Automobile Wheels And Tyres
In earlier older days when motor vehicles Automobiles were introduced wooden wheels were used. To stop faster were on wear on wheel rims of these wooden wheels, steel rings were placed on these. As time passed and the speed of the vehicle increased, more road shocks were felt by the passengers. To avoid this, wooden wheel rings were replaced by rubber cushioned lining. It has steel rings fitted with wooden wheels that were equipped with rubber lining it has been used in tanga wheels. This system worked for some time but when the vehicles speed increased it could not sustain jerks and the ride quality of high speed became uncomfortable then hence it was replaced by the pneumatic (Air) wheels. Pneumatic wheels were first introduced in 1920 and since they are being used as a standard fitting on all modern automobiles.
Pneumatic wheels are generally known as tyres and some it also called wheels assembly. Automobiles wheels consist of the wheel hub, disc, rim, tyre and tube. wheels are made of steel, aluminium alloys metal, tyres made of synthetic rubber with butyl steel-belted, a round-shaped tube is fitted inside the tyre and filled with air-inflated with compressed air, it's mounted on the wheel rim. Truly speaking this compressed air in a tyre or tyre carries the load of the vehicle and also provide a cushioning effect and cope with steering control.
WHEEL
Wheels are used for an automobile to drive along the road easily. Therefore, the wheels are the most essential for motor vehicles without wheels and tyres truly incomplete for automobiles. The wheels assembly is generally thought to comprise of the wheel hub, wheel disc or spoke (spokes wheel used in motorcycles) wheel rim, tyres and tube. Wheels are used for the movement of Automobiles (motor vehicles) and tyres and tubes contribute to speed and safety in addition to comfort.
Wheel must be:
• Strong enough to withstand the weight of the vehicles.
• Flexible to absorb the road shock
• Able to grip the road surface
• Perfectly balanced dynamically and statically.
• Light and easily remarkable.
TYPES OF WHEELS
In general, there are three types of wheels, they are:
(i) Pressed Steel Disc Wheel
(ii) Spokes (Wire) Wheel
(iii) Light Alloy Cast Wheel (Alloy Wheel)
Pressed Steel Disc Wheel
This type of disc wheel is predominantly used in types of motor vehicles. The disc wheels are made of Pressed Steel. The outer circular part of the wheel on which the tyre and tube are fitted is called the wheel Rim. That part of the wheel on which the tyre is mounted and supported. The wheel rim of both side portions is welded with the disc. In some rims bolt and nut, is also used. Pressed Steel Disc Wheel used for all based or as the standard variant of the light motor vehicle including all cars. Heavy-duty pressed Steel Disc wheels used for trucks and buses. Two-piece wheel rim mostly used for scooter/Scotty and as well as used for tractor and trailers.
SPOKES (WIRE) WHEEL
This type of wheel consists of a separate hub connected to the rim with several spokes or wires used. These wheels are not used in four-wheeler vehicles nowadays, but they are used in some motorcycles and bicycles.
LIGHT ALLOY CAST WHEEL (ALLOY WHEEL)
These wheels are made from either aluminium or magnesium alloy. These alloy wheels are cast and they are commonly mopping the ride because less bouncing is felt. Alloy wheels run cooler and this can improve brake and better tyre performance.
AUTOMOBILE TYRES
The tyres are mounted on the wheel rim.it has to carry the vehicle load and provide a cushioning effect absorbing flexing action. The tyre has to be strong enough to retain the compressed air in the tube and to save it from damage.
The basic purpose of the tyre is to grip the road and provide good traction. The chassis components the drive the vehicle and support its weight is the wheel and tyre only the vehicle tyre have to contact with the road surface. The most commonly used material for tyres and tubes is butyl.
The main two functions of the tyres
First, they are air filled with a cushion that absorbs most of the shock caused by road irregularities. Tyre flex as they meet those irregularities reduced the effect of road shock on the vehicle passengers and load.
Second, the tyres grip the road to provide good traction. This enables the vehicle to the accelerator, brake and makes turns without skidding and to provide cornering power smooth steering.
TYPES OF TYRES
There are two types of automobiles tyres
(i) Tube tyre (Inner tube) and
(ii) Tubeless (Without tubes) tyres
Tube Tyre (Inner Tube Tyre)
Tube tyres have an inner tube inside the here. This is a round rubber container that holds the air (inflated by high-pressure air) which supports the vehicles. Both the tyre and tube are mounted on the wheel rim. Tube tyres are used for heavy-duty vehicles as well as light-duty vehicles.
TUBELESS (WITHOUT TUBE) TYRES
The tubeless tyre does not enclose the tube, it is directly attached to the rim. The air under pressure is fill in the tyre itself. the tyre inflated by high-pressure air. The main advantage of a tubeless tyre is that it retains air for long period even after being punctured by a nail remaining in the tyre. Tubeless tyres are lighter and run cooler they are easy to repair by simply plugging a hole. They are made to retain air pressure for a longer period. In generally tubeless tyres are preferred to light-duty vehicles like all variants of the passenger's cars.
CONSTRUCTION OF TYRES
Tyre construction is a fabric carrying rubber tread moulded onto it. Tyre and tubeless tyres are made in about the same way. Layers of cords called plies are shaped on a form and impregnated with rubber. The rubber sidewalls and treads are then applied. Tyre tread is that part of the tyre that meets the road. It has raised pattern moulded into it. There are many designs, depending on the intended use of the tyres.
In generally, Tyre construction is divided into two classes: (i) Cross-ply or Bias tyre construction. (ii) Radial ply tyre construction.
These tyres have the plies crisscrossed. One-ply runs one way and the other ply runs diagonally the other way. Due to overlapping plies, the carcass becomes strong in all directions. However, The plies move against each other, this produces heat especially at high speed and increase tyre wear. Generally, a Cross-ply bias tyre has better heavy load capability and the ability to handle or tackle rough road conditions. That is why heavy-duty vehicles used cross-ply tyres because of better support heavy load conditions with moderate speed in any road condition. A
RADIAL PLY TYRES
Radial tyre plies run parallel to each other and vertical to the tyre bead. Stabilizer belts are applied over the plies to give strength parallel to the bead. Belts are made*-duty vehicles that have radial tyre construction. It has sidewall of the tyre is more than the cross-ply or bias-ply tyres and provides better fuel economy than cross-ply tyres.
TYRE PROPERTIES
A tyre must have many desired properties of any type of tyre construction. These are the following main properties:
Non-Skidding
The tyre should not skid or slip on the road surface.it should have a good grip.
Uniform Wear
The tyre must get uniform over its outer circumstance.
Load Carrying
The tyre should be able to carry the vehicle load and also alternate stresses during each revolution.
Cushioning
The tyre should be able to absorb vibration set up by the road surface. this provides cushioning effect.
Power Consumption
while rolling on the road, the tyre should consume the least power developed by the engine.
Noise
Balancing
The tyre should be balanced dynamically as well statically.
Tyre Pressure
The amount of air pressure in the tire depended on the type of tyre and how it is used in different road conditions. Passenger Cars tyre is inflated from 22 to 36 psi (152 to 248 kph. Heavy-duty tyres on trucks and buses may be inflated 90 to 110 psi ( 690 kph).
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