Patent ID: 6261066
Filing Date: 2001-07-17
Classification: F04B,F15C,F16K

Abstract:
A micromembrane pump comprising:a pump membrane which is adapted to be moved to a first and a second position with the aid of a drive means; anda pump body connected to said pump membrane so as to define a pump chamber between these two components,said pump body being defined by two semiconductor plates having each formed therein a valve seat and a valve flap which are formed integrally with the respective semiconductor plate, the two semiconductor plates being connected in such a way that a respective passive non-return valve is defined by a valve seat of one semiconductor plate and by a valve flap of the other semiconductor plate, one of said passive non-return valves being arranged in an inlet opening penetrating both semiconductor plates, whereas the other of said non-return valves is arranged in an outlet opening penetrating both semiconductor plates,said pump membrane increasing the volume of the pump chamber substantially by a stroke volume when moving from the first to the second position and reducing the volume of the pump chamber substantially by a stroke volume when moving from the second to the first position, whereinwhen the pump membrane is at the first position, the ratio .epsilon. of the stroke volume to the volume of the pump chamber satisfies the following equation: ##EQU4##wherein p.sub.0 is the atmospheric pressure, .GAMMA. the adiabatic coefficient, and .DELTA.p.sub.crit the maximum pressure value which depends on the valve geometry and on the wetting of the valves and which is required for opening the valves.