JPS60102834A - Motor - Google Patents

Abstract

PURPOSE:To effectively position a bearing and to enable to readily machine in high accuracy by forming a projection by calking a shaft and hence forming a hole by a projecting article, and uniforming arranged the projections on the outer periphery of the shaft. CONSTITUTION:Small irregular surfaces are formed by calking on both sides of a rotor 2 in the circumferential direction of a shaft 1. A bearing 4 made of a ball bearing is press-fitted by the end of the shaft to the outside of the irregular surface 3. The bearing 4 is press-fitted to the shaft 1, and positioned by pressure contacting with the outside of the irregular surface 3. The irregular surface 3 of the shaft 1 is formed by strongly pressing a projecting article axially, a hole 5 is formed at the center, plastically deformed by the formation of the hole 5 to project a projection 6 around the hole 5. When the bearing 4 is press-fitted to the shaft 1, the press-fitted bearing 4 collides with the projection 6 to be positioned.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a structure of an electric motor that is easy to manufacture and has less shaft runout.

The shaft of the electric motor has a bearing in addition to the rotor, and is connected to a negative shaft.

In this case, there is no problem in press-fitting the rotor, but providing the first bridge at a predetermined position requires machining and forming a step on the shaft for positioning, which is time-consuming and time-consuming. , advanced processing techniques were used.

Conventionally, in order to position the bearing on the shaft, a step was formed by cutting, a collar was inserted between the rotor and the bearing, and a circumferential groove was formed on the rotor side of the bearing to form a ring. Measures were taken such as wearing a

Machining such shafts is not only time consuming and time-consuming, but also requires changing machine settings each time the bearing spacing differs.
This led to an increase in stoppage time.

For this reason, attempts have been made to roll irregularities in the circumferential direction on the outer periphery of the shaft, and results have been obtained through machining.

However, with this method, the axial force does not act uniformly on the shaft during machining when turning, and the axial force acts only on the local part of the machining process, so the shaft ends up bending at the machined part. It was necessary to correct the shaft runout.

Although this type of shaft runout is slight, it is extremely difficult to correct, and in fact, even if there is some shaft runout, it will be 1? It was limited to those without titles.

SUMMARY OF THE INVENTION An object of the present invention is to solve these problems and provide an electric motor equipped with a 414-shaft shaft that is easy to manufacture and can easily achieve excellent machining accuracy.

Hereinafter, the present invention will be illustrated in the drawings. The plan view and FIG. 2 are enlarged vertical cross-sectional views of the main parts thereof, and FIG. 3 is a diagram simply showing one embodiment of the processing equipment.

In the electric motor shown at J3 in FIG. 1, a rotor 2 is press-fitted onto a shaft 1, and small unevenness made of caulking is provided on both sides of the rotor 2 in the circumferential direction of the shaft 1.

A bearing 4 formed by a ball hair ring 114 is press-fitted on the outside of the unevenness 3 with an axial tilt.

The bearing 4 is press-fitted into the shaft 1 and is positioned by being pressed against the outside of the unevenness 3.

43 in Fig. 2, the unevenness 3 of φ1111 is formed by pressing strongly in the axial direction with a protrusion, and the hole 5 is placed on medium heat.
When the hole 5 is formed, the hole 5 is plastically deformed due to the formation of the hole 5.
A protrusion 6 is provided around the periphery.

A slight curved portion 7 formed at a corner of the bearing 1 is pressed into contact with the projection 6.

d3 in Fig. 3, the shaft 1 is configured to be strongly pressed toward the shaft center by protrusions 8 having sharp tips, and the protrusions 8 are located at four locations around the shaft 1. It is arranged.

In such a configuration, the electric motor uses a simple bar material as the shaft 1, which is cut to a predetermined size, and the rotor 2 is press-fitted therein.

Then, as shown in FIG. 3, the shaft 1 is
Press firmly in 4 places from the outer periphery.

