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A wheel is a rotating component (typically circular in shape) that is intended to turn on an axle bearing. The wheel is one of the key components of the wheel and axle which is one of the Simple machine. Wheels, in conjunction with axles, allow heavy objects to be moved easily facilitating movement or transportation while supporting a load, or performing labor in machines. Wheels are also used for other purposes, such as a ship's wheel, steering wheel, potter's wheel, and flywheel.
Common examples can be found in transport applications. A wheel reduces friction by facilitating motion by rolling together with the use of . In order for a wheel to rotate, a moment must be applied to the wheel about its axis, either by gravity or by the application of another external force or torque.
The invention of the solid wooden disk wheel falls into the late Neolithic, and may be seen in conjunction with other technological advances that gave rise to the early Bronze Age. This implies the passage of several wheel-less millennia even after the invention of agriculture and of pottery, during the Pre-Pottery Neolithic.
The Halaf culture of 6500–5100 BCE is sometimes credited with the earliest depiction of a wheeled vehicle, but there is no evidence of Halafians using either wheeled vehicles or pottery wheels. Potter's wheels are thought to have been used in the 4th millennium BCE in the Middle East. The oldest surviving example of a potter's wheel was thought to be one found in Ur (modern day Iraq) dating to approximately 3100 BCE. However, a potter's wheel found in western Ukraine, of the Cucuteni–Trypillia culture, dates to the middle of the 5th millennium BCE which pre-dates the earliest use of the potter's wheel in Mesopotamia. (2025). 9780199545841, OUP Oxford. ISBN 9780199545841Holm, Hans J. J. G.: The Earliest Wheel Finds, their Archaeology and Indo-European Terminology in Time and Space, and Early Migrations around the Caucasus. Series Minor 43. ARCHAEOLINGUA ALAPÍTVÁNY, Budapest, 2019. . Wheels of uncertain dates have been found in the Indus Valley civilization of the late 4th millennium BCE covering areas of present-day India and Pakistan.
The oldest indirect evidence of wheeled movement was found in the form of miniature clay wheels north of the Black Sea before 4000BCE. From the middle of the 4th millennium BCE onward, the evidence is condensed throughout Europe in the form of toy cars, depictions, or ruts, with the oldest find in Northern Germany dating back to around 3400BCE.Holm, Hans J. J. G. "The Earliest Wheel Finds, Their Archeology and Indo-European Terminology in Time and Space, and Early Migrations around the Caucasus". Archaeolingua Alapítvány, Budapest, 2019, In Mesopotamia, depictions of wheeled found on clay tablet pictographs at the Eanna district of Uruk, in the civilization are dated to c.3500–3350BCE. In the second half of the 4thmillennium BCE, evidence of wheeled vehicles appeared near-simultaneously in the Northern (Maykop culture) and South Caucasus and Eastern Europe (Cucuteni-Trypillian culture).
Depictions of a wheeled vehicle appeared between 3631 and 3380 BCE in the Bronocice pot excavated in a Funnelbeaker culture settlement in southern Poland. In nearby Olszanica, a 2.2m wide door was constructed for wagon entry; this barn was 40m long with three doors, dated to 5000 BCE, and belonged to the Neolithic Linear Pottery culture. Surviving evidence of a wheel-axle combination, from Stare Gmajne near Ljubljana in Slovenia (wooden Ljubljana Marshes Wheel), is dated within two standard deviations to 3340–3030 BCE, the axle to 3360–3045 BCE.Velušček, A.; Čufar, K. and Zupančič, M. (2009) "Prazgodovinsko leseno kolo z osjo s kolišča Stare gmajne na Ljubljanskem barju", pp. 197–222 in A. Velušček (ed.). Koliščarska naselbina Stare gmajne in njen as. Ljubljansko barje v 2. polovici 4. tisočletja pr. Kr. Opera Instituti Archaeologici Sloveniae 16. Ljubljana. Two types of early Neolithic European wheel and axle are known: a circumalpine type of wagon construction (the wheel and axle rotate together, as in Ljubljana Marshes Wheel), and that of the Baden culture in Hungary (axle does not rotate). They both are dated to c.3200–3000 BCE.Fowler, Chris; Harding, Jan and Hofmann, Daniela (eds.) (2015). The Oxford Handbook of Neolithic Europe. OUP Oxford. . p. 109. Some historians believe that there was a diffusion of the wheeled vehicle from the Near East to Europe around the mid-4th millennium BCE.
