generally, as shown in Fig. 1, a commutator piece 1 has a substantially trapezoidal shape when viewed from all axial directions and has an outer diameter larger than the finished outer diameter of the commutator, and the outer surface of the commutator piece 1 is insulated. Insulators 3 made of mica or the like are arranged and fixed alternately in the circumferential direction on top of the commutator body 2, which is then machined to a predetermined finished outer diameter shown by the broken line. The corners 4 on both sides are finished by chamfering.

Chamfering is an indispensable process to prevent flashover caused by so-called copper dragging. However, the chamfering work performed on each commutator piece of the assembled commutator requires a great deal of man-hours and requires a fairly high level of skill. The object of the present invention is to provide a method for manufacturing a commutator that eliminates these drawbacks.

In order to achieve this object, the present invention uses a commutator piece with a large seat in which a taper corresponding to the chamfered shape after assembly is formed in advance on the commutator piece before assembly, so that chamfering work after assembly can be omitted. , and furthermore,
By filling the space between each commutator piece with a heat-releasable filler in advance, it is possible to omit the burr removal work after cutting the outer lining.This will be explained below with reference to the drawings. According to the present invention, as shown in FIG. 2a, the commutator is finished with tapers 5 formed as commutator pieces from both circumferential end corners of the outer periphery toward the center outside, corresponding to the chamfered shape at the time of finishing. A commutator piece 6 having an outer diameter larger than the outer diameter is used.

This commutator piece 6 can of course be made by cutting, but it is convenient to make it by drawing using a die. A commutator is formed by arranging and fixing commutator pieces 6 alternately with insulators 8 between commutator pieces in the circumferential direction on a commutator body 7 whose outer surface is insulated. By cutting each commutator piece 6 to the finished outer diameter shown by the broken line in FIG. 2a, the commutator 10 is chamfered as shown in FIG. 2b without having to be chamfered again. can be obtained. Note that if the material of the commutator piece is hard, the manufacturing method explained with reference to Fig. 2 a and b is sufficient, but if the commutator piece is made of a relatively soft material, cutting the outer diameter is necessary. Sometimes unnecessary protrusions, so-called burrs, protruding in the cutting direction may occur to some extent.

To prevent this, you can do the following. That is, as shown in FIG. 3a, thermal exfoliation occurs in the approximately trapezoidal space formed between the inter-commutator piece insulator 8 placed and fixed on the commutator body 7 and the commutator pieces on both sides thereof. After filling and solidifying the filler 9, the gap between the commutator pieces on the insulator 8 is cut as shown in FIG. A commutator semi-finished product 11 filled with the filler 9 is obtained. In this case, the presence of the filler 9 prevents burrs from forming on the outer cut portion of the commutator piece 6. Thereafter, a heat treatment is applied to peel off the filling 9 from the semi-finished product 11, thereby completing a commutator as shown in FIG. 2b. As described above, according to the present invention, since a large-diameter commutator piece material with a taper formed to correspond to the chamfered shape is used, it is extremely complicated and requires a high level of skill to assemble the commutator, which is required in the secondary structure. It is possible to omit chamfering work, and therefore, a high quality commutator can be provided at a lower cost.

In addition, by filling the space between the commutator pieces with a thermally releasable filler before cutting the outer diameter, it is possible to eliminate burrs that tend to occur during cutting, especially when commutator pieces are made of soft materials. The deburring work can be omitted, and the filling work can be easily peeled off, thereby improving product quality and work efficiency. In addition, by filling the space between the commutator pieces with a releasable filler before the cutting process, it is possible to avoid the inconvenience of varnish filling the commutator pieces when applying varnish treatment to the commutator. can.

[Brief explanation of drawings]

FIG. 1 is an explanatory diagram of a method for manufacturing a subordinate column, FIGS. 2 a and b are explanatory diagrams of an example of the manufacturing method according to the present invention, and FIGS. 3 a and b are explanatory diagrams of another example of the manufacturing method according to the present invention. It is. 5... Napper, 6... Commutator piece, 7.
... Commutator feeder, 8 ... Insulator between commutator pieces, 9
...Thermal releasable filling, 10... Commutator. Multi 1 drawing multi 2 drawing multi 3 boxes

Claims (1)

[Claims] 1 A commutator body with an insulated outer surface is made up of a plurality of commutator pieces each having an outer diameter larger than the finished commutator outer diameter, with tapers corresponding to the finished chamfered shape formed at both circumferential end corners of the outer periphery. A commutator is formed by arranging and fixing each other in the circumferential direction through an insulator between the commutator pieces, and cutting the outer circumferential surface of this commutator to a predetermined finished outer diameter dimension. A method of manufacturing a commutator for rotating electric machines.