Rotor bearing pre-load for a radial piston pump

摘要

A radial piston pump is provided with a plurality of valve/piston cartridges. Each cartridge includes the piston and at least one of the valves connecting the piston to the inlet and outlet passages of the pump. The bearings for the main rotor are pre-loaded using a threadedly adjustable end guill. Once adjusted, the end quill is held in location by a pin or the like. The rotor itself is provided with counterweights to balance the eccentric cam surface. These features allow construction of a pump housing which is substantially a single unit, rather than two pump halves. A significant reduction in the number of machined bores also is obtained.