The invention relates to a method, a device and a means for driving a reciprocating linear motion double acting pump. A method for controlling a drive unit mechanically connected to a reciprocating linear-motion double-acting pump includes the use of speed-regulating control during the phase in which the piston is moving in just one direction, ascent (109) or descent (102), and the use of torque-regulating control immediately after the reversal (107, 114) of the direction of travel. The method is applicable to a control device and to a drive unit mechanically connected to a reciprocating linear-motion double-acting pump.