| 摘要 |
<p>The pump has a plunger (2) reciprocating in a cylinder in the casing (1). The cylinder liner (3) has an annular groove (6) to which a sealing liquid of a higher viscosity than the liquid being pumped is admitted. The sealing liquid leaks through a gap (8) between the liner and the plunger to a chamber (9) from which it returns to the reservoir (10). A pump (11) takes it from the reservoir and delivers it to the sealing groove (6) through a control cylinder (22). A piston (26) in the control cylinder is loaded on one side by the liquid being pumped and exerts a pressure on the other side on the sealing liquid. The pressure of the sealing liquid is thus controlled by that of the liquid being pumped.</p> |
