JP2507182Y2 - Clearance adjustable radial bearing - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to an improvement of a radial bearing used for a car cooler or the like.

[Prior Art] As shown in FIG. 3, a radial bearing used in a car cooler or the like has an outer ring 2 fitted to a housing 1 with a tightening margin, and needle-like rollers 3 arranged on the raceway surface of the outer ring 2. Composed of. Then, the shaft 6 is inserted through the inner diameter portion of the needle roller 3, and the outer peripheral surface of the shaft 6 directly forms the inner raceway surface. A radial skimmer 7 is provided between both raceway surfaces and the rolling surface of the needle roller 3. This clearance 7 is used for bearing life, heat generation, vibration,
Or because it has a great effect on the bearing performance such as sound,
It is set to an amount suitable for the bearing operating conditions. In theory,
The life of the bearing is maximized when the operating clearance of the bearing in steady-state operation is slightly negative. However, in consideration of usage conditions and the like, generally, the initial clearance is set so that the driving clearance is slightly larger than zero.

[Problems to be Solved by the Invention] As described above, the radial clearance is set to an amount suitable for the usage conditions of the bearing, but the thermal expansion amount of the housing is larger than that of the outer ring when the temperature rises. In such cases (for example, when an aluminum housing is used), the tightening margin between the housing and the outer ring decreases as the temperature rises, and the outer ring slightly expands in diameter. Grows beyond. An increase in radial clearance causes problems such as a decrease in bearing life due to a decrease in load factor and an increase in vibration value and sound level value of the bearing.

Therefore, an object of the present invention is to always maintain the radial clearance of the bearing in an appropriate amount and prevent the bearing performance from deteriorating.

[Means for Solving the Problem] The radial adjustment radial bearing of the present invention has an outer raceway surface on the inner circumference and an outer raceway surface fitted to the housing at the outer diameter surface, and the outer raceway surface of the outer race and faces this. The rolling element that is interposed between the inner raceway surface and the clearance adjusting member that is interposed between the outer diameter surface of the outer ring and the fitting surface of the housing.
The linear expansion coefficient of the material forming the housing and the clearance adjusting member is set in the relationship of clearance adjusting member>housing> outer ring, and when the housing thermally expands, the outer ring is bent toward the inner diameter side by the thermal expansion of the clearance adjusting member and the inner raceway. The radial gap between the surface and the rolling element is prevented from increasing.

[Operation] When the temperature rises, both the housing and the clearance adjusting member thermally expand, but since the clearance adjusting member has a larger linear expansion coefficient than the housing, the thermal expansion amount of the clearance adjusting member is larger than that of the housing. growing. Therefore, even if the tightening margin between the housing and the outer ring is reduced due to the thermal expansion of the housing, the outer ring is pressed by the thermally expanded clearance adjusting member and slightly bent toward the inner diameter side.
Radial skimmer increases are avoided.

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

FIG. 1 shows an embodiment of a clearance adjusting type radial bearing of the present invention. This bearing includes an outer ring 2 fitted and fixed to a fitting surface 1a of an aluminum housing 1, needle-like rollers 3 arranged on a raceway surface of the outer ring 2, and a fitting surface 1a of the housing 1 and an outer portion of the outer ring 2. The clearance adjusting member 5 is interposed between the clearance adjusting member 5 and the radial surface 2a. A shaft 6 is inserted on the inner diameter side of the needle roller 3, and the needle roller 3 is positioned with a predetermined radial gap 7 between the outer peripheral surface of the shaft 6 serving as the inner raceway surface and the raceway surface of the outer ring 2. To do. The clearance adjusting member 5 is an annular member formed of a material having a linear expansion coefficient larger than that of aluminum, which is a material for forming the housing 1, for example, a resin material, and an annular groove provided on the outer diameter surface 2a of the outer ring 2. Fitted in 2b.

The housing 1, the outer ring 2, and the clearance adjusting member 5 are thermally expanded due to the temperature rise during rotation. Since aluminum has a larger linear expansion coefficient than that of a general bearing constituent material, the housing 1 thermally expands more than the outer ring 2 and reduces the interference with the outer ring 2. With the decrease in the tightening margin, the outer ring 2 tries to increase the radial skimmer 7 by expanding its diameter toward the housing 1. On the other hand, since the resin material has a larger coefficient of linear expansion than aluminum, the clearance adjusting member 5 interposed between the housing 1 and the outer ring 2 expands more than the housing 1 as shown in FIG. The outer diameter surface 2a is pressed toward the inner diameter side. Therefore, the outer ring 2 slightly bends toward the inner diameter side,
Maintain radial clearance 7 in proper amount.

In the present embodiment, the present invention is applied to the needle roller bearing, but the present invention is not limited to this, and can be applied to general radial bearings such as cylindrical roller bearings and deep groove ball bearings. Further, as the clearance adjusting member, one having a resin material coated on the outer diameter surface of the outer ring or the fitting surface of the housing may be used.

[Advantage of the Invention] According to the present invention, since the radial clearance of the bearing is always maintained at an appropriate amount by the clearance adjusting member,
It is possible to prevent deterioration of bearing performance such as acoustic characteristics and vibration characteristics.

[Brief description of drawings]

 1 and 2 are sectional views showing an embodiment of the present invention, and FIG. 3 is a sectional view showing a conventional radial bearing. 1: Housing, 2: Bearing outer ring 1a: Mating surface, 2a: Outer diameter surface 5: Clearance adjusting member, 7: Radial clearance

Claims (1)

(57) [Scope of utility model registration request] Claim: What is claimed is: 1. An outer ring having an outer raceway surface on the inner circumference and fitted into a housing by an outer diameter surface, a rolling element interposed between the outer raceway surface of the outer ring and an inner raceway surface opposite to the outer raceway surface, and an outer ring. Of the outer ring, the housing, and the material forming the skimmer adjusting member, the coefficient of linear expansion of the material forming the outer ring, the housing, and the skimmer adjusting member When the housing is thermally expanded, the outer race is bent toward the inner diameter side by thermal expansion of the skimmer adjusting member to prevent an increase in radial skimmer between the inner raceway surface and the rolling elements. Clearance adjustable radial bearing.