Early wheels were simple wooden disks with a hole for the axle. Some of the earliest wheels were made from horizontal slices of tree trunks. Because of the uneven structure of wood, a wheel made from a horizontal slice of a tree trunk will tend to be inferior to one made from rounded pieces of longitudinal boards.
The wheel was invented more recently and allowed the construction of lighter and swifter vehicles. The earliest known examples of wooden spoked wheels are in the context of the Sintashta culture, dating to c.2000 BCE (Krivoye Lake). Soon after this, horse cultures of the Caucasus region used horse-drawn spoked-wheel war for the greater part of three centuries. They moved deep into the Greek peninsula where they joined with the existing Mediterranean peoples to give rise, eventually, to classical Greece after the breaking of Minoan dominance and consolidations led by pre-classical Sparta and Athens. chariots introduced an iron rim around the wheel in the 1stmillennium BCE.
In China, wheel tracks dating to around 2200BCE have been found at Pingliangtai, a site of the Longshan Culture. Similar tracks were also found at Yanshi, a city of the Erlitou culture, dating to around 1700 BCE. The earliest evidence of spoked wheels in China comes from Qinghai, in the form of two wheel hubs from a site dated between 2000 and 1500BCE.Barbieri-Low, Anthony (February 2000) "Wheeled Vehicles in the Chinese Bronze Age (c. 2000–741 B.C.E)", pp. 11-12. Sino-Platonic Papers Wheeled vehicles were introduced to China from the west.
In Britain, a large wooden wheel, measuring about in diameter, was uncovered at the Must Farm site in East Anglia in 2016. The specimen, dating from 1,100 to 800 BCE, represents the most complete and earliest of its type found in Britain. The wheel's hub is also present. A horse's spine found nearby suggests the wheel may have been part of a horse-drawn cart. The wheel was found in a settlement built on stilts over wetland, indicating that the settlement had some sort of link to dry land.
Although large-scale use of wheels did not occur in the Americas prior to European contact, numerous small wheeled artifacts, identified as children's toys, have been found in Mexican archeological sites, some dating to approximately 1500 BCE. Some argue that the primary obstacle to large-scale development of the wheel in the Americas was the absence of domesticated large animals that could be used to pull wheeled carriages. The closest relative of cattle present in Americas in pre-Columbian times, the American bison, is difficult to domesticate and was never domesticated by Native Americans; several horse species existed until about 12,000 years ago, but ultimately became extinct. The only large animal that was domesticated in the Western hemisphere, the llama, a pack animal, was not physically suited to use as a draft animal to pull wheeled vehicles, and use of the llama did not spread far beyond the Andes by the time of the arrival of Europeans.
On the other hand, never developed the wheelbarrow, the potter's wheel, nor any other practical object with a wheel or wheels. Although present in a number of toys, very similar to those found throughout the world and still made for children today ("pull toys"), the wheel was never put into practical use in Mesoamerica before the 16th century. Possibly the closest the Mayas came to the utilitarian wheel is the spindle whorl, and some scholars believe that these toys were originally made with spindle whorls and spindle sticks as "wheels" and "axes".
Aboriginal Australians traditionally used circular discs rolled along the ground for target practice.
from after about 400BCE used wheels for spinning pottery and as water wheels. It is thought that Nubian waterwheels may have been ox-driven. It is also known that Nubians used horse-drawn chariots imported from Egypt.
