INTRODUCTION
The wheel which we have designed and fabricated has shock absorber. This enables the availability of suspension and cushioning during the bicycle riding. It reduced damaged to the cycle wheel and the rider during accident by deforming and reforming within its elastic limit. Movement is essence in life. All animals move to find food, attack prey, or escape a predator. Snakes slide, caterpillars crawl, kangaroos hop, horses trot and men walk. Of all animals, humans move the most. Most travel a few kilometers to their workplace and back every day, go visiting relatives to a city a few hundred kilometer away. Or travel halfway across the globe to a business meeting. Some travel purely for adventure. For compulsive travelers’ humans are not particularly well equipped. A cheetah can run the best of men b 10 tol. A horse ha much more endurance and consumes only about one-half the energy per kilogram of body weight. But humans design machines which increase their physical capacity. The invention of wheel is the single most important milestones in the human attempt to increase locomotion. Oxen, horses and camels at first and then steam and the gasoline engines increased human movement dramatically. But the idea of using its own muscular effort in driving a wheel has always fascinated man. It is interesting to note the bicycle was perfected much after railways trains were full commercial operation and a horseless carriage was just knocking on the doors. Inventors everywhere are struggling even today to perfect a flying machine driven by muscular effort alone eight-five years after the successful petrol engine powered flight. The humble bicycle has a glorious past. First conceived as a plaything of the rich, its soon evolved into an efficient and convenient means of transport. The coming the automobile, however relegated it to a role of an exerciser or a sports machine, through in large parts of the world, notably China and Southeast Asia, it is still used as the primary means of daily transportation. In the industrialized world it seems to have come a full circle. The bicycle is re-emerging as a vehicle of choice for short runs in urban areas. It does pollute the atmosphere space and wide roads. It has been estimated that for distances up to 8 in city center’ s a bicycle may be faster than a car given the time taken for taking the car out of garage, finding parking space walking from the car park to the place you intend to go. And above all, a bicycle provides you valuable physical exercise while you ride to work.
First step: The First mention of a two- wheeled vehicle propelled by the rider himself occurs for a 1791 toy- like machine which was simply a wooden beam on two wheels, one behind the other. The rider sat on the beam and drove the machine by pushing his feet alternately against the ground as if skating. One could not turn this machine by lifting and dragging the front wheel to one side. It didn’t stay erect if both feet were off the ground. The velocipede through a bicycle in true sense of word, was never a commercial success and not many persons knew about its bold design. For the following forty year of design of the bicycles stagnated at least in method of converting the motion of feet into rotary motion of the wheel. The first commercially successful bicycle appeared in 1863. It had pair of pedals connected to the front wheel and was ridden in the same manner as the basic children’s tricycles of today. Its wooden wheels (with iron tires) on the cobbled roads of the day gave the rider such a rough ride that it was nick- named the bone shaker. In a bicycle we are interested in increasing velocity ratio and the decreased mechanical advantage is the price that we pay for it. The increased diameter of front wheel is only one of the ways of obtaining a large velocity ratio. A simple pair of unequally sized gear a belt over two pulleys, or a chain running between a large chain- wheel and a small sprocket (a toothed wheel) are some other ways. In each of these cases the velocity ratio is the ratio of sizes of two wheels, gears or sprockets. From the automobile practice, where gears are used almost exclusively for the purpose, the velocity ratio is commonly referred to the gear ratio. Each of the above transmissions (that is, the method of transmitting power from the pedals to the wheel while obtaining a mechanical advantage) has it own advantages and disadvantages. For example, the performances of a belt on the pulley (i.e. of the friction), decrease sharply when the belt becomes sharply, when the belt becomes dirty, grimy or loose. Gears give better performances, but are more expensive rigor of cycling. The bicycles were uses by vendors.
Common Wheel Types: Wheels are the most essential moving part of bicycle. These wheels have gone many changes in term of its size, shape and environment in which they are used. Likewise, the tires used for the wheel also have undergone many changes. Such as rough road tires, racing wheels, mountain biking wheels, etc. the knobs used in tires are also of different types with respect to the wheel such as auto, presto, woods. Even though a lot of evolution have occurred in the cycle wheel the rim of the wheel is the only part that has under gone limited or no changes in these 100 years.
