Industrial Fluid Power

1. Industrial Fluid Power

2. Basic Hydraulic Systems Overview Typical Lift / Ram Circuit (mobile or industrial – open center system) Relief Valve Control Valve Cylinder Pump Tank Filter

3. Applications of Hydraulic System • Machine tool : CNC machines, Hydraulic shaper, Hydraulic press etc. • Material Handling : Elevetors, Fork lift, • Earth Moving equipment : Dumpers, Excavators. • Railways / vehicles : Hydraulic brake, suspension

4. Double Acting Cylinder Circuit A B P T

5. Advantages of Hydraulic system • Large load capacity • High accuracy and precision. • Smooth movement. • Automatic lubricating provision to reduce to wear. • Division and distribution of hydraulic force are easily performed. • Automatic and safety circuits are possible. • Flexible

6. Disadvantages of Hydraulic system • A hydraulic element needs to be machined to a high degree of precision. • Leakage problem. • Special treatment is needed to protect them from rust, corrosion, dirt etc., • Fire Hazard • Hydraulic oil may pose problems if it disintegrates due to aging and chemical deterioration. • Hydraulic oils are messy and almost highly flammable. • Slower

7. Important properties of hydraulic oils • Compressibility: Liquids are incompressible in nature, Hydraulic oil should have low compressibility for better performance. • Viscosity: • Too high viscosity: pressure loss in the pipes and fittings. • The low viscosity: oil do not lubricate very well and have leakage problem • Hence the right balance between pressure loss and lubricity is required while selecting oil viscosity • Demulsibility : The ability of oil to resist with mixing with water is known as demulsibility. • Low foaming tendency: A good hydraulic fluid will not absorb air easily and will release it quickly without causing foam. • Oxidation: Oxidation causes the oil to thicken and produces varnishes which strain the component surface. It reduces life of oil. Chemicals may be added to improve oxidation of • oil.

8. Important properties of hydraulic oils • Good heat dissipation: The oil should carry out the heat generated and dissipate to the atmosphere easily and at faster rate. • Wear resistant (good lubricity): Chemicals are added to improve wear resistance of oil for reduction of wear during contact with moving components. • Corrosion resistance : The oil should have high corrosion resistance to eliminate the problems related to corrosion. • Pour points : It is important during low temperature application in cold climates. The oil should have low pour point temperature. • Flash point: It is the temperature at which vapor of oil given off when in contact with flame. It is required for high temperature application. • Non toxic : Hydraulic oil should be nontoxic for safe use and handling. • Available: It should be easily available at economic price.

9. Pumps Classification • Roto dynamic (NPDP) (Non -Positive Displacement Pumps) • Centrifugal • Axial flow • Positive Displacement Pumps (PDP) • Reciprocating • Rotary

10. Roto-dynamic (Non Positive Displacement) Pumps • Centrifugal Pump • Axial flow Pump

11. Pumps • Positive Displacement Pumps • Reciprocating • Rotary

12. RECIPROCATING PUMP

13. Disadvantages of reciprocating pump • More parts mean high initial cost. • High maintenance cost. • No uniform torque. • Low discharging capacity. • Pulsating flow. • Difficult to pump viscous fluid. • High wear in parts.

14. ROTARY PUMPS • Gear pumps: • External gear pump, • Internal gear pump, • Lobe pump , • Gerotor pump, • Screw pump. • Vane pump: • Unbalanced vane pump • Balanced vane pump • Piston pump: • Axial piston pumps • Straight axis piston pump • Bent axis piston pump • Radial piston pumps • Stationary cylinder type • Rotating cylinder type

15. Comparison of Hydraulic Pumps

16. EXTERNAL GEAR PUMP

20. LOBE PUMP

30. Hydraulic Valves • Pressure Control Valves • Pressure Relief valve • Pressure Reducing Valve • Unloading Valve • Counter Balance Valve • Sequence Valve • Direction Control Valves • 2/2, 3/2, 4/2, 5/2. 4/3 • Check Valve • Shuttle Valve <OR> • Twin Pressure Valve <AND> • Flow Control Valves • Variable Restriction FCV • Pressure and Temp Compensated FCV

31. Pressure Relief Valve Simple PRV Valves

32. Compound Pressure Relief Valve Valves

33. Pressure Reducing Valve Valves

34. Pressure Reducing Valve A B P T Pressure Reducing Valve

35. Unloading Valve Valves

36. Unloading Valve Circuit A B P T Valves

37. Counter Balance Valve A B P T Valves

38. Sequence Valve Valves

39. Check Valve Valves

40. 4/3 DAC Circuit Valves

41. 3/2 Direction Control Valve A P T Valves

42. 3/2 Direction Control Valve A P T Valves

43. 4/2 Direction Control Valve A B P T Valves

44. 4/2 Direction Control Valve A B P T Valves

45. 5/2 Direction Control Valve Valves

46. 4/3 Direction Control Valve Mid positions A B A B P T P T Closed center type Regenerative center type A B A B P T P T Open center type Float center type A B P T Tandem center type

47. Flow Control Valve Valves

48. Pressure Temp Compensated Flow Control Valve Valves

49. Shuttle Valve

50. Twin Pressure Valve