FUNDAMENTALS OF HYDRAULICS Master Copy for IRTMTCALD by

FUNDAMENTALS OF HYDRAULICS Master Copy for IRTMTC/ALD by IRICEN

INTRODUCTION OF HYDRAULICS • The word hydraulics originates from the Greek. This is made of two words-hydor and aulos. • Hydor means water and aulos means pipe i. e. flow of water through pipes. • Today the term hydraulic commonly refers to “Power hydraulics” in which fluid is used under controlled pressure to do work • Hydraulic power is used in every branch of industry in a machine tool, missiles, man made satellite, boat, planes, cranes, lifts, track machines etc.

PASCAL’S LAW 200 Kg 40 Kg 10 cm 2 20 kg/ cm 2 It states that when pressure is applied on a confined fluid it is transmitted undiminished in all directions, and acts with equal force on equal areas, and at right angles to them.

BERNOULLI’S PRINCIPLE • Bernoulli’s principle states that, “The total energy of the fluid always remains constant. ” • Hydraulic fluid in a system possesses two types of energy KINETIC and POTENTIAL kinetic energy is present when the fluid is in motion. Potential energy is a result of the fluid pressure. • Therefore, when the flow in a system increases, the pressure must be decrease.

ADVANTAGES OF HYD. SYSTEM • • • Variable speed Reversibility Overload protection Self lubrication Cooling Sealing Easy to install and handle Portable Compactness

ADVANTAGE OF HYDRAULIC • Variable Speed: The actuator of a hydraulic system can be driven at variable speeds by varying the pump delivery or using a flow control valve. • Reversibility: An actuator can be reversed instantly while in full motion without damage. • Self Lubrication: In most hydraulic components internal lubrication is provided by the fluid.

ADVANTAGE OF HYDRAULIC • Cooling: Circulation of the fluid through lines and around the walls of the reservoir allow the fluid to give up the heat that has been generated in the system. • Sealing: In many instances the fluid is the only seal against pressure inside the hydraulic component. • Portable: Hydraulic plant can be used in mobile application.

ADVANTAGE OF HYDRAULIC • Compactness: Hydraulic components can provide high power output with very small weight and size. • Transmission loss: In hydraulic system power transmission losses are very less in • comparison to mechanical transmission. • Easy to Install and Handle: Hydraulic components can be easily installed and handled due to less weight and size in compare to mechanical system.

BASIC HYDRAULIC CIRCUIT. 4/3 way valve Cylinder pump Relief valve Piston Filter Piston rod Tank

HOW PRESSURE IS CREATED ? Pressure results whenever the flow of a fluid is resisted. The resistance may come from (i) a load on an actuator or (ii) A restriction (or orifice) in the piping. 400 kg 10 cm 2 40 Kg/cm 2 PUMP