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A tire or tyre is a ring-shaped component that surrounds a wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide traction on the surface over which the wheel travels. Most tires, such as those for automobiles and bicycles, are pneumatically inflated structures, providing a flexible cushion that absorbs shock as the tire rolls over rough features on the surface. Tires provide a footprint, called a contact patch, designed to match the vehicle's weight and the bearing on the surface that it rolls over by exerting a pressure that will avoid deforming the surface.
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The following outline is provided as an overview of and topical guide to tires:
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A train wheel or rail wheel is a type of wheel specially designed for use on railway tracks. The wheel acts as a rolling component, typically press fitted onto an axle and mounted directly on a railway carriage or locomotive, or indirectly on a bogie, also called a truck. The powered wheels under the locomotive are called driving wheels. Wheels are initially cast or forged and then heat-treated to have a specific hardness. New wheels are machined using a lathe to a standardized shape, called a profile, before being installed onto an axle. All wheel profiles are regularly checked to ensure proper interaction between the wheel and the rail. Incorrectly profiled wheels and worn wheels can increase rolling resistance, reduce energy efficiency and may even cause a derailment. The International Union of Railways has defined a standard wheel diameter of 920 mm (36 in), although smaller sizes are used in some rapid transit railway systems and on ro-ro carriages.
Joseph D. Walter is a retired American tire industry mechanical engineering researcher and Bridgestone executive.
References
- ↑ "Rolling Resistance Measurement Procedure for Passenger Car, Light Truck, and Highway Truck and Bus Tires J1269_202012". sae.org. SAE. Retrieved 3 February 2024.
- ↑ Hall, D. E.; J. C. Moreland (2001). "Fundamentals of Rolling Resistance". Rubber Chemistry and Technology. 74 (3): 525–539. doi:10.5254/1.3547650.
- ↑ Mars, W. V.; J. R. Luchini (1999). "An Analytical Model for the Transient Rolling Resistance Behavior of Tires". Tire Science and Technology. 27 (3): 161–175. doi:10.2346/1.2135982.
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