What is the main purpose of a pressurized reservoir in a hydraulic system?

The main purpose of a pressurized reservoir in a hydraulic system is to prevent hydraulic pump cavitation. Cavitation occurs when there is a drop in pressure at the pump inlet, leading to the formation of vapor bubbles in the hydraulic fluid. These bubbles can collapse violently as they move into higher pressure areas, potentially causing damage to pump components and leading to reduced efficiency.

By maintaining the fluid in a pressurized state, the reservoir ensures that the pump receives a consistent flow of fluid without significant pressure drops. This constancy of pressure helps to keep the hydraulic fluid above its vapor pressure at all times, effectively preventing cavitation from occurring.

Other functions of a pressurized reservoir can include the storage of hydraulic fluid for system demands, but the primary and critical role, particularly regarding pump efficiency and operational safety, relates to preventing cavitation.