Hydraulic Power Hydraulics vs Pneumatics Hydraulic Systems Use

Hydraulic Power

Hydraulics vs. Pneumatics Hydraulic Systems. . . • • • Use a relatively incompressible liquid Have a slower, smoother motion Are generally more precise Lubricate naturally Are not as clean as pneumatics when leakage occurs • Often operate at pressures of 500 - 5000 psi • Generally produce more power

Hydrodynamic Systems • Fluid is in motion • Force and energy are transmitted by flow

Hydrostatic Systems • Fluid does not flow quickly or continuously • Fluid is pressurized • Force and energy transmitted by pressure • Most common in industrial settings

Liquid Flow Rate The volume of fluid that moves through a system in a given period of time Flow Velocity The distance the fluid travels through a system in a given period of time Symbol Definition Q Flow Rate Example Units gpm or gal/min in. 3 / min (gallons per minute) v Flow Velocity A Area fps or ft/s (feet per second) in. 2 in. / min

Mechanical Advantage National Fluid Power Association & Fluid Power Distributors Association

Bernoulli’s Principle Conservation of Energy: An increase in velocity results in a decrease in pressure. Likewise, a decrease in velocity results in an increase in pressure.

Viscosity The measure of a fluid’s thickness or resistance to flow Crucial for lubricating a system Measured in slugs/sec-ft (US) or centistokes (metric) – Hydraulic oil is usually around 1. 4 slugs/sec-ft Decreases as temperature increases

Common Hydraulic System Components Cylinder Filter National Fluid Power Association & Fluid Power Distributors Association

Common Hydraulic System Components Click the lever on the valve to extend and retract the cylinder. Cylinder Valve Reservoir Pump