Hydraulic Foundations GOLF TURF John Deere Training Department & 2017-04-28 Hydraulic GOLF TURF Training Department & John Deere Foundations Hydraulic Fundamentals

Hyd Fundamentals Slide Index 2017-04-28 Hyd Fundamentals Slide Index (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 Hydraulic Fundamentals

Liquids Have no Shape of their own

Practically Incompressible Liquids are Practically Incompressible

Liquids under pressure follow what path? Path of least Resistance

Path of Least Resistance 2017-04-28 Path of Least Resistance 10 lbs Hydraulic Fundamentals

2017-04-28 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. --Hydraulics is a means of power transmission --Oil is the most commonly used medium because it serves as a lubricant and is practically non-compressible (it will compress approximately 1/2 of a 1 percent per 1000 PSI). --Weight of oil varies with viscosity, but averages between 55 to 55 lbs per cubic foot. (at 100 degrees F). NOTE: A cubic foot of oil is 1728 Cu.In (12x12x12). A gallon is 231 Cu.In., so a Cubic Foot of oil is equivalent to 7.48 Gallons. --A liquid is pushed, NOT DRAWN, into a pump. Atmospheric pressure equals 14.7 PSI at sea level. --Oil takes the course (path) of least resistance. FORMULAS; 1. H.P. = GPM x Pressure x .000583 -or- H.P. = GPM x PSI / 1714 2. One H.P. = 33000 ft./lbs. per minute (33000 lbs raised 1 ft in 1 minute) One H.P. = 746 Watts, One H.P. = 42.4 BTU per minute 3. Required Area of a transmission line; Area = GPM x .3208 / velocity (ft./sec) -or- Velocity (ft./sec) = GPM / 3.117 x Area Pascal’s Law, named after Blaise Pascal (French 1623-1662) 7 Hydraulic Fundamentals

This slide illustrates one of the basic principles of hydraulics; 2017-04-28 This slide illustrates one of the basic principles of hydraulics; LIQUIDS TRANSMIT APPLIED PRESSURE EQUALLY IN ALL DIRECTIONS. BUILDS: 1. When a 1 lb (.45kg) force is applied to this handle and the area of the piston is 1sq in (.65cm2), with the confined fluid, what PSI (kpa) pressure will be produced? (1psi (6.9kpa)) Note that this pressure is exerted in every direction. 2. With a 10 sq in (6.5cm2) piston, how much weight will this system lift? This principle is what allows us to multiple our work efforts. With 1 lb (.45kg) of down pressure, we are able to lift 10 lbs (4.5kg). Pressure is caused by a resistance to flow, in this case the 10 lb (4.5kg) weight. Point out that resistance to flow is what causes pressure. In this example, if there were a 100 lb (45kg) weight on the right side (in place of the 10 lb (4.5kg) weight), how much pressure would be required to lift it. (10 PSI (69kpa)). Hydraulic Fundamentals

Pascal’s Law, named after Blaise Pascal (French 1623-1662) IMPERIAL 2017-04-28 --Hydraulics is a means of power transmission --Oil is the most commonly used medium because it serves as a lubricant and is practically non-compressible (it will compress approximately 1/2 of a 1 percent per 1000 PSI). --Weight of oil varies with viscosity, but averages between 55 to 55 lbs per cubic foot. (at 100 degrees F). NOTE: A cubic foot of oil is 1728 Cu.In (12x12x12). A gallon is 231 Cu.In., so a Cubic Foot of oil is equivalent to 7.48 Gallons. --A liquid is pushed, NOT DRAWN, into a pump. Atmospheric pressure equals 14.7 PSI at sea level. --Oil takes the course (path) of least resistance. FORMULAS; 1. H.P. = GPM x Pressure x .000583 -or- H.P. = GPM x PSI / 1714 2. One H.P. = 33000 ft./lbs. per minute (33000 lbs raised 1 ft in 1 minute) One H.P. = 746 Watts, One H.P. = 42.4 BTU per minute 3. Required Area of a transmission line; Area = GPM x .3208 / velocity (ft./sec) -or- Velocity (ft./sec) = GPM / 3.117 x Area Pascal’s Law, named after Blaise Pascal (French 1623-1662) Hydraulic Fundamentals

