Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Suspension > In Service Suspension Systems > Flashcards

In Service Suspension Systems Flashcards

1
Q

What is the purpose of suspension?

A

To provide a flexible support for mse whistle isolating the imperfections in the road

Secondarily to provide stability under all conditions- acceleration, braking, cornering

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What are the purpose of road springs?

A

Absorb the bumps and shocks transmitted by the road surface to prevent them reaching the body

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is sprung weight?

A

Anything supported by the spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is unsprung weight?

A

Mass supported by the wheel up to the spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the benefits of a low unsprung weight?

A

Suspension works less to control movement

Body will shake less when travelling over rough surfaces therefore improving ride

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are semi-elliptic leaf springs used on?

A

Solid beam axles

Used on light commercial vehicles and heavy trucks

MSE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What is the purpose of the rubber bushes in the eye?

A

Allow for movement and act as noice insulators

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Why are the leaves varied in length?

A

Give constant stress throughout the spring

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What does the centre bolt do?

A

Secured the leaves together and acts as a locating dowel

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What do rebound clips do?

A

Transmit load to some of the lower leaves during the return motion and prevent splaying

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

What allows for alteration of spring length?

A

Swinging shackle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What does the rubber bush in the spring eye do?

A

Prevent transmission of shocks

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the purpose of the u bolt?

A

Clamp spring to the axle

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are the methods of reducing inter plate friction?

A

Synthetic rubber buttons

Inner leaf plates

Reduce number of leaves

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Why is the middle thicker on the semi elliptic one leaf spring?

A

To avoid overstressing the centre of the leaf

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What is spring rate?

A

The amount of deflection of the spring for a given load

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

The load that the equipment is designed to carry determines?

A

Number of springs

Length of springs

Thickness of springs

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

What does a helper leaf spring do

A

Overcomes variations between unladen and laden running conditions

Acts in unison with the main spring to increase spring rate

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

What is the maintenance requirements of a leaf spring?

A

Cracking of the leaf spring

Missing or broken rebound clip

Loose, cracked or corroded u bolts

Security of mountings

Perished or worn bushes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

What are the cross sectional areas of torsion bars?

A

Straight , round or square

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

How is the torsion bar anchored?

A

Anchored to the body or chassis at one end , other end connected to the suspension arm

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

What does large diameters at the ends of torsion bar reduce?

A

Stress concentrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

What does adjusting the torsion bar do?

A

Change ride or standing height

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

How is spring rate set by on torsion bar?

A

Length and diameter of bar

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

How does a torsion bar work?

A

Wheel travels up, torsion bar also travels up and this upwards travel induces a twist , this is a result of the bar absorbing energy , then pushes it back down

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

What are the 3 main types of torsion bar adjuster?

A

Internal jacking screw

Trunnion mounted jacking screw

Lockable eccentric cam

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

What are the purposes of a torsion bar adjuster?

A

Used to set the ride height or standing height

28
Q

What is the purpose of rubber suspension?

A

Can store more energy for its size than any spring material

Energy released is less than what is absorbed

Can stiffen suspension

29
Q

What is fitted in conjunction with metal springs to modify suspension characteristics?

A

Rubber suspension

30
Q

What is rubber suspension commonly used on?

A

Light vehicles, common on heavy equipment and tandem axle bogies

31
Q

What is the operation of the rubber suspension?

A

The suspension arm pivots on the bolt

This causes the arm to extend , expanding the rubber element

Rubber element contracts , this absorbs road shocks

32
Q

What are the 3 types of rubber bump stops?

A

Solid conical

Hollow conical

Hollow cylindrical

33
Q

What do rubber bump stops do?

A

Stiffen suspension when they are at maximum deflection

34
Q

What is the inderspension unit construction?

A

Square or round metal tube bolted to the chassis

Has 4 rubber blocks which absorbs motion and shocks

Square bar connected to arm from stub axle

35
Q

What is a helical coil spring?

A

Torsion bar wound into a spring

Used on light vehicles

36
Q

What are the advantages and disadvantages of the coil spring?

A

No inner plate friction, superior energy storage

Requires additional suspension members

37
Q

What is the spring rate governed by?

