1. Hydraulics

2. An area of engineering science that deals with liquid flow and pressure

3. Hydraulic Fluids Liquid pumped through a hydraulic system Petroleum-based or synthetic oil Serve four major functions: 1. Power transmission 2. Lubrication of moving parts 3. Sealing of spaces between moving parts 4. Heat removal Relatively Incompressible!

4. Two Types or Conditions of Hydraulic Systems Hydrostatic Hydrodynamic

5. Hydrostatics - a “No Flow” Scenario “Static” means “stationary” or “non flowing” in a hydraulic system Hydraulic systems are considered static when there is no flow Pascal’s Law (for hydrostatics): a pressure applied to a confined hydrostatic fluid is transmitted with equal intensity throughout the fluid Same pressure all throughout!

6. Hydrodynamics – a “Flow” scenario “Dynamic” means “moving” or “flowing” in a hydraulic system Hydraulic systems are considered dynamic when there is flow Pascal’s Law does not apply! Pressure does not have equal intensity in a flowing dynamic system Pressure drops along the length of a hydraulic line in flowing systems

7. Flow and Pressure Flow, Q volume flow rate amount of fluid moving through system per unit time Pressure, P force per unit area of fluid moving through a system

8. Mechanical Advantage Ideal mechanical advantage (IMA) Assumes no frictional losses Calculated as ratio of output force to input force Actual mechanical advantage (AMA) always less than ideal difficult to calculate

9. Application of Pascal’s Law in a Simple Hydrostatic System How much force must you exert on piston A to lift a load on piston B of 500 lbs? What is the ideal mechanical advantage of this system?

10. Problem Solving Step 1: Determine the pressure in the system using information about piston B Known Unknown A = 500 in 2 P=? F = 500 lb Equation No algebra needed Substitution & Solution STEP 2: Use the pressure calculated in STEP 1 and information about piston A to calculate force Known Unknown A = 1.0 in 2 F=? Equation and algebra: Substitution & Solution

11. Problem Solving Step 3: Determine the ideal mechanical advantage (IMA) of the system using information from STEPS 1 & 2 Known Unknown F(input) = 1 lb IMA=? F(output) = 500 lb Equation No algebra needed Substitution & Solution

12. A Hydraulic System

13. Tank/Reservoir Storage device which is open and not pressurized Filter

14. Pumps Positive displacement pump (Gear Pump): a specific amount of fluid passes through the pump for each rotation Centrifugal pump (Vane Pump): no specific amount of fluid flow per rotation; flow depends on speed of blades

15. Accumulators Storage device which is closed and is under pressure

16. Valves Check Valve Directional Control

17. Linear Actuators Use hydraulic power to move linearly Single Acting Double Acting

18. Rotary Actuators Use hydraulic power to rotate Single-Vane Double-Vane

19. Applications Robotics Oil systems in vehicles (e.g. brakes) Presses Heavy equipment Wood splitter Aircraft control systems

20. The Hydraulic Trainer Motor Pump Return line from reservoir Pressure line Pressure Regulator In-line Pressure Gauge Flow Control Valve Check Valve Actuators Directional Control Valve Inline-Tee Return line Connections Supply line Connections