The invention relates to a pump device comprising a pump
piston (12) which is longitudinally movable in a pump housing (10) and which, controlled by a
magnetic actuation apparatus (14), acts on an
inlet valve (16) and an outlet valve (18), the
inlet valve (16) opening during the intake
stroke of the pump
piston (12), and the outlet valve (18) opening during the delivery
stroke thereof. The
inlet valve (16) has an annular valve
piston (20) which encompasses the pump housing (10) which has an
entry point (22) and an
exit point (24) for fluid. The valve piston (20) has a pressure-sensing surface (26) which is controlled by the pump piston (12) in such a way that, during the intake
stroke, the pressure-sensing surface (26) of the valve piston (20) is moved counter to the action of an energy store (28) in the movement direction of the pump piston (12) and in the process vacates a fluid path into a
pump chamber (30) of the pump housing (10) by means of the pump piston (12) and, during the delivery stroke, the valve piston (20) of the inlet valve (16), under the action of the energy store (28) and the pressure-sensing surface (26), blocks this fluid path and opens the outlet valve (18).