CATERPILLAR FUEL SYSTEMS

The Caterpillar diesel engine uses the pump and nozzle injection system. Each pump measures the amount of fuel to be injected into a particular cylinder, produces the pressure for injection of the fuel, and times the exact point of injection. The injection pump plunger is lifted by cam action and returned by spring action.

The turning of the plungers in the barrels varies the metering of fuel. These plungers are turned by governor action through a rack that meshes with the gear segments on the bottom of the pump plungers. Each pump is interchangeable with other injection pumps mounted on the pump housing.

The sleeve metering and scroll-type pumps that are used by Caterpillar operate on the same fundamentals—a jerk pump system (where one small pump contained in its own housing supplied fuel to one cylinder). Individual "jerk" pumps, that are contained in a single injection pump housing with the same number of pumping plungers being the same as that of the engine cylinders, are commonly referred to as in-line multiple-plunger pumps.