JPH02294241A - Rotating shaft of electric rotating machine - Google Patents

Abstract

PURPOSE:To fit bearings without lowering mechanical strength by knurling the core-fitting part of a rotating shaft for fitting a rotor core and by fitting said bearings in the manner of bringing said bearings into contact with both end stepped parts of said knurled part. CONSTITUTION:A knurl works the core-fitting part of a rotating shaft 11 for fitting a rotor core 2 over the inside end faces of a pair of bearings 3. The outside diameter of a knurled part is made about 0.1-0.2mm larger than the rotating shaft 11 before knurling so that stepped parts 11a are produced at both ends. Said bearings 3 bring inner ring end faces into contact with said stepped parts 11a to determine axial position and are fitted by press fit. When a fit pressure between said core 2 and rotating shaft 21 is sufficiently large, said knurl can also make a divided work by omitting the inner periphery central part of said core 2. Thus, it is possible to position and fit said bearings by a simple structure without lowering mechanical strength.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a rotating shaft of a rotating electric machine in which a bearing can be fitted without reducing mechanical strength.

[Conventional technology]

A conventional example of a rotating shaft of a rotating electrical machine will be explained based on FIG. In this figure, a cylindrical rotor core 2 is fitted into a knurled core fitting portion of a rotating shaft 1 by press fitting, etc., and a bearing 3 is fitted into an annular groove 1a of the rotating shaft 1, for example, with a C-shaped stopper. The end face of the inner ring is brought into contact with a positioning member 4 such as a ring, and the inner ring is fitted by press-fitting or the like.

[Problem to be solved by the invention]

The above structure not only requires a lot of work to process the annular groove 1a and attach the positioning member 4 to the groove 1a, but also has the disadvantage that the groove 1a reduces the mechanical strength of the rotating shaft l.

(d) In order to eliminate the above-mentioned drawbacks, this invention provides a rotating shaft of a rotating electrical machine that allows a bearing to be fitted in a simple structure without reducing mechanical strength. for the purpose of serving.

[Means to solve the problem]

In order to achieve the above-mentioned object, this invention has a rotor core 2
A knurling is machined on the iron core fitting portion of the rotating shaft l1 to which the bearing 3 is fitted, and the bearing 3 is fitted by abutting against stepped portions 11a at both ends of the knurling portion.

[Effect]

The outer diameter of the row left part is the rotation axis 1 before knurling.
Since it is about 0.1=0.2 mm larger than l, stepped portions 11a are formed at both ends, and the axial position of the bearing 3 can be determined by abutting against the stepped portions 11a. Further, since the annular groove 1a described in the conventional example is not required, it is possible to prevent a decrease in mechanical strength due to the groove 1a.

〔Example〕

FIG. 1 shows an embodiment of the present invention, and the same parts as in FIG. 3 are denoted by the same reference numerals. In this figure, a knurling is machined over the inner end surfaces of the pair of bearings 3 at the core fitting portion of the rotating shaft 11 into which the rotor core 2 is fitted. Since the outer diameter of the knurled portion is approximately 0.1 to 0.2w larger than the rotating shaft 11 before knurling, stepped portions 11a are formed at both ends. The bearing 3 is fitted by a press-fit cap after its axial position is determined by bringing the inner ring end surface into contact with the stepped portion 11a. If the fitting pressure between the iron core 2 and the rotary shaft 21 is sufficiently large, the knurling can be divided into parts by omitting the central part of the inner circumference of the iron core 2, as shown in FIG.

According to the embodiment, since the annular groove 1a described in the conventional example is not required, it is possible not only to prevent a decrease in mechanical strength due to the groove 1a, but also to reduce the number of required parts by the positioning member 4, resulting in lower cost. becomes.

〔Effect of the invention〕

According to this invention, in the rotating shaft of a rotating electric machine, a knurling is machined on the rotor core fitting part, and the bearing is fitted by making contact with the stepped parts at both ends of this knurling part, which is different from the conventional example. This provides the effect that the bearing can be positioned and fitted with a simple structure without reducing mechanical strength like the annular groove described above.

[Brief explanation of drawings]

FIG. 1 is a longitudinal sectional view of an embodiment of the present invention, FIG. 2 is a longitudinal sectional view of another embodiment of the invention, and FIG. 3 is a longitudinal sectional view of a conventional example.

Claims (1)

[Claims] 1) A rotating electric machine characterized in that a core fitting portion of a rotating shaft into which a cylindrical rotor core is fitted is knurled, and a bearing is fitted by making contact with stepped portions at both ends of the knurling portion. axis of rotation.