Transcript JIC Symbols
Hydraulic John Deere GOLF TURF & Training Department Foundations (Left Click Selection Box) Hydraulic Fluid Check Valve Least Resistance Relief Valve Pascal’s Law Pressure Differential Relief Application Principles Conditioners JIC Open vs Closed Pumps Hydraulic Valve JIC Axial Piston Pump Hydraulic Cylinder Principles Gear Pump Cylinder Leakage Test Motors Build With JIC’s Reservoirs Lines and Connections Liquids Have no Shape of their own 3 Liquids are Practically Incompressible 4 Liquids under pressure follow what path? Path of least Resistance 5 Path of Least Resistance 10 lbs 6 Imperial Pascal’s Law Metric Pressure Exerted on a Confined Fluid is Transmitted Undiminished in All Directions and Acts With Equal Force on Equal Areas and at Right Angles to Them. 7 Application Principles 1 lb (.45kg) Force 10 lbs (4.5kg) 10 sq in (6.5cm2) Piston Area 1 sq in (.65cm2) Piston Area 1 psi (6.9kpa) 11 Pump Types Positive Displacement -With each revolution a specific amount is pumped somewhere – Low Volume, High Pressure Non Positive (IE: Water Pump) – High Volume, Low Pressure 13 JIC Symbols Joint Industry Council Symbolic Drawings used in Schematics to Represent Components. 14 Pumps (JIC Symbols) Constant Displacement Single Direction Arrow Showing Oil Flow OUT Bi-Directional, Variable Displacement Pumps convert mechanical power into hydraulic force 16 Axial Piston Pump Neutral Position Vertical Swashplate Pressure Oil Each Piston Piston Engine Shaft Piston Pumps Piston Swash Plate Rotating Group Typically 9 Pistons 18 Axial Piston Pump Forward Position Angled Swashplate Charge Oil Pressure Rotating Group Typically 9 Pistons 20 Axial Piston Pump Reverse Position Angled Swashplate Pressure Charge Rotating Group Typically 9 Pistons 21 Gear Pump or Motor In Out 23 Motors (JIC Symbols) Single Direction Bi-Directional Arrow Showing Oil Flow IN Motors converts hydraulic force into mechanical power 25 Reservoirs 1. Vented 3. Return Above Fluid Level 2. Pressurized 4. Return Below Fluid Level 26 Lines and Connections or Working Line (Main) Crossing Lines Pilot Control Line Drain Line Connecting Lines Flexible Line Flow Direction 27 Check Valve Checked Flow Free Flow Spring Assisted Pilot Operated 28 Relief Valves Protects the Pump and Lines from excessive pressure Returns fluid back to the reservoir 29 Relief Valve Supply Return to Reservoir Pilot supply 30 Pressure Differential Valve Supply Senses the DIFFERENCE in Pressure 31 Manual On/Off Valve 32 Fluid Conditioners Filter Oil Cooler 33 Filters Internal Filter Bypass Valve (Optional) Micron 1 Millionth of a Meter or 1 Thousandth of a Millimeter 34 Types of Hydraulic Systems Open Center Closed Center The control valve that regulates the flow from the pump determines if system is open or closed. Do not confuse Hydraulics with the “Closed Loop” of the Power Train. (Hydro) 35 Hydraulic Valve JIC Closed Open Center Center Hydraulics Flow in Neutral Trapped Oil 36 Hydraulic Valve JIC Extend 38 Hydraulic Valve JIC Retract 39 Hydraulic Valve JIC Neutral Again 40 Lift Cylinder Extend Lift Cylinder Leak Down Where Does the Oil Go?? Lift Cylinder Is it Possible for This Rod to Retract Even With the Piston Removed?? Cylinder Hose Failures Effects On Line Pressure When a Cylinder Piston Packing is Leaking 15000 lbs of Down Force 1.5” Diameter Rod .75 x .75 x 3.1416 = 1.77 sq.in. Results in 8475 PSI 3” Diameter Piston 1.5 x 1.5 x 3.1416 = 7.07 sq.in. Results in 2122 PSI Hydraulic Cylinder Leakage Test Depending on the System, You May Have to Cap This Line To Prevent Return Oil From Leaking Out Retract 49 JIC Symbols Would This Hydraulic Drive System Work? PM Yes, In one direction Common Reservoir Common Reservoir Hydraulic Drive Does NOT Provide Dynamic Braking Build the System 50 JIC Symbols PM Hill Simulation Closed Loop Hydrostatic Transmission 51 JIC Symbols PM Hill Simulation Closed Loop Hydrostatic Transmission 52 JIC Symbols Oil Filter Inlet Check PM Common Reservoir Inlet Check Oil Cooler Common Reservoir Build the System 53 JIC Symbols Oil Filter Oil Cooler Bypass Valve PM Charge Relief Valve Filter Bypass Valve Oil Cooler Build the System 55 JIC Symbols Oil Filter Oil Cooler Bypass Valve PM Charge Relief Valve Filter Bypass Valve Oil Cooler Hydrostatic Transmission Components 57