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Non-synchronous Transmission
A non-synchronous transmission, also called a crash gearbox, is a form of manual transmission based on gears that do not use synchronizing mechanisms. They require the driver to manually synchronize the transmission's input speed (engine RPM) and output speed (driveshaft speed). Non-synchronous transmissions are found primarily in various types of industrial machinery; such as tractors and semi-tractors. Non-synchronous manual transmissions are also found on motorcycles, in the form of constant-mesh sequential manual transmissions. Prior to the 1950s and 1960s, most cars used constant-mesh (and also sliding-mesh) but non-synchronous transmissions. History Most early automobiles were rear-engined, using a single-speed transmission and belt-drive to power the rear wheels. In 1891, the French Panhard et Levassor automobile used a three-speed manual transmission and is considered to have set the template for multi-speed manual transmissions in motor vehicles. This transmis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Float Shifting
Float shifting or floating gears, also called "slip shifting", "dead sticking", or "bang shifting", is the process of changing gears, in typically a non-synchronous transmission, without depressing the clutch. Shifting in this manner is also used with synchronous manual transmissions, particularly after a clutch failure, to prevent destroying the synchromeshes with the power of the engine. Drivers can shift non-synchronous transmissions without using the clutch by bringing the engine to exactly the right RPM in neutral before attempting to complete a shift. If done improperly, it can damage or destroy a transmission. Some truck drivers use this technique with the higher gears. The technique is sometimes also used on motorcycles, but has largely been replaced by quickshifters for competitive use. Technique After bringing the engine up to speed in a gear, the driver senses the need to upshift. To get out of the current gear without using the clutch, the driver backs off slightly on ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Engineering
Mechanical engineering is the study of physical machines and mechanism (engineering), mechanisms that may involve force and movement. It is an engineering branch that combines engineering physics and engineering mathematics, mathematics principles with materials science, to design, analyze, manufacture, and maintain mechanical systems. It is one of the oldest and broadest of the List of engineering branches, engineering branches. Mechanical engineering requires an understanding of core areas including mechanics, Analytical dynamics, dynamics, thermodynamics, materials science, design, structural analysis, and electricity. In addition to these core principles, mechanical engineers use tools such as computer-aided design (CAD), computer-aided manufacturing (CAM), computer-aided engineering (CAE), and product lifecycle management to design and analyze manufacturing plants, industrial equipment and industrial machinery, machinery, HVAC, heating and cooling systems, transport systems, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gear Ratio
A gear train or gear set is a machine element of a mechanical system formed by mounting two or more gears on a frame such that 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 Antikyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dog Clutch
A dog clutch (also known as a dog box, dog gears, dog ring, clutch dog, or positive clutch) is a type of clutch that couples two rotating shafts or other rotating components by engagement of interlocking teeth or dogs rather than by friction. The two parts of the clutch are designed such that one will push the other, causing both to rotate at the same speed and will never slip. In engineering, a "dog" is a tool or device used to lock two components in relation to each other. Dog clutches are used where slip is undesirable and/or the clutch is not used to control torque. Without slippage, dog clutches are not affected by wear in the same way that friction clutches are, but result in shock when shafts of different speeds are engaged. For this reason they are best used when sudden starting action is acceptable and the inertia of the system is small. Dog clutches are used inside constant-mesh manual transmissions to lock different gears to the rotating input and output shafts. A s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semi-automatic Transmission
A semi-automatic transmission is a multiple-speed Transmission (mechanics), transmission where part of its operation is Automation, automated (typically the actuation of the clutch), but the driver's input is still required to launch the vehicle from a standstill and to manually change gears. Semi-automatic transmissions were almost exclusively used in motorcycles and are based on conventional manual transmissions or sequential manual transmissions, but use an automatic clutch system. But some semi-automatic transmissions have also been based on standard hydraulic automatic transmissions with torque converters and Epicyclic gearing, planetary gearsets. Names for specific types of semi-automatic transmissions include ''clutchless manual'', ''auto-manual'', ''auto-clutch manual'', and ''paddle-shift'' transmissions. These systems facilitate gear shifts for the driver by operating the clutch system automatically, usually via switches that trigger an actuator or servomechanism, servo, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Automatic Transmission
