| 摘要 |
PURPOSE:To reduce the fluctuation in the flow rate of a single pumping chamber, by providing the cross section of the inside circumferential surface of a cam ring with a form made by synthesizing a sine wave with a wave three times higher in frequency than the sine wave, at a prescribed ratio. CONSTITUTION:A pump with thirty-three cylinders comprises three eccentric cam rings 30 and eleven vanes 20. The cross section of the inside circumferential surface of the cam ring 30 is provided with a form which is made by synthesizing a sine wave with a wave three times higher in frequency than the sine wave, at an appropriate ratio, and accords to a formula R(theta)=a+(b/2)X{1+(9sin3theta+NXsin9theta)/(9-N)} where R(theta) denotes the distance between the center of gyration of a rotor 40 and the inside circumferential surface of the cam ring 30, a and b constants, and N an optional number within a range of 0.4<=N<=1.2. As a result, the fluctuation in the flow rate of a suction port is very much reduced. |
