Patent ID: 6364640
Filing Date: 2002-04-02
Classification: F04B

Abstract:
A pump with a pulsation suppression device comprising:a pump head wall having inflow and out-flow passages for liquid; an air-driven reciprocal pump portion comprising: a first bellows which is made of a resin, and which is extendable and contractible in an axial direction in a casing that is disposed in one side portion of said pump head wall; an air cylinder portion which drives said first bellows so as to extend and contract; and a pump working chamber in which a check valve for sucking and a check valve for discharging are disposed inside said first bellows, said check valves being alternately opened and closed in accordance with the extending and contracting operations of said first bellows to suck and discharge the liquid; and a pulsation suppressing portion comprising: a second bellows which is made of a resin, which is disposed in a casing that is disposed in another side portion of said pump head wall, and which is extendable and contractible; a liquid chamber which is formed inside said second bellows, and which can temporarily store the liquid that is to be discharged from said pump working chamber via said discharge check valve; and an air chamber which is formed outside said second bellows to be isolated from said liquid chamber, and which is to be filled with air for suppressing pulsation, said pulsation suppressing portion causing pulsation due to a discharge pressure of the liquid which is discharged from said pump working chamber, to be absorbed by a change in a capacity of said liquid chamber due to the extending and contracting operations of said second bellows, wherein an extension rate of said second bellows is set to be larger than an extension rate of said first bellows.