JPH0135559Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] The present invention relates to a bearing support device suitable for, for example, a small rotating electric machine.

[Technical background of the invention and its problems]

As shown in Fig. 3, in a typical small motor, a bracket 1 serving as a frame member and a frame 2 holding a stator winding 3 are integrated using screws, while a rotor 4 is attached. The shaft 5 is rotatably supported by ball bearings (hereinafter referred to as bearings) 7 and 8 fitted in the bracket 1 and frame 2, respectively.

In this case, the inner rings of the bearings 7 and 8 are each fixed to the shaft 5 by shrink fitting, press fitting, gluing, or the like. The outer ring of the bearing 7 on the load side is axially tightened and fixed by the bearing cover 6. Note that instead of the bearing cover 6, it may be fixed by adhesive or other means.

On the other hand, the outer ring of the bearing 8 on the anti-load side is fitted to the housing with a small gap, and a wave spring 9 applies axial pressure to this outer ring to suppress the gap inside the bearing. . Note that a coil spring, a claw spring, or the like may be used instead of the wave spring 9.

In this way, so-called bearing defects such as abnormal rotational noise, rotational vibration, and decreased rigidity of the bearing are prevented.

By the way, this type of motor is used with a pulley attached to the load shaft, but in information terminal equipment, a disc made of metal, plastic, glass, etc. as an information medium is attached to the load shaft, and this is rotated at high speed. I often let them do it.

In such cases, if there is misalignment or surface runout in the disc attached to the load shaft, the rotating body is likely to become eccentric. At this time, if there is a slight gap between the outer ring of the bearing and the housing, a creep phenomenon may occur. In addition to accelerating wear due to the relative movement known as oscillation, it also causes functional problems due to heat generation.

This phenomenon becomes more pronounced as the gap between the outer ring and the housing becomes larger, and as misalignment and surface runout become larger, and abnormal noise may also be generated due to collision in the radial direction.

In this regard, with the bearing support structure shown in Figure 3, there is almost no problem since the outer ring on the load side is tightened and fixed by the bearing cover 6, but the outer ring on the opposite load side is attached to the housing. On the other hand, since there is a minute gap, there is a drawback that creep phenomenon and abnormal noise are likely to occur.

[Purpose of invention]

The present invention has been made to eliminate the above-mentioned drawbacks, and is capable of applying a predetermined axial pressure to the outer ring.
Another object of the present invention is to provide a bearing support device that can reliably suppress creep phenomena and abnormal noise.

[Summary of the idea]

In order to achieve this object, the present invention provides a pair of ball bearings each having an inner ring fixed to a spaced position on the same axis, the outer ring of one of the ball bearings being fixed to a frame member, and the outer ring of the other ball bearing being fixed to a frame member. In a bearing support device in which an outer ring of a ball bearing is supported by the frame member, the outer ring of the other ball bearing is fitted inside, and the axial end face has a step with respect to the axial end face of the frame member. , a cylindrical member whose outer peripheral portion is supported by the frame member via an O-ring, and a plate surface is fixed to each axial end face of the frame member and the cylindrical member, and the cylindrical member is attached to the frame member. It is characterized by being equipped with a leaf spring that urges the in the axial direction.

[Example of idea]

FIG. 1a is a longitudinal cross-sectional view of one embodiment of the present invention;
FIG. b is a cross-sectional view taken along the - arrow direction of the same embodiment, and the same reference numerals as in FIG. 3 indicate elements that are the same or have the same effect. The inner ring of the bearing 8 is fixed to the shaft 5, and the outer ring is fitted into a collar 10, which is further connected to an O-ring 11.
It is attached to the housing of the frame 2 via. In this case, the housing of the frame 2 and the collar 10 have an annular end face perpendicular to the axis exposed in the free end direction as seen from the shaft 5, and a leaf spring 13 is attached to these end faces with respect to the axial end face of the collar 10. They are fixed with screws 14 via spacers 12 to provide a step difference. Further, the end portion of the frame 2 is covered with a dustproof cover 15.

