Pump device

Abstract

The purpose of the present invention is to suppress the occurrence of unevenness in a rotor of an internal gear pump, suppress the formation of gaps between the end surfaces (side surfaces) of an inner rotor and an outer rotor, and to prevent a decline in volume efficiency. Thus, the pump device of the present invention includes an internal gear pump ( 10 ), in which an inner rotor ( 13 ) is inscribed to an outer rotor ( 12 ), and includes a plate member ( 7 ) which is provided to an end surface of the rotors. The plate member ( 7 ) is formed of a material having high hardness, has a shape that does not block a suction port ( 150 ), has a through-hole ( 73 ) formed therein, and has O-ring grooves ( 71,72 ), which each have a continuous shape and house an O-ring formed therein.

1 . A pump device characterized in that the pump device comprises an internal gear pump in which an inner rotor is inscribed to an outer rotor, wherein a plate member is provided on end surfaces of the rotors, and the plate member is made of a material with high hardness, formed into a shape which does not block a suction port, has a through-hole formed therein, and also has O-ring grooves formed thereon which have continuous shapes and in which O-rings are accommodated therein. 
     
     
         2 . The pump device according to  claim 1 , wherein, in the present invention, said O-ring grooves are formed on a surface of the plate member which is apart from the rotors, and the O-rings are attached in the O-ring grooves with a prescribed tightening margin. 
     
     
         3 . The pump device according to  claim 1 , wherein a blind space is formed in the plate member on an opposite side of the rotors, and elastic members are accommodated in the blind space.