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Chain Drives
Chain drive is a way of transmitting mechanical power from one place to another. It is often used to convey power to the wheels of a vehicle, particularly bicycles and motorcycles. It is also used in a wide variety of machines besides vehicles. Most often, the power is conveyed by a roller chain, known as the drive chain or transmission chain, passing over a sprocket, with the teeth of the gear meshing with the holes in the links of the chain. The gear is turned, and this pulls the chain putting mechanical force into the system. Another type of drive chain is the Morse chain, invented by the Morse Chain Company of Ithaca, New York, United States. This has inverted teeth. Sometimes the power is output by simply rotating the chain, which can be used to lift or drag objects. In other situations, a second gear is placed and the power is recovered by attaching shafts or hubs to this gear. Though drive chains are often simple oval loops, they can also go around corners by placing mor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use: * Those designed for lifting, such as when used with a hoist; for pulling; or for securing, such as with a bicycle lock, have links that are torus-shaped, which make the chain flexible in two dimensions (the fixed third dimension being a chain's length). Small chains serving as jewellery are a mostly decorative analogue of such types. * Those designed for transferring power in machines have links designed to mesh with the teeth of the sprockets of the machine, and are flexible in only one dimension. They are known as roller chains, though there are also non-roller chains such as block chains. Two distinct chains can be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Su Song
Su Song (, 1020–1101), courtesy name Zirong (), was a Chinese polymathic scientist and statesman who lived during the Song dynasty (960–1279). He exceled in numerous fields including but not limited to mathematics, astronomy, cartography, geography, metallurgy, mechanical engineering, hydraulic engineering, poetry, and statesmanship. Su Song was the engineer for a hydro-mechanical astronomical clock tower located in Kaifeng. It employed an early escapement mechanism.Needham, Volume 4, Part 2, 445.Needham, Volume 4, Part 2, 448.Bodde, 140.Fry, 10. The escapement mechanism of Su's clock tower was invented by the Tang dynasty Buddhist monk Yi Xing and government official Liang Lingzan in 725 AD to operate a water-powered armillary sphere, however Su's armillary sphere was the first to utilize a mechanical clock drive.Needham, Volume 3, 351. Su's clock tower also featured the oldest known endless power-transmitting chain drive, called the ''tian ti'' (), or "celestial la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safety Bicycle
A safety bicycle (or simply a safety) is a type of bicycle that became very popular beginning in the late 1880s as an alternative to the penny-farthing (also known as an "ordinary" or "high wheeler") and is now the most common type of bicycle. Early bicycles of this style were known as safety bicycles because they were noted for, and marketed as, being safer than the high wheelers they were replacing. Even though modern bicycles use a similar design, the term is rarely used today and is considered obsolete outside circles familiar with high wheelers. Definition The term 'safety bicycle' was used in the 1880s for any alternative to the penny-farthing. The front and rear wheel were not necessarily the same size. Later historians began to use the term in a more restricted way for the design that was a direct ancestor to most modern bicycles. "Diamond frame" is also sometimes used as a term for safety bicycles, even though this technically only refers to a certain type of safety bic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drive Shaft
A drive shaft, driveshaft, driving shaft, tailshaft (Australian English), propeller shaft (prop shaft), or Cardan shaft (after Girolamo Cardano) is a component for transmitting mechanical power (physics), power, torque, and rotation, usually used to connect other components of a drivetrain that cannot be connected directly because of distance or the need to allow for relative movement between them. As torque carriers, drive shafts are subject to torsion (mechanics), torsion and shear stress, equivalent to the difference between the input torque and the load. They must therefore be strong enough to bear the stress, while avoiding too much additional weight as that would in turn increase their inertia. To allow for variations in the alignment and distance between the driving and driven components, drive shafts frequently incorporate one or more universal joints, jaw couplings, or rag joints, and sometimes a Rotating spline, splined joint or prismatic joint. History The term '' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conveyor Belt
A conveyor belt is the carrying medium of a belt conveyor system (often shortened to a belt conveyor). A belt conveyor system consists of two or more pulleys (sometimes referred to as drums), with a closed loop of carrying medium—the conveyor belt—that rotates about them. One or both of the pulleys are powered, moving the belt and the material on the belt forward. The powered pulley is called the drive pulley, while the unpowered pulley is called the idler pulley. There are two main industrial classes of belt conveyors; Those in general material handling such as those moving boxes along inside a factory and bulk material handling such as those used to transport large volumes of resources and agricultural materials, such as grain, salt, coal, ore, sand, overburden and more. Overview Conveyors are durable and reliable components used in automated distribution and warehousing, as well as manufacturing and production facilities. In combination with computer-controlled pallet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Derailleur Gears
