 This is Mr. Nagesh R. Thambake, Assistant Professor, Department of Mechanical Engineering, Vulture Institute Technology, Sholapur. In the second session, we will discuss on automobile steering system layout. Learning outcome, at the end of this session, students will be able to explain the steering system layout and its components. In this particular session, we are going to discuss steering system layout, components of steering system, types of steering gearboxes. This is the steering system layout in the vehicle. This is the steering wheel that is connected on one end of the steering shaft. And shaft is housed by the steering column. And at the end of the steering column, there is a steering gearbox which converts the rotary motion of this particular steering wheel into the oscillating motion of a drop arm. This drop arm is connected to the steering gearbox and this drop arm is connected to again the center link of the steering system. This center link is also called as a relay rod. And on the other side of the drop arm, there is an idler arm. We serve the purpose of the drop arm, but which is not having any steering movement that is directly given. So it is following the path of the drop arm, therefore it is called as an idler arm. And to this particular center link, there are two tires which is connected to the wheel with the help of a short arm. This is an arm of a wheel and that is connected to the tire arm. And whenever the steering wheel rotates, that time steering shaft is rotating and steering shaft is giving the motion to the steering gearbox. Steering gearbox converting the rotary motion into the oscillatory motion. Whenever pitman arm is getting oscillated, that time this is reciprocating in this longitudinal direction and due to that this particular short arm is having the oscillations. Due to oscillation of this short arm, the vehicle is having a turn. This particular wheel is having a swivel pin around which the wheels are swinging to get a design turn. Now we will see the different components of the steering system in detail. Now first one is steering wheel. This steering wheel is used by the driver to rotate a steering shaft that passes through the steering column. Here this is the steering wheel which is having a ring of a pipe which is having elliptical section and that is having also the spokes which is welded together with the help of a center hub. So this all together it is welded and created a steering wheel. This steering wheel for cars that is having the diameters from 41 to 45 and for commercial vehicles 50 to 55 cm diameter is there. So like this, this particular steering wheel is designed in such a way that this particular steering wheel should give comfort to the driver and also according to the cabin space this particular steering wheel diameter is designed. Next one is steering shaft. Steering shaft transfers turning motion from the steering wheel to the steering gearbox. It is a still cylinder shaft which is having a sliding joint over here. Whenever a vehicle is coming across holes and bumps that time this particular sliding joint is changing the length of this particular steering shaft. Therefore whatever the road shocks are there that cannot be transmitted towards the steering wheel and the shocks can be absorbed by this particular steering shaft. At the two ends of this particular steering shaft the universal joints are given for required angle that is transmitted the motion to be transmitted towards the steering gearbox. Next one steering column. Steering column supports the steering shaft where this particular steering shaft, steering column is a housing of the steering column and also which is supporting to the steering system and we are having two types of steering column. One is till steering column assembly and second one is collapsible steering column assembly. Because the steering column is rigid in that particular steering system we do not have any adjustment therefore that particular steering system is designed in a such a way that during design designing of that particular steering system the common height of a human being is considered. But while designing this particular flexible steering system a range of heights, gesture and posture is taken into the consideration. Here whatever the first tilt steering column is there in that the driver can change the direction of the steering wheel in any angle. If the driver's height is less than that time this particular steering wheel he can take down. If the driver's height is more than that time this steering wheel he can take up. So likewise the steering can be adjusted and the second one is collapsible steering column. This collapsible steering column is used when a vehicle is coming across a accident that time what will happen. So driver forehead, driver is thrown forward that time driver is having impact over the steering wheel and that leads to a serious injury and that may lead to again death also therefore if such type of steering system is there collapsible steering column is there then what will happen whenever a driver driver is thrown forward on a steering wheel that time the steering column is going to collapse and impact will be less therefore the driver is having a less injury and also on the steering column there are two levers one lever will have the lightning system and other lever is having a wiper system which will activate the wiper and another will activate the lights. Next one steering gearbox, steering gearbox changes turning motion into a slight straight line motion to the left or right. Steering gearbox ratio range from 15 is to 1 to 24 is to 1 with 15 is to 1 the worm gear turns 15 times to turn the selector shaft once. So here there is a steering gearbox, steering gearbox will reduce the driver's effort which is also known as a reduction gearbox. So whenever a driver is going to turn a steering wheel that time this particular steering gearbox will help that rotating motion that can be converted into oscillatory motion of the pitman arm and due to that pitman arm the tire rod is going to oscillate and with the help of a short arms the vehicle wheel can be turned in the desired direction. Now the steering linkages, steering linkage connects the steering gearbox to the steering knuckles and wheels. Now here in this case you can see there is a idler arm and there is a pitman arm and to the idler arm and the pitman arm there is a center link is connected that is also called as a relay rod and to that relay rod again the tire rod is connected and the tire rod is connected to short arm and short arm is connected that is pivoted to the wheel hub. So whenever the steering wheel is rotating that time these linkages will help the vehicle to rotate the wheels in the desired direction. Now in the steering linkage we will see again in detail what is a pitman arm, the pitman arm transfers gearbox motion to the steering linkage, pitman arm is splined to the gearbox. This is the splined hole which is connected to the gearbox and this is the threaded hole that is connected to the center link as well as a relay rod. Center link that is also called as a relay rod, it is the steel bar connects the right and left side of the steering linkage it connects to the pitman arm, tire rod ends and idler arm. Now idler arm, the idler arm in actual it is looked like this, idler arm supports the end of the center link on the passenger side of the vehicle, bolts to the vehicle frame if once will cause excessive steering play. Now tire rod assembly here you can see the blue color it is shown that is a tire rod which is connected to the center link of the vehicle to the this particular wheel hub. Tire rod assemblies, two tire rod assemblies are used to fasten the center link to the steering knuckles. Assembly is consist of inner tire rod end, outer tire rod end and a tire, a tow adjustment slew be sure to check the tow setting after replacing the tire rod ends. These are the references, thank you.