Pascal’s Law, named after Blaise Pascal (French 1623-1662) METRIC 2017-04-28 --Hydraulics is a means of transmitting power. --Oil is the most commonly used medium because it serves as a lubricant and is practically non-compressible (it will compress approximately 1/2 of 1 percent per 690 kpa). --Weight of oil varies with viscosity, but averages between 23 to 25 kg per cubic foot. (at 100 degrees F). NOTE: A cubic foot of oil is 1728 Cu.In (12x12x12). A gallon is 231 Cu.In., so a Cubic Foot of oil is equivalent to 7.48 Gallons. --Liquid is pushed (by Atmospheric Pressure), NOT DRAWN, into a pump. Atmospheric pressure equals 14.7 PSI at sea level. --Oil takes the path (line) of least resistance. FORMULAS; 1. H.P. = GPM x Pressure x .000583 -or- H.P. = GPM x PSI / 1714 2. One H.P. = 33000 ft./lbs. per minute (33000 lbs raised 1 ft in 1 minute) One H.P. = 746 Watts, One H.P. = 42.4 BTU per minute 3. Required Area of a transmission line; Area = GPM x .3208 / velocity (ft./sec) -or- Velocity (ft./sec) = GPM / 3.117 x Area Pascal’s Law, named after Blaise Pascal (French 1623-1662) Hydraulic Fundamentals

Application Principles 2017-04-28 Application Principles 1 lb (.45kg) Force 1 sq in (.65cm2) Piston Area 10 lbs (4.5kg) 10 sq in (6.5cm2) Piston Area This slide illustrates one of the basic principles of hydraulics; LIQUIDS TRANSMIT APPLIED PRESSURE EQUALLY IN ALL DIRECTIONS. BUILDS: 1. When a one pound force is applied to this handle and the area of the piston is one square inch, with the confined fluid, what PSI pressure will be produced? Note that this pressure is exerted in every direction 2. With a 10 square in piston, how much weight will this system lift? This principle is what allows us to multiple our work efforts. With one lb of down pressure, we are able to lift 10 lbs. --Pressure is caused by a resistance to flow. In this case the 10 lb weight. Point out that resistance to flow is what causes pressure. In this example, if there were a 100 lb weight on the right side (in place of the 10 lb weight), how much pressure would be required to lift it. (10 PSI). 1 psi (6.9kpa) 11 Hydraulic Fundamentals

THE TWO MAIN TYPES OF PUMPS: 2017-04-28 THE TWO MAIN TYPES OF PUMPS: 1. With a positive displacement pump, with each revolution, a specific amount of fluid is pumped somewhere. 2. The non-positive pump can rotate all day and not necessarily cause fluid to flow. Thus the positive displacement pump is used in applications that require higher pressures and the non-positive displacement pumps are used in applications that require high volumes (flow rates). Hydraulic Fundamentals

Pump Types Positive Displacement 2017-04-28 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 The two main types of Pumps 1. With a positive displacement pump, with each revolution, a specific amount of fluid is pumped somewhere. 2. The non-positive pump can rotate all day and not necessarily cause fluid to flow … Thus the positive displacement pump is used in applications that require higher pressures and the non-positive displacement pumps are used in applications that require high volumes (flow rates) 13 Hydraulic Fundamentals

JIC Symbols Joint Industry Council Symbolic Drawings used in Schematics to Represent Components.

