| 摘要 |
<p>A piston accumulator comprising a piston (2) reciprocating within the bore of a cylinder (4) to divide the bore into a hydraulic chamber (5) and a gas chamber (6). The piston (2) includes a piston-poppet assembly (1) to equalise substan- tiallythe liquid-gas pressure appearing across the piston seal (13). The assembly (1) projects into the hydraulic chamber (5) from its housed position within a socket recess (15) formed in the piston (2). In response to an excess pressure differential between the gas chamber (6) and liquid chamber (5) of the accumulator, the assembly (1) prematurely seals off the hydraulic passage (9) which communicates with the hydraulic chamber (5) of the accumulator. This premature sealing operation traps and pressurises a small portion of hydraulic liquid within the reduced hydraulic chamber (5) so that the pressure differential which would otherwise appear across the piston seal (13) is reduced or eliminated.</p> |
