JP2001208055A - Rolling bearing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rolling bearing device which combines both maintainablity and noiselessness by avoiding a metal-to-metal contact between a turning shaft and an inner race of a supporting bearing. SOLUTION: The rolling bearing device can reduce the noise level by eliminating a hitting noise due to the metal to metal contact during operation so that the inner race 16 of the supporting bearing is tightly fitted to an outer surface of a resin tube 17 which is fitted tightly to the outer surface of the shaft 2 and the inner race 16 can support the shaft 2 all over the area of the contact surface in the radial direction unlike an O ring insert type. Therefore, the shaft 2 supported by the inner race 16 by means of the resin tube 17 can be removed more easily in comparison with the case that the inner race 16 is attached directly to the shaft 2 to enable to raise the level of the maintenace.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling bearing device for a motor used, for example, as a loose fit in a state where a rotary shaft and an inner ring of a rolling bearing are fitted.

[0002]

2. Description of the Related Art A conventional rolling bearing device for a motor is shown in FIG. This rolling bearing device includes two rolling bearings 103, 1 that support a shaft 102 of a motor 101 at two locations separated by a predetermined dimension in the axial direction.
05. These two rolling bearings 103, 10
5 are arranged on both axial sides of the motor body 101A,
It is fitted inside the housing 106. The shaft 10
A rotor (not shown) is attached to the second end 102A.

The rolling bearing 103 on the tip side near the rotor has an inner ring 103A and an outer ring 103B tightly fitted to the shaft 102 and the housing 106. On the other hand, in the bottom rolling bearing 105, the outer ring 105B is tightly fitted to the housing 106, but the inner ring 105A is loosely fitted to the shaft 102, and the O-ring 107 is press-fitted into the clearance. As a result, the rolling bearing 105 on the bottom side, which is fragile because a large whirling load is applied compared with the rolling bearing 103 on the tip side, is easily detached from the shaft 102, thereby improving maintainability.

[0004]

However, in the above-described conventional rolling bearing device, since the bottom rolling bearing 105 has a loose fit with respect to the shaft 102, the inner race 105A of the rolling bearing 105 and the shaft 102 are in use during use. Hitting sound occurs,
There is a problem of impairing quietness.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a rolling bearing device which can achieve both maintainability and quietness.

[0006]

According to a first aspect of the present invention, there is provided a rolling bearing device in which a resin tube is closely fitted to a shaft, and an inner ring is closely fitted to the outside of the resin tube. It is characterized by being fixed.

According to the first aspect of the present invention, since the inner ring is closely fitted to the outside of the resin tube closely fitted to the shaft,
The inner ring can support the shaft over the entire area in the axial direction, so that no sound is produced between the shaft and the inner ring during rotation, and noise can be reduced. Further, since the inner ring is fitted to the shaft via the resin tube, the inner ring is easily detached from the shaft as compared with a case where the inner ring is directly tightly fitted to the shaft, and maintenance performance such as replacement can be improved. .

Further, the rolling bearing device according to the second aspect of the present invention is such that the resin tube is closely fitted to the outer ring, and the resin tube is tightly fitted to the housing between the outer ring and the housing. Features.

According to the second aspect of the present invention, since the resin tube closely fitted to the outer ring is closely fitted to the housing, the outer ring is supported by the housing over the entire area in the axial direction, and the outer ring is connected to the housing during rotation. The noise with the outer ring is eliminated and noise can be reduced. Further, since the outer ring is fitted to the housing via the resin tube, it is easier to remove the outer ring from the housing than in a case where the outer ring is directly fitted to the housing, thereby improving maintenance such as replacement. .

According to a third aspect of the present invention, there is provided the rolling bearing device according to the first or second aspect, wherein the resin tube has a locking portion for preventing the resin tube from moving in the axial direction. It is characterized by having.

According to the third aspect of the present invention, it is possible to prevent the resin tube from being displaced with respect to the shaft or the outer ring by the locking portion of the resin tube.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail with reference to the illustrated embodiments.

FIG. 1 shows an embodiment of a rolling bearing device according to the present invention. In this embodiment, the shaft 2 of the motor 1 is supported by two rolling bearings 3 and 5 separated by a predetermined distance in the axial direction. A rotor (not shown) having a predetermined weight is attached to the tip 2A of the shaft 2 of the motor 1.

