Wheel
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 six simple machines. 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 axles. In order for wheels to rotate, a moment needs to be applied to the wheel about its axis, either by way of gravity or by the application of another external force or torque. Using the wheel, Sumerians invented a device that spins clay as a potter shapes it into the desired object.
Terminology
The English word wheel comes from the Old English word hwēol, from Proto-Germanic *hwehwlaz, from Proto-Indo-European *kwékwlos,[1] an extended form of the root *kwel- 'to revolve, move around'. Cognates within Indo-European include Icelandic hjól 'wheel, tyre', Greek κύκλος kúklos, and Sanskrit chakra, the last two both meaning 'circle' or 'wheel'.[2]
History
The place and time of the invention of the wheel remains unclear, because the oldest hints do not guarantee the existence of real wheeled transport, or are dated with too much scatter[further explanation needed].[3] Mesopotamian civilization is credited with the invention of the wheel by several, mainly old sources.[4][5][6] However, some recent sources either suggest that it was invented independently in both Mesopotamia and Eastern Europe or credit prehistoric Eastern Europeans with the invention of the wheel[7][8][9][10] and that unlike other breakthrough inventions, the wheel cannot be attributed to a single nor several inventors. Evidence of early usage of wheeled carts has been found across the Middle East, in Europe, Eastern Europe, India and China. It is not known whether Chinese, Indians, Europeans and even Mesopotamians invented the wheel independently or not.[11][12]
The invention of the solid wooden disk wheel falls into the late
- 4500–3300 BCE (Copper Age): invention of the potter's wheel; earliest solid wooden wheels (disks with a hole for the axle); earliest wheeled vehicles; domestication of the horse
- 3300–2200 BCE (Early Bronze Age)
- 2200–1550 BCE (
The
The oldest indirect evidence of wheeled movement was found in the form of miniature clay wheels north of the Black Sea before 4000 BCE. From the middle of the
Depictions of a wheeled vehicle appeared between 3631 and 3380 BCE in the
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
In
In Britain, a large wooden wheel, measuring about 1 m (3.3 ft) 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.[27]
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.[28] 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.[29] 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.[30] 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,[31] and use of the llama did not spread far beyond the Andes by the time of the arrival of Europeans.
On the other hand, Mesoamericans never developed the wheelbarrow, the potter's wheel, nor any other practical object with a wheel or wheels.[32][33] Although present in a number of toys, very similar to those found throughout the world and still made for children today ("pull toys"),[32][33] the wheel was never put into practical use in Mesoamerica before the 16th century.[32][33] 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".[33]
Aboriginal Australians traditionally used circular discs rolled along the ground for target practice.[34]
Starting from the 18th century in West Africa, wheeled vehicles were mostly used for ceremonial purposes in places like Dahomey.[38] The wheel was barely used for transportation, with the exception of Ethiopia and Somalia in Sub-Saharan Africa well into the 19th century.[39][38]
The spoked wheel was in continued use without major modification until the 1870s, when
The invention of the wheel has also been important for
Mechanics and function
A wheeled vehicle requires much less work to move than simply dragging the same weight. The low resistance to motion is explained by the fact that the frictional work done is no longer at the surface that the vehicle is traversing, but in the bearings. In the simplest and oldest case the bearing is just a round hole through which the axle passes (a "plain bearing"). Even with a plain bearing, the frictional work is greatly reduced because:
- The normal force at the sliding interface is same as with simple dragging.
- The sliding distance is reduced for a given distance of travel.
- The coefficient of friction at the interface is usually lower.
Example:
- If a 100 kg object is dragged for 10 m along a surface with the .
- Now give the object 4 wheels. The normal force between the 4 wheels and axles is the same (in total) 981 N. Assume, for wood, μ = 0.25, and say the wheel diameter is 1000 mm and axle diameter is 50 mm. So while the object still moves 10 m the sliding frictional surfaces only slide over each other a distance of 0.5 m. The work done is 981 × 0.25 × 0.5 = 123 joules; the work done has reduced to 1/40 of that of dragging.
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 simple machines. 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.
Construction
Rim
The rim is the "outer edge of a wheel, holding the tire".
In the 1st millennium BCE an iron rim was introduced around the wooden wheels of chariots.
Hub
The hub is the center of the wheel, and typically houses a bearing, and is where the spokes meet.
A
Spokes
A spoke is one of some number of rods radiating from the center of a wheel (the
Wire
The rims of wire wheels (or "wire spoked wheels") are connected to their hubs by wire spokes. Although these wires are generally stiffer than a typical wire rope, they function mechanically the same as tensioned flexible wires, keeping the rim true while supporting applied loads.
Wire wheels are used on most
Tire/Tyre
A tire (in American English and Canadian English) or tyre (in some Commonwealth Nations such as UK, India, South Africa, Australia and New Zealand) is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground. The word itself may be derived from the word "tie", which refers to the outer steel ring part of a wooden cart wheel that ties the wood segments together (see Etymology above).
