| 摘要 |
In a hydraulic pressure intensifier, a high pressure hydraulic pump (16, 17) is driven by hydraulic reciprocating drive apparatus (10) in which a reciprocable low pressure driving piston (15) carries control valve means (29, 30) operable to direct fluid from a source of fluid under pressure alternately to the opposite sides of the low pressure piston. The control valve means (29, 30) comprises mutually separate valves of which one (29) is adapted to be operable by pressure fluid and is arranged for reversing the action of the piston (15). The other valve (30) is a pilot valve arranged for controlling the action of the reversing valve (29). The action of the reversing valve (29) is bi-stable and occurs over a relatively short period of time whereas the action of the pilot valve (30) occurs at the speed of the movement of the low pressure piston (15). A feature of the low pressure drive apparatus (10) is an absence of dynamic seals in the reversing valve (29) and the pilot valve. |
