| 摘要 |
<p>A reciprocable piston hydraulic pump is provided with a piston periphery sealing means 24 comprising, at the pressure side, a contactless seal 25 of flexible material and adapted to surround the piston periphery, a ring 27 separating the contactless seal 25 from a moulded pressure seal, with a reservoir 28 defined between the contactless seal 25 and the pressure seal, and spring means 29 operable on the contactless seal 25 to urge the latter towards the pressure seal 26.</p> |
