Lesson. Using Hydraulic Systems

Transcription

1 Lesson Using Hydraulic Systems

2 Interest Approach n Have you ever used a floor jack or driven an automobile equipped with power brakes or power steering?

3 Student Learning Objectives n Define hydraulics and explain its major operating systems. n Discuss the basic principles of hydraulics. n Describe the primary components of a hydraulic system. n Describe the advantages and disadvantages of hydraulic systems.

4 Terms n Connectors n Cycle time n Directional control valve n Energy n Filter n Flow rate n Hydraulic actuator n Hydraulics n Hydrodynamics n Hydrostatics n Law of Conservation of Energy n Linear actuator

5 Terms n Micron n Multiplication of force n Pascal s Law n Piping n Positive displacement pump n Pressure gauge n Pressure relief valve n Prime mover n Pump n Reservoir n Rotary actuator n Strainer

6 Hydraulics n A branch of physics dealing with the mechanical properties and practical applications of fluids in motion. n Hydraulic systems do not create power.

7 Hydraulics n They transfer power from an outside source. Prime mover the outside source of power.

8 Hydrodynamics n The use of liquids at high flow and low pressure to perform work. n An example would be a dam, or a mill.

9 Hydrostatics n Use of liquids at high pressure and low flow to perform work. n Example would be hydraulics on a vehicle.

10 Pascal s Law n Pressure applied to a confined fluid is transmitted undiminished in all directions.

11 Application of Pascal s Law

12 Multiplication of force n The hydraulic system takes a small input force and transforms it into a larger output force.

13 Cycle time n The amount of time required for one complete set of operations to occur. Flow rate the measure of how many gallons per minute of hydraulic fluid would run into a container.

14 Law of Conservation of Energy n Energy may be changed from one form to another, but it cannot either be created or destroyed. Energy the capacity to do work.

15 Components of a Hydraulic System n Reservoir supplies oil to the hydraulic pump and stores oil that returns after passing through the hydraulic circuit. Strainer directs the hydraulic oil in a straight line through an element made of metal screens attached to a metal core. Filter directs hydraulic oil through one of more layers of a porous elements that may trap particles. Micron equal to 39 millionths of an inch.

16 Primary Components of a Hydraulic System

17 Components (continued) n Pump causes hydraulic oil to flow through the circuit Positive displacement pump delivers the same volume of oil per cycle regardless of the pressure at the pump outlet.

18 Components (continued) n Pressure gauge measure and shows the pressure being produced in a hydraulic system.

19 A bourdoin tube pressure gauge

20 Components (continued) n Directional control valve controls the operation of the system s cylinder sand motors by direction the flow of the fluid in the system.

21 Primary parts of a typical cylinder

22 Components (continued) n Hydraulic actuator converts fluid energy into mechanical energy. Linear actuator the output of the cylinder occurs in a straight-line manner. Rotary actuator produces a rotating output force.

23 Components (continued) n Piping fluid conducting lines that connect various components of a hydraulic system. Connectors used to join one piece of piping to another, or to hydraulic system components.

24 Advantages of hydraulic systems n Increased flexibility n Variable speed n Multiplication of force n Reduced wear n Reversibility

25 Disadvantages of hydraulic systems n High pressure n Need for cleanliness n Safety hazards

26 Review / Summary n What is hydraulics and what are its major operating systems? n What principles govern the use of hydraulics? n What are the primary components of a hydraulic system? n What are the advantages and disadvantages associated with hydraulic systems?