Reciprocating pump and check valve

Abstract

A reciprocating pump introduces a liquid into a pump chamber through a suction valve and discharges the liquid from the pump chamber through a discharge valve by reciprocating movement of a reciprocating member facing the pump chamber. The suction valve and the discharge valve include: a body portion having therein a flow path for a liquid; a valve seat portion provided at an entrance side of the flow path of the body portion and having therein a hole through which the liquid flows; a valving element provided in the body portion and able to open and close the hole of the valve seat portion; and a spring provided in the body portion for pressing the valving element into the hole of the valve seat portion. The spring has projections which are formed on an outer circumferential portion of its surface to project toward the inner wall of the body portion.

1 . A reciprocating pump which introduces a liquid into a pump chamber through a suction valve and discharges the liquid from the pump chamber through a discharge valve by reciprocating movement of a reciprocating member facing the pump chamber,
 the suction valve and the discharge valve each comprising:   a body portion having therein a flow path for a liquid;   a valve seat portion provided at an entrance side of the flow path of the body portion and having therein a hole through which the liquid flows;   a valving element provided in the body portion and able to open and close the hole of the valve seat portion; and   a spring provided in the body portion for pressing the valving element to the hole of the valve seat portion and having projections which are formed on an outer circumferential portion of its surface, the projections being projecting toward an inner wall of the body portion.   
     
     
         2 . The reciprocating pump according to  claim 1 , wherein the spring is made of resin. 
     
     
         3 . The reciprocating pump according to  claim 1 , wherein the suction valve and the discharge valve are connected to a pump head in parallel with each other such that they protrude from the pump head in a direction of a central axis of the pump head. 
     
     
         4 . A check valve, comprising:
 a body portion having therein a flow path for a liquid;   a valve seat portion provided at an entrance side of the flow path of the body portion and having therein a hole through which the liquid flows;   a valving element provided in the body portion and able to open and close the hole of the valve seat portion; and   a spring provided in the body portion for pressing the valving element to the hole of the valve seat portion and having projections which are formed on an outer circumferential portion of its surface, the projections being projecting toward an inner wall of the body portion.