The fundamental materials of modern tires are
Protruding or covering attachments
Extreme off-road conditions have resulted in the invention of several types of wheel cover, which may be constructed as removable attachments or as permanent covers. Wheels like this are no longer necessarily round, or have panels that make the ground-contact area flat.
Examples include:
- Snow chains - Specially designed chain assemblies that wrap around the tire to provide increased grip, designed for deep snow.[42]
- Dreadnaught wheel - A type of permanently attached hinged panels for general extreme off-road use. These are not connected directly to the wheels, but to each other.
- Pedrail wheel - A system of rails that holds panels that hold the vehicle. These do not necessarily have to be built as a circle (wheel) and are thus also a form of Continuous track.
- A version of the above examples (name unknown to the writer) was commonly used on heavy artillery during World War I. Specific examples: Cannone da 149/35 A and the Big Bertha. These were panels that were connected to each other by multiple hinges and could be installed over a contemporary wheel.
- Continuous track - A system of linked and hinged chains/panels that cover multiple wheels in a way that allows the vehicles mass to be distributed across the space between wheels that are positioned in front of / behind other wheels.
- "Tire totes" - A bag designed to cover a tire to improve traction in deep snow.[43][44]
Truck and bus wheels may block (stop rotating) under certain circumstances, such as brake system failure. To help detect this, they sometimes feature "wheel rotation indicators": colored strips of plastic attached to the rim and protruding out from it, such that they can be seen by the driver in the side-view mirrors. These devices were invented and patented in 1998 by a Canadian truck shop owner.[45]
Alternatives
While wheels are very widely used for ground transport, there are alternatives, some of which are suitable for terrain where wheels are ineffective. Alternative methods for ground transport without wheels include:
- Maglev
- Sled, ski or travois
- ekranoplans
- walking machine
- Horse riding
- Caterpillar tracks (operated by wheels)
- Pedrailwheels, using aspects of both wheel and caterpillar track
- Spheres, as used by Dyson vacuum cleaners and hamster balls
- Screw-propelled vehicle
Symbolism
The wheel has also become a strong cultural and spiritual metaphor for a cycle or regular repetition (see chakra, reincarnation, Yin and Yang among others). As such and because of the difficult terrain, wheeled vehicles were forbidden in old Tibet. The wheel in ancient China is seen as a symbol of health and strength and used by some villages as a tool to predict future health and success. The diameter of the wheel is indicator of one's future health. The Kalachakra or wheel of time is also a subject in some forms of Buddhism, along with the dharmachakra.[46][47]
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 introduction of spoked (
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.[citation needed]
Some
See also
- Types: Wagon wheel, Wire wheel
- Components:
- Related technologies and concepts: Pottery wheel, Propeller, Reinventing the wheel, Spindle whorl, Trackball, Wagon-wheel effect, Water wheel, Wheelbarrow, Wheelie, Wheel of Fortune, Wheelwright, Windlass, Windmill
- Alternatives: Wing-in-ground-effect
- History: Terrestrial locomotion in animals: Rolling, Robot locomotion
- Theory: Rolling resistance, Rotational energy, Torque, Wheel and axle (simple machine), Wheel sizing
References
- ^ "wheel". Online Etymology Dictionary. Archived from the original on 3 July 2017. Retrieved 28 March 2007.
- ^ "American Heritage Dictionary Entry: wheel". Houghton Mifflin Harcourt Publishing Company. Archived from the original on 20 July 2013. Retrieved 26 November 2012.
- ISBN 978-615-5766-30-5.
- ISBN 9788184972436. Archivedfrom the original on 22 March 2023. Retrieved 9 January 2021.
- ISBN 9781600377709.
- ISBN 9789059724372.
- ISBN 978-0-19-954584-1.
- ISBN 9781315510446. Archivedfrom the original on 22 March 2023. Retrieved 21 March 2023.
- ISBN 9780231540612. Archivedfrom the original on 22 March 2023. Retrieved 21 March 2023.
- ^ Man and Wound in the Ancient World A History of Military Medicine from Sumer to the Fall of Constantinople By Richard A. Gabriel 65 page
- ^ "When was the wheel invented?". New Scientist. Archived from the original on 20 August 2021. Retrieved 21 August 2021.
- ^ "The Invention of the Wheel". www.thoughtco.com. Archived from the original on 20 August 2021. Retrieved 21 August 2021.
- ^ V. Gordon Childe (1928). New Light on the Most Ancient East. p. 110.
- ^ Potts, D. T. (2012). A Companion to the Archaeology of the Ancient Near East. p. 285.
- ISBN 978-1-57506-042-2. Archivedfrom the original on 17 October 2017. Retrieved 26 October 2017.
- ISBN 9788120611795.
