Basic HydraulicFundamentals of HydraulicPage 1/16 Hands-on Training Fundamentals of Hydraulic Basic Hydraulic

Fundamentals of HydraulicPage 2/16 Contents Topic 1. Pressure 2. Flow and Pressure 3. Merit & Demerit 4. Oil

Basic HydraulicFundamentals of HydraulicPage 3/17 1. Atmospheric Pressure2. Seawater Pressure 3. Tap Water Pressure 1.Pressure 1) Pressure in our ordinary life

Basic HydraulicFundamentals of HydraulicPage 4/17 Pascal's Law. P F A P = Pressure.Kg/cm2 F = Force.Kg A= Areacm2 P= F A or F= P X A

Basic HydraulicFundamentals of HydraulicPage 5/17 Pressure Static fluid Right angle Equal strength Transmittance of strength 1. Pressure 2) Pressure in Confined and Static Fluid

Basic HydraulicFundamentals of HydraulicPage 6/17 Pressure Pressure = 1 N 1 m2 Newton and Pascal Force (F) = 1 kg x 1 m/sec2 = 1 Newton (N) = 1 Pascal (Pa) On the earth Force (F) = 1 kg x 9.81 m/sec2 = 1 kgf Pressure = 1 kgf 1 cm2 = 1 kgf / cm2 1 kgf = 9.81 N 1,000 Pa = 1 kPa 1,000,000 Pa = 1MPa 1 kgf / cm2 = 9.81N 100 x 100/ m2 = 98,100 Pa 1 kgf / cm2 = 98.1 kPa = MPa 1. Pressure 3) Unit of Pressure Pressure = Area Force Area (m 2 ) Force (Newton) Universal GravityGravity force

Basic HydraulicFundamentals of HydraulicPage 7/17 Cylinder A Cylinder B Area 1 cm 2 Area 10 cm 2 Pushing force 10kgObtainable force 100kg Pressure 10kg/cm2 Pressure 10kg/cm2 1. Pressure 4) Force Amplification

Basic HydraulicFundamentals of HydraulicPage 8/17 Cylinder A Cylinder B Area 1 cm 2 Area 10 cm 2 Pushing force 10kgObtainable force 100kg Pressure 10kg/cm2 Pressure 10kg/cm2 Large Small 1. Pressure 5) Distance Reduction

Basic HydraulicFundamentals of HydraulicPage 9/17 Pressure = Zero 1. Pressure 6) No Pressure without Resistance

Basic HydraulicFundamentals of HydraulicPage 10/17 Weight Pressure is created 1. Pressure 7) Pressure with Resistance

Basic HydraulicFundamentals of HydraulicPage 11/17 Weight 1. Pressure 8) Difference Pressure with Throttle Throttle or Variable Orifice

Basic HydraulicFundamentals of HydraulicPage 12/17 Gauge Pressure Vacuum Atmospheric pressure Gauge Pressure Negative Gauge Pressure Zero 1. Pressure 9) Gauge pressure

Basic HydraulicFundamentals of HydraulicPage 13/17 2. Flow and Pressure Q = Flow rate : liter / min High pressure Low speed Large area Small area High speed Low pressure Same Flow Rate Pressure AreaSpeed Weight V S C = 0.16 m/sec V (m/sec) = C x Q / S

Basic HydraulicFundamentals of HydraulicPage 14/17 3. Merit and Demerit of Hydraulic Merit 1. Design is simpler 2. Flexibility 3. Quiet 4. Stepless control 5. High efficiency 6. Easy system protection Demerit 1. Expensive 2. Sensitive to dirt 3. Need oil change 4. Oil leak possibility

Basic HydraulicFundamentals of HydraulicPage 15/17 4. Hydraulic Oil 1) Function of Hydraulic Oil 1. To transmit power 2. To lubricate 3. To cool 4. To clean 5. To seal

Basic HydraulicFundamentals of HydraulicPage 16/17 4. Hydraulic Oil 2) Komatsu Recommended Oil

Basic HydraulicFundamentals of HydraulicPage 17/17 4. Hydraulic Oil 3) Viscosity What is the Viscosity of Oil? 2. Viscosity change Low temperature High viscosity High temperature Low viscosity 3. Viscosity grade comparison SAE ViscosityISO Viscosity 15wVG46 KOMATSU HO46-HM = = 1 - Much leakage 2 - Low performance 3 - Low pressure 3 Negative points 1. Viscosity = Thickness of oil