| 摘要 |
PURPOSE:To reduce the fluctuating width of flow amount due to leakage in the pump and obtain effects capable of restricting the fluctuation of discharging flow amount as well as reducing the pulsation of pressure by a method wherein the back pressure groove of the vane and the stages relative to the leakages inbetween each pump chambers are constituted so as not to be varied by the rotating position of the vane. CONSTITUTION:When the center of the vane 21 is opposing to the beginning end of a suction port 25, the outer end of the preceding fourth vane 21 opposes to the final end of a delivery port 27. The angular width of the suction port 25 is determined so as to have a slightly smaller value then two times of the angular pitch of the vane 21 while the angular width of the delivery port 27 is determined so as to have a value in which an angle corresponding to the thickness of the vane 21 is added to the angular pitch of the vane 21. The number of sectors (chambers of pump) generating the leakage from the back pressure groove 37 of the vane toward the suction port 25 are not varied in any angular position of the vane 21. Accordingly, the change of the stages relative to the leakage will never be caused. |