J I C Symbols Joint Industrial Council 2017-04-28 J I C Symbols Joint Industrial Council 2139 Wisconsin Ave, NW Washington, DC 20007 This organization was founded in 1965. JIC standards replaced those written by the Joint Industrial Conference (mostly auto manufacturing) BUILDS 1. Circle, the major components in a JIC schematic are circles. For a pump with start with a circle. 2. Then we add an arrow head. The arrow pointing out of the circle signifies the direction of the fluid flow. OUT, indicating a pump 3. Continue to build showing two arrows heads, meaning this pump is capable of pumping oil in two directions 4. The arrow signifies that this pump is capable of varying the amount of flow, so it is a variable displacement pump. Hydraulic Fundamentals

Pumps (JIC Symbols) Constant Displacement Single Direction 2017-04-28 Pumps (JIC Symbols) Constant Displacement Single Direction Arrow Showing Oil Flow OUT Bi-Directional, Variable Displacement J I C Symbols Joint Industrial Council 2139 Wisconsin Ave, NW Washington, DC 20007 This organization was founded in 1965. JIC standards replaced those written by the Joint Industrial Conference (mostly auto manufacturing) BUILDS 1. Circle, the major components in a JIC schematic are circles. For a pump with start with a circle. 2. Then we add an arrow head. The arrow pointing out of the circle signifies the direction of the fluid flow. OUT, indicating a pump 3. Continue to build showing two arrows heads, meaning this pump is capable of pumping oil in two directions 4. The arrow signifies that this pump is capable of varying the amount of flow, so it is a variable displacement pump. Lastly, ask the students based on the symbols shown, what type of pump is this? Then ask, what configuration of pump is capable of variable displacement and pumping in two directions? Pumps convert mechanical power into hydraulic force 16 Hydraulic Fundamentals

“Heavy Duty” applications that require variable displacement 2017-04-28 “Heavy Duty” applications that require variable displacement bi-directional pumps, typically use axial piston pumps. POINT OUT THE: 1. Rotating group 2. Swash plate 3. Pistons Hydraulic Fundamentals

Axial Piston Pump Neutral Position Vertical Swashplate Pressure Oil 2017-04-28 Axial Piston Pump Neutral Position Vertical Swashplate Pressure Oil Each Piston Piston Engine Shaft Pumps Piston “Heavy Duty” applications that require variable displacement bi-directional pumps, typically use axial piston pumps. Point out the: 1. Rotating group 2. Swash plate 3. Pistons Piston Rotating Group Typically 9 Pistons Swash Plate 18 Hydraulic Fundamentals

SWASHPLATE ANGLE, FORWARD POSITION: 2017-04-28 SWASHPLATE ANGLE, FORWARD POSITION: 1. As the hydro linkage is slowly moved forward (swashplate angle changes) the vehicle starts to move forward. 2. The movement of the swashplate controls the direction of the motor rotation. 3. When the swashplate is moved further forward (swashplate angle increases), the piston assemblies start to travel further, generating more flow, more oil is being pumped and the speed of the vehicle is increased. 4. Flow rate is determined by length and frequency of strokes. When full swashplate travel is reached (maximum swashplate angle), the maximum volume of oil is being discharged from the pump, then the speed of the motors are at maximum. Hydraulic Fundamentals

Axial Piston Pump Forward Position Angled Swashplate Charge Oil 2017-04-28 Axial Piston Pump Forward Position Angled Swashplate Charge Oil Swashplate Angle Forward Position As the hydro linkage is slowly moved forward the vehicle starts a forward movement. The movement of the swashplate controls the direction of the motor rotation. When the swashplate is moved further, the piston assemblies start to reciprocate further, generating more flow, more oil is being pumped and the speed of the vehicle is increased. Flow rate is determined by length of and frequency of strokes (RPM). When full swashplate angle is reached, the maximum volume of oil is being discharged from the pump the speed of the motors are at the greatest. Pressure Rotating Group Typically 9 Pistons 20 Hydraulic Fundamentals

