When employing a variable displacement pump, what can directly affect flow rate?

The flow rate of a variable displacement pump is directly influenced by the swash plate angle adjustment because this design allows for control over the displacement volume of the pump. By changing the angle of the swash plate, the effective stroke length of the pistons is altered, which in turn modifies the volume of fluid being pumped per cycle. This mechanism enables operators to fine-tune the output flow rate according to the requirements of the system.

In contrast, while inlet pressure, fluid medium type, and pump length do have roles in the overall efficiency and performance of a hydraulic system, they do not provide the same direct level of control over the flow rate as the swash plate angle. The swash plate adjustment is a primary method to vary output flow instantaneously, making it crucial for responding to varying operational demands.