Among the two rolling bearings 3, 5, one of the rolling bearings 3 on the tip side has an inner ring 6 tightly fitted on the shaft 2, and an outer ring 7 formed on a cylindrical inner peripheral surface of a lid member 11 of a housing 10. 11A is tightly fitted.

On the other hand, the rolling bearing 5 on the bottom side is disposed in the bottom cylindrical portion 13 of the main body 12 of the housing 10 and its outer ring 1
Reference numeral 5 is tightly fitted to the inner peripheral surface of the bottom cylindrical portion 13. The inner race 16 of the bottom rolling bearing 5 is tightly fitted to the outer circumferential surface of the resin tube 17 closely fitted to the outer circumferential surface of the shaft 2.

As shown in FIG. 2A, the resin tube 17 has inner bent portions 17a and 17b which are bent radially inward at both ends in the axial direction. , 1
7b is engaged with two annular grooves 20, 21 formed on the outer peripheral surface of the shaft 2 at predetermined intervals in the axial direction. This engagement prevents the resin tube 17 from being displaced in the axial direction, and also facilitates positioning during assembly.

It is desirable to use a heat-shrinkable resin tube as the resin tube 17. Examples of the heat-shrinkable resin tube include PET (polyethylene terephthalate resin), FEP (ethylene tetrafluoride-propylene hexafluoride copolymer resin) and PFA (polyethylene tetrafluoride).
Fluororesins such as -perfluoroalkyl vinyl ether copolymer resin), PC (polycarbonate), PVC (polyvinyl chloride), PS (polystyrene resin), and polyolefin resin can be used. Also, this resin tube 1
The thickness of 7 is preferably 0.02 mm to 0.5 mm. The reason is that if the thickness is too large, the uniformity of the thickness and the finishing accuracy after processing are reduced, while if the thickness is too small, the cushioning effect is lacking and the soundproofing effect is reduced. The radial dimension of the resin tube 17 is 105% to 115% of the inner diameter of the bearing 5, and the axial dimension is 105% to 140% of the axial dimension of the bearing 5.

The heat-shrinkable resin tube 17 is
In a state where the shaft is fitted to the shaft 2, the shaft is closely fitted to the shaft 2 by heat shrinking at, for example, 60 ° C. to 120 ° C. (the tempering temperature for the bearing or less). Thereby, the shrinkage in the radial direction becomes 10 to 50%, and the shrinkage in the axial direction becomes 0 to 30%.
%Became.

When the shaft 2 of the motor 1 rotates, the inner bearings 6, 16 rotate while the inner bearings 6, 16 are supported by the balls 4, 14 with respect to the outer bearings 7, 15 fixed to the housing 10. The shaft 2 is rotatably supported by the housing 1.

In this embodiment, the inner race 16 is tightly fitted to the outside of the resin tube 17 tightly fitted to the shaft 2, so that the inner race 16 can support the shaft 2 over its entire area in the axial direction. The sound of the shaft 2 and the inner ring 16 at the time is no longer produced,
Noise can be reduced. The inner ring 16 is formed of the resin tube 1.
Since the inner ring 16 is fitted to the shaft 2 via 7, the inner ring 16 is easily detached from the shaft 2 as compared with the case where the inner ring 16 is directly tightly fitted to the shaft 2, and the maintenance property such as replacement can be improved.

In the above embodiment, the annular grooves 20 and 21 are formed at two places on the shaft 2 as shown in FIG.
As shown in FIG. 2B, a predetermined fitting area in the axial direction of the shaft 2 may be a large diameter portion 22, and the resin tube 17 may be closely fitted to the large diameter portion 22. In this case, the inwardly bent portions 17a and 17b of the resin tube 17 are fitted to both end step portions 22a and 22b of the large diameter portion 22.

As shown in FIG. 2C, the resin tube 17 is replaced with a resin tube 18 having an annular engaging portion 18a which is recessed inward at substantially the center in the axial direction. The shaft 2 may be fitted tightly, and the annular engaging portion 18 a may be engaged with the annular groove 25 of the shaft 2. In this case, axis 2
It is sufficient to form the annular groove 25 at one location in the axial direction of
Shaft machining man-hours can be reduced.

