(1) The presentation covered the conditions for true rolling, skidding phenomena, and steering linkage for conventional and independent suspension systems. (2) For true rolling to occur, the direction of motion must be perpendicular to the wheel axis and toward the forward force. When a side force acts parallel to the wheel axis, scrub action is produced. (3) Skidding occurs when the vehicle loses control of steering and slides sideways without wheel rotation. Causes include braking while turning and slipping on icy or wet surfaces. Steering linkage connects the steering gear to front wheels using rods, arms, and tie rods in a parallelogram configuration for conventional suspensions.

1. GALGOTIAS UNIVERSITY
SCHOOL OF MECHANICAL ENGINEERING
PRESENTATION/SEMINAR ON STEERING SYSTEM
SUB:-TRANSMISSION SYSTEM THEORY AND DESIGN
SUBMITTED TO, PRESENTED BY,
Mr. Brahma Agrawal Shubhesh Ranjan
Dept. of Mechanical engineering M.TECH(AUTOMOBILE)
1ST YEAR(1ST SEM)
ENROLLMENT NO -19032030031

2. OVERVIEW
The Presentation will Cover:
(a) Condition for True Rolling
(b) Skidding Phenomena
(c) Steering Linkage for Conventional and Independent suspension

3. Condition For True Rolling:-

4. Contd.
(1) It occurs when the direction of motion of
vehicle is perpendicular to the wheel axis and it going toward
forward force.
(2) when the wheel subjected to side force that acts parallel to the
wheel axis, a true Scrub action is produced
(3) when wheel is subjected to both forward and side forces, This
movement is called true rolling.
(4) The main Condition when wheel are steered, the direction is
motion is neither parallel nor perpendicular to the axis of rotation

5. Road wheel and Tyre Rolling Conditions

6.  SCRUB ACTION :- (a) Due to misalignment of wheels
(b) Due to camber Angle
 STUB AXLE :- (a) Also name as stud axle
(b) An axle supporting only one wheel of a pair on opposite side of a
vehicle
CONTINUED.. WITH THE TYRE ROLLING CONDITION
(1) When vehicle take turn, the front wheel must turn in a definite
manner both in relation to the axes.
(2) Axis of the real wheels so that the slip may be avoided
(3) And after that true rolling of all the wheels is obtained

7. STEERING GEAR PHENOMENA
 If the axes of front wheel meets at the point or intersect at
the point this point is known as Instantaneous Centre (I-
Centre) point.
 Vehicle must be turn about Instantaneous centre
 If the Axes don’t intersect at the Instantaneous centre
vehicle skid
 Inner wheel make larger angle (θ) at I-centre
 Outer wheel make smaller angle (Ф) at I-centre

8. SKIDDING PHENOMENON

9. SKID IN AN AUTOMOBILE :-
It means sliding of vehicle without rotating
It occurs when you lose your control of your
steering
After that vehicle failing to grip the road and
sliding sideways on the road
It happens when applies brake when turn.
In this condition where one or more slipping
relative to the road
Overall handling of the vehicle has been
affected when skidding take place

10. TYPES OF SKID
FISHTAILING :-cyclical skid combining oversteer (rear wheel skidding) with over correction in opposite
direction
SPIN-OUT :- In this where the vehicle starts to skid while rotating, or develop rotation while skidding and
rotates out of control
BURNOUT :- It is also called burning of rubber, If vehicle applies torque to the wheels during acceleration to
cause the tyre to skid while rotating.
SKIDDING DURING BREAKING :- This is simplest type of skid, where directional change doesn’t exist in this
vehicle lock the tyres moving forward when movement
CORNERING SKID :- Lose steering control in a turn, and the car begins to skid
BLOWOUT SKID :- Suddenly loses air pressure, and the car begins to skid

11. What we Have to Do when Car is skidding
 Get your foot off the accelerator and the brake
 Steer gently in the direction you want the car to go

12. How to Prevent or Stop Vehicle Skidding
Slow Down the vehicle at the curves to reducing curves
Drive within your sight distance to reduce sudden stops and braking skids
Maintain adequate distance to reduce quick stops
Slow Down on slippery surface
Adjust speed to the surface condition and the curvature of the road
Don’t over brake

13. Causes of Skidding(Loss of Traction)
Basically divided into three groups:-
•Ice, Snow or Frost
•Wet Road
•Mud on the Road
•Broken or uneven Road Surface
Condition Of Road :-
•Tyres should have good threads so that the front and rear should be matched
•Tire Pressure Should be correct on both the tires
Condition of the vehicle
(mainly brakes and
tires):-
•Steering Wheel (sudden steering action on slippery surface)
•Accelerator (sudden changes in vehicle speed)
•Brakes (Panic stops)
Action Of Driver:-

14. Steering Linkage for conventional and
independent Suspension
 Steering Linkage :- It is a series or arms, rods and ball socket that connects the
steering mechanism to the steering knuckle.
 It is used with both manual
and power steering
mechanism.
 Steering System that con-
nect the steering box to
the front wheels consist
of a number of rods.

15.  The Steering linkage relays steering forces from the steering gear to the front wheels.
 Most conventional Steering linkage used is Parallelogram type.
 Parallelogram is a geometric box type shape where opposite side are parallel and equal
distance.
 This type uses four tie rods, two inner and two outer(left and right),A centre link between
the tie rods and the idler arm on the passenger side called pitman arm.

16. Steering linkage for conventional suspension
system
In Case of conventional rigid axle:-
The main axle beam ensures the movement of stub axle in the horizontal plane.
The is no vertical deflection of the suspension
There is no change track rod length.

17. Contd.
 Steering linkage In case of Independent Suspension system:-

18. Two stub axle can move up or down independent of each other.
Three piece track rod is used
The Centre portion is called relay rod
Two stub axle can move up or down independent which each other.
Relay rod connected to the idler arm.
And it supported to the body structure

19. A good steering mechanism is must for a
vehicle’s stability at the time of turning.
Steering of four wheeler is designed in a
manner so it will not permit lateral slip of
front wheel during steering.
Steering is done by providing a suitable
gearing and linkage between front wheel
and steering wheel.

20. THANKING YOU