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Mechanical Advantage Device
A simple machine that exhibits mechanical advantage is called a mechanical advantage device - e.g.: * Lever: The beam shown is in static equilibrium around the fulcrum. This is due to the moment created by vector force ''"A"'' counterclockwise (moment ''A''*a) being in equilibrium with the moment created by vector force ''"B"'' clockwise (moment ''B''*b). The relatively low vector force ''"B"'' is translated in a relatively high vector force ''"A"''. The force is thus increased in the ratio of the forces ''A : B'', which is equal to the ratio of the distances to the fulcrum ''b : a''. This ratio is called the mechanical advantage. This idealised situation does not take into account friction. * Wheel and axle motion (e.g. screwdrivers, doorknobs): A wheel is essentially a lever with one arm the distance between the axle and the outer point of the wheel, and the other the radius of the axle. Typically this is a fairly large difference, leading to a proportionately large mechanical a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Screw
A screw and a bolt (see '' Differentiation between bolt and screw'' below) are similar types of fastener typically made of metal and characterized by a helical ridge, called a ''male thread'' (external thread). Screws and bolts are used to fasten materials by the engagement of the screw thread with a similar ''female thread'' (internal thread) in a matching part. Screws are often self-threading (also known as self-tapping) where the thread cuts into the material when the screw is turned, creating an internal thread that helps pull fastened materials together and prevents pull-out. There are many screws for a variety of materials; materials commonly fastened by screws include wood, sheet metal, and plastic. Explanation A screw is a combination of simple machines: it is, in essence, an inclined plane wrapped around a central shaft, but the inclined plane (thread) also comes to a sharp edge around the outside, which acts as a wedge as it pushes into the fastened material, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanics
Mechanics (from Ancient Greek: μηχανική, ''mēkhanikḗ'', "of machines") is the area of mathematics and physics concerned with the relationships between force, matter, and motion among physical objects. Forces applied to objects result in displacements, or changes of an object's position relative to its environment. Theoretical expositions of this branch of physics has its origins in Ancient Greece, for instance, in the writings of Aristotle and Archimedes (see History of classical mechanics and Timeline of classical mechanics). During the early modern period, scientists such as Galileo, Kepler, Huygens, and Newton laid the foundation for what is now known as classical mechanics. As a branch of classical physics, mechanics deals with bodies that are either at rest or are moving with velocities significantly less than the speed of light. It can also be defined as the physical science that deals with the motion of and forces on bodies not in the quantum r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Engineering
Mechanical engineering is the study of physical machines that may involve force and movement. It is an engineering branch that combines engineering physics and mathematics principles with materials science, to design, analyze, manufacture, and maintain mechanical systems. It is one of the oldest and broadest of the engineering branches. Mechanical engineering requires an understanding of core areas including mechanics, dynamics, thermodynamics, materials science, structural analysis, and electricity. In addition to these core principles, mechanical engineers use tools such as computer-aided design (CAD), computer-aided manufacturing (CAM), and product lifecycle management to design and analyze manufacturing plants, industrial equipment and machinery, heating and cooling systems, transport systems, aircraft, watercraft, robotics, medical devices, weapons, and others. Mechanical engineering emerged as a field during the Industrial Revolution in Europe in the 18th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simple Machines
A simple machine is a mechanical device that changes the direction or magnitude of a force. In general, they can be defined as the simplest mechanisms that use mechanical advantage (also called leverage) to multiply force. Usually the term refers to the six classical simple machines that were defined by Renaissance scientists: * Lever * Wheel and axle * Pulley * Inclined plane * Wedge * Screw A simple machine uses a single applied force to do work against a single load force. Ignoring friction losses, the work done on the load is equal to the work done by the applied force. The machine can increase the amount of the output force, at the cost of a proportional decrease in the distance moved by the load. The ratio of the output to the applied force is called the '' mechanical advantage''. Simple machines can be regarded as the elementary "building blocks" of which all more complicated machines (sometimes called "compound machines") are composed. For example, wheels, levers, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gear Ratio