Axial Piston Pump Reverse Position Angled Swashplate Pressure Charge 2017-04-28 Axial Piston Pump Reverse Position Angled Swashplate Pressure In the reverse position, the pump shaft still rotates in the same direction, but the discharge of oil from the pump is reversed, thus reversing the motor rotation. Charge Rotating Group Typically 9 Pistons 21 Hydraulic Fundamentals

Before going back into JIC symbols, lets show another very popular 2017-04-28 Before going back into JIC symbols, lets show another very popular type of pump or motor. 1. What clues might we have to determine whether this device is a pump or a motor? NOTE: Typically, a pump will have a larger INLET opening. 2. If this were a Pump and with the pump turning in the direction illustrated by the arrows, which side is the inlet and which side is the outlet? Build shows inlet and outlet. Hydraulic Fundamentals

In Out Gear Pump or Motor 23 2017-04-28 Gear Pump or Motor In Out Before going back into JIC symbols, lets show another very popular type of pump or motor. 1. What clues might we have to determine whether this device is a pump or a motor. NOTE: Typically, a pump will have a larger INLET opening. 2. If this were a Pump and with the pump turning in the direction illustrated by the arrows, which side is the inlet and which side is the outlet. Build shows inlet and outlet 23 Hydraulic Fundamentals

1. Circle; as mentioned some of the major components in the hydraulic 2017-04-28 BUILDS: 1. Circle; as mentioned some of the major components in the hydraulic schematic are shown as circles. 2. Add an arrow head, but note how this arrow head differs from the pump shown earlier .. it points “IN”. 3. Second circle with arrowhead. This arrowhead comes down from the top. Does this signify any difference? (NO). 4. Second arrowhead. What type of motor is this? (bi-directional) Hydraulic Fundamentals

Motors (JIC Symbols) Single Direction Bi-Directional 2017-04-28 Motors (JIC Symbols) Single Direction Bi-Directional Arrow Showing Oil Flow IN BUILDS 1. Circle, as mentioned some of the major components in the hydraulic schematic are circles 2. Add an arrow head, but note how this arrow head differs from the pump shown earlier .. it point “IN” 3. Second circle with arrowhead. This arrowhead comes down from the top. Does this signify any difference? NO. 4. Second arrowhead 5. What type of motor is this, bi-directional Motors used in turf equipment are typically fixed displacement type delivering a constant output torque for a given pressure throughout the speed range of the motor. Motors converts hydraulic force into mechanical power 25 Hydraulic Fundamentals

Reservoirs 1. Vented 2. Pressurized 3. Return Above Fluid Level 2017-04-28 Reservoirs 1. Vented 2. Pressurized 3. Return Above Fluid Level 4. Return Below Fluid Level 26 Hydraulic Fundamentals

Lines and Connections or Working Line (Main) Crossing Lines 2017-04-28 Crossing Lines or Working Line (Main) Pilot Control Line Connecting Lines Drain Line Standard pipe ID is larger than nominal size. Steel and Copper tubing size indicates the OUTSIDE diameter. Flexible Line Flow Direction 27 Hydraulic Fundamentals

Check Valve Checked Flow Free Flow Spring Assisted Pilot Operated 28 2017-04-28 Check Valve Checked Flow Free Flow Spring Assisted Pilot Operated 28 Hydraulic Fundamentals

Relief Valves Protects the Pump and Lines from excessive pressure Returns fluid back to the reservoir

Relief Valve Supply Return to Reservoir Pilot supply 30 2017-04-28 Hydraulic Fundamentals

Pressure Differential Valve 2017-04-28 Pressure Differential Valve Supply Senses the DIFFERENCE in Pressure 31 Hydraulic Fundamentals

2017-04-28 Manual On/Off Valve 32 Hydraulic Fundamentals

Fluid Conditioners Filter Oil Cooler 33 2017-04-28 Hydraulic Fundamentals

Filters Micron 1 Millionth of a Meter or 1 Thousandth of a Millimeter 2017-04-28 Filters Internal Filter Bypass Valve (Optional) Micron 1 Millionth of a Meter or 1 Thousandth of a Millimeter 34 Hydraulic Fundamentals