Further, as shown in FIG. 3, the inner ring 16 is tightly fitted to the shaft 2 without fitting the resin tube to the outer periphery of the shaft 2, and the resin tube is fitted to the outer peripheral surface of the outer ring 15 of the rolling bearing 5. 27 may be wound, and both end portions 27 a and 27 b may be brought into close contact with both end surfaces of the outer race 15. This both ends 27
a, 27b are contracted by heat, for example,
5 may be brought into close contact with both end faces. In this case, the outer ring 15 of the rolling bearing 5 is fitted to the housing 10 via the resin tube 27, and the resin tube 27 is
Tightly fitted to the inner peripheral surface of the According to this, the outer ring 15
Since the resin tube 27 that covers the entire outer peripheral surface of the outer ring 15 is interposed between the outer ring 15 and the housing 10, it is possible to prevent the striking sound between the outer ring 15 and the housing 10 and reduce noise. Further, since the outer ring 15 is fitted to the housing 10 via the resin tube 27, the outer ring 15 is tighter than the case where the outer ring 15 is directly fitted to the housing 10.
It is easy to remove from zero, and maintenance such as replacement can be improved.

Further, as shown in FIG. 2, a resin tube 17 is closely fitted to the shaft 2 and, as shown in FIG. 3, a resin tube 18 is closely fitted to the outer periphery of the outer ring 15. Is also good. In this case, the noise reduction can be further improved, and the rolling bearing 5 can be more easily removed.

[0025]

As is apparent from the above description, in the rolling bearing device according to the first aspect of the present invention, the inner ring is closely fitted to the outside of the resin tube tightly fitted to the shaft. The shaft can be supported in all directions, and no noise is produced between the shaft and the inner ring during rotation, so that noise can be reduced. Further, since the inner ring is fitted to the shaft via the resin tube, the inner ring is easily detached from the shaft as compared with a case where the inner ring is directly tightly fitted to the shaft, and maintenance performance such as replacement can be improved. .

Further, in the rolling bearing device according to the second aspect of the present invention, since the resin tube closely fitted to the outer ring is closely fitted to the housing, the outer ring is supported by the housing over the entire area in the axial direction. . Therefore, even when the housing is deformed, the noise between the outer ring and the housing during rotation is eliminated, and noise can be reduced. Further, since the outer ring is fitted to the housing via the resin tube, the outer ring can be easily removed from the housing as compared with a case where the outer ring is directly tightly fitted to the housing, so that maintenance such as replacement can be improved.

According to a third aspect of the present invention, there is provided the rolling bearing device according to the first or second aspect, wherein the resin tube has a locking portion for preventing the resin tube from moving in the axial direction. Accordingly, the resin tube can be prevented from being displaced with respect to the shaft or the outer ring.

[Brief description of the drawings]

FIG. 1 is a sectional view of an embodiment of a rolling bearing device of the present invention.

FIG. 2A is a partial cross-sectional view showing a fitted state of the shaft 2 and the rolling bearing 5 in the embodiment, and FIG.
FIG. 2B is a partial cross-sectional view showing a fitted state of a shaft and a rolling bearing in a modified example, and FIG. 2C is a partial sectional view showing a fitted state of a shaft and a rolling bearing in another modified example. FIG.

FIG. 3 is a partial cross-sectional view showing a state in which a resin tube is closely fitted to the outer peripheral surface of an outer ring 15 of the rolling bearing 5;

FIG. 4 is a sectional view showing a conventional rolling bearing device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Motor, 2 ... Shaft, 4,14 ... Ball, 3,5 ... Rolling bearing, 6,16 ... Inner ring, 7,15 ... Outer ring, 10 ... Housing, 11 ... Lid member, 12 ... Main body, 13 ... Bottom cylinder Part 17,
18, 27: resin tube, 17a, 17b: inwardly bent portion, 20, 21: annular groove, 22: large diameter portion.

Claims (3)

[Claims] 1. A rolling bearing device wherein a resin tube is closely fitted to a shaft, and an inner ring is fitted and fixed to the outside of the resin tube. 2. A rolling bearing device, wherein a resin tube is closely fitted to an outer race, and the resin tube is tightly fitted to the housing between the outer race and a housing. 3. The rolling bearing device according to claim 1, wherein the resin tube has a locking portion for preventing the resin tube from moving in the axial direction.