To continuously lower both discharge pressure and discharge capacity of a pump down to zero when revolving speed of a driving shaft is excessive and obtain both discharge pressure and discharge capacity as nearly high as those of a fixed discharge capacity type pump for high discharge capacity operation.
In housings 2, 3, a large number of semicircular grooves 12a, 12b are formed in the radial direction on the side surface of a disc-like impeller 11 installed in a driving shaft 6, while working chambers 18, 19 as nearly an annular groove having a semicircular sectional form and facing the grooves 12, 13 are formed on the inner wall surface of the housings 2, 3. A discontinuous part of the working chambers 18, 19 remains in between a neighboring intake port 16 and a discharge port, and both ends of it are connected to the intake port and discharge port, respectively. The discontinuous part of the working chambers 18, 19 comprises piston-like movable partitioning parts 22, 23 for controlling the quantity of liquid leaking from the discharge port side into the intake port 16 side by opening/closing a gap between the side surface of the impeller 11 and the inner wall surface of the housings 2, 3.
ONIMARU SADAHISA
MATSUI HIROHITO
INAGAKI MITSUO
MORIKAWA TOSHIO
DENSO CORP