A gear train is a mechanical system formed by mounting gears on a frame so the teeth of the gears engage. Gear teeth are designed to ensure the Pitch circle diameter (gears), pitch circles of engaging gears roll on each other without slipping, providing a smooth transmission of rotation from one gear to the next. Features of gears and gear trains include: * The gear ratio of the pitch circles of mating gears defines the speed ratio and the mechanical advantage of the gear set. * A epicyclic gearing, planetary gear train provides high gear reduction in a compact package. * It is possible to design gear teeth for gears that are non-circular gear, non-circular, yet still transmit torque smoothly. * The speed ratios of chain drive, chain and belt (mechanical), belt drives are computed in the same way as gear ratios. See bicycle gearing. The transmission of rotation between contacting toothed wheels can be traced back to the Antikythera mechanism of Greece and the south-pointing cha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balanced Arm Lamps
A balanced-arm lamp, sometimes called a floating arm lamp, is a lamp with an adjustable folding arm which is constructed such that the force due to gravity is always counteracted by springs, regardless of the position of the arms of the lamp. Many lamp brands (such as the Anglepoise lamp, Anglepoise, originator of the concept, and Luxo L-1), as well as other devices, use this principle. Configuration The five terms This article uses the terminology: * ''lamp cap'', * ''forearm'', * ''upper arm'', * ''stand'' or ''body'' and * ''base'' for the five basic parts of these lamps. The general design A balanced-arm lamp has a ''base'', a ''stand'' or ''body'', (in most cases) ''two'' connected ''arms'' (in many cases fitted with springs), and a ''lamp-head''. The lamp can be moved into almost any position, and the balancing device will maintain the position until moved again. The same overall mechanism can be employed in ''other'' devices with similar requirements, such as: * co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclined Plane
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six classical simple machines defined by Renaissance scientists. Inclined planes are used to move heavy loads over vertical obstacles. Examples vary from a ramp used to load goods into a truck, to a person walking up a pedestrian ramp, to an automobile or railroad train climbing a grade. Moving an object up an inclined plane requires less force than lifting it straight up, at a cost of an increase in the distance moved. The mechanical advantage of an inclined plane, the factor by which the force is reduced, is equal to the ratio of the length of the sloped surface to the height it spans. Owing to conservation of energy, the same amount of mechanical energy (work) is required to lift a given object by a given vertical distance, disregarding losse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lead (engineering)
Lead is the axial advance of a helix or screw during one complete turn (360°) The lead for a screw thread is the axial travel for a single revolution. ''Pitch'' is defined as the axial distance between adjacent threads on a helix or screw. In most screws, called "''single start''" screws, which have a single helical thread along their length, the lead and pitch are equal. They only differ in "''multiple start''" screws, which have several intertwined threads. In these screws, the lead is equal to the pitch multiplied by the number of "''starts''". Lead angle is the angle between the helix and a plane of rotation. It is the complement of the helix angle, and is used for convenience in worms and hobs. It is understood to be at the standard pitch diameter unless otherwise specified. The lead angle can be expressed as: :\mbox = \arctan \left( \frac \right) where :''l'' is lead of the helix :''dm'' is mean diameter of the helix In American literature ''λ'' is used to n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Four Pulleys
4 (four) is a number, numeral (linguistics), numeral and numerical digit, digit. It is the natural number following 3 and preceding 5. It is the smallest semiprime and composite number, and is tetraphobia, considered unlucky in many East Asian cultures. In mathematics Four is the smallest composite number, its proper divisors being and . Four is the sum and product of two with itself: 2 + 2 = 4 = 2 x 2, the only number b such that a + a = b = a x a, which also makes four the smallest squared prime number p^. In Knuth's up-arrow notation, , and so forth, for any number of up arrows. By consequence, four is the only square one more than a prime number, specifically 3, three. The sum of the first four prime numbers 2, two + 3, three + 5, five + 7, seven is the only sum of four consecutive prime numbers that yields an Parity (mathematics), odd prime number, 17 (number), seventeen, which is the fourth super-prime. Four lies between the first proper pair of twin primes, 3, three and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inclined Plane
An inclined plane, also known as a ramp, is a flat supporting surface tilted at an angle from the vertical direction, with one end higher than the other, used as an aid for raising or lowering a load. The inclined plane is one of the six classical simple machines defined by Renaissance scientists. Inclined planes are used to move heavy loads over vertical obstacles. Examples vary from a ramp used to load goods into a truck, to a person walking up a pedestrian ramp, to an automobile or railroad train climbing a grade. Moving an object up an inclined plane requires less force than lifting it straight up, at a cost of an increase in the distance moved. The mechanical advantage of an inclined plane, the factor by which the force is reduced, is equal to the ratio of the length of the sloped surface to the height it spans. Owing to conservation of energy, the same amount of mechanical energy (work) is required to lift a given object by a given vertical distance, disregarding losse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