When such a step 1a is carried out, a hole 5 is formed in the shaft 1 by the unevenness 3 formed by the protrusion 8, and a protrusion 6 is formed around the hole 5 to protrude outward due to its plastic deformation.

When the bearing 4 is press-fitted into the shaft 1 from its end, the press-fitted bearing 4 collides with the protrusion 6 and its position is determined.

When this protrusion 6 is disposed on the outer periphery of the shaft 1, it can obtain a strong positioning effect on the bearing 4.

In particular, when the protrusions 6 are arranged evenly around the outer circumference of the support 1, the bearing 4
When pushed in the axial direction, each protrusion 6 shares the opposing force, so a strong opposing force can be obtained, and the ability of the bearing 4 to function as a stepped portion can be fully demonstrated.

Therefore, the protrusion 6 can be sufficiently effective in positioning the bearing 4 without having to have an unreasonably large shape.

The bearing 4, such as a ball bearing, has a slight bend 7 formed at the corner of the inner ring to facilitate press-fitting.
Since the curved portion 7 and the protrusion 6 abut each other, the corner of the bearing 4 will not cut the protrusion 6 and cause the position to become unstable.

Formation of the protrusion 6 in the hole 5 as described above is achieved by applying a relatively small force J to the shaft 1 (well, moreover, by applying J from the outer circumference of the shaft 1 all at once), the shaft 1 is Problems such as bending do not occur, and center runout can be avoided.

The formation of the protrusions 6 through the holes 5 is not limited to four locations as in this embodiment, but sufficient effects can be obtained by forming the protrusions 6 at about two to six locations.

When holes 5 are formed, it is desirable to arrange them as evenly as possible around the outer circumference of the shaft 1. If they are arranged evenly, the force will be better distributed when the bearing 4 is pressed in the axial direction.
Demonstrates powerful force for positioning. Furthermore, when the holes 5 are arranged evenly, the bearing 4 is not tilted with respect to the shaft 1, and accuracy can be easily improved.

Furthermore, if you set the hole 5 to an appropriate size and quantity,
The force applied when press-fitting the bearing 4 in the axial direction deforms the protrusion 6 and changes the position, albeit slightly, so that the loose fitting of the motor in the axial direction can be adjusted.

Furthermore, the position of the hole 5 in the shaft 1 can be easily changed, and in the case where the bearings 4 have different spacings, it is easy to change the spacing to a predetermined spacing.

If the position of the hole 5 is slightly changed, even if the size of the hole 5 is changed, the position of the protrusion 6 due to the hole 5 will change, so the same effect can be obtained, and the position of the protrusion 8 will be changed. There are possibilities even if you don't.

Of course, the bearing need not be limited to a ball bevel 7 ring, but in the case of metal (6), in this case, it is possible to use a structure that prevents the metal from coming into direct contact with the protrusion 6 by interposing a crackle, which is the conventional technology. That's fine.

As described above, according to the present invention, strong bearing positioning is achieved by caulking the shaft, that is, forming holes with protrusions to form protrusions, and distributing the protrusions evenly around the outer circumference of the shaft. In addition to easy machining, the shaft does not suffer from bending during machining, making it easy to obtain a high-precision electric reshaping machine. can.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view of the main part showing the shaft part of an electric motor according to an embodiment of the present invention, FIG. 2 is an enlarged vertical cross-sectional view of the main part, and FIG. FIG. 1 is a diagram showing an embodiment of the device simply showing the mouth 11; 7... shaft, 2... rotor, 3... unevenness, 4
...Bearing, 6...Protrusion, 8...Protrusion. QJ n'1 Applicant Shibaura Seisakusho Co., Ltd. Rumen 4

Claims (1)

[Claims] 1. An electric motor, characterized in that a rotor is press-fitted onto a shaft, caulking is applied to the outer periphery of the shaft in the axial direction, and a bearing is press-fitted from the end of the shaft and positioned on the protrusion formed by the caulking.