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)

Hydraulic Valve JIC Closed Center Hydraulics 2017-04-28 Hydraulic Valve JIC Closed Center Hydraulics Open Center Flow in Neutral Trapped Oil Open Center Valve Hydraulic flow continually moves through the system because the hydraulic pump is constantly pumping fluid. The valve is open to return in neutral to allow the fluid to circulate back to the reservoir. Oil is drawn out of the reservoir because atmospheric pressure (14.7 psi) pushes it through the lines into the pump. 36 Hydraulic Fundamentals

1. Hydraulic flow continually moves through the system. 2017-04-28 OPEN CENTER VALVE: 1. Hydraulic flow continually moves through the system. 2. The hydraulic pump is constantly pumping fluid. 3. The control valve is open to return in neutral to allow the fluid to circulate. Hydraulic Fundamentals

2017-04-28 Hydraulic Valve JIC Extend 38 Hydraulic Fundamentals

2017-04-28 Hydraulic Valve JIC Retract 39 Hydraulic Fundamentals

2017-04-28 Hydraulic Valve JIC Neutral Again 40 Hydraulic Fundamentals

2017-04-28 Let’s examine what happens when a cylinder is extended. Pressure oil is routed to the piston end. Oil from the rod end is allowed to return to the reservoir. Hydraulic Fundamentals

2017-04-28 Lift Cylinder Extend Let’s examine what happens when a cylinder is extended. Pressure oil is routed to the piston end. Oil from the rod end is allowed to return to the reservoir. Hydraulic Fundamentals

This IS NOT TRUE!! So where does the hydraulic oil go? 2017-04-28 When cylinders “leak down” over a period of time, it is commonly believed that the cylinder piston “packings” (O-ring seals) are the cause of the problem. This IS NOT TRUE!! So where does the hydraulic oil go? Hydraulic Fundamentals

Lift Cylinder Leak Down Where Does the Oil Go?? 2017-04-28 Lift Cylinder Leak Down Where Does the Oil Go?? When cylinders “leak down” over a period of time, it is commonly believed that the cylinder piston “packings” (O-ring seals) are the cause of the problem. This IS NOT TRUE!! So where does the hydraulic oil go? Hydraulic Fundamentals

2017-04-28 This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area. Hydraulic Fundamentals

2017-04-28 Lift Cylinder Is it Possible for This Rod to Retract Even With the Piston Removed?? This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area. Hydraulic Fundamentals

Cylinder Hose Failures 2017-04-28 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 This illustration goes beyond the practical but makes the point. Because of the volume of oil trapped in the cylinder, the rod CANNOT retract any further unless the trapped oil is allowed to escape somewhere. In this case and always with cylinders that leak down by retracting, the control valve is leaking allowing the oil out of the cylinder. Remember, this rule applies only when the cylinder rod retracts (oil leaking from the piston end to the rod end and out through the control valve). Oil can leak from the rod side to the piston side (allowing the rod to extend) because the rod side with less volume of oil can leak into the piston side with a greater area. 3” Diameter Piston 1.5 x 1.5 x 3.1416 = 7.07 sq.in. Results in 2122 PSI Hydraulic Fundamentals

2017-04-28 To test a cylinder for internal leakage (past the piston seals), remove the cylinder pin from the rod (what ever the cylinder works on will have to be supported). Either extend or retract the rod completely. Then remove the oil line closest to the cylinder’s internal piston. Connect a hydraulic hose to the cylinder where the line was removed. Place the other end of the hydraulic hose in a clean bucket. Pressurize the opposite side of the cylinder with hydraulic oil. Measure leakage into the bucket. If excessive leakage is observed into the bucket, replace cylinder piston seals. NOTE: On some systems, such as the John Deere light weight fairway mowers, the line returning the lift valve will need to be capped to prevent return oil from flowing out the line. Hydraulic Fundamentals

