JPH02202332A - Ball bearing fixing device - Google Patents

Abstract

PURPOSE:To enable fixing a ball bearing through only one part by providing the end face of a ball bearing holder with a plurality of projected parts coming in contact with the end face of said ball bearing and by providing the cylindrical part of said holder with a plurality of projected parts fitted into recesses formed in the outer periphery of a housing. CONSTITUTION:An elastic ball bearing holder 2 is fitted in the outer periphery of a housing 3 holding a ball bearing 1. Also, a plurality of projected parts 2b provided on said cylindrical face are inserted and fixed in recesses 3b formed in the outer periphery of said housing 3. At the same time, the end face of said ball bearing 1 is energized by a plurality of projected parts 2a provided on the end face of said holder to fix said ball bearing 1 at the housing 3. Thus, the ball bearing can be fixed simply, by only one part and without requiring almost no space, because the ball bearing holder 2 is fixed at the housing 3 by elasticity and the projected parts 2a of said end face bias the end face of the ball bearing by elasticity so that a ball bearing outer ring is axially pressed to the housing stepped part.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a ball bearing fixing device for an electric motor.

Conventional technology When ball bearings are used as bearings for electric motors, especially when the housing is made of a material with a relatively large coefficient of thermal expansion such as aluminum, the gap between the outer ring and the housing of the ball bearing widens at high temperatures. This causes a creep phenomenon that causes adverse effects such as wear on the housing.

In order to prevent this, it is necessary to fix the outer ring of the ball bearing in some way.

The conventional ball bearing fixing device will be explained below.

FIGS. 4(a) and 4(b) are a front view and a sectional view of a conventional ball bearing fixing device.

In Fig. 4, 1 is a ball bearing, 1a is an outer ring of ball bearing 1, 3 is a housing into which ball bearing 1 is inserted and whose dimensions are such that the end face of the ball bearing is slightly exposed, and 3a is a ball bearing of housing 3. Step portion 4 in contact with the axial end surface of the outer ring 1a
Reference numeral denotes a shaft into which the ball bearing 1 is press-fitted, 6 a metal fitting in contact with the outer ring 1a of the ball bearing, 7 a screw for fixing the metal fitting 6 to the housing 3, and 5 a coil end portion of the stator winding.

The operation of the bearing fixing device configured as described above will be explained below.

Since the outer ring 1a of the ball bearing is pressed against the stepped portion 3a of the housing 3 by a metal fitting 6 which is axially tightened to the housing 3 by a plurality of screws 7, even if the gap between the outer periphery of the ball bearing 1 and the housing 3 becomes large, Does not cause creep phenomenon.

Problems to be Solved by the Invention However, in the conventional configuration described above, the thickness of the housing part must be increased in order to tighten the screws, and the space for inserting the coil end of the stator winding becomes smaller. It is particularly difficult to use in applications that require miniaturization. In addition, screw tightening work is required, which takes a lot of man-hours, and
Depending on the outer diameter of the rotor, tightening the screws may be difficult. In addition, with this structure, the outer ring of the ball bearing is completely fixed to the housing, so if an impact is applied to the shaft 4 in the axial direction, the inner raceway surface or rolling surface of the ball bearing may be damaged. It had drawbacks.

The present invention solves the above-mentioned conventional problems. It not only occupies almost no space inside the electric motor and fixes the ball bearing with a single component without the need for screw tightening, but also prevents impact from being applied to the shaft in the axial direction. The ball bearing provides a fixing device that does not damage the internal raceway surface or transfer surface even in such cases.

Means for Solving the Problems To achieve this object, the ball bearing of the present invention has a fixing device that includes a ring-shaped recess formed on the outer circumferential surface of the annular portion of the housing, and an elastic material that can be fitted on the outer circumference of the housing. The cup-shaped bearing is equipped with a presser foot, and the presser has a plurality of protrusions on its end surface that abuts the end surface of the ball bearing;
The cylindrical surface has a plurality of protrusions that fit into the recesses on the ring, and the ball bearing is inserted into the inner diameter of the housing and fitted into the outer diameter of the housing.

Function: With this configuration, the ball bearing made of an elastic material fixes the presser foot to the housing by fitting the plurality of protruding parts of the presser foot into the ring-shaped recess on the outer periphery of the housing, and the ball bearing fixes the presser foot to the housing due to its elasticity. The protrusion elastically presses the end surface of the ball bearing, thereby pressing the outer ring of the ball bearing against the housing stepped part in the axial direction. Therefore, the ball bearing can be fixed with one component, taking up almost no space.

