Hydraulics

Question 1

Fluid definition

Answer 1

• 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

Question 2

Area

Answer 2

Area of piston face

Question 3

Force

Answer 3

force acting on a piston / force transmitted by a piston

Question 4

Pressure

Answer 4

pressure exerted on the system fluid

Question 5

Equation

Answer 5

F = A x P

Question 6

Name the Advantages of Hydraulics

Answer 6

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

Question 7

Name the Disadvantages for Hyrldraulics

Answer 7

• Fire risk with mineral oil systems
• Noise
• Risk of contamination
• Less efficient (85-95%)

Question 8

Why should denso steel working mastic and pvc self adhesive tapes be stored on the upper deck?

Answer 8

Because when ignited they give off toxic gasses

Question 9

Where is tape stored

Answer 9

Flammable store

Question 10

Pipework sealing joints carry….

Answer 10

O rings

Question 11

What are o rings wlmade from

Answer 11

Fluorocarbon elastomers

Question 12

At what temperature does fluorocarbon give off a toxic gas?

Answer 12

Above 300’C

Question 13

What is the gas that is given off by fluorocarbon at extreme temperatures?

Answer 13

Hydrogen Fluoride

Question 14

Name all the fluorocarbon elastomer PPE

Answer 14

• PVC gauntlets
• Rubber boots
• PVC coveralls
• Full-face visor

Question 15

Name the 2 types of Hydraulics fluod

Answer 15

Petroleum based
Synthetic Based

Question 16

What is petroleum based hydraulic fluid?

Answer 16

Petroleum based oils are general purpose (inexpensive) mineral oils.

Question 17

What is synthetic based hydraulic fluid?

Answer 17

Synthetic oils are man-made, for specific purposes.

Question 18

Name the 3 oils used

Answer 18

1. OM33
2. OX30
3. OX40

Question 19

What is OM33 used for?

Answer 19

Yellow / Orange colour

Used in T42s T22s and CVS

Question 20

What is OX30 used for?

Answer 20

Red

Used on subs

Question 21

What is OX40 used for?

Answer 21

Green

T23s T45s

Question 22

What is rust veto?

Answer 22

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.

Question 23

Name the requirement of hydraulic fluid

Answer 23

• 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.

Question 24

The most common causes of contamination are…

Answer 24

· Airborne particles and moisture

· Construction dirt

· Dirt in new fluid

· Dirt produced by wearing in new system

· Dirt from human sources

Question 25

Name the methods of reducing contamination

Answer 25

• 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

Question 26

Draw the Hydraulic System

Answer 26

Draw the Hydraulic System

Question 27

The Hydraulic System will generally have 3 sets of pipework, name them

Answer 27

Pressure, Supply, Drain

Question 28

What does the drain leg do?

Answer 28

returns oil that has been used for Cooling, Sealing and Lubricating

Question 29

Name the types if hydraulic pump

Answer 29

Axial Piston Positive displacement

Question 30

Name the types of Positive displacement pump

Answer 30

• Internal gearwheel type • External gearwheel type • Vane type • Lobe type • Radial piston type • Axial Piston Pump (These types of pump use a Swash Plate)

Question 31

Where are axial piston pumps used

Answer 31

Stabiliser systems CPP systems Steering systems

Question 32

What does an actuator do?

Answer 32

Actuators convert hydraulic energy (system pressure) into mechanical motion

Question 33

Name the 2 types of Actuator

Answer 33

Linear, Rotary

Question 34

Name the 2 types of linear actuators

Answer 34

Single, Double Acting

Question 35

What is an accumulator

Answer 35

a device in which potential energy is held under pressure.

Question 36

Where are accumulators used?

Answer 36

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.

Question 37

Hydraulic System symbols

Answer 37

Hydraulic System Symbols

Question 38

Why are anti oxidants added to oil?

Answer 38

Prevents it turning thick, and sludgy

Question 39

Demulsibility Meaning

Answer 39

Ability to separate water