| 摘要 |
<p>The nut or screw (9) fixing the piston (7) to the piston rod (1) is recessed, allowing the cover (14) to be made from flat plate. The dead space in the vacuum chamber (13) is also reduced. The valves (25,27) in the secondary vacuum chamber (12) are installed in the main casing (4) directly beneath the piston (7). An oil seal valve (20) closed by a spring (19) against the flow is axially guided by three guide bars (21) in the base (22) of a tube (17) screwed into the main pump body (4).</p> |
