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 psi Generally produce more power

Hydrodynamic Systems Fluid is in motion Force and energy are transmitted by flow Water Turbine Propeller

National Fluid Power Association & Fluid Power Distributors Association 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 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 SymbolDefinitionExample Units Q Flow Rategpm or gal/min (gallons per minute) in. 3 / min v Flow Velocity fps or ft/s (feet per second) in. / min A Areain. 2

Mechanical Advantage National Fluid Power Association & Fluid Power Distributors Association

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

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 National Fluid Power Association & Fluid Power Distributors Association Cylinder Transmissio n Lines Directional Control Valve Pump Reservoir Filter

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