Wheel Geometry: In the bicycle wheel, wire replace the rigid spokes of wooden wheels. Although wires are strong; they cannot directly replace wooden spokes that carry loads in compression. In other words, wires must be tensioned to prevent their buckling under load. Even though the wheels only vary with the no of spokes used the wheel geometry is studied in order to acre of load acting which cause buckling and wheel collapse. Spokes and wheel are the wheel component that fail most often. They fail both from sudden load, as in a crash and from fatigue. Although the progression of fatigue failure is mostly invisible; it can be substantially retarded through appropriate wheel building technique. Hubs and spokes nipples are not subjected to sufficiently large dynamic loads to cause significant metal fatigue. Aluminum nipples fails during wheel building, but rarely during use. Spokes break and rim cracks mainly from fatigue. However, rim can also fail from brake abrasion. Road grit, swept up into the brake’s pads in wet weather, abrades rim sidewalls until they become too thin to contain tire pressure. They then bent outward and release the tire, causing a blowout.
WHAT IS WHEEL?
The wheel is a load carrying device which has facilitated the transportation of goods and people. The circular form of the wheel is used in many machinery applications today such a gears and pulleys. The bicycle is a vehicle that utilizes wheels and is a good example of how wheels have evolved over centuries to more sophisticated designs. A bicycle wheel consist of wire spokes are fastened to by threaded spoke nipples.
Prior to the invention of the wire- spoked wheel, carriages and wagons had thick wooden- spooked wheels that were able to resist compressive loads. Around the middle of the nineteenth century, wire- spoke wheels replaced wooden wheels due to their lightweight quality, durability and strength (see Figure 1). However, unlike their wooden counterparts, wire spokes are not compressible structure and therefore, would buckle under compression. To overcome this obstacle, the wire spokes are prestressed in tension so that a compressive load would result in reduction of pretension.
Wire wheels can carry more than hundred times their own weight. In off – road bicycling, skilled riders often jump from high obstacle, subjecting their wheels to forces of more than a quarter ton. The wheels ’s strength is even more impressively demonstrated in the heat of competition where these forces are encountered repeatedly at high speed
HOW THE WHEEL SUPPORT A LOAD
Wire wheels are prestressed, with built- in stresses that are subjected to a load. An understanding of prestressed structures will make the forces at work in a wheel more apparent.
The wheel can stand on its bottom spokes. Stress change occur only in the bottom spokes, not in the top ones. Structurally, bottom spokes are acting as compression members in the wheel, and no measurement of their elastic movement reveals that they are anything but rigid columns. Because individual spoke tension results from tension in all spokes, the wheel can be analyzed only by considering all its spokes. The concept that the hub hangs from the upper spokes contradicts all measured and computed behavior of bicycle wheels.
WHEEL COLLAPSE
Wheels can collapse from several causes, but the failure usually occurs the same way. The rim is forced to one side where the tire touches the ground, and the wheel takes on the shape of a saddle. Another less common failure results from the rim breaking and releasing all spoke tension. This can happen when the wheel strikes a curb or falls into a grating in the road. Most wheels collapse during crashes that cause large side forces. The rim may also receive a side force such as a broad slide.
However, radial overload can also cause a wheel to collapse. For instance, a bicycle landing from a sufficiently high jump could untension its bottom spokes on impact and leave its rim laterally unsupported. At this moment the wheel is unstable and will collapse to the side.
COMPONENT FAILURE
Spokes and rims are the wheel components that fail most often. They fail both from sudden loads, as in a crash, and from fatigue. Although the progression of fatigue failure is mostly invisible, it can be substantially retarded through appropriate wheel building techniques. Hubs and spoke nipples are not subjected to sufficiently large dynamic loads to cause significant metal fatigue.
