摘要 |
<p>A piston ring formed from a plastics material and having a maximum pressure against the associated cylinder of between 0.10 and 1.50 MN/m2 and preferably 0.50 MN/m2. One possible material for such piston rings is polyetheretherketone. The benefits obtained are greater conformability which leads to a reduction in the number of piston rings which need be used for a particular piston. This in turn reduces friction so increasing the performance of the associated engine. Acceptable wear rates and ability to withstand operating temperatures have been found in these piston rings.</p> |