High pressure hot liquid pump piston - has radially expandable piston guide ring at least partly in recess of piston lip seal (DK 20.2.78)

摘要

The piston is intended for a pump, particularly for a high-pressure pump handling hot liquid. It comprises a piston body (2) carried on a piston rod (5) with radial play. The body has a circumferential groove (16) containing a lip seal (3) in contact with the cylinder (1) wall and an annular piston guide element (12) on the low-pressure side of the seal. The element is radially expandable, and its inner wall is in contact with the seal over at least part of its axial length. The element may be contained, at least partly, in a stepped recess (24) at the low-pressure side in the seal.