What component drives the pumps in a multiple plunger inline injection system?

In a multiple plunger inline injection system, the component that drives the pumps is the internal camshaft. The internal camshaft's primary function is to convert the rotational motion generated by the engine or mechanical system into the linear motion necessary to operate the plungers within the injection pumps. As the camshaft rotates, its lobes push against the plungers, causing them to move in and out and effectively inject fuel into the engine at the appropriate timing and pressure.

This mechanism is crucial for achieving the precise control required in fuel injection systems, contributing to efficient engine performance and reduced emissions. In contrast, while the crankshaft and external drive motors are essential elements in an engine's operation, they are not directly responsible for delivering the specific motion needed to operate the pumps in this context. Similarly, the piston assembly primarily relates to the engine's combustion cycle rather than the injection system itself.