Sliding bearing
A helically continuous projection 1a is formed around a sliding surface 1A of a sliding bearing 1 at a given pitch p. The surface roughness h of the sliding surface 1A, including the projection 1a, is chosen to be equal to or less than one-half the height H of the projection. This provides a sliding bearing 1 which exhibits an improved running-in performance.
Latest Taiho Kogyo Co., Ltd. Patents:
The invention relates to a sliding bearing, and more particularly, to a sliding bearing having an annular projection formed on a sliding surface thereof.
BACKGROUNDA sliding bearing having an annular projection formed around its sliding surface is disclosed, for example, in Japanese Patent Publication No. 11,530/1988. However, in the disclosed sliding bearing, no consideration is paid to the relationship between the roughness of the sliding surface including the surface of the annular projection and the height of the annular projection.
DISCLOSURE OF THE INVENTIONThe present inventor has found that running-in performance of the sliding surface of a sliding bearing can be improved by a suitable choice of the roughness of the sliding surface, including the surface of the annular projection, and the height of the annular projection. Specifically, in a sliding bearing having a plurality of annular projections formed to a given height around the sliding surface, in accordance with the invention, the roughness of the sliding surface, including the surface of the annular projections, is chosen to be equal to or less than one-half the height of the annular projections. With this arrangement, the running-in performance of the sliding bearing can be improved over the prior art, as will be demonstrated by results of experiments conducted, which will be described later.
The invention will now be described with reference to an embodiment shown in the drawings.
As shown to an enlarged scale in
In this embodiment, the surface roughness h over the entire sliding surface 1A, including the surface of the projection 1a, is chosen to be equal to or less than one-half the height H of the projection 1a. Thus, when a height H of 4 μm is chosen for the projection 1a, the surface roughness h over the entire sliding surface 1A is chosen to be equal to or less than 2 μm.
In
In the embodiment described above, the projection 1a is formed so as to be continuous in a helical configuration, but a plurality of annular projections which are spaced apart axially at a given pitch may be used instead as well.
Claims
1. A sliding bearing having a plurality of annular projections formed to a given height around a sliding surface; characterized in that a surface roughness of the sliding surface, including the surface of the annular projections, is chosen to be equal to or less than one-half the height of the annular projections, and in which the height of the projections is in a range from 2 to 10 μm, and the height of the projections in microns is denoted by H and the roughness in microns is denoted by h, these parameters being related by the following inequality:
- h≦0.25H+0.5.
2. A sliding bearing according to claim 1 in which the height of the projection in microns is denoted by H and the roughness in microns is denoted by h, these parameters being related by the following inequality:
- h≦0.25H+0.5.
3. A sliding bearing according to claim 1 in which the height of the projections is in a range from 2 to 10 μm.
4. A sliding bearing according to claim 1 having a plurality of annular projections formed to a given height around a sliding surface; characterized in that a surface roughness of the sliding surface, including the surface of the annular projections, is chosen to be equal to or less than one-half the height of the annular projections, and in which the height of the projections is in a range from 3 to 5 μm.
5. A sliding bearing according to claim 1 in which the pitch between axially adjacent projections is in a range from 0.1 to 0.4 mm.
6. A sliding bearing according to claim 4, in which the pitch between axially adjacent projections is in a range from 0.1 to 0.4 mm.
7. A sliding bearing according to claim 1, in which the height of the projections is in a range from 3 to 5 μm.
8. A sliding bearing according to claim 7, in which the pitch between axially adjacent projections is in a range from 0.1 to 0.4 mm.
9. A sliding bearing having a plurality of annular projections formed to a given height around a sliding surface; characterized in that a surface roughness of the sliding surface, including the surface of the annular projections, is chosen to be equal to or less than one-half the height of the annular projections, and the height of the projections is in a range from 2 to 6 μm.
10. A sliding bearing according to claim 9, in which the height of the projection in microns is denoted by H and the roughness in microns is denoted by h, these parameters being related by the following inequality:
- h≦0.25H+0.5.
11. A sliding bearing according to claim 9, in which the pitch between axially adjacent projections is in a range from 0.1 to 0.4 mm.
12. A sliding bearing according to claim 10, in which the pitch between axially adjacent projections is in a range from 0.1 to 0.4 mm.
13. A sliding bearing having a plurality of annular projections formed to a given height around a sliding surface; characterized in that a surface roughness of the sliding surface, including the surface of the annular projections, is chosen to be equal to or less than one-half the height of the annular projections, and the height of the projections is in a range from 2 to 5 μm.
14. A sliding bearing according to claim 13, in which the height of the projection in microns is denoted by H and the roughness in microns is denoted by h, these parameters being related by the following inequality:
- h≦0.25H+0.5.
15. A sliding bearing according to claim 13, in which the pitch between axially adjacent projections is in a range from 0.1 to 0.4 mm.
16. A sliding bearing according to claim 14, in which the pitch between axially adjacent projections is in a range from 0.1 to 0.4 mm.
4561787 | December 31, 1985 | Ehrentraut et al. |
5094550 | March 10, 1992 | Momose et al. |
5211483 | May 18, 1993 | Blaurock |
5238311 | August 24, 1993 | Katou et al. |
U-63-30619 | February 1988 | JP |
B2-63-11530 | March 1988 | JP |
U-63-53922 | April 1988 | JP |
B2-2-36825 | August 1990 | JP |
A-4-54311 | February 1992 | JP |
Y2-4-39461 | September 1992 | JP |
- Translation of Sep. 29, 1999 Decision in Japanese Opposition.
- JIS Handbook 1989, Machine Elements.
- Fig. No. W-31049, Oct. 1986 (and partial translation).
- Bearing Wear and Countermeasure, p. 262, Mar., 1971 (and partial translation).
- Grinding Process Technology Manual, “Lubrication of a Sliding Surface with Uniform Irregularities”, Suenaga et al., 1970 (and partial translation).
Type: Grant
Filed: Mar 17, 1995
Date of Patent: Sep 6, 2005
Assignee: Taiho Kogyo Co., Ltd. (Aichi)
Inventors: Makoto Shibata (Toyota), Masao Takahashi (Toyota)
Primary Examiner: Donald J. Loney
Attorney: Oliff & Berridge, PLC
Application Number: 10/207,958