| 摘要 |
PURPOSE:To prevent a reverse flow of oil in a pump and prevent its noise, by providing a rotor groove, which communicates with a sealed space, formed by the internal tooth of an outer rotor and the external tooth of an inner rotor, in a back surface of the inner rotor and relieving the pressure oil in said space to a delivery chamber. CONSTITUTION:If an inner rotor 12 rotates, a sealed space 15, formed by an internal tooth 11a of an outer rotor 11 and an external tooth 12a of the inner rotor 12, gradually decreases the capacity not communicating with a delivery chamber 14, and the pressure of oil in the space, having no delivery part for oil of this decreased capacity, increases. If the inner rotor 12 rotates a predetermined angle, a shallow rotor groove 19, provided on a back surface of the inner rotor 12 so as to communicate with the sealed space 15, communicates with a housing groove 18. As a result, oil in the space 15 is allowed to gradually flow out to the delivery chamber 14 through the rotor grove 19 and the housing groove 18. In this way, an oil pump, blocking a reverse flow of oil to the sealed space 15 from the delivery chamber 14 and enabling the generation of a change of pressure in the space 15 to be prevented, can prevent a nose and wearing of the tooth. |
