A reciprocating adjustable stroke positive displacement fluid pump is provided with an expandable chamber driven in the displacement or feed direction by an eccentric drive acting through a driven member. The eccentric drive moves the expandable chamber to its limit of excursion in the displacement or feed direction. Adjustment means cooperating with stop means limits the excursion of the driven member and the expansion of the expandable chamber in the suction or intake direction so that the amount of fluid pumped is continuously adjustable from no volume to the capacity of the expandable chamber by positioning the stop means. The pump is further provided with means for driving a plurality of individually adjustable pumps from the same drive motor and with means for equalizing the load on the pump motor.