- ^ "Ancient wheel tracks in Northern Germany". 15 April 2022. Archived from the original on 19 October 2022. Retrieved 19 October 2022.
- ^ "Wheel I Never: Europes Oldest Stone Age Cart Tracks Found". 29 April 2022. Archived from the original on 19 October 2022. Retrieved 19 October 2022.
- ISBN 978-963-9911-34-5
- ISBN 9789077922187. Archivedfrom the original on 22 August 2020. Retrieved 1 May 2019.
- ISBN 978-0-691-05887-0.
- ^ 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.
- ISBN 0-19-166688-2. p. 109.
- ISBN 9789077922187. Archivedfrom the original on 22 August 2020. Retrieved 1 May 2019.
- ^ "Central China discovers earliest wheel ruts". Xinhua. Archived from the original on 22 August 2020. Retrieved 20 January 2020.
- ^ Barbieri-Low, Anthony (February 2000) "Wheeled Vehicles in the Chinese Bronze Age (c. 2000–741 B.C.E)", pp. 11-12. Sino-Platonic Papers
- ^ "Bronze Age wheel at 'British Pompeii' Must Farm an 'unprecedented find'". BBC. Archived from the original on 9 November 2018. Retrieved 18 February 2016.
- S2CID 163472346.
- ISBN 978-0-393-31755-8. Archivedfrom the original on 26 March 2020. Retrieved 9 November 2019.
- ^ Singer, Ben (May 2005). A brief history of the horse in America. Canadian Geographic Magazine. Archived from the original on 19 August 2014.
- ^ Ryder, Thomas (1986). The Carriage Journal: Vol 23 No 4 Spring 1986. Carriage Assoc. of America. p. 209. Archived from the original on 22 March 2023. Retrieved 2 June 2018.
- ^ a b c Chasin Calvo, Sherri. "The Technology of the Incas and Aztecs". Encyclopedia.com. Archived from the original on 20 August 2021. Retrieved 21 August 2021.
There were no wheeled carts, or even wheelbarrows. Although wheeled toys and decorations have been found at Mesoamerican sites, the wheel was never put to practical use.
- ^ a b c d Smith, Herman. "Real smart folks, but no wheel". Dig It. Archived from the original on 20 August 2021. Retrieved 21 August 2021.
- ^ koorihistory.com (1 December 2019). ""Aboriginal people never even invented the wheel."". Koori History - Aboriginal History of South Eastern Australia. Archived from the original on 19 August 2022. Retrieved 5 August 2022.
- ^ "Crafts – Uncovering Treasures of Ancient Nubia". NYTimes.com. 27 February 1994. Archived from the original on 22 August 2020. Retrieved 18 September 2017.
- ^ "What the Nubians Ate". Discover Magazine. Archived from the original on 1 March 2009. Retrieved 5 February 2009.
- ISBN 978-0-521-21592-3. Archivedfrom the original on 10 June 2020. Retrieved 22 February 2020.
- ^ S2CID 148903113.
- ^ Chaves, Isaías; Engerman, Stanley L.; Robinson, James A. (2012). Reinventing the Wheel: The Economic Benefits of Wheeled Transportation in Early Colonial British West Africa (PDF). Weatherhead Center for International Affairs. p. 1. Archived from the original (PDF) on 6 January 2014. Retrieved 5 January 2014.
One of the great technological puzzles of Sub-Saharan African economic history is that wheeled transportation was barely used prior to the colonial period. Instead, head porterage was the main method of transportation.
- ^ bookrags.com Archived 27 May 2008 at the Wayback Machine – Wheel and axle
- ISBN 978-0-19-530715-3. Archivedfrom the original on 4 May 2016. Retrieved 4 January 2012.
- ^ "Examples of snow chains". Archived from the original on 12 December 2022. Retrieved 6 December 2020.
- ^ "Examples of "tire totes"". Archived from the original on 17 May 2022. Retrieved 6 December 2020.
- ^ "Another example of "tire totes"". Archived from the original on 3 November 2020. Retrieved 6 December 2020.
- ^ "Here Is What Those Strips Hanging Off Of Truck Wheels Are For". Jalopnik. Archived from the original on 7 January 2022. Retrieved 7 January 2022.
- ISBN 978-1-55939-779-7. Archivedfrom the original on 22 March 2023. Retrieved 9 December 2021.
- ^ John C. Huntington, Dina Bangdel, The Circle of Bliss: Buddhist Meditational Art, p. 524.
- ISBN 978-1-59605-593-3. Archivedfrom the original on 8 May 2016. Retrieved 17 October 2015.
- ^ Williams, Liz (29 July 2013). "Paganism, part 3: the Wheel of the Year". The Guardian. Archived from the original on 26 October 2021. Retrieved 9 December 2021.
External links
- University of Kiel. "3400 BC: The oldest evidence for the use of the wheel and wagon originates from Northern Germany". Online: April 11, 2022. Retrieved: April 14th, 2022.