Hydraulic systems use pressurized fluid to transmit force and motion. They deliver very high force from compact components, which makes them essential in presses, injection molding machines, mobile equipment and heavy lifting.
How It Works
Pascal’s law states that pressure applied to a confined fluid is transmitted equally in all directions. A pump creates flow, valves direct and control that flow, and actuators such as cylinders and motors convert fluid power back into mechanical work.
Main Components
- Reservoir: stores fluid, helps dissipate heat and allows air and contaminants to separate.
- Pump: gear, vane or piston types supply flow.
- Valves: pressure relief, directional and flow control valves manage system behavior.
- Actuators: cylinders for linear motion, motors for rotary motion.
- Filters and coolers: maintain fluid cleanliness and temperature.
Fluid Cleanliness
Contamination causes the majority of hydraulic failures. Even microscopic particles can score valve spools and wear pumps. Use proper filtration, keep fills and breathers clean, and test oil cleanliness regularly using standard ISO cleanliness codes.
Troubleshooting Tips
Slow actuators often point to internal leakage or a worn pump. Excessive heat can result from a relief valve working constantly or an undersized cooler. Noise and erratic movement may indicate air in the oil or cavitation at the pump inlet. Always depressurize the system and follow lockout procedures before working on any hydraulic circuit.