Hydraulics Flashcards
Fluid definition
• It is a substance that will readily take the shape of its container
• It is capable of transmitting power
• It can be a liquid or gas
Area
Area of piston face
Force
force acting on a piston / force transmitted by a piston
Pressure
pressure exerted on the system fluid
Equation
F = A x P
Name the Advantages of Hydraulics
It is reliable
Simple and easy to understand
Infinite speed range
Easily reversed
Ability to withstand overload
No spark risks
High torque at low speeds
1/12 size of equivalent electric motor
Name the Disadvantages for Hyrldraulics
• Fire risk with mineral oil systems
• Noise
• Risk of contamination
• Less efficient (85-95%)
Why should denso steel working mastic and pvc self adhesive tapes be stored on the upper deck?
Because when ignited they give off toxic gasses
Where is tape stored
Flammable store
Pipework sealing joints carry….
O rings
What are o rings wlmade from
Fluorocarbon elastomers
At what temperature does fluorocarbon give off a toxic gas?
Above 300’C
What is the gas that is given off by fluorocarbon at extreme temperatures?
Hydrogen Fluoride
Name all the fluorocarbon elastomer PPE
• PVC gauntlets
• Rubber boots
• PVC coveralls
• Full-face visor
Name the 2 types of Hydraulics fluod
Petroleum based
Synthetic Based
What is petroleum based hydraulic fluid?
Petroleum based oils are general purpose (inexpensive) mineral oils.
What is synthetic based hydraulic fluid?
Synthetic oils are man-made, for specific purposes.
Name the 3 oils used
- OM33
- OX30
- OX40
What is OM33 used for?
Yellow / Orange colour
Used in T42s T22s and CVS
What is OX30 used for?
Red
Used on subs
What is OX40 used for?
Green
T23s T45s
What is rust veto?
used during upkeep periods where hydraulic oil has been removed from a system.
Rust Veto is put in as a substitute for the hydraulic fluid to prevent corrosion.
Name the requirement of hydraulic fluid
• The main requirement of a hydraulic fluid is for the transmission of power
• The fluid must flow easily through lines
• It must be as incompressible
• Lubrication is another important requirement
• Sealing Properties
• Cooling is another role for hydraulic fluid.
The most common causes of contamination are…
· Airborne particles and moisture
· Construction dirt
· Dirt in new fluid
· Dirt produced by wearing in new system
· Dirt from human sources
Name the methods of reducing contamination
• Good system design
• Filtration and filter maintenance
• Operation of filter and clogging indicators
• Good working practices
• Use of Guardian filter pack
• Caps should be fitted to open pipework
• Clean working area
Draw the Hydraulic System
Draw the Hydraulic System
The Hydraulic System will generally have 3 sets of pipework, name them
Pressure, Supply, Drain
What does the drain leg do?
returns oil that has been used for Cooling, Sealing and Lubricating
Name the types if hydraulic pump
Axial Piston
Positive displacement
Name the types of Positive displacement pump
• Internal gearwheel type
• External gearwheel type
• Vane type
• Lobe type
• Radial piston type
• Axial Piston Pump (These types of pump use a Swash Plate)
Where are axial piston pumps used
Stabiliser systems
CPP systems
Steering systems
What does an actuator do?
Actuators convert hydraulic energy (system pressure) into mechanical motion
Name the 2 types of Actuator
Linear, Rotary
Name the 2 types of linear actuators
Single, Double Acting
What is an accumulator
a device in which potential energy is held under pressure.
Where are accumulators used?
They are useful in fluid power systems to store energy and to smooth out pulsations. They are used as a surge or pulsation dampener or absorber.
Hydraulic System symbols
Hydraulic System Symbols
Why are anti oxidants added to oil?
Prevents it turning thick, and sludgy
Demulsibility Meaning
Ability to separate water
