Piston
US5839351A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Feb 3, 1997 |
| Grant date | Nov 24, 1998 |
| Priority date | — |
| Expiry date | Feb 3, 2017 |
Classification
- Technology area (CPC F)Mechanical Engineering; Lighting; Heating
- CPC primaryF05C2251/042
- WIPO fieldEngines, pumps, turbines
- WIPO sectorMechanical engineering
Abstract
In this piston, oil grooves 5 are provided in the selected parts of a surface of a skirt portion 3 which are liable to encounter the breakage of an oil film, and which are on the thrust side and anti-thrust side, and not in the parts of the surface of the skirt portion to which a load is imparted. The oil grooves 5 are formed in the positions higher than a piston pin 22 and lower than piston ring grooves 12, and cooling cavity 45 and oil grooves 5 communicate with each other by oil passages 47, the cooling cavity 45 and a lower open end 48 of a piston body 1 communicating with each other by an oil passage 46. Accordingly, even when the piston is inclined toward the anti-thrust direction, an oil is supplied to the clearances between outer members 7 and skirt portion 3, and the breakage of an oil film does not occur. Even when the piston body is inclined toward the thrust side and going to collide with the outer members 7, a satisfactory oil film is formed securely in the portion of the clearance which is around the colliding portion of the piston body, and the oil in the clearance is forced out. Thus, the colliding force of the piston against a cylinder liner is lessened by the oil,…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.