Aluminum nipples sometimes fail during wheel building, but rarely during use. Spokes break and rims crack mainly from fatigue. However, rims can also fail from brake abrasion. Road grit, swept up into the brake pads in wet weather, abrades rim sidewalls until they become too thin to contain tire pressure. They then bend outward and release the tire, causing a blowout.
RIM FAILURE
Rims usually fail during crashes or from hitting road hazards such as potholes and rocks that bend or dent the rim beyond repair. Rims also fail from fatigue. They can develop cracks around the spoke sockets and from one socket to the next. The cracks gradually weaken the wheel by releasing spoke tension. If the spokes are retensioned to retrue the wheel, they will eventually pull out of the rim. Such failures will probably not cause wheel collapse because the spokes pull out one at a time causing a wobble that prevents the wheel from being ridden further.
BACKGROUND AND LITERATURE SURVEY
COMPARISON BETWEEN THE TRADITIONAL AND THE PROPOSED WHEEL DESIGN
What exactly are Futuristic wheel?
Futuristic wheel are a new type of bicycle wheel that have been designed to make cycling more comfortable. A spring system between the hub and the rim of the wheel provides suspension, cushioning the rider from bumps and potholes in the road. Wheels have a conventional hub with a hub brake and hub gears. But the spokes are replaced by a spring system. This gives an amazingly smooth, comfortable ride compared with a conventional spoked wheel.
How do they make cycling more comfortable?
Futuristic wheels feature a spring system between the hub and the rim of the wheel which provides suspension – cushioning the rider from bumps and potholes in the road. They also have a conventional hub with a hub brake and hub gears. Because of the suspension within the wheel, you can use high-pressure or puncture-resist tyres. So you don’t need to rely on fat tyres to cushion your ride.
How does Futuristic wheel technology work?
Futuristic wheel springs are made from a carbon composite, carefully developed and tested to give optimum compression and lateral stability as well as strength and durability. Specially designed connectors attach the springs to the hub and rim. There are three springs in each wheel, which work together as a self-correcting system. The spring configuration allows for the torque to be transferred smoothly between the hub and the rim. Front and rear wheels have different spring rates. A front and rear wheel can be used together as a set, or you can use a single wheel alongside a conventional spoked wheel.
What are the benefits for the rider?
This gives you a really smooth ride. People find they can tackle bumps, kerbs and cobbles much more easily on futuristic wheels than on normal, spoked wheels.
COMPONENT IMPLEMETATION OF THE PROJECT
SHOCK ABSORBER
In a vehicle, shock absorbers reduce the effect of traveling over rough ground, leading to improve ride quality and vehicle handling. While shock absorbers serve the purpose of limiting excessive suspension movement, their intended sole purpose is to damp spring oscillations. Shock absorbers use valving of oil and gasses to absorb excess energy from the springs. Spring rates are chosen by the manufacturer based on the weight of the vehicle, loaded and unloaded. Some people use shocks to modify spring rates but this is not the correct use. Along with hysteresis in the tire itself, they damp the energy stored in the motion of the unsprung weight up and down. Effective wheel bounce damping may require tuning shocks to an optimal resistance. Shock absorber is the major load carrying setup in the design. These hold the central hub and the wheel rim. These absorber keeps intact both the hub and rim. These absorbers are held in contact by welding it along hub and the rim.
The Rim is outer casing which holds the tire and the spokes here rim holds shock absorber. The Shock absorber is welded along the inner sides of rim. The rim is made up of aluminium now a days they are made up of alloy of aluminium. Torque is a twisting force in the hub that produce or retard wheel rotation. As the chain turn the rear wheel sprocket it exerts torque on the hub. The lever arm is the distance by the line of the spokes misses the intersecting the centerline of rear axle. The force is the total change in tension among the spoke, some of which become tighter and some looser. The rim is the “outer edge of a wheel, holding the tire.” For example, on a bicycle wheel the rim is a large hoop attached to the outer ends of the spokes of the wheel that holds the tire and tube.
