| 摘要 |
PURPOSE:To improve the characteristics of lubrication in the neighbor of an upper dead point by enabling to apply oil to the surface of a wall of cylinder around the upper dead point of a piston, by a method wherein two rings are installed to the grooves of rings of a piston which slides on the inside of a cylinder, with some clearance in the axial direction. CONSTITUTION:The ring grooves 12a-12c are formed on the external surface of a piston 11 which reciprocate slidingly contacting with the inside of a cylinder 10, at the predetermined intervals in the axial direction, and to these grooves, the first and the second rings 13 and 14, and an oil ring 15 are installed, respectively in order from the upper position. The above-mentioned, the first ring 13 is consisted of two piston rings 16 and 17, which are combined with each other, so as to reduce the external diameter in accordance with the tapered surfaces 16A and 17A, formed on the respective external surface, axially put in layers, are separated from each other, and a back up ring 19, installed so as to seal the internal surfaces of two piston rings 16 and 17. With such an arrangement, the clearance between both rings 16 and 17 is reduced around the upper dead point of a piston 11, and the lubricating oil accumulated in the clearance is pushed out to the surface of a wall of cylinder 11. |
