AUTOMOBILE STEERING SYSTEM & STEERING GEARS

AUTOMOBILE STEERING SYSTEM & STEERING GEARS

In modern automobiles or automotive steering systems one of the major control systems for under chassis components of the vehicle. " A device for controlling the directional change of vehicles travel".

The Purpose of the Steering System:

The steering system allows the driver to control the direction of vehicles travel. This system consisting ( made up) steering linkage that connects the steering wheel to the steerable wheels and tyres. The system may be either manual or power steering. The main energy source for the steering system, to the driver, applies to force or steer the steering wheel, quite more force to applies to steer on the manual steering system and less force/ effort applies to steer the power steering system. The steering system gets movement from the steering wheel, steering gears, steering linkage, wheels and tyres. the power steering includes additional components like a hydraulic pump and their system or electric motor to assist the driver effort and easiest operation for the steering system. These are the main power resources for the power steering system. The basic operation is the same both manual and power steering. 

The Function of the steering system are as follow:

It helps in swinging the wheel to the left or right.

It helps in turning the vehicle at the will of the driver.

It provides directional stability.

It helps in achieving the self rightening effect.

 It converts the rotary movement of the steering wheel into an angular turn of the front wheels. 

Components of a steering system:

The automobile steering system is composed of the following components:-

• Steering Gear and assembly

• Steering Linkages

• Steering Knuckle 

Steering gear and assembly, it devices for controlling the directional change of your vehicles. It is consisting of the components are steering wheel, steering column, steering box and gear assembly. Steering wheels are circular wheel-mounted to the steering shaft and act as a control to steer the vehicles. The steering column is a hollow shaft with universal joints, one end connected to the steering wheel and another end connect to the steering gear and assembly.  These days special steering columns have been employed in modern cars which provide safety and of operation to the driver like the Tilt wheel steering column, Tilt and telescopic steering column and steering column with anti-theft lock. Steering gear provides a mechanical advantage and enables the driver to steer the vehicle easily with the steering linkage.

Steering Linkage :

The main purpose of steering linkage transfers the different movements of the pitman's arm or drop arm into the left and right movements at the wheels. The steering linkage consisting of various parts on the steering system, they are the pitman's arm or drop arm, the drag link, the centre arm, the tie rods, the ball joints, the stub axle, and the steering knuckle. The steering linkage connects the steering gear to the steering knuckle arm of the front wheel and the drop arm at the steering gear. The pitman arm or drop arm placed at the steering shaft gives movement to the linkage. They carry backwards and forward swinging effects of the drop arm to the steering knuckle. The steering knuckle is a steering spindle using which wheels are turned especially using the front wheels. 

Type of steering linkage :

The steering linkage as employed in different vehicles are of the following types:

• Conventional types

• Centre arm steering linkage type.

• Parallelogram steering linkage type. 

Ball joint :

A flexible joint consisting of the ball with a socket is used in the steering and suspension system.

Stub axle :

It is the spindle over which the road wheel is mounted through the brake drum and disc. It acts as an axis for the wheel. It takes a load of the wheel and enables it to spin around. A steering knuckle arm is connected to it. 

Tie rod end :

A rod that joins the two front stub axles through an arm attached to it is called a tie rod end.

Type of steering gear system:

The steering gear can be classified as under 

• worm and sector

• worm and roller

• Recirculating ball steering gear

• Rack and pinion

These top first and second steering gear are used on older day vehicles. Nowadays all modern vehicles using Recirculating Ball steering gear and Rack and Pinion steering gear systems. Both steering gear is made in manual and power versions steering system.

Recirculating ball steering gear :

A steering gearing that uses a series of recirculating balls on worm gear to transfer steering wheel movement to a ball nut. The ball nut meshes with a sector gear and shaft which moves the attached pitman arm or drop arm and parallelogram steering linkage. These steering gear using light-duty and heavy-duty vehicles in both manual and power steering variants.

Rack and Pinion steering gear :

A steering gear in which a pinion on the end of the steering shaft meshes with a rack of gear teeth on the major cross member of the steering linkage. This kind of steering gear system is very the simplest, compact and lightweight low maintenance steering system rest of the other steering systems.  Nowadays on the modern vehicle commonly wildly using Front-wheel drive (FWD) vehicle and as well as Rear wheels Drive RWD and SUVs cars and military vehicles comes in both manual and power steering systems.

Power steering :

Power steering is that type of steering in which external power is utilised to assist in operating the steering. It uses hydraulic pressure, compressed air, electrical mechanism. The power steering helps to make parking easier. The most commonly used power steering in modern vehicle hydraulic Power steering and luxurious high-end variant vehicle uses electronic powered steering means electric motor operating power steering system. 

Advantages of power steering :

• Drive effort is substantially reduced.

• when the vehicle is suddenly driven over a bump, there is no return back of steering.

• Even if the power steering system fails the steering can be operated by manual steering.

Hydraulic Power Steering System :

The power steering hydraulic system includes a control valve and power cylinder.in addition, the system has a hydraulic pump, fluid reservoir and connecting hoses. The reservoir may be attached to the pump or separately mounted. A filter may be located in the reservoir or hose to move dirt and particles from the fluid. some power steering systems have a fluid cooler. The power steering pump usually mounts at the front of the engine and is driven by a belt from the engine crankshaft pulley. The pump can produce high pressure when the engine is started power steering constantly smoothly functions with less driver effort.

Electronic Power Steering (EPS) :

Some high-end variant cars or SUVs cars have electronic rack and pinion power steering systems. A fast-acting electric motor inside the rack housing supplies the power to assist the pinion meshes with helical grooves which serve as the rack teeth. A steering angle sensor senses or measure the wheels angles direction wheels and send a signal to the Electronic Control Unit (ECU). Similarly, torque sensor how much torque is applied and in which direction it reports to ECU. According to that ECU send the signal to outputs actuators for the assistance of the driver. Electronic power steering does not require a hydraulic pump hose and another hydraulic system instead an electric motor operating power steering system.The electronic power steering also known as EPS is an electronically controlled assistance steering mechanism.

Electronic power steering is more reliable and has constant power flows, however, engine rpm and speeds and provides steering assistance in terms of operation to improve the driver comfort and to provide the overall efficient performance of steering. It is better than the hydraulic system in terms of response time and intelligence it allows the driver to control the vehicle at high speed even with minor assistance.