The steering wheel is one of the most crucial parts of a motor vehicle; without it, the driver cannot turn or guide the vehicle in any direction. Connected to the steering wheel is the steering column (shaft). This column essentially converts the power employed to turn the steering wheel into power that turns the tires. How this is done is dependent on the vehicle’s steering system. There are three main steering systems and the steering column is utilised based on the steering make-up.
Rack-and-pinion steering is one of the most used types of steering in cars today. It is a rather simple mechanism based on, as its name suggests, a rack and a pinion. The pinion is a gear connected to the end of the steering column. When the steering wheel turns, so does the steering column, and the gear (pinion) moves in the direction the steering wheel turns, along the grooves of a metal tube called the rack. This movement consequently causes the wheels to turn, as they are connected to the mechanism by what is known as tie rods.
As always, the steering column is directly attached to the steering wheel, but it is what happens at the end of the steering column that differentiates this type of steering from the rack-and-pinion. In this instance, there is a threaded rod (worm gear) at the base of the steering column that runs through holes in a recirculating ball gearbox. The gearbox is threaded inside to accommodate the grooves in the rod, as well as ball bearings that ‘recirculate’ around it when the steering column turns. The ball bearings help the gearbox turn more smoothly as it rotates what is known as the pitman arm.
POWER STEERING SYSTEM
This system employs a pump which allows the driver to use the least amount of resistance when steering the motor vehicle. Here, the steering column connects the steering wheel to a rotary valve. The purpose of this valve is to tell the pump whether or not the vehicle is being turned; indicated by the motion of the steering
column The power steering is required only when the motor vehicle is being turned; if not, the pump is disengaged.
Fundamentally, the steering column bridges the driver and his/her ability to manoeuvre the motor vehicle. Regardless of the system, the presence of this part is possibly the most crucial; so much so, that while other components may differ, the steering column, and its purpose, remain consistent.