Bosch PF Single Plunger Pumps
PF single-plunger injection pumps are used for small engines, diesel locomotives, marine engines, and construction machinery. They have no camshaft of their own, although they correspond to the PE in-line injection pumps regarding their method of operation. In the case of large engines, the mechanical-hydraulic governor or electronic controller is attached directly to the engine block. The fuel-quantity adjustment as defined by the governor (or controller) is transferred by a rack integrated in the engine.
The actuating cams for the individual PF single-plunger pumps are located on the engine camshaft. This means that injection timing cannot be implemented by rotating the camshaft. Here, by adjusting an intermediate element (for instance, a rocker between camshaft and roller tappet) an advance angle of several angular degrees can be obtained.
Single-plunger injection pumps are also suitable for operation with viscous heavy oils.