JPS6441688A - Pumping equipment - Google Patents

Abstract

PURPOSE:To make a pumping action easily stoppable by making a pressure fluid passage, interconnecting a back pressure chamber to a discharge passage at the one end side of a vane in a rotor, possible to be opened or closed by a control part, and closing the pressure fluid passage by means of this control part. CONSTITUTION:Each of rotors 5a, 5b, clamped to a turning shaft 2 and fitted with plural vanes 4a, 4b around free of slide motion in the radial direction, is rotated in respective cam rings 3a, 3b fitted in a housing 1, whereby a fluid sucked out of suction passages 12a, 12b is discharged out of discharge passages 13a, 13b after being pressurized. In side plates 6a, 6b, there are provided with pressure fluid passages 60a, 60b which interconnect back pressure chambers 50a, 50b at the vane inner end side to these discharge passages 13a, 13b. In a suchlike pumping plant, the pressure fluid passage 60a on one side is made controllable for its opening or closing with a control part 9 inclusive of a solenoid valve 90, and this valve 90 is controlled to be opened when working fluid temperature becomes more than the specified one.