JPS6343017A - Electric motor - Google Patents

Abstract

PURPOSE:To obtain a good sliding characteristic by farming a stepped section on a shaft and providing the first washer brought into contact with the stepped section, the second washer and the third washer freely coupled with the shaft, and the fourth washer sliding on a metal. CONSTITUTION:A shaft 3 is supported by a metal 6 at one end, and the first- fourth washers 10-13 are provided at the other end between a rolled stepped section 8 and a metal 9. The positioning of the shaft 3 during rotation is performed by applying the axial force to the stepped section 8 with the first washer 10. In addition, the second washer 11 is freely coupled to supplement the insufficient precision of the rolled stepped section 8 and can absorb the inclination and size error between the stepped section 8 and the end face of the metal 9 together with the rubber-made third washer 13, and the stepped section 8 is smoothly rotated against the metal 9.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an electric motor in which a stepped portion is formed by rolling on the shaft of a rotor so that the rotor slides on metal.

"Prior Art" The relationship between a shaft and a bearing in an electric motor is such that the shaft is configured to rotate and is restricted from moving in the axial direction.

If the bearing is a ball bearing, by press-fitting the inner ring of the pole bearing onto the shaft, the position can be controlled with sufficient strength even if a slight protrusion is formed on the shaft. However, if the bearing is metal, the shaft and metal and slide, so the position regulation must exhibit a certain degree of resistance in the axial direction.

For this reason, generally, a step that slides in the axial direction is formed on the shaft by machining a step that has a considerably large axial area in the radial direction, and the part of the step that slides on the end surface of the metal is formed by machining. was forming.

However, forming such a step on the shaft not only requires cutting the shaft, but also when determining the diameter of the end of the shaft, it is necessary to use a shaft with a larger diameter than the radial dimension required for the step. However, there was a problem in that a thick material was required for the shaft.

For this reason, it has become common to form steps on the shaft using radial protrusions to regulate the position of the bearing, rather than forming steps on the shaft by mechanical cutting.

"Problems to be Solved by the Invention" When regulating the position of the bearing by forming a step with a protrusion on the shaft, the protrusion forms an axial surface of the same extent as a large step in the radial direction by machining, Moreover, if the axial surface is perpendicular to the axis, the same problem does not occur, but there is a problem in that the protrusions cannot be formed with the same precision and strength as the steps made by cutting.

In other words, since stepping by protrusions is achieved by plastic deformation of the shaft, the amount of protrusion in the radial direction is limited, and the formation of the protrusions makes the shaft easy to bend. This poses the problem of not being able to achieve the high precision that can be obtained with cutting.

In order to improve this kind of problem even a little, we formed circumferential protrusions on the shaft by rolling, and when rolling, we made the sides of the protrusions that slide on the bearings as much as possible in the shape of a flange similar to the step formed by machining. There are some things that are not effective.

With this configuration, sufficient strength and accuracy can be obtained for regulating the position in the axial direction, at least in the case of a bearing that is press-fitted into the shaft, such as a ball bearing.

However, it is not possible to form the metal bearing with high precision until the metal bearing is slid onto the rolled protrusion.

In other words, the formation of protrusions during rolling is due to the plastic deformation of the shaft, which makes it impossible to obtain a large enough axial sliding area for the metal to slide in the axial direction, and even if it is formed into a brim shape, the shaft The boundary between the protrusion and the metal becomes curved, and the sliding surface of the metal must be machined, or a washer must be interposed between the protrusion and the metal.

However, even if a washer is inserted between the steps, the steps are often not exactly parallel to the metal end surface, and the washer may tilt and slide against the metal end surface, impairing reliability. .

"Means for Solving the Problems" The present invention provides a first part that contacts the stepped part and is tightly fitted to the shaft.
The problem was solved by including a washer, a second washer that loosely fits on the shaft, a third rubber-based washer, and a fourth fiber-based washer that tightly fits on the shaft and slides on the metal. has been resolved.

"Function" The first washer exhibits axial strength with respect to the stepped part, the second washer and the third washer adjust the accuracy with respect to the axis perpendicular to the stepped part, and the fourth washer , has good sliding characteristics against metal.

The combination of these first to fourth washers allows the metal to slide on the stepped portion formed by rolling, and also provides good one-stroke characteristics.

