| 摘要 |
1. Piston ring for the pistons of damper units, such as shock absorbers, shock struts or level controllers, consisting of a steel backing and a porous layer of tin or tin-lead bronze 0.2 to 0.35 mm thick which is sinter-bonded or sprayed thereon, whereon there is a bearing layer 0.01 to 0.2 mm thick of fluorine-containing polymer, such as polytetrafluoroethylene (PTFE), polyvinylidene fluoride (PVDF) or a mixture thereof, with 10 to 50% weight lead powder with a grain size of =< 35 mu m, with which the pores of the bronze layer are also filled, and which may also optionally contain, individually or in combination, additives for improving the sliding properties or for reducing wear, such as graphite powder, molybdenum disulphide, zinc sulphide, barium sulphate, lead borosilicate, glass fibres and carbon fibres, in a quantity of 5 to 50% weight, characterised in that one front face (1, 5, 6) has a projection (2, 7, 8) at the joint surface and the other front face (3, 5, 6) has a recess (4, 9, 10) at the joint surface which corresponds to the projection in size and shape, the projection engages in the recess without play and completely seals off the operating chamber from the pressure chamber. |
