Post on 06-Apr-2018
8/3/2019 simboluri hidro
1/57
GOLFTURF
Training Department
&
John Deere
Foundations
Hydraulic
8/3/2019 simboluri hidro
2/57
Pumps
Axial Piston Pump
Gear Pump
Motors
Check Valve
Reservoirs
Conditioners
Pascals Law
Application Principles
Hydraulic Valve JIC
Build With JICs
(Left Click Selection Box)
Hydraulic Cylinder Principles
Cylinder Leakage Test
Relief Valve
Lines and Connections
Pressure Differential Relief
Hydraulic Fluid
Least Resistance
Open vs ClosedJIC
8/3/2019 simboluri hidro
3/57
3
Liquids Have no Shape of their own
8/3/2019 simboluri hidro
4/57
4
Liquids are
Practically Incompressible
8/3/2019 simboluri hidro
5/57
5
Liquids under pressure follow
what path?
Path of least Resistance
8/3/2019 simboluri hidro
6/57
6
Path of Least Resistance
10 lbs
8/3/2019 simboluri hidro
7/57
Pascals LawPascals Law
Pressure Exerted on a Confined Fluid is
Transmitted Undiminished in All
Directions and Acts With Equal Forceon Equal Areas and at Right Angles to
Them.
7
Imperial
Metric
8/3/2019 simboluri hidro
8/57
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)).
8/3/2019 simboluri hidro
9/57
--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 / 17142. 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
Pascals Law, named after Blaise Pascal (French 1623-1662)
IMPERIAL
8/3/2019 simboluri hidro
10/57
--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 / 17142. 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
Pascals Law, named after Blaise Pascal (French 1623-1662)
METRIC
8/3/2019 simboluri hidro
11/57
Application PrinciplesApplication Principles1 lb (.45kg)
Force
1 sq in
(.65cm2)
Piston Area
1 psi
(6.9kpa)
10 sq in(6.5cm2)
Piston Area
10 lbs (4.5kg)
11
8/3/2019 simboluri hidro
12/57
THE TWO MAIN TYPES OF PUMPS:
1. With a positive displacement pump, with each revolution, a specificamount 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).
8/3/2019 simboluri hidro
13/57
Pump TypesPump 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
8/3/2019 simboluri hidro
14/57
14
JIC SymbolsJIC Symbols
Joint Industry Council
Symbolic Drawings used in Schematics
to Represent Components.
8/3/2019 simboluri hidro
15/57
J I C Symbols
Joint Industrial Council
2139 Wisconsin Ave, NWWashington, DC 20007
This organization was founded in 1965. JIC standards replaced those
written by the Joint Industrial Conference (mostly auto manufacturing)
BUILDS1. 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 iscapable 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.
8/3/2019 simboluri hidro
16/57
Pumps (JIC Symbols)Pumps (JIC Symbols)
Arrow
ShowingOil Flow
OUT
Constant
Displacement
Single Direction
Bi-Directional,
VariableDisplacement
16Pumps convert mechanical power into hydraulic force
8/3/2019 simboluri hidro
17/57
Heavy Duty applications that require variable displacement
bi-directional pumps, typically use axial piston pumps.
POINT OUT THE:
1. Rotating group
2. Swash plate3. Pistons
8/3/2019 simboluri hidro
18/57
Axial Piston PumpAxial Piston Pump
Neutral Position
Vertical Swashplate
Rotating Group
Typically 9 Pistons
Piston
Swash
Plate 18
Piston
Piston
Engine Shaft Pumps
Pressure Oil
Each Piston
8/3/2019 simboluri hidro
19/57
SWASHPLATE ANGLE, FORWARD POSITION:
1. As the hydro linkage is slowly moved forward (swashplate anglechanges) 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 swashplateangle), the maximum volume of oil is being discharged from the
pump, then the speed of the motors are at maximum.
8/3/2019 simboluri hidro
20/57
Axial Piston PumpAxial Piston Pump
Forward Position
Angled Swashplate
Rotating Group
Typically 9 Pistons 20
Pressure
Charge Oil
8/3/2019 simboluri hidro
21/57
Axial Piston PumpAxial Piston Pump
Reverse Position
Angled Swashplate
Rotating Group
Typically 9 Pistons 21
Charge
Pressure
8/3/2019 simboluri hidro
22/57
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.
