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Abstract

A device for reducing friction in a variable flow rate oil pump in which two discharge ports are provided and which uses three rotors while maintaining characteristics identical to the pressure characteristics of a common oil pump. The device is configured from a first discharge passage to an engine, a return passage that returns to an intake side of an outer circumferential side rotor, a second discharge passage to the engine, a return passage that returns to an intake side of an inner circumferential side rotor, and a pressure control valve whose valve main body is provided between a discharge port from the inner circumferential side rotor and the first discharge passage. The first discharge passage and second discharge passage are coupled, and a flow passage control is executed in each of: a low revolution range in a state in which only the first discharge passage and the second discharge passage are open; an intermediate revolution range in a state in which the first discharge passage and second discharge passage are open and a first intake side of the return passage is closed while a second intake side of the return passage is open; and a high revolution range in a state in which the second discharge passage is closed while the first discharge passage and the return passage are open.

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First Claim