Hydraulic systems

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1. HYDRAULIC SYSTEMS by Mohanraj M.E Erode

2. Fluid Power System The pressure fluids to move one place to another. Hydraulic System (Hydour-Water in Greek word ) (High accuracy) Examples: Space, defense, machine tool applications, agriculture and automobiles. Pneumatic System ( Pneuma - Air in Greek word) (Less accuracy) Examples: pneumatic hammers, drills, hoists, cranes.

3. Fluid power system and Hydraulic System Oil Hydraulic System

4. SERVICE PRPERTIES OF HYDRAULIC FLUIDS Viscosity -To affect the running fluid Depends on, -Temperature -Thickness - Pressure Density = Viscosity Temperature +++ Viscosity --- Pressure +++ Viscosity --- So we chose fluid is to reduced the above failures

5. 2) Viscosity Index -Temperature Changes to Change the Viscosity -Integer (0 to 100) To choose the High viscosity index fluid.

6. 3) Oxidation stability Chemical Oil + AIR(OXYGEN) Oxidation Reaction Oxidation Inhibitors Or Additives … Ex: Silicon Polymers, Nitrogen Components etc. 4) De-emulsibility -Reduce the Forming in hydraulic fluid Separate the forming and hydraulic fluid

7. 5) Lubricity -Lubricate the all engine parts during function of system. -avoid friction loss by using high lubricity having fluid will choose, 6) Rust Prevention - Rust is an  iron oxide , usually red  oxide  formed by the  redox  reaction of  iron  and  oxygen  in the presence of water or air moisture Ex: Sprayer Paints etc.

8. 7) Toxicity -Poison character or Silly Character. - This behaviour defiantly affect the human being.. 8) Cloud point  - Cloud point refers to the temperature below which wax in oil . 9) Flash and Fire Point At the  flash point , the vapor may cease to burn when the  ignition  source is removed. The  flash point  is not to be confused with the auto ignition temperature (which does not require an  ignition  source) or with the fire point  (the temperature at which the vapor continues to burn after being ignited).

9.   HYDRAULIC ACCUMULATOR A hydraulic accumulator is a  pressure  storage reservoir in which a  non-compressible   hydraulic fluid  is held under pressure by an external source. The external source can be a spring , a raised  weight , or a compressed  gas .

10. Usage of Accumulator Leakage compensation Shock absorber Secondary power sources Emergency power sources Thermal expansion compensator Temporary storage receiver etc. Leakage compensation

11. SHOCK ABSORBER A  shock absorber  (in reality, a shock "damper") is a mechanical or  hydraulic  device designed to absorb and  damp   shock  impulses. SECONDARY POWER SOURCE Supply to extra fluid to hydraulic system. EMERGENCY SOURCE During Emergency time to supply hydraulic fluid from accumulator. If any fault in pump.

12. THERMAL EXPANSION

13. Types of accumulator Weight loaded accumulator Spring loaded accumulator Gas loaded accumulator

14. Gas Loaded Accumulators

15. Symbols of Accumulator

16. PRESSURE INTENSIFIER Pascal's law  - pressure applied anywhere to a body of fluid causes a force to be transmitted equally in all directions; the force acts at right angles to any surface in contact with the fluid; "the hydraulic press is an application of  Pascal's law "  Pascal's law  of fluid pressures. PASCAL'S LAW

17. A hydraulic intensifier is a device which is used to increase the intensity of pressure of any hydraulic fluid or water, with the help of the hydraulic energy available from a huge quantity of water or hydraulic fluid at a low pressure. These devices are very important in the case of hydraulic machines, mainly hydraulic presses, which require water or hydraulic fluid at very high pressure which cannot be obtained from the main supply directly. There are three main parts in the hydraulic intensifiers to be noted. They are Fixed ram, Hollow inverted sliding cylinder, Fixed inverted cylinder. Application : Moulding Machine, Riveting machine, Spot Welding Machine and Hydraulic Presses.

18. Fluid Power Pumps Pump: -Important system in hydraulic system -Motor helps to convert electrical energy into mechanical energy -Pump helps to convert mechanical energy into fluid flow energy. Classification of pumps: Gear pump External Gear Pump Vane pump Radial pump Internal Gear Pump External Gear Pump: Mostly Used in hydraulic system. Equal two meshing gear fixed inside of casing. Merits: 1)Simple in construction 2) Comfortable for all area 3)High pressure (Apporx. 150bar) 4) Low cost.

19. Internal Gear Pump: Here Spur and internal gear meshing with help of crescent seal and casing Merits: 1)Simple in construction 2) Comfortable for all area 3) Low cost. Demerits: 1) Less pressure (70bar) 2) Less Capacity Vane Pump: Here Casing, Shaft, rotor and eccentricity. Merits: Oil Leakage less and High Volumetric efficiency 95% and medium cost. Demerits: 1) Less pressure 2) Less Capacity

20. Radial Gear Pump Fixed pintle , cylinder block and reaction ring. Merits: 1) Smooth Operation 2) Pump Output high 3) high volumetric efficiency (98%) 4) High Pressure (Above 500bar) Demerits : 1) Difficult Construction and High cost.

21. Thank u