PURPOSE: To perform simple and accurate detection of the feed of resin by arranging a sensor, which detects arrival of resin before the starting of operation, to a recovery circuit which returns resin, fed to a clearance formed between a pump housing and a gear rotor, to a suction port.
CONSTITUTION: A pair of gear rotors 6 comprising a gear part 4 and a shaft part 5 are rotatably disposed, in a state to be geared with a gear part 4, in a pump housing 3 having a suction port and a delivery port. A plurality of clearances A and B in which resin is caused to flow from the gear part 4 are formed between the journal bearing body 30 of the pump housing 3 and the shaft part 5 of the gear rotor 6. Further, a circuit 8 through which resin in each clearance 7 is returned to the suction port is formed. In which case, since a sensor 40 to detect arrival of resin fed before the starting of operation is arranged to the recovery part 8, it is simply and accurately detected that the resin is fed to each clearance 7.
FUKUMIZU SHINICHI
ORIMO YASUJI