A

Diameter and length of bar

38
Q

Length of spring is governed by?

A

Diameter and active coils

39
Q

What are the 3 types of helical coil?

A

Two flat tail

One flat and one tangent tail

Two pigtail

40
Q

What does the two flat tail spring do?

A

Remains stationary relative to vehicle structure

41
Q

What does the one flat one tangent tail do?

A

Tangent seats against abutment

Prevents rotational creep

42
Q

When are two pigtail ends used?

A

The ends of the spring are positively clamped to the stationary or moving abutments

43
Q

What are the 4 reasons spring deflections occur?

A

Road conditions

Off road terrain

Weight of driver and passengers

Cargo

44
Q

What is coil bound?

A

When a heavy load is placed on a coil spring it could compress the spring the entire amount of available length

45
Q

By changing the shape of the coil , what happens ?

A

Length of travel can be increased

Sometimes called telescopic

46
Q

What is an advantage of changing coil shape ?

A

More stable

47
Q

What do coil spring rubber isolators do?

A

Incorporated in the coil spring mountings to reduce noise

48
Q

What checks should be done when inspecting coil springs?

A

Check for cracking

Check for signs of corrosion

Check serviceability of any rubber components

Check securely located

49
Q

Why use air suspension?

A

Free

Compressible

Ride comfort is only affected a little

Good for fitting to heavy goods vehicles

50
Q

What are the advantages of air suspension?

A

Smoother ride

Fragile cargo is protected

Provides better height control

Allows constant height to be maintained

Allows provision for lift axle

51
Q

What are the components of an air suspension?

A

Compressor- reciprocating , engine or motor driven

Receiver- stores air

Rubber air bellows- inflate and deflate to raise and lower

Levelling valve- height control

52
Q

What does the levelling valve do?

A

Control supply of air to bellows, raises vehicle to set height and maintains ride height

Have predetermined time delay (lost motion connection)

53
Q

What is the operation of the air suspension?

A

Driver turns ignition on

Compressor starts charges receiver and supplies air via a solenoid

ECU and electronics set suspension height or driver can override

Trailing arm sets the spring rate to ensure ride comfort

54
Q

What is the operation of the levelling valve when unladen?

A

Trailing arm down

Check valve and inlet valve closed preventing air to bellows

Air from bellows exhausted through stem to atmosphere

55
Q

What is the operation of the levelling valve when laden?

A

Trailing arm in the up position

Check valve and inlet valve open

Air enters goes round valves and out to bellows

56
Q

What is the purpose of the lost motion connection?

A

To provide time delay and allow trailing arm to ignore normal ride motions

57
Q

What is the lost motion connection operation?

A

Trailing arm moves up and down in hollow block due to normal conditions

Not a constant force so it cannot overcome spring pressure

Trailing arm senses increase in load moves up, ball actuator overcomes spring and air can now flow

58
Q

What is the purpose of lift axles?

A

Used to lift and retain a non driven axle

59
Q

What are the advantages of lift axles?

A

Extends tyre life

Reduces fuel consumption

Temporarily transfers weight to driven axle improving traction

60
Q

How is the axle retracted on a lift axle?

A

Bell crank motion when bellows are pressurised

61
Q

What is the operation of the lift axle?

A

Air spring is sandwiched between chassis frame and leaf spring

If air spring is charged with air the axle comes down

Exhausting air enables the axle to come up

62
Q

What are the common checks on air suspension?

A

Check for air leaks

Check for signs or perishing air bellows

Check for any corrosion of pipes and correct routing

63
Q

What are the differences of a hydro-pneumatic suspension?

A

Supported by mass of gas

The mass of gas is constant in respect of load

Pressure increased as volume is smaller

Springs can be hydraulically connected to improve stability

64
Q

What is the operation of the hydro-pneumatic suspension?

A

Pump starts draw fluid from reservoir and feeds accumulator

Accumulator feeds height corrector/levelling valve

Height corrector in central position supply port closed

As it is loaded , the downward movement causes rotation of bar

Control rod then moves slide valve to uncover supply port

Oil forces diaphragm up and stiffens suspension

65
Q

What is the delay valve also known as?

A

Dash pot

Suspension (5 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions