| 摘要 |
PROBLEM TO BE SOLVED: To provide a simply formed and inexpensive gear pump capable of stably and securely starting an electric motor having a difficulty in startability when a high load acts on a discharge passage. SOLUTION: In inter-gear chambers 21 formed between external teeth 19 formed on the outer periphery of an inner rotor 12 and internal teeth 20 formed on the inner periphery of an outer rotor 13 and meshed with the external teeth 19, a liquid is sucked from a suction chamber 22 in an area where the liquid is expanded according to the rotation of both rotors, and discharged to a discharge chamber 3 in an area where the liquid is contracted. If the high load acts on the discharge passage when the gear pump is started, the liquid discharged to the discharge chamber 23 by the low speed rotation of both rotors is bypassed to a suction passage 26 through a bypass passage 28 with a specified flow passage resistance, and the rise of a pressure in the discharge chamber 23 is suppressed in a low speed area in starting the gear pump to reduce the rotational resistance of both rotors. Thus, the electric motor can be stably and securely started. COPYRIGHT: (C)2005,JPO&NCIPI
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