Answer :
Final answer:
The mechanical safety device designed to protect a gear-type hydraulic pump from overload is a relief valve. It releases excess pressure to prevent damage to the system, distinguishing it from other components like check valves, pressure regulators, and drive couplings.
Explanation:
In a gear-type hydraulic pump, a mechanical safety device incorporated to protect the pump from overload is known as a relief valve. This device is essential for preventing damage to the hydraulic system by releasing excess pressure when it reaches a predetermined limit. The overload can occur when the system's fluid encounters resistance greater than the pump's design can handle. In contrast to other options such as the check valve (which prevents reverse flow), pressure regulator (which maintains a constant outlet pressure), or drive coupling (which connects the pump to its driving mechanism), the relief valve specifically functions to relieve pressure and thereby protect against overload conditions.
