JPH10299764A - Slide bearing - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a slide bearing capable of preventing leakage of lubricant even if it is affected by outside disturbance during rotation. SOLUTION: A slide bearing is provided with a sleeve, a shaft inserted through a through hole of the sleeve, and lubricant filled in a clearance between the sleeve and the shaft, and the sleeve and the shaft are relatively rotated. In this case, the inner peripheral surface of the end of the through hole 2 of the sleeve 1 is taken as a conical surface 6 whose inside diameter is increased toward the releasing side, a spiral groove 7 extending in such a direction that lubricant 4 may be allowed to flow into the sleeve 1 when the sleeve 1 and the shaft 3 are relatively rotated is formed on at lease either the conical surface or the shaft part facing the conical surface 6, and the spiral groove 7 is continuously formed into one line in the axial direction in a state where respective grooves mutually adjacent to each other are directly connected to each other.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a sliding bearing.

[0002]

2. Description of the Related Art Conventionally, as shown in FIG.
A shaft 42 inserted into the through hole 41 of the sleeve 40;
Lubricant 43 sealed in the gap between sleeve 40 and shaft 42
A sliding bearing in which a dynamic pressure bearing 44 is provided between the sleeve 40 and the shaft 42 and the sleeve 40 and the shaft 42 rotate relative to each other is known.

[0003]

In the above-mentioned conventional plain bearing, there is a problem that the lubricant 43 leaks from the open end 40a of the sleeve 40. Therefore,
The inner peripheral surface of the end portion 40a of the sleeve 40 is formed into a cylindrical surface slightly larger in diameter than the other inner peripheral surface, and the internal lubricant is utilized by utilizing the surface tension in the gap between the cylindrical surface and the outer peripheral surface of the shaft. Although it has been considered to prevent the leakage of lubricant, even with this structure, there still remains a problem that the leakage of the lubricant cannot be sufficiently prevented due to the influence of disturbance during rotation of the slide bearing.

Accordingly, an object of the present invention is to provide a sliding bearing which can prevent leakage of a lubricant even under the influence of disturbance during rotation.

[0005]

Means for Solving the Problems As means for solving the above problems, in claim 1, a sleeve, a shaft inserted in a through hole of the sleeve, and a lubricant sealed in a gap between the sleeve and the shaft are provided. In the sliding bearing in which the sleeve and the shaft rotate relative to each other, the inner peripheral surface at the end of the through hole of the sleeve is a conical surface whose inner diameter increases toward the open side, and faces the conical surface and the conical surface. At least one of the shaft portions is formed with a spiral groove in a direction in which the lubricant is drawn into the sleeve when the sleeve and the shaft rotate relative to each other, and the spiral groove is formed in a state in which the axially adjacent grooves are directly coupled. And is formed continuously.

According to a second aspect, the sleeve includes:
In a plain bearing having a shaft inserted into a through hole of a sleeve and a lubricant sealed in a gap between the sleeve and the shaft, the shaft facing the end of the through hole of the sleeve in a sliding bearing in which the sleeve and the shaft rotate relative to each other. The portion is a conical surface that reduces the outer diameter toward the sleeve opening side, and at least one of the conical surface and the inner peripheral surface of the through hole of the sleeve facing the conical surface receives lubricant during relative rotation of the sleeve and the shaft. A spiral groove in the direction of being drawn into the sleeve is formed, and this spiral groove is
Each of the grooves adjacent to each other in the axial direction is directly connected to each other, and is continuously formed in a single line.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. FIGS. 1 and 2 show an embodiment of a sliding bearing according to the present invention, which is sealed in a sleeve 1, a shaft 3 inserted into a through hole 2 of the sleeve 1, and a gap between the sleeve 1 and the shaft 3. And a lubricant 4.
A dynamic pressure bearing portion 5 is provided between the sleeve 1 and the shaft 3 by a herringbone-shaped dynamic pressure groove formed on the shaft 3, and the sleeve 1 and the shaft 3 are relatively rotated.

The inner peripheral surface at the end of the through hole 2 of the sleeve 1 is a conical surface 6 whose inner diameter increases toward the open side,
A spiral groove 7 into which the lubricant 4 is drawn from the open side of the sleeve 1 when the shaft 3 rotates is formed on the conical surface 6, and the spiral groove 7 is in a state in which adjacent grooves in the axial direction are directly connected. Are formed continuously in a single line, and as a result,
No flat hill portion is formed between the adjacent grooves 8 in the axial direction. The spiral groove 7 is set so that the lubricant 4 is drawn into the sleeve 1 from the open side when the sleeve 1 and the shaft 3 rotate relative to each other. For example, when the shaft 3 rotates clockwise, the spiral groove direction is formed counterclockwise.

