JPH0670461U - Small electric motor - Google Patents

Abstract

(57) [Abstract] [Purpose] An object of the present invention is to provide a small-sized electric motor that uses a ball bearing to easily and accurately position the ball bearing, and at a low cost. [Structure] The ball bearing 3 is positioned by forming a ring-shaped raised portion 4a on the straight shaft 4 by pressurization, so that the ball bearing 3 can be positioned accurately and easily at a very low cost.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a small electric motor using a ball bearing used for industrial purposes such as home appliances.

[0002]

[Prior art]

 Conventionally, small electric motors that use ball bearings are generally regarded as important as long-life electric motors and are used in large numbers.

Hereinafter, a small electric motor (hereinafter referred to as an electric motor) using the conventional ball bearing described above will be described with reference to the drawings.

FIG. 4 is a sectional view of a finished rotor of an electric motor using a conventional stepped shaft and a ball bearing, and FIG. 5 is a sectional view of a finished rotor of an electric motor using a conventional straight shaft and a ball bearing. FIG. 6 is a detailed view of the retaining ring insertion portion of the straight shaft of FIG.

In FIG. 4, 6 is a stepped shaft to which the rotor 2 is fixed. A ball bearing 3 supports a stepped shaft 6. The ball bearing 3 is positioned by the shaft step portion 6a of the stepped shaft 6.

Further, in FIGS. 5 and 6, 7 is a straight shaft to which the rotor 2 is fixed. 3 is a ball bearing which supports the straight shaft 7. The ball bearing 3 is positioned by a retaining ring 8 inserted in the groove 7a of the straight shaft 7.

[0007]

[Problems to be solved by the device]

 However, in the structure as shown in FIG. 4, a shaft material having a large diameter must be used in order to form the shaft step portion 6a for positioning the ball bearing 3 on the stepped shaft 6. Further, even in the cutting process, since the shaft step portion 6a is provided, a long processing time is required. Furthermore, materials and processing costs were high, as grinding (through centerless polishing) was not possible through grinding.

In the configuration shown in FIG. 5, the shaft 7 is grooved to position the ball bearing 3 because it is a straight shaft, and the retaining ring 8 must be inserted into the groove 7a. The cost and the insertion cost were expensive.

As described above, there is a problem in that the cost is very high in the ball bearings in which the retaining ring is inserted in the stepped shaft or the straight shaft for positioning.

In view of the above problems, it is an object of the present invention to provide an inexpensive electric motor that can easily position a ball bearing.

[0011]

[Means for Solving the Problems]

 In order to achieve this object, the electric motor of the present invention has a structure in which a ring-shaped raised portion due to pressure is attached on the circumference of a straight shaft.

[0012]

[Action]

 With this configuration, the ball bearing can be easily positioned.

[0013]

【Example】

 An electric motor using a ball bearing according to an embodiment of the present invention will be described below with reference to the drawings.

1, 2 and 3 show a shaft in one embodiment of the present invention. In the drawings, 1 is a stator core of an electric motor, 2 is a rotor, and a straight shaft having the same diameter over the entire length. It is fixed to 4. 3 is a ball bearing that supports the shaft 4. A ring-shaped raised portion 4a is formed on the shaft 4 by pressurization to position the ball bearing 3.

Since the ring-shaped raised portion 4a is processed by the pressure roller, the ball bearing can be positioned with high precision by very simple processing.

As described above, according to the present embodiment, the ball bearing 3 can be accurately positioned by forming the ring-shaped raised portion 4a by pressing on the straight shaft 4.

[0017]

[Effect of device]

 As described above, the present invention forms a ring-shaped raised portion by pressurization on the circumference of a shaft without using expensive parts such as a stepped shaft and a snap ring, thereby positioning the ball bearing. Can be performed easily and accurately, and an inexpensive electric motor can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of an electric motor using a ball bearing according to an embodiment of the present invention.

FIG. 2 is a partially enlarged view of a positioning portion of the ball bearing shown in FIG.

FIG. 3 is a sectional view showing a ring-shaped raised portion for positioning a ball bearing before the ball bearing of FIG. 2 is inserted.

FIG. 4 is a sectional view of a finished rotor of an electric motor using a conventional stepped shaft and a ball bearing.

[Fig. 5] Cross-sectional view of a finished rotor of an electric motor using a conventional straight shaft and a ball bearing.

6 is a detailed view of the snap ring insertion portion of the straight shaft of FIG.

[Explanation of symbols]

 2 Rotor 3 Ball bearing 4 Shaft 4a Raised part

Claims (1)

[Scope of utility model registration request] 1. A shaft having a rotor fixed thereto and a ball bearing for supporting the shaft, wherein a ring-shaped bulge portion is formed on the shaft, and the bulge portion and the ball bearing are brought into contact with each other. A characteristic small electric motor.