FIG. 2a is a plan view showing the detailed shape of the leaf spring 13, and FIG. 2b is a sectional view taken along Y-O-Y. This leaf spring 13 has an outer shape that looks like a square with rounded corners, and has a circular hole 13a formed in the axial center, and mounting holes 13b in one set of corners with the largest outer diameter. Attachment holes 13c are formed in portions close to the circular holes 13a in a direction perpendicular to the attachment direction of the attachment holes. Then, a screw 14 is passed through the mounting hole 13b to fix this part to the housing, while a screw 14 is passed through the mounting hole 13c to fix this part to the collar 10.
It will be deflected by the dimension shown by δ.

In the above configuration, the inner ring of the bearing 8 is fixed to the shaft 5, and the outer ring is fitted to the collar 10, so that when a radial force is applied to the shaft, the collar 10 and the housing into which it is inserted are connected. Although the gap is a problem, since the O-ring 11 is interposed between the two, it can be said that there is almost no problem with respect to the force in the radial direction.

However, even if an O-ring is interposed between the collar 10 and the housing, the collar 10 will rotate when a certain amount of rotational torque is applied.

In order to suppress this rotation and to apply an axial force to the outer ring, leaf springs 13 are provided, and the leaf springs 13 are screwed into the collar and the housing at two locations each, perpendicular to each other and at different radial dimensions. At the same time, it is screwed in a biased state as shown in FIG. 2b. This takes advantage of the fact that the leaf spring 13 has spring properties in the axial direction and rigidity in the circumferential direction, and its thickness, inner and outer dimensions are based on the rating of the bearing 8.
It is determined appropriately depending on the tightening pressure of the O-ring 11, etc. The collar 10 is provided to solve the difficulty of providing a screw hole in the outer ring of the bearing.

Thus, according to this embodiment, the creep phenomenon can be suppressed while a predetermined axial pressure is applied to the outer ring.

In the above embodiment, a leaf spring with a square outer shape and a circular hole in the center is used, and is screwed to the housing and collar at different positions in the cross direction, but other shapes may also be used. too,
In short, as long as a plate surface is fixed to each axial end face of the frame and collar, and the collar is biased in the axial direction with respect to the frame, the same effect as described above can be performed.

Further, in the above embodiment, the spacer 12 is provided to facilitate bending of the leaf spring 13, but a protrusion having the same function as the spacer 13 may be provided on the collar and the housing.

Further, in the above embodiment, the O-ring insertion groove was provided on the housing side, but it goes without saying that almost the same effect as described above can be achieved even if the O-ring insertion groove is provided on the collar.

[Effect of idea]

As is clear from the above description, according to the present invention, the cylindrical member into which the outer ring of the other ball bearing is fitted has an axial end surface that is stepped with respect to the axial end surface of the frame member. The outer periphery is supported by the frame member via an O-ring so as to hold the frame member, and leaf springs are fixed to each axial end surface of the frame member and the cylindrical member to bias the cylindrical member in the axial direction. As a result, a predetermined axial pressure can be applied to the outer ring, and creep phenomena and abnormal noises can be reliably suppressed.

[Brief explanation of the drawing]

Figures 1a and b are longitudinal and cross-sectional views showing one embodiment of the present invention, Figures 2a and b are plan views and cross-sectional views showing detailed shapes of the main elements of the embodiment, and FIG. 3 is a longitudinal sectional view of a small motor showing the configuration of a conventional device. 1...Bracket having a housing, 2...
a frame having a housing, 5... shaft, 6...
Bearing cover, 7, 8... Ball bearing, 10...
Color, 11...O ring, 13...Plate spring, 1
4...Screw.

Claims (1)

[Scope of utility model registration request] Of a pair of ball bearings 7 and 8, each having an inner ring fixed to a spaced position on the same shaft 5, the outer ring of one of the ball bearings 7 is fixed to the frame member 1, and the outer ring of the other ball bearing 8 is fixed to the frame member 1. In the bearing support device supported by the frame member 2, the outer ring of the other ball bearing 8 is fitted inside, and the outer peripheral portion is arranged such that the axial end surface has a step with respect to the axial end surface of the frame member 2. is a cylindrical member 10 supported by the frame member 2 via an O-ring 11, and a plate surface is fixed to each axial end face of the frame member 2 and the cylindrical member 10, and A bearing support device comprising a leaf spring 13 that urges a cylindrical member 10 in the axial direction.