A hub is the center part of a bicycle wheel. It consists of an axle, bearing and a hub shell. The hub shell typically has two machined metal flanges to which spokes can be attached. Hub shells can be one-piece with press-in cartridge or free bearings or, in the case of older designs, the flanges may be affixed to a separate hub shell.
A bicycle tire is a tire that fits on the wheel of a bicycle or similar vehicle. They may also be used on wheelchairs and handcycle, especially for racing. Although the use of a pneumatic tire greatly reduces rolling resistance compared to the use of a rigid wheel or solid tire, the tires are still typically the second largest source, after air drag, of power consumption on a level road. The modern detachable pneumatic bicycle tire contributed to the popularity and eventual dominance of the safety bicycle.
Modern trends are leaning towards cartridge bearings. It consists of a cartridge, that is inserted in a “sleeve” in the appropriate bicycle part that needs to turn – a wheel hub, headset, BB shell etc.
Hub with a cartridge bearing
Balls are packed with two races in a “sealed” cartridge. Sealed as can’t be disassembled, not as (completely) sealed from dirt and water! On top there is usually some sort of plastic, or rubber seal. These seals don’t prevent dirt and water from entering the bearing – just slow the contamination down a bit. That’s why these bearings too need to be cleaned and lubricated to last longer.
These bearings are not better than the old and tested cup and cone system. But they are cheaper to produce in decent quality, than cup and cone bearings.
Advantages
• Negligence resistant. Advantage compared to cup and cone bearings is that, even if very neglected and totally worn, only cartridges are replaced – just like non-worn cartridges. Cup and cone hub bearing, for example, calls for the whole hub replacement in case cups get worn. With cartridge bearings, only cartridges are replaced, so hub would be fine, even in case of a totally busted old cartridge needing replacement.
• Simple and straight forward replacement. No need to fine tune preload like with cup and cone bearings.
• Low rolling resistance, like cup and cone system. At least while they are new.
(1) Shock Absorber
Hydraulic fluid cylinder along with steel coiled spring made of silicon alloy steel is used for making of shock absorbers.
ASTM A228 (0.80–0.95% carbon) – It is called as music wire and it is best known material used for shock absorbing spring.
Spring steel:
Spring steel is a low alloy, medium carbon steel with a very high yield strength. This allows objects made of spring steel to return to their original shape despite significant bending or twisting.
Silicon is the key component to most spring steel alloys. An example of a spring steel used for cars would be AISI 9255 containing 1.50%-1.80% silicon, 0.70%-1.00% manganese and 0.52%-0.60% carbon.
Most spring steels (as used in cars) are hardened and tempered to about 45 Rockwell C
(2) Rim
Material: Various metals can be used for the rim. Commonly seen are alloy (magnesium and aluminum), mag(magnesium), aluminum and chrome. Teflon coatings are sometimes also applied for an extra layer of protection.
(3) Hub
The central hub is the major load and impact carrying system which allows the seating of roller ball bearing which enable the rotation of wheel. The central hub is made up of mild steal material. Since no spokes are used the hub can be of any diameter. The two materials considered for the wheel hub are Aluminium 6061 T6 and EN8 Mild Steel.
(4) Tire
The materials of modern pneumatic tires are Synthetic rubber natural rubber, fabric and wire, along with carbon black and other chemical compounds. They consist of a tread and a body. The tread provides traction while the, the first versions of tires were simply bands of metal fitted around wooden wheels to prevent wear and tear. Early rubber tires were solid (not pneumatic). Pneumatic tires are used on many types of vehicles, including cars, bicycles, motorcycles, buses, trucks, heavy equipment, and aircraft. Metal tires are still used on locomotives and railcars, and solid rubber (or other polymer) tires are still used in various non-automotive applications, such as some casters, carts, and wheel barrows.
(5) Bearing
With standard bearings, both balls and races are made of steel. Bearings with ceramic balls are often marketed as “ceramic bearings”, even though only balls are ceramic, while races are still made of steel. Ceramic balls can be machined to be smoother surfaced than steel ones. They are also harder, more wear resistance.
