| 摘要 |
<p>The control piston (22) is arranged in the short-circuiting by-pass bore (20) of a variable-output hydraulic pump (10). In its middle position, corresponding with the zero-output setting of the pump, it connects the pump flow and return lines (12, 14), as it does in its end positions, so as to limit pressure build-up. In other positions it separates the lines (12, 14). The hollow piston has bores in its cylindrical wall which can register with bores (34) in the by-pass housing (24) to provide an additional by-pass, whilst the latter passage is closed when the piston moves outside its middle position area.</p> |