Hydraulic Cylinder Leakage Test 2017-04-28 Hydraulic Cylinder Leakage Test Depending on the System, You May Have to Cap This Line To Prevent Return Oil From Leaking Out To test a cylinder for internal leakage (past the piston seals), remove the cylinder pin from the rod (what ever the cylinder works on will have to be supported). Either extend or retract the rod completely. Then remove the oil line closest to the cylinder’s internal piston. Connect a hydraulic hose to the cylinder where the line was removed. Place the other end of the hydraulic hose in a clean bucket. Pressurize the opposite side of the cylinder with hydraulic oil. Measure leakage into the bucket. If excessive leakage is observed into the bucket, replace cylinder piston seals. NOTE: On some systems, such as the John Deere light weight fairway mowers, the line returning the lift valve will need to be capped to prevent return oil from flowing out the line. Retract 49 Hydraulic Fundamentals

JIC Symbols Build the System Would This Hydraulic Drive System Work? 2017-04-28 Would This Hydraulic Drive System Work? PM Common Reservoir Yes, In one direction Hydraulic Drive Does NOT Provide Dynamic Braking Build the System 50 Hydraulic Fundamentals

JIC Symbols Closed Loop Hydrostatic Transmission PM Hill Simulation 51 2017-04-28 PM Hill Simulation Closed Loop Hydrostatic Transmission 51 Hydraulic Fundamentals

JIC Symbols Closed Loop Hydrostatic Transmission PM Hill Simulation 52 2017-04-28 PM Hill Simulation Closed Loop Hydrostatic Transmission 52 Hydraulic Fundamentals

JIC Symbols Build the System PM Oil Filter Oil Cooler Inlet Check 2017-04-28 Oil Filter Inlet Check PM Common Reservoir Inlet Check Build the System Oil Cooler 53 Hydraulic Fundamentals

1. Oil cooler bypass will open with a differential of 80-130 PSI 2017-04-28 Both the Oil Cooler Bypass and Oil Filter Bypass are “Differential Relief Valves” which have the capability of comparing pressures on the inlet side and the pressure on the outlet side; On the 3365 WARM, these reliefs open: 1. Oil cooler bypass will open with a differential of 80-130 PSI 2. Filter bypass will open with a differential of 20-30 PSI Leak off lines are NOT shown, but are required to provide; 1. Lubrication 2. Cooling 3. Cleaning Hydraulic Fundamentals

JIC Symbols Build the System PM Oil Filter Oil Cooler 55 2017-04-28 Oil Filter Oil Cooler Bypass Valve PM Charge Relief Valve Filter Bypass Valve Build the System Oil Cooler 55 Hydraulic Fundamentals

This slide shows normal oil flow; 2017-04-28 This slide shows normal oil flow; 1. Hydro turns providing oil flow to motors. 2. Motors turn, some oil is lost to case drain 3. Charge pump provides oil flow through; Cooler Filter Inlet Check Valves Hydraulic Fundamentals

JIC Symbols Hydrostatic Transmission Components PM Oil Filter 2017-04-28 PM JIC Symbols Oil Filter Oil Cooler Bypass Valve Charge Relief Valve Both the Oil Cooler Bypass and Oil Filter Bypass are “Differential Relief Valves” which have the capability of comparing pressures on the inlet side and the pressure on the outlet side; On the 3365 WARM, these reliefs open: 1. Oil cooler bypass will open with a differential of 80-130 PSI 2. Filter bypass will open with a differential of 20-30 PSI Leak off lines are NOT shown, but are required to provide; 1. Lubrication 2. Cooling 3. Cleaning Filter Bypass Valve Hydrostatic Transmission Components Oil Cooler 57 Hydraulic Fundamentals