| 摘要 |
A double-acting piston and cylinder assembly has a piston which in turn has an outer piston surface centered on an axis, a radially outwardly open piston groove and a pair of axially oppositely facing piston ends. The cylinder has an inner surface centered on the axis and spaced radially outside the outer piston surface. A tubularly annular element received in the piston groove has an outer surface centered on the axis and bearing radially outwardly on the cylinder so the piston is guided in the cylinder by the outer element surface. The annular element has an element groove open radially inwardly to the piston between the end element surfaces and having a pair of axially spaced element-groove flanks, a pair of seal lips axially level with the element groove and having juxtaposed seal-lip ends lying when unstressed radially outside the outer element surface but normally bearing against the cylinder surface, and radially inner web surfaces exposed in the element groove, and respective end scraper lips having respective outer scraper-lip ends extending axially beyond the piston ends and lying when unstressed radially outside the outer element surface but normally bearing radially outward on the cylinder surface. The assembly also has an elastomeric ring in the element groove bearing radially inward on the piston and radially outward on the inner lip surfaces. Thus the ring urges the webs elastically outward against the cylinder surface.
|