Shimano 600 front derailleur (1980) A derailleur () is a variable-ratio bicycle gearing system consisting of a chain, multiple sprockets of different sizes, and a mechanism to move the chain from one sprocket to another. Modern front and rear derailleurs typically consist of a moveable chain-guide that is operated remotely by a Bowden cable attached to a shifter mounted on the down tube, handlebar stem, or handlebar. When a rider operates the lever while pedalling, the change in cable tension moves the chain-guide from side to side, "derailing" the chain onto different sprockets. Etymology ''Dérailleur'' () is a French word, derived from the derailment of a train from its tracks. Its first recorded use was 1930. History A modern road bicycle drivetrain with front and rear derailleurs Various derailleur systems were designed and built in the late 19th century. One example is the Protean two-speed derailleur available on the Whippet safety bicycle. The Fren ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flywheel
A flywheel is a mechanical device that uses the conservation of angular momentum to store rotational energy, a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, assuming the flywheel's moment of inertia is constant (i.e., a flywheel with fixed mass and second moment of area revolving about some fixed axis) then the stored (rotational) energy is directly associated with the square of its rotational speed. Since a flywheel serves to store mechanical energy for later use, it is natural to consider it as a kinetic energy analogue of an electrical Inductor. Once suitably abstracted, this shared principle of energy storage is described in the generalized concept of an accumulator. As with other types of accumulators, a flywheel inherently smooths sufficiently small deviations in the power output of a system, thereby effectively playing the role of a low-pass filter with respect to the mechanical veloc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inertia
Inertia is the natural tendency of objects in motion to stay in motion and objects at rest to stay at rest, unless a force causes the velocity to change. It is one of the fundamental principles in classical physics, and described by Isaac Newton in his Newton%27s_laws_of_motion#First, first law of motion (also known as The Principle of Inertia). It is one of the primary manifestations of mass, one of the core quantitative properties of physical systems. Newton writes: In his 1687 work ''Philosophiæ Naturalis Principia Mathematica'', Newton defined inertia as a property: History and development Early understanding of inertial motion Joseph NeedhamProfessor John H. Lienhard points out the Mozi (book), Mozi – based on a Chinese text from the Warring States period (475–221 BCE) – as having given the first description of inertia. Before the European Renaissance, the prevailing theory of motion in western philosophy was that of Aristotle (384–322 BCE). On the surface ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Another important consequence of many types of friction can be wear, which may lead to performance degradation or damage to components. It is known that frictional energy losses account for about 20% of the total energy expenditure of the world. As briefly discussed later, there are many different contributors to the retarding force in friction, ranging from asperity deformation to the generation of charges and changes in local structure. When two bodies in contact move relative to each other, due to these variou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belt (mechanical)
A belt is a loop of flexible material used to link two or more rotating shafts mechanically, most often parallel. Belts may be used as a source of motion, to transmit power efficiently or to track relative movement. Belts are looped over pulleys and may have a twist between the pulleys, and the shafts need not be parallel. In a two pulley system, the belt can either drive the pulleys normally in one direction (the same if on parallel shafts), or the belt may be crossed, so that the direction of the driven shaft is reversed (the opposite direction to the driver if on parallel shafts). The belt drive can also be used to change the speed of rotation, either up or down, by using different sized pulleys. As a source of motion, a conveyor belt is one application where the belt is adapted to carry a load continuously between two points. History The mechanical belt drive, using a pulley machine, was first mentioned in the text of the ''Dictionary of Local Expressions'' by the Han ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toothed Belt
A toothed belt, timing belt, cogged belt, cog belt, or synchronous belt is a flexible belt with teeth moulded onto its inner surface. Toothed belts are usually designed to run over matching toothed pulleys or sprockets. Toothed belts are used in a wide array of mechanical devices where high power transmission is desired. Design and application ''Timing belts'', ''toothed belts'', ''cogged'' or ''cog belts'', and ''synchronous belts'' are non-slipping mechanical drive belts. They are made as flexible belts with teeth moulded onto their inner surface. The belts run over matching toothed pulleys or sprockets. When correctly tensioned, these types of belts have no slippage, and are often used to transfer motion for indexing or timing purposes (hence their name). They are often used in lieu of chains or gears, so there is less noise and a lubrication bath is not necessary. Toothed belts are used widely in mechanical devices, including sewing machines, photocopiers and many others. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Escapement
An escapement is a mechanical linkage in mechanical watches and clocks that gives impulses to the timekeeping element and periodically releases the gear train to move forward, advancing the clock's hands. The impulse action transfers energy to the clock's timekeeping element (usually a pendulum or balance wheel) to replace the energy lost to friction during its cycle and keep the timekeeper oscillating. The escapement is driven by force from a coiled spring (device), spring or a suspended weight, transmitted through the timepiece's gear train. Each swing of the pendulum or balance wheel releases a tooth of the escapement's ''escape wheel'', allowing the clock's gear train to advance or "escape" by a fixed amount. This regular periodic advancement moves the clock's hands forward at a steady rate. At the same time, the tooth gives the timekeeping element a push, before another tooth catches on the escapement's pallet, returning the escapement to its "locked" state. The sudden stoppi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
