Low friction balanced piston ring
US4040637A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Mar 4, 1976 |
| Grant date | Aug 9, 1977 |
| Priority date | — |
| Expiry date | Mar 4, 1996 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF16J9/20
- WIPO fieldMechanical elements
- WIPO sectorMechanical engineering
Abstract
A low friction piston ring of split annular construction has a circumferentially extending recess formed at its upper outer portion to define an outer radial ledge which divides the outer axial surface of the ring into a recessed outer face and a reduced (as compared to the total outer axial surface) bearing surface. The bearing surface preferably has a wear resistant coating thereon. The outside diameter of the recessed outer face is less than the outside diameter of the bearing surface by an amount at least equal to the radial wear depth of the bearing surface. A peripheral recess is also formed at the upper-inner portion of the ring to reduce or eliminate torsional twisting of the ring. The ring provides a reduction in frictional resistance between the ring and the cylinder wall, good sealing against gas blow-by and enhanced engine performance and exhaust emissions control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.