Variable flow pump

摘要

A variable flow pump incorporating a flexible cam ring 6. The variability of the discharge flow rate of the pump is controlled by varying the shape of the cam ring. The shape of the cam ring may be controlled by the pressure of fluid contained in high pressure regions 14 located between the cam ring 6 and an outer ring 7 which supports the cam ring 6. The pressure within regions 14 is preferably linked to the pressure of the outlet port of the pump such that the pump can be self-compensating (i.e. a high pressure at the outlet corresponding to a low discharge flow rate). <IMAGE>