FIG. 3 shows another embodiment, in which a portion of the shaft 3 facing the end of the through hole 2 of the sleeve 1 is formed as a conical surface 3a whose outer diameter decreases toward the open side of the sleeve 1. A spiral groove 7 is formed on the inner peripheral surface of the through hole 2 of the sleeve 1 facing the sleeve 3a in a direction in which the lubricant 4 is drawn into the sleeve 1 when the sleeve 1 and the shaft 3 rotate relative to each other. As in the first embodiment, the grooves adjacent to each other in the axial direction are formed continuously in a single line in a state of being directly connected.
This embodiment has the advantage that when the sleeve 1 rotates, it is less susceptible to centrifugal force.

In the embodiments shown in FIGS. 1 and 2, the spiral groove 7 is formed on the sleeve side. However, the spiral groove 7 may be formed on the shaft 3 side, or may be formed on both the sleeve 1 and the shaft 3 as necessary. Is also good.

The operation of the present invention will be described. When the sleeve 1 and the shaft 3 rotate relative to each other, the lubricant 4 expands in volume due to a temperature change inside the sleeve 1 and tries to leak from the end of the sleeve 1. However, the lubricant is sealed inside by the surface tension of the conical surface portion and is sealed outside. Leakage is prevented. At this time,
Since the volume between the sleeve 1 and the shaft 3 at the conical surface is large, the space for holding the lubricant 4 is large, and the sealing effect due to the surface tension of the lubricant 4 is improved. Further, the lubricant 4 is drawn into the inside by the spiral groove 7 in the conical surface portion, and the leakage of the lubricant is more effectively prevented. In general, the surface tension becomes weaker as the surface has irregularities of a certain width. However, the spiral groove 7 can maintain a high surface tension because there is no flat hill between the adjacent grooves 8 in the axial direction. Furthermore, the gap 8
If there is a flat hill, the flat hill has a higher surface tension than the groove, and there is a possibility that bubbles generated inside the lubricant 4 remain in the groove and are not released to the outside. There is no such fear because there are no hills.

[0012]

According to the present invention, a conical surface is formed on at least one of the inner peripheral surface of the end of the sleeve and the shaft so that the gap between the sleeve and the shaft is widened on the open side of the sleeve, and a lubricant is formed on the conical surface. The spiral groove is formed in the direction in which the spiral groove is drawn, and furthermore, this spiral groove is formed continuously in a single line in a state where the adjacent grooves in the axial direction are directly connected, so that the volume of the conical surface portion increases and the spiral groove The surface tension can be improved by the shape. Therefore, when the sleeve and the shaft rotate relative to each other, the lubricant is effectively sealed by the surface tension, and the lubricant is drawn into the inside by the spiral groove, so that leakage of the lubricant is further prevented.

[Brief description of the drawings]

FIG. 1 is a partial sectional view of one embodiment of the present invention.

FIG. 2 is an enlarged view of a sleeve end portion of FIG. 1;

FIG. 3 is a partial cross-sectional view of another embodiment of the present invention.

FIG. 4 is a partial sectional view of a conventional plain bearing.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Sleeve 2 Through-hole 3 Shaft 4 Lubricant 6 Conical surface 7 Spiral groove 8 Between grooves

Claims (2)

[Claims] A sliding bearing having a sleeve, a shaft inserted through a through hole of the sleeve, and a lubricant sealed in a gap between the sleeve and the shaft, wherein the sleeve and the shaft rotate relative to each other; The inner peripheral surface at the end of the through hole is a conical surface that increases the inner diameter toward the open side, and at least one of the conical surface and the shaft portion facing the conical surface receives lubricant during relative rotation of the sleeve and the shaft. A sliding bearing, wherein a spiral groove is formed in a direction in which the spiral groove is drawn into the inside of the sleeve, and the spiral groove is formed continuously in a single line in a state in which axially adjacent grooves are directly connected. 2. A sliding bearing having a sleeve, a shaft inserted into a through hole of the sleeve, and a lubricant sealed in a gap between the sleeve and the shaft, wherein the sleeve and the shaft rotate relative to each other. The shaft portion facing the end of the through hole is a conical surface whose outer diameter decreases toward the sleeve opening side, and at least one of the conical surface and the inner peripheral surface of the through hole of the sleeve facing the conical surface includes a sleeve and Spiral grooves are formed in the direction in which the lubricant is drawn into the sleeve during relative rotation of the shaft, and the spiral grooves are formed continuously in a single line with the axially adjacent grooves directly connected. Features sliding bearings.