| 摘要 |
<p>A pump (100) for fluid, comprising a pump body (102) defining a bore (104), a pumping plunger (108) having an end region which is slidably received within the bore, a spill port (154) defined by the pump body (102) in a wall of the bore (104) which port is coverable by the end region of the pumping plunger (108) as the plunger is driven on a pumping stroke, in use, so as to initiate fluid pressurisation within a pumping chamber (134); and a spill groove (172) defined by the pumping plunger (108) being arranged to uncover the spill port (154) during a pumping stroke so as to cause depressurisation of the pumping chamber (134). The pumping plunger (108) further defines a speed sensitive feature (176) configured to permit a controlled leak of fluid from the pumping chamber (134) to the spill port (154) towards the end of a pumping stoke. The invention also encompasses a pumping plunger particularly suited for use in the above described pump.</p> |
