What is the function of a gear pump in hydraulics?

• A. To filter contaminants from hydraulic fluid.
• B. Generate hydraulic pressure by delivering a fixed amount per rotation.
• C. To cool the hydraulic fluid.
• D. To measure fluid temperature.

Answer: (B)

A gear pump is a positive-displacement device, so with each rotation it moves a fixed volume of hydraulic fluid. That fixed displacement means it delivers a specific amount of fluid into the circuit per turn, which creates flow and, under system load, builds hydraulic pressure. The pressure you see in the system comes from the resistance the hydraulic components provide and the pump keeps delivering that fixed volume as it turns. It’s not designed to filter contaminants, cool the fluid, or measure its temperature—those functions belong to filters, coolers, and sensors, respectively.