8/3/2019 simboluri hidro
23/57
In Out
Gear Pump
or Motor
Gear Pump
or Motor
23
8/3/2019 simboluri hidro
24/57
BUILDS:
1. Circle; as mentioned some of the major components in the hydraulicschematic 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)
8/3/2019 simboluri hidro
25/57
Motors (JIC Symbols)Motors (JIC Symbols)
Single Direction
Arrow Showing
Oil Flow IN
Bi-Directional
25Motors converts hydraulic force into mechanical power
8/3/2019 simboluri hidro
26/57
ReservoirsReservoirs
1. Vented 2. Pressurized
3. Return Above
Fluid Level
4. Return Below
Fluid Level26
8/3/2019 simboluri hidro
27/57
Lines and ConnectionsLines and Connections
27
Working Line (Main)
Pilot Control Line
Drain Line
Flow Direction
Crossing Lines
or
Connecting Lines
Flexible Line
8/3/2019 simboluri hidro
28/57
Check ValveCheck Valve
28
Checked Flow Free Flow
Pilot Operated
Spring Assisted
8/3/2019 simboluri hidro
29/57
29
Relief Valves
Protects the Pump and Lines
from excessive pressure
Returns fluid back to the reservoir
8/3/2019 simboluri hidro
30/57
Relief ValveRelief Valve
30
Supply
Pilot supply
Return to
Reservoir
8/3/2019 simboluri hidro
31/57
Pressure Differential ValvePressure Differential Valve
31
Supply
Senses the DIFFERENCE in Pressure
8/3/2019 simboluri hidro
32/57
Manual On/Off ValveManual On/Off Valve
32
8/3/2019 simboluri hidro
33/57
Fluid ConditionersFluid Conditioners
Filter
Oil Cooler33
8/3/2019 simboluri hidro
34/57
34
FiltersFilters
Micron
1 Millionthof a Meter or
1 Thousandth
of a Millimeter
Internal Filter
Bypass Valve
(Optional)
8/3/2019 simboluri hidro
35/57
35
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)
8/3/2019 simboluri hidro
36/57
36
Hydraulic Valve JICHydraulic Valve JIC
Trapped Oil
Closed Center HydraulicsOpen Center
Flow in Neutral
8/3/2019 simboluri hidro
37/57
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.
8/3/2019 simboluri hidro
38/57
Extend 38
Hydraulic Valve JICHydraulic Valve JIC
8/3/2019 simboluri hidro
39/57
Retract 39
Hydraulic Valve JICHydraulic Valve JIC
8/3/2019 simboluri hidro
40/57
Neutral Again 40
Hydraulic Valve JICHydraulic Valve JIC
8/3/2019 simboluri hidro
41/57
Lets 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.
8/3/2019 simboluri hidro
42/57
Lift CylinderLift Cylinder
Extend
8/3/2019 simboluri hidro
43/57
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?
8/3/2019 simboluri hidro
44/57
Lift CylinderLift Cylinder
Leak Down Where Does
the Oil Go??
8/3/2019 simboluri hidro
45/57
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 thiscase 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.
8/3/2019 simboluri hidro
46/57
Lift CylinderLift Cylinder
Is it Possible forThis Rod to Retract
Even With
the Piston
Removed??
8/3/2019 simboluri hidro
47/57
Cylinder Hose FailuresCylinder Hose Failures
Effects On LinePressure When a
Cylinder Piston
Packing is
Leaking
3 Diameter Piston
1.5 x 1.5 x 3.1416 = 7.07 sq.in.
Results in 2122 PSI
1.5 Diameter Rod
.75 x .75 x 3.1416 = 1.77 sq.in.
Results in 8475 PSI
15000 lbs
of Down
Force
8/3/2019 simboluri hidro
48/57
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 removethe oil line closest to the cylinders 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 preventreturn oil from flowing out the line.
8/3/2019 simboluri hidro
49/57
Retract49
Hydraulic Cylinder
Leakage Test
Hydraulic Cylinder
Leakage Test
Depending on the
System, You May
Have to Cap This Line
To Prevent ReturnOil From Leaking Out
JIC S b lJIC S b l
8/3/2019 simboluri hidro
50/57
50
JIC SymbolsJIC Symbols
PMWould This Hydraulic
Drive System Work?
Hydraulic Drive Does NOT
Provide Dynamic Braking
Common
Reservoir
Common
Reservoir
Build the System
Yes, In one direction
JIC S b lJIC S b l
8/3/2019 simboluri hidro
51/57
51
JIC SymbolsJIC Symbols
PM
Closed Loop Hydrostatic Transmission
Hill Simulation
JIC S b lJIC S b l
8/3/2019 simboluri hidro
52/57
52
JIC SymbolsJIC Symbols
PM
Closed Loop Hydrostatic Transmission
Hill Simulation
JIC S b lJIC S b l Oil il
8/3/2019 simboluri hidro
53/57
53
JIC SymbolsJIC Symbols
PM
Oil Cooler
Build the System
CommonReservoir
Common
Reservoir
Oil Filter
Inlet
Check
Inlet
Check
8/3/2019 simboluri hidro
54/57
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
JIC S b lJIC S b l Oil Fil
8/3/2019 simboluri hidro
55/57
55
JIC SymbolsJIC Symbols
Build the System
PM
Oil Cooler
Oil Filter
ChargeRelief
Valve
Oil CoolerBypassValve
Filter
BypassValve
8/3/2019 simboluri hidro
56/57
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
JIC S b lJIC S b l Oil Filt
8/3/2019 simboluri hidro
57/57
57
JIC SymbolsJIC Symbols
Hydrostatic
Transmission
C t
Oil Cooler
Oil Filter
PM
ChargeRelief
Valve
Oil CoolerBypassValve
Filter
BypassValve