JPH11101229A - Roller bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously and sufficiently absorb both axial directional displacement and misalignment by forming an orbital plane of an inner ring in a cylindrical surface shape, forming an orbital plate of an outer ring in a spherical surface shape, and forming an axial directional central part in a cylindrical surface part and both end parts in a projecting curved surface part respectively of a roller interposed between both rings. SOLUTION: In an inner ring 1, an outside diameter surface is formed on an orbital plane of a cylindrical shape. In an outer ring 2, the almost whole of an inside diameter surface is formed as an orbital plane of a spherical surface shape. A roller 3 is formed in a barrel shape where an axial directional central part is formed in a cylindrical surface part 3a and both end parts are formed in a projecting curved surface part 3b, and is almost densely juxtaposed between these inner and outer rings 1 and 2. By this constitution, the automatic aligning action can be obtained by contact of the orbital plane of the outer ring 2 being a spehrical surface shape and the projecting curved surface part 3b of the roller 3, and misalignment γ of a shaft 6 with a housing is absorbed. Axial directional elongation by thermal expansion of the shaft 6 fixed to the inner ring 1 by contact of the inner ring 1 being a cylindrical surface shape and the cylindrical surface part 3a of the roller 3, can also be absorbed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a roller bearing used for a portion where both elongation due to thermal expansion of a shaft and misalignment due to a mounting error occur, for example, for supporting a dryer roll used in a papermaking machine. About.

[0002]

2. Description of the Related Art In a bearing for supporting a dryer roll used in a papermaking machine, a shaft may be elongated by hot air for drying the paper, and at the same time, misalignment may occur due to a mounting error or the like. Conventionally, in such places of use,
Self-aligning or cylindrical roller bearings are commonly used.

[0003]

However, self-aligning bearings can tolerate misalignment, but can hardly tolerate elongation of the shaft. Further, in a cylindrical roller bearing, elongation of the shaft can be allowed, but misalignment can hardly be allowed. Therefore, there is a problem that satisfactory support is difficult when using either type of bearing. Roller bearings that can tolerate both axial displacement and misalignment have been proposed.However, this type of conventional bearing has both inner and outer rings formed with curved surfaces where the axial cross section of the raceway surface is curved. Because
It is difficult to allow sufficient axial displacement.

An object of the present invention is to solve the above-mentioned problems, and an object of the present invention is to provide a roller bearing capable of simultaneously sufficiently absorbing both axial displacement and misalignment.
Another object of the present invention is to provide a roller bearing in which the contact surface pressure used between the rollers and the inner and outer rings can be equalized, thereby preventing the progress of local wear and the reduction in load capacity. It is to be.

[0005]

The roller bearing according to the present invention comprises:
A flangeless inner ring having a cylindrical raceway surface, an outer ring having a spherical raceway surface, an axial center portion formed between the inner ring and the outer ring, the center portion in the axial direction being formed on the cylindrical surface portion, and both ends being outer rings. And a roller formed on a convex curved surface portion having a curvature along the spherical raceway surface. According to this configuration, the self-aligning action is obtained by the contact of the spherical outer raceway with the convex curved surface portion at the raceway surface, and the misalignment of the shaft with respect to the housing can be absorbed. Further, the axial displacement of the shaft fixed to the inner ring can be absorbed by contact with the cylindrical surface portion at the raceway surface of the cylindrical inner ring.

In the roller bearing having the above configuration, it is preferable that the axial length of the cylindrical surface portion of the roller and the sum of the axial lengths of the convex curved surface portions on both sides are substantially the same. Thereby, the contact surface pressure acting between the rollers and the inner ring and the contact surface pressure acting between the rollers and the outer ring become substantially equal. Therefore, the wear does not locally progress at the contact portion between the roller and the inner and outer rings, and the load capacity is not limited at a place where the contact surface pressure is high, so that a decrease in the load capacity is prevented. .