Starting from the 18th century in West Africa, wheeled vehicles were mostly used for ceremonial purposes in places like Dahomey. The wheel was barely used for transportation, with the exception of Ethiopia and Somalia in Sub-Saharan Africa well into the 19th century. The spoked wheel was in continued use without major modification until the 1870s, when wire-spoked wheels and were invented. bookrags.com – Wheel and axle Pneumatic tires can greatly reduce rolling resistance and improve comfort. Wire spokes are under tension, not compression, making it possible for the wheel to be both stiff and light. Early radially spoked wire wheels gave rise to tangentially spoked wire wheels, which were widely used on cars into the late 20th century. Cast are now more commonly used; forged alloy wheels are used when weight is critical.
The invention of the wheel has also been important for technology in general, important applications including the water wheel, the cogwheel (see also antikythera mechanism), the spinning wheel, and the astrolabe or torquetum. More modern descendants of the wheel include the propeller, the jet engine, the flywheel (gyroscope) and the turbine.
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Additional energy is lost from the wheel-to-road interface. This is termed rolling resistance which is predominantly a deformation loss. It depends on the nature of the ground, of the material of the wheel, its inflation in the case of a tire, the net torque exerted by the eventual engine, and many other factors.
A wheel can also offer advantages in traversing irregular surfaces if the wheel radius is sufficiently large compared to the irregularities.
The wheel alone is not a machine, but when attached to an axle in conjunction with bearing, it forms the wheel and axle, one of the . A driven wheel is an example of a wheel and axle. Wheels pre-date driven wheels by about 6000 years, themselves an evolution of using round logs as rollers to move a heavy load—a practice going back in pre-history so far that it has not been dated.
In the 1st millennium BCE an iron rim was introduced around the wooden wheels of .
A hubless wheel (also known as a rim-rider or centerless wheel) is a type of wheel with no center . More specifically, the hub is actually almost as big as the wheel itself. The axle is hollow, following the wheel at very close tolerances.
Wire wheels are used on most and still used on many motorcycles. They were invented by aeronautical engineer George Cayley and first used in bicycles by James Starley. A process of assembling wire wheels is described as wheelbuilding.
The fundamental materials of modern tires are synthetic rubber, natural rubber, fabric, and wire, along with other compound chemicals. They consist of a tread and a body. The tread provides traction while the body ensures support. Before rubber was invented, the first versions of tires were simply bands of metal that fitted around wooden wheels to prevent wear and tear. Today, the vast majority of tires are pneumatic inflatable structures, comprising a doughnut-shaped body of cords and wires encased in rubber and generally filled with compressed air to form an inflatable cushion. Pneumatic tires are used on many types of vehicles, such as , , motorcycles, , earthmovers, and aircraft.
Examples include:
The winged wheel is a symbol of progress, seen in many contexts including the coat of arms of Panama, the logo of the Ohio State Highway Patrol and the State Railway of Thailand. The wheel is also the prominent figure on the flag of India. The wheel in this case represents law (dharma). It also appears in the flag of the Romani people, hinting to their nomadic history and their Indian origins.
The sixth century monk Dorotheus of Gaza used the image of a spiked wheel to explain how interdependent ethic of compassion worked, in which those that get closer to God get closer to other people and reverse. (2025). 9780367133764, Routledge, Taylor & Francis Group. ISBN 9780367133764 In medieval Europe, the Wheel of Fortune aimed to show the transitory, ephemeral, and almost illusionary character of power, in which a person that has risen to the top may go down again by the turn of the wheel.
The introduction of spoked (chariot) wheels in the Middle Bronze Age appears to have carried somewhat of a prestige. The sun cross appears to have a significance in Bronze Age religion, replacing the earlier concept of a solar barge with the more 'modern' and technologically advanced solar chariot. The wheel was also a solar symbol for the .
In modern usage, the 'invention of the wheel' can be considered as a symbol of one of the first technologies of early civilization, alongside farming and metalwork, and thus be used as a benchmark to grade the level of societal progress.
Some Modern Paganism such as have adopted the Wheel of the Year into their religious practices.
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