In hydrostatic systems, a supplementary pump, often termed a replenishing or makeup pump, ensures adequate fluid volume within the closed hydraulic circuit. This component addresses the inherent leakage present in hydraulic components like motors and pumps. Its primary function is to supply cooled and filtered oil to compensate for this leakage, maintaining optimal system pressure and preventing cavitation. The replenishing pump operates at a lower pressure than the main system pressure and typically draws oil from a reservoir.
The utilization of a replenishing pump is critical for several reasons. It prevents the hydrostatic system from running dry, which would lead to component damage and failure. By maintaining adequate pressure, it ensures consistent and reliable power transmission. Moreover, the replenishing pump often incorporates filtration and cooling mechanisms, contributing to the overall cleanliness and temperature control of the hydraulic fluid, extending the lifespan of system components. Historically, these pumps were relatively simple gear pumps, but modern systems increasingly utilize more efficient and sophisticated designs.