``Embodiment'' The present invention will be described based on an embodiment shown in the drawings. FIG. 1 is a longitudinal sectional view showing the main parts of the electric motor according to the invention, and FIG. 2 is a longitudinal sectional view showing the main parts. FIG. 2 is an enlarged vertical cross-sectional view of a main part shown in an enlarged manner.

In FIG. 1, the electric motor is equipped with a rotor 2 on the inner diameter side of a stator 1, and the rotor 2 rotates with respect to the stator 1 and its position is regulated in the axial direction. .

A shaft 3 passes through the rotor 2 and is fixed by caulking 4.

One end of the shaft 3 is rotatably supported by a metal 6 provided on a bracket 5, and the shaft end is regulated in position to one side by a sliding plate 7.

Roughly speaking, the other side of the shaft 3 has a stepped portion 8 formed by rolling, and a first washer 10 that contacts the stepped portion and is tightly fitted to the shaft, between the metal 9 and the stepped portion 8. A second washer 11 loosely fitted to the shaft, and a third rubber washer 12
, and a fourth fiber-based washer 13 that tightly fits on the shaft and slides on the metal.

Further, the metal 9 is supported by the bracket 14,
An oil core 15 is provided on the outer periphery.

In FIG. 2, the electric motor has a stepped portion 8 formed on the shaft 3.
The first washer 10 interposed between the metal and the shaft 3 is configured to tightly fit into the shaft 3, and abuts against the stepped portion 8 of the shaft 3 to regulate the axial direction. It has great strength.

The second washer 11 is loosely fitted to the shaft 3, forming a gap 16.

Roughly, the third washer 12 is made of rubber and has elasticity, and the fourth washers 1 and 3 are made of a material such as fiber and have no resistance to speech and behavior with the metal 9. It is made of a material that exhibits smooth sliding characteristics with little wear.

In such a configuration, when the rotor 2 rotates, the electric motor can rotate smoothly by the metal 6.9, and the rotor 2
When trying to move in the axial direction, the shaft end collides with the sliding member 7 and cannot move toward the -5 side, and the stepped portion 8 moves the first to fourth washers toward the other side. The position is regulated by abutting against the end face of the metal 9 via the metal 9.

The position of the shaft 3 on the other side is restricted by interposing the first washer 10 to the entire stepped portion 8 in the axial direction, since the stepped portion 8 cannot be formed with a large protrusion in the radial direction due to its nature. is exerting the force of

When a force in the axial direction is applied to the stepped portion 8 through the first washer 10 in this manner, the stepped portion 8 exhibits sufficient strength in the axial direction, similar to when a ball bearing is press-fitted. be able to.

Further, although the stepped portion 8 does not have high precision due to machine cutting, since the second washer 11 is loosely fitted to the shaft 3, the end surface of the metal 9 should If the stepped portions 8 are not parallel, they will have some adjustment effect.

Moreover, since the third washer 12 made of rubber is interposed, the inclination between the stepped portion 8 and the end face of the metal 9 is absorbed.
In general, dimensional errors between the stepped portion 8 and the metal 9 can be absorbed, and the stepped portion 8 can slide smoothly with respect to the metal 9.

For the washer interposed on such a shaft 3, an appropriate washer may be additionally interposed for rough dimensional adjustment, etc.
The configuration according to this embodiment is the lowest component.

"Effects of the Invention" According to the present invention, the strength and accuracy of the stepped part is increased by interposing the first to fourth washers when forming the stepped part by rolling on the shaft and sliding the metal. It solves the problem of rough metal, has good fixing properties against rough metal, and can demonstrate the same level of performance as conventional machining of the shaft.
The effect on the production of electric motors is extremely large.

[Brief explanation of the drawing]

FIG. 1 is a vertical cross-sectional view showing the main parts of the electric motor according to the present invention, and FIG. 2 is an enlarged vertical cross-sectional view showing the main parts. 3...Shaft, 8...Stepped part, 9...Metal,
10...First washer, 11...Second washer, 12...Third washer, 13...Fourth washer, 16...Gap.

Claims (1)

[Claims] In an electric motor in which a stepped part is formed on the rotor shaft by rolling and the rotor slides on metal, a first washer that contacts the stepped part and is tightly fitted to the shaft, and a second washer that is loosely fitted to the shaft. An electric motor characterized by comprising a second washer, a third rubber-based washer, and a fourth fiber-based washer that slides on a metal shaft.