CLUTCH CONNECTED MULTI-STAGE IMPELLER PUMP

A boost pump incorporates a low-flow impeller pump for charging the inlet of a gas producer fuel pump and a high-flow impeller pump for charging the inlet of an augmentor fuel pump. The low-flow pump is connected to a drive shaft so as to be continuously driven thereby. The drive shaft may be placed in driving connection with the high-flow pump through the medium of a friction clutch which is engageable by the application of a fluid pressure. Disengagement of the high-flow impeller, when augmentation is not required, significantly contributes to an increase in pump efficiency and a reduction in heating of the fluid being pumped.