Slide 1: firstname.lastname@example.org Don Bosco Auto STEERING SYSTM Automobile Slide 2: STEERING SYSTM Slide 3: INTRODUCTION LOCATION : LOCATION FUNCTION OF STEERING SYSTEM : FUNCTION OF STEERING SYSTEM to convert the rotary motion of the steering wheel into angular displacement of the front wheels.
maintain the straight ahead motion of the vehicle while it encounters potholes and road bumps.
operate with minimum effort. QUALITIES OF STEERING SYSTEM : QUALITIES OF STEERING SYSTEM Should be light and easy to operate.
Should be capable of keeping the wheels in true rolling motion at all times without rubbing or scuffing of tires on road QUALITIES OF STEERING SYSTEM : QUALITIES OF STEERING SYSTEM should have a certain degree of self steering action to keep the vehicle on a straight course.
should not transmit road shocks to the steering wheel. MAIN PARTS OF THE STEERING SYSTEM : MAIN PARTS OF THE STEERING SYSTEM Steering wheel
Steering drop arm
Steering shaft Slide 9: Steering gear box
Steering knuckle arm
Tie rod MAIN PARTS OF THE STEERING SYSTEM STEERING WHEEL : STEERING WHEEL a circular wheel mounted at the steering shaft and acts as a control to steer the wheel. STEERING COLUMN : STEERING COLUMN A hollow shaft enclosed by a casing called steering outer tube.
At its upper end the steering wheel is attached and at the lower end steering gear box is employed.
This way the steering shaft connects the steering wheel with the steering gear. STEERING GEAR BOX PURPOSE : STEERING GEAR BOX PURPOSE enables the driver to steer the vehicle easily.
changes the movement of the steering shaft at a right angle, which in turn is converted into a straight line motion by the pitman or drop arm. CONSTRUCTION OF A STEERING GEAR BOX : CONSTRUCTION OF A STEERING GEAR BOX Steering gears are enclosed in a casing known as steering gear box. CONSTRUCTION OF A STEERING GEAR BOX : CONSTRUCTION OF A STEERING GEAR BOX It consists of a worm welded to steering shaft and a sector integrated at the sector shaft which carries the pitman arm. CONSTRUCTION OF A STEERING GEAR BOX : CONSTRUCTION OF A STEERING GEAR BOX A screw and lock nut is provided at the box to fix the endwise position of the sector shaft for setting free play or backlash between the sector and worm gear. CONSTRUCTION OF A STEERINGGEAR BOX : CONSTRUCTION OF A STEERINGGEAR BOX The worm gear is supported in taper roller bearings at its outer ends in the steering gear box.
A plain bearing supports the sector shaft. TYPES OF STEERING GEAR BOX : TYPES OF STEERING GEAR BOX This type of steering is used in heavy commercial vehicles such as TATA and ASHOK LEYLAND trucks. Re-circulating ball type CONSTRUCTION : CONSTRUCTION The worm at the end of the steering shaft has a nut having re-circulating steel ball in between grooves of worm and nut.
The balls reduce the friction, increasing the efficiency of the mechanism by 90%. Re-circulating ball type Slide 19: Teeth formed on the outside of the nut are in mesh with a toothed wheel sector.
The pitman arm attached to this sector steers the front wheels through the link rod and the steering arms. Re-circulating ball type CONSTRUCTION WORKING : WORKING As the driver turns the steering wheel, the two steel ball races roll in the groove and the nut travels along the length of the worm.
The wheel sector gets its motion from the nut, which, in turn, moves the drop arm to displace the front wheels.
The ball guides re-circulate the steel balls in the worm groove. ADJUSTMENT : ADJUSTMENT The back lash between the sector and the external teeth on the nut is adjusted by turning a screw till the required adjustment is effected.
The worm shaft end play is adjusted with the help of adjuster nut or with addition or subtraction of shims at its ends.
It is also adjusted by bushing. RACK AND PINION STEERING : RACK AND PINION STEERING It consists of :
Spring pads CONSTRUCTION : CONSTRUCTION The pinion is attached to the end of the steering shaft.
A universal joint is provided at the end of the steering shaft to mount the steering box centrally and to provide more leg space.
The casing houses the pinion on bearings and sometimes a yoke damper also.
It engages with the rack to move sideways to give lateral movement to the front wheels. RACK AND PINION STEERING CONSTRUCTION : CONSTRUCTION The tie rods are attached to this rack with the help of ball joints enclosed with the help of rubber bellows.
This allows for rise and fall of the wheels.
Spring pads on the underside of the rack tend to reduce the back lash between gears to a minimum. RACK AND PINION STEERING ADJUSTMENT : ADJUSTMENT The rack backlash is adjusted by adding shims to the damper cover plate.
The pinion end play is adjusted by adding shims to the bearing cover plate. WORKING : WORKING On revolving the pinion shaft through steering wheel the pinion revolves.
As the pinion gear is in mesh with rack teeth, rack moves to and fro. while moving to one side it pushes the tie rod to that side while the other tie rod is pulled, with the result the stub axle being tied up with these tie rods, also move and the vehicle gets steered. Working video STEERING DROP ARM(Pitman arm) : STEERING DROP ARM(Pitman arm) Also known as pitman arm.
One side of it has splines which match the splines of the sector shaft and it is held on this shaft with the help of nut. STEERING DROP ARM (Pitman arm) : STEERING DROP ARM (Pitman arm) The other end has a taper hole in which ball end is held tight with the help of a nut.
It converts rotary motion of the shaft into linear motion through the steering gear and sector shaft. STEERING DROP ARM(Pitman arm) : STEERING DROP ARM(Pitman arm) It swings like the pendulum of a clock when the steering wheel is rotated.
It creates a pulling and pushing effect at the steering knuckle through the drag link or pull push rod resulting in turning of the road wheels. DRAG LINK : DRAG LINK It connects the pitman arm and the steering knuckle.
Ball joints connect it to the steering arm and drop arm.
These joints provide rotational motion and angular motion. DRAG LINK : DRAG LINK Sometimes also known as steering spindle.
Integrated with the stub axle and it moves around the pivot known as the kingpin. STEERING KNUCKLE ARM : STEERING KNUCKLE ARM Each stub axle has its own steering knuckle arm which is connected to each other with the help of tie rods.
The steering effort is conveyed to the steering knuckle by means of drag link for turning the road wheels to the right or to the left. QUALITIES OF STEERING SYSTEM : QUALITIES OF STEERING SYSTEM It connects the bottom right side knuckle of the stub axle to the bottom left side knuckle of left stub axle through the ball joints.
It provides angular motion to both the front wheels. Slide 34: Don Bosco Auto