Independant Suspension Flashcards
What are the disadvantages of beam axles?
Axle movement is limited
Camber angle is altered if one wheel hits a bump causing shimmy
Deflection of the leaf spring alters castor angle
High un-sprung weight
What is independent suspension?
Overcomes all the disadvantages of solid beam axles
Any system that connects the wheels to the frame , one wheel has no effect on the other
Three common types of IFS?
Double wishbone
Double link and radius rod
MacPherson strut
What type of suspension do double wishbone and double link use?
Leaf, coil and torsion
What construction does McPherson use?
Coil springs
What are the advantages of IFS?
Improved ride comfort
Better road holding
More accurate steering
Reduced steering wobble
Increased passenger space
What does the shape of the wishbone provide?
Provides stiffness resisting breaking torque
How many bearings do each wishbone have?
3
How can the diving of the wishbone be prevented when brakes are applied?
By placing the rear pivot point of the lower wishbone higher than the front pivot point
How is castor angle maintained?
By mounting the top of the wishbone slightly behind the lower wishbone
What type of load can double link and radius rod not take?
Longitudinal dynamic loads and braking torques
What can overcome the disadvantage of the double link and radius rod?
By a semi-trailing radius rod which is fitted in between the lower link and the frame
What type of tube is incorporated in the MacPherson?
Long telescopic tube with the damper
How is the MacPherson pivoted?
By a bearing at the top
How is the track control maintained?
By a single transverse link also know as a track control arm
How is the MacPherson connected to the stub axle?
Ball joint
When are the castor and camber angles set?
During production
What is a common means of attachment?
Ball joint
Why can’t you use a one piece track rod on a IFS?
Wheel alignment would altered if one wheel was deflected up or down
How can you overcome the problem of misalignment when using a one piece track rod?
Stub axle moves in an arc, track rod also needs to move in a similar motion
Therefore a three piece track rod is used
What are the 2 three piece track rod layouts?
Steering box and rack and pinion
What are the advantages of IRS?
Improved ride comfort
Improved traction on rear wheels , due to lack of torsional movement
Vehicle handling is enhanced
How can springing be provided ?
Torsion bar connected to the lower wishbone
Coil springs between wishbone and body
How is drive transmitted?
From the final drive to angle universal joints