An automatic transmission (AT) or automatic gearbox is a multi-speed transmission (mechanics), transmission used in motor vehicles that does not require any input from the driver to change forward gears under normal driving conditions. The 1904 Sturtevant "horseless carriage gearbox" is often considered to be the first true automatic transmission. The first mass-produced automatic transmission is the General Motors ''Hydramatic'' two-speed hydraulic automatic, which was introduced in 1939. Automatic transmissions are especially prevalent in vehicular drivetrains, particularly those subject to intense mechanical acceleration and frequent idle/transient operating conditions; commonly commercial/passenger/utility vehicles, such as buses and waste collection vehicles. Prevalence Vehicles with internal combustion engines, unlike electric vehicles, require the engine to operate in a narrow range of rates of rotation, requiring a gearbox, operated manually or automatically, to drive t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchromesh
A manual transmission (MT), also known as manual gearbox, standard transmission (in Canada, the United Kingdom and the United States), or stick shift (in the United States), is a multi-speed motor vehicle transmission system where gear changes require the driver to manually select the gears by operating a gear stick and clutch (which is usually a foot pedal for cars or a hand lever for motorcycles). Early automobiles used ''sliding-mesh'' manual transmissions with up to three forward gear ratios. Since the 1950s, ''constant-mesh'' manual transmissions have become increasingly commonplace, and the number of forward ratios has increased to 5-speed and 6-speed manual transmissions for current vehicles. The alternative to a manual transmission is an automatic transmission. Common types of automatic transmissions are the hydraulic automatic transmission (AT) and the continuously variable transmission (CVT). The automated manual transmission (AMT) and dual-clutch transmission (DCT ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Racecars
Auto racing (also known as car racing, motor racing, or automobile racing) is a motorsport involving the racing of automobiles for competition. In North America, the term is commonly used to describe all forms of automobile sport including non-racing disciplines. Auto racing has existed since the invention of the automobile. Races of various types were organized, with the first recorded as early as 1867. Many of the earliest events were effectively Classic trials, reliability trials, aimed at proving these new machines were a practical mode of transport, but soon became an important way for automobile makers to demonstrate their machines. By the 1930s, specialist racing cars had developed. There are now numerous different categories, each with different rules and regulations. History The first prearranged match race of two self-powered road vehicles over a prescribed route occurred at 4:30 A.M. on August 30, 1867, between Ashton-under-Lyne and Old Trafford, England, a di ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
All-terrain Vehicle
An all-terrain vehicle (ATV), also known as a light utility vehicle (LUV), a quad bike or quad (if it has four wheels), as defined by the American National Standards Institute (ANSI), is a vehicle that travels on low-pressure tires, has a seat that is straddled by the operator, and has handlebars, similar to a motorcycle. As the name implies, it is designed to handle a wider variety of terrain than most other vehicles. It is street-legal in some countries, but not in most states, territories and provinces of Australia, the United States, and Canada. By the current ANSI definition, ATVs are intended for use by a single operator, but some ATVs, referred to as tandem ATVs, have been developed for use by the driver and one passenger. The rider sits on and operates these vehicles like a motorcycle, but the extra wheels give more stability at slower speeds. Although most are equipped with three or four wheels, six or eight wheel (tracked) models exist and have existed historicall ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sequential Manual Transmission
A sequential manual transmission, also known as a sequential gearbox or sequential transmission, is a type of Non-synchronous transmission, non-synchronous manual transmission used mostly in motorcycles and Auto racing, racing cars. It produces faster shift times than traditional Manual transmission#Synchronized transmission, synchronized manual transmissions, and restricts the driver to selecting either the next or previous gear, in a successive order. Design A sequential manual transmission is non-synchronous transmission, unsynchronized, and allows the driver to select either the next gear (e.g. shifting from first gear to second gear) or the previous gear (e.g., shifting from third gear to second gear), operated either via electronic paddle-shifters mounted behind the steering wheel or with a sequential shifter. This restriction avoids accidentally selecting the wrong gear; however, it also prevents the driver from deliberately "skipping" gears. The use of dog clutches (ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Power Take-off
A power take-off or power takeoff (PTO) is one of several methods for taking power from a power source, such as a running engine, and power transmission#Mechanical power, transmitting it to an application such as an attached implement or separate machine. Most commonly, it is a spline (mechanical), splined drive shaft installed on a tractor or truck allowing implements with mating fittings to be powered directly by the engine. Semi-permanently mounted power take-offs can also be found on industrial and marine engines. These applications typically use a drive shaft and bolted joint to transmit power to a secondary implement or accessory. In the case of a marine application, such as shafts may be used to power fire pumps. In aircraft applications, such an accessory drive may be used in conjunction with a constant speed drive. Jet aircraft have four types of PTO units: internal gearbox, external gearbox, radial drive shaft, and bleed air, which are used to power engine accessories. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
