Steering Flashcards
What is the purpose of Toe?
Is to compensate for any deflection in the steering linkage.
What is Steering Axis?
It is an invisible line drawn through the centre of the kingpin when viewed from the side.
What is positive Caster?
Result when the top of the steering axis is tilted toward the rear of the vehicle. The kingpin centreline must be to the rear of the vehicle.
What is negative Caster?
Result when the top of the steering axis is tilted toward the front of the vehicle. The kingpin centreline must be in front of the centre line.
What is Zero Caster?
Result when the kingpin centre line and the vertical line overlap.
What is the purpose of Caster?
Caster increase the vehicle’s tendency to want to go straight and help return the steering wheel to the straight head position after a turn.
What are the steering angles that make up steering geometry?
Toe Caster Camber Kingpin inclination Turning radius Thrust and Scrub
What are tire wearing angles?
Camber, Toe, and turning radius
What are directional control angles?
Caster, and kingpin inclination
What is Toe?
It is the difference in distance between the front and the rear of the wheels on the same axle, measured at hub/spindle centreline.
What is Caster
Caster is the forward or backward tilt of the kingpin at the top viewed from the side
Where is attached the Pitman arm?
To the sector shaft.
What is the Worm shaft (input shaft)?
It is where the steering shaft is attached.
How is attached the steering shaft to the worm shaft?
Via a split yoke and pinch bolt
What is the purpose of the steering gear?
Is to transmit the driver’s intentions from the steering wheel to the linkage.
What is the steering knuckle?
It is the assemble that contains the Kinpin.
What is the Hinge pin?
One side is called the steering knuckle and the other the I beam axle.
What is the steering stop screw?
It is a stop that limit the amount of pivot of each tire assembly.
What is SRS?
Supplemental restrain systems (air bag)
What is the position of a steering wheel?
8-4 +- 10%
What are the types of steering gear?
- Manual steering gear
- Integral power steering gear
- Rack and pinion steering
What is the purpose of the pitman arm?
To change the rotary motion of the sector shaft into linear motion that can be transferred to the drag link.
What is the purpose of the upper steering arm?
To transmit the motion of the drag link to the steering knuckle.
What is the purpose of the steering knuckle?
To allow each wheel assembly to pivot during cornering.
What is the Thrust bearing?
It withstand the load imposed on the axle and steering knuckle by the weight of the vehicle.
Which angles are tire wearing angles
Camber, turning radius, toe
Which angles are directional control angles
Caster and kingpin inclination
What is Camber
Camber is the outward or inward tilt of the wheel at the top viewed from the front.
What is KPI
Kingpin inclination angle
What is camber pull
Result in a pull on the side of the most positive setting.
Purpose of KPI
- reduces the need for high camber
- brings the point of contact more directly under the point of load
- provide a pivot point for the wheel to turn
- provides steering stability
- reduces road shock
- reduces brake pull
What is induced angle
camber angle + KPI angle
What is scrub radius
the distance between the projected steering axis and the center of the tire contact area measured at the road surface.
What is turning radius
toe out on turns
What is the purpose of turning radius
to reduce tire scuffing during cornering
What is Ackerman principal
Draw a line that passes through the center of the kingpin and tie rod end it will meet at the center of the rear axle on a single axle and will meet at the center of the rear axles on tandem
What is thrust angle
it is the angle formed by the thrust line and the geometric center line and is the difference between GCL and thrust line
What is VCL
Vehicle center line and runs down the middle of the vehicle
What is GCL
Geometric center line and is determined by the midpoints of the front and rear wheels
What is scrub angle
Is the angle formed by the intersection of the horizontal lines drawn through the rear axle when total toe and offset is zero
Positive scrub?
Will push front of vehicle to the right and scrub the right side of tires
Negative scrub?
Will push the front of the vehicle to the left and scrub the left side of the tires
What is a trammel bar?
used to measure the distance from the center shaft of axlesrear
What are non adjustable angles?
KPI Kingpin inclination and turning radius