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. This roller bearing is configured as a single row roller bearing in which a roller 3 is interposed between an inner ring 1 and an outer ring 2. The rollers 3 are arranged substantially densely between the inner and outer rings 1 and 2, and are so-called full-roller type bearings, and no cage is used. The inner ring 1 has a raceway surface 1a having a cylindrical outer diameter surface.
And a flangeless type. Outer ring 2
Substantially the entire inner diameter surface is a spherical raceway surface 2a. The spherical raceway surface 2a is formed with a radius of curvature R whose center of curvature coincides with the center of the bearing. Roller 3
It has a barrel shape in which a central portion in the axial direction is formed on the cylindrical surface portion 3a and both ends are formed on the convex curved surface portion 3b. The convex curved surface portion 3b has a cross section along the axial direction that is a curve along the spherical raceway surface 2a of the outer race 2. The convex curved surface portion 3b is formed into a rotating body-shaped convex curved surface obtained by rotating this curve around the roller center. ing. The axial length A of the cylindrical surface portion 3a of the roller 3 is substantially equal to the sum of the axial lengths B of the convex curved surface portions 3b on both sides.
That is, A ≒ 2 × B. At the center in the width direction of the outer ring 1, an oil groove 4 for lubrication formed of a circumferential groove is formed. Have been.

[0008] According to the roller bearing of this configuration, the self-aligning action is obtained by the contact between the raceway surface 2a and the convex curved surface portion 3b of the spherical outer ring 2 at the position 3 as shown in FIG. 2 (A). 6 can absorb the misalignment γ with respect to the housing (not shown). In addition, the contact between the raceway surface 1a and the cylindrical surface portion 3a of the cylindrical inner ring 1 at the cylindrical surface portion 3a can absorb the axial elongation due to the thermal expansion of the shaft 6 fixed to the inner ring 1. Further, since the raceway surface 1a of the inner ring 1 is a cylindrical surface, the inner ring 1 can be separated from the assembly of the outer ring 2 and the rollers 3, and the incorporation of the inner ring 1 into the shaft 6 is facilitated. Further, since the oil hole 5 is formed in the outer ring 2, lubrication performance is improved. This oil hole 5
According to the conventional single row rolling bearing, since the opening is formed on the raceway surface, the formation of the rolling bearing is difficult to perform due to the deterioration of the function. However, in the roller bearing of the present invention, the oil hole 5 is formed. Since the outer ring inner diameter surface portion is a portion corresponding to the cylindrical surface portion 3a of the roller 3 and is a portion that does not contact the roller 3,
The roller 3 is not adversely affected.

In this embodiment, the axial length A of the cylindrical surface portion 3a of the roller 3 and the sum (B + B) of the axial length B of the convex curved surface portions 3b on both sides are substantially the same. The contact surface pressure acting between the inner ring 1 and the inner ring 1 and the contact surface pressure acting between the roller 3 and the outer ring 2 become substantially equal. Therefore, the wear does not locally progress at the contact portions between the rollers 3 and the inner and outer rings 1 and 2, and the load capacity is not limited at the place where the contact surface pressure is high, and the load capacity is reduced. Is prevented.

In the above-described embodiment, a case in which the cage is not provided is described. However, as shown in FIG. 3, a cage 7 for holding the rollers 3 may be provided. The example of FIG. 7 is the same as the example of FIG. 1 except for the configuration in which the retainer 7 is provided.

[0011]

According to the roller bearing of the present invention, the raceway surface of the inner ring is cylindrical, the raceway surface of the outer ring is spherical, and the roller is interposed between the two wheels. Since the portions are formed on the convex curved surface portions, both the axial displacement and the misalignment can be sufficiently absorbed simultaneously. When the axial length of the cylindrical surface portion of the roller and the sum of the axial lengths of the convex curved surface portions on both sides are substantially the same length, a contact surface pressure acting between the roller and the inner ring,
Since the contact surface pressure acting between the rollers and the outer ring can be made uniform, it is possible to prevent the progress of local wear and the reduction of the load capacity.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a roller bearing according to an embodiment of the present invention.

FIG. 2 is an explanatory diagram of the operation.

FIG. 3 is a sectional view of a roller bearing according to another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Inner ring 2 ... Outer ring 3 ... Roller 3a ... Cylindrical surface part 3b ... Convex curved surface part 5 ... Oil hole

Claims (2)

[Claims] 1. A collarless inner ring having a cylindrical raceway surface, an outer ring having a spherical raceway surface, and an axially central portion formed between the inner ring and the outer ring is formed in the cylindrical surface portion. And a roller having both ends formed on a convex curved surface portion having a curvature along the spherical raceway surface of the outer ring. 2. The roller bearing according to claim 1, wherein the axial length of the cylindrical surface portion of the roller and the sum of the axial lengths of the convex curved surface portions on both sides are substantially the same length.