Furthermore, even when an axial impact is applied to the shaft, the elasticity of the presser foot in the ball bearing cushions the impact on the ball bearing, making it possible to prevent damage to the internal raceways and transfer surfaces.

EXAMPLE Hereinafter, an example of the present invention will be described with reference to the drawings.

FIG. 1 shows a cross section of a ball bearing fixing device according to an embodiment of the present invention.

In FIG. 1, a cup-shaped ball bearing made of a metallic elastic material is fitted onto the outer periphery of an annular portion of a housing 3 that holds a ball bearing 1, and a presser foot 2 is fitted on the outer periphery of a housing 3 that holds a ball bearing 1. is fitted into a ring-shaped recess 3b formed on the outer periphery of the annular portion of the housing 3 and fixed therein, and the end face of the ball bearing 1 is urged by a plurality of protrusions 2a provided on the end face, thereby tightening the ball bearing 1. 1 is fixed to the housing.

Note that 4 is a shaft, and 5 is a coil end portion of the stator winding.

The ball bearing fixing device having the above structure first inserts the ball bearing presser 2 into the shaft 4, and then press-fits the ball bearing 1 into the shaft 4. Next, the ball bearing 1 is inserted into the housing 3, and finally the ball bearing is assembled by fitting the presser foot 2 into the housing 3.

The operation of the fixing device for the ball bearing of this embodiment constructed as described above will be explained below.

FIG. 2 shows the operation of the ball bearing when fitting the presser foot 2 into the housing.

The ball bearing fits into the ring-shaped recess 3b formed on the outer circumferential surface of the housing.The protruding part 2b of the presser foot 2 is dimensionally inside the outer circumferential surface of the housing, but since it has elasticity, the protruding part can be pushed in the axial direction. 2b to the outside, and the ball bearing pushes the presser foot 2 in the axial direction, and the ball bearing then pushes the protruding portion 2b provided on the end surface of the presser foot 2 into contact with the outer ring. come into contact with When the ball bearing is further pushed in the axial direction, the plurality of protrusions 2b provided on the end surface of the presser foot 2 fit into the recesses 3b on the outer peripheral surface of the housing, and the ball bearing cannot be removed. At this point, the ball bearing of the presser foot 2 has been deformed from the state shown by the two-dot chain line to the state shown by the solid line in FIG. In the ball bearing, the outer ring 1a is pressed in the axial direction, and the ball bearing 1 is fixed. In addition, when an impact is applied to the shaft in the axial direction, the elasticity of the ball bearing's holding part 2a that contacts the outer ring acts as a cushion, and the ball bearing prevents damage to the internal raceway surface and transfer surface. Can be done.

In this embodiment, a ball bearing made of a metallic elastic material is used as a presser, but it goes without saying that a molded product made of synthetic resin may also be used.

Effects of the Invention As described above, the present invention makes it possible to easily fix a ball bearing with one component, taking up almost no space, which not only prevents the creep phenomenon caused by thermal expansion, but also saves space for windings. An excellent ball bearing can realize a fixing device because it can effectively reduce the size of the motor and protect the ball bearing from axial shocks applied to the shaft.

[Brief explanation of the drawing]

Figure 1 is a cross-sectional view of the fixing device for the ball bearing in the embodiment of the present invention, Figures 2 (a), (b), and (C) are assembled views of the presser foot for the ball bearing, and Figure 3 is the operation of the protrusion. The explanatory drawings and FIGS. 4(a) and 4(b) are a front view and a sectional view of a main part of a conventional ball bearing fixing device. 1...Ball bearing, 2...Ball bearing is presser, 3...Housing, 4...Shaft. Name of agent: Patent attorney Shigetaka Kurino and 1 other famous Kazuzu 1--Wang Shusho 2--Ichio J

Claims (1)

[Claims] A housing that holds a ball bearing in an annular portion, a ring-shaped groove formed on the outer periphery of the annular portion of the housing, and a cup-shaped ball bearing holder made of an elastic material fitted to the outer periphery of the housing. A plurality of protrusions are provided on the cylindrical surface of the ball bearing holder, and the protrusions on the cylindrical surface are fitted into the grooves of the housing. A ball bearing fixing device in which a protruding portion is brought into contact with an outer ring end face of the ball bearing to press and bias the ball bearing.