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Freewheel
Freewheel mechanism In mechanical or automotive engineering, a freewheel or overrunning clutch is a device in a transmission that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft. An overdrive is sometimes mistakenly called a freewheel, but is otherwise unrelated. The condition of a driven shaft spinning faster than its driveshaft exists in most bicycles when the rider stops pedaling. In a fixed-gear bicycle, without a freewheel, the rear wheel drives the pedals around. An analogous condition exists in an automobile with a manual transmission going downhill, or any situation where the driver takes their foot off the gas pedal, closing the throttle: the wheels drive the engine, possibly at a higher RPM. In a two-stroke engine, this can be catastrophic—as many two stroke engines depend on a fuel/oil mixture for lubrication, a shortage of fuel to the engine starves oil from the cylinders, and the pistons can soon seiz ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freewheel En
Freewheel mechanism In mechanical or automotive engineering, a freewheel or overrunning clutch is a device in a transmission that disengages the driveshaft from the driven shaft when the driven shaft rotates faster than the driveshaft. An overdrive is sometimes mistakenly called a freewheel, but is otherwise unrelated. The condition of a driven shaft spinning faster than its driveshaft exists in most bicycles when the rider stops pedaling. In a fixed-gear bicycle, without a freewheel, the rear wheel drives the pedals around. An analogous condition exists in an automobile with a manual transmission going downhill, or any situation where the driver takes their foot off the gas pedal, closing the throttle: the wheels drive the engine, possibly at a higher RPM. In a two-stroke engine, this can be catastrophic—as many two stroke engines depend on a fuel/oil mixture for lubrication, a shortage of fuel to the engine starves oil from the cylinders, and the pistons can soon seize, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ratchet (device)
A ratchet (occasionally spelled rachet) is a mechanical device that allows continuous linear or rotary motion in only one direction while preventing motion in the opposite direction. Ratchets are widely used in machinery and tools. The word ''ratchet'' is also used informally to refer to a ratcheting socket wrench. __TOC__ Theory of operation A ratchet consists of a round gear or a linear rack with teeth, and a pivoting, spring-loaded finger called a '' pawl'' (or ''click'', in clocks and watches) that engages the teeth. The teeth are uniform but are usually asymmetrical, with each tooth having a moderate slope on one edge and a much steeper slope on the other edge. When the teeth are moving in the unrestricted (i.e. forward) direction, the pawl easily slides up and over the gently sloped edges of the teeth, with a spring forcing it (often with an audible 'click') into the depression between the teeth as it passes the tip of each tooth. When the teeth move in the opposite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ratchet (device)
A ratchet (occasionally spelled rachet) is a mechanical device that allows continuous linear or rotary motion in only one direction while preventing motion in the opposite direction. Ratchets are widely used in machinery and tools. The word ''ratchet'' is also used informally to refer to a ratcheting socket wrench. __TOC__ Theory of operation A ratchet consists of a round gear or a linear rack with teeth, and a pivoting, spring-loaded finger called a '' pawl'' (or ''click'', in clocks and watches) that engages the teeth. The teeth are uniform but are usually asymmetrical, with each tooth having a moderate slope on one edge and a much steeper slope on the other edge. When the teeth are moving in the unrestricted (i.e. forward) direction, the pawl easily slides up and over the gently sloped edges of the teeth, with a spring forcing it (often with an audible 'click') into the depression between the teeth as it passes the tip of each tooth. When the teeth move in the opposite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Car Controls
Car controls are the components in automobiles and other powered road vehicles, such as trucks and buses, used for driving and parking. While controls like steering wheels and pedals have existed since the invention of cars, other controls have developed and adapted to the demands of drivers. For example, manual transmissions became less common as technology relating to automatic transmissions became advanced. Earlier versions of headlights and signal lights were fueled by acetylene or oil. Acetylene was preferred to oil, because its flame is resistant to both wind and rain. Acetylene headlights, which gave a strong green-tinted light, were popular until after World War I; even though the first electric headlights were introduced in 1898 (and those were battery-powered), it wasn't until high-wattage bulbs and more powerful car electrical generating systems were developed in the late 1910s that electric lighting systems entirely superseded acetylene. Steering The first automo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Manual Transmission
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 (mechanics), 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 Automatic transmission#Hydraulic automatic transmissions, hydraulic automatic transmission (AT), and the continuously variable transmissio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clutch
A clutch is a mechanical device that engages and disengages power transmission, especially from a drive shaft to a driven shaft. In the simplest application, clutches connect and disconnect two rotating shafts (drive shafts or line shafts). In these devices, one shaft is typically attached to an engine or other power unit (the driving member), while the other shaft (the driven member) provides output power for work. Typically the motions involved are rotary, but linear clutches also exist. In a motor vehicle, the clutch acts as a mechanical linkage between the engine and transmission, and briefly disconnects, or separates the engine from the transmission system. This disconnects the drive wheels whenever the clutch pedal is depressed, allowing the driver to smoothly change gears. In a torque-controlled drill, for instance, one shaft is driven by a motor, and the other drives a drill chuck. The clutch connects the two shafts so they may be locked together and spin at the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saab 96
The Saab 96 is an automobile manufactured and marketed by Saab from 1960 to January 1980, replacing the 93. The 96 featured aerodynamic two-door bodywork, four-passenger seating and at first a two-stroke, three-cylinder engine, later a four-stroke V4. Body design Compared with its predecessor, the Saab 93, the 96 featured greater and more easily accessible storage space and larger rear window. The front end was lengthened for 1965 models, in preparation for a new engine, and the radiator was placed ahead of the engine, rather than above and behind, a leftover from the thermosiphon cooling days. Both front and rear windows were enlarged slightly for 1968 models. Engine The Saab 96 had a longitudinally mounted engine layout. As first designed, it had an 841 cc displacement, three-cylinder Saab two-stroke engine. By 1965 this was increased to . An optional version of the engine, with triple carburetors and oil injection, was used in the Sport and Monte Carlo models ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bicycle
A bicycle, also called a pedal cycle, bike or cycle, is a human-powered or motor-powered assisted, pedal-driven, single-track vehicle, having two wheels attached to a frame, one behind the other. A is called a cyclist, or bicyclist. Bicycles were introduced in the 19th century in Europe. By the early 21st century, more than 1 billion were in existence. These numbers far exceed the number of cars, both in total and ranked by the number of individual models produced. They are the principal means of transportation in many regions. They also provide a popular form of recreation, and have been adapted for use as children's toys, general fitness, military and police applications, courier services, bicycle racing, and bicycle stunts. The basic shape and configuration of a typical upright or "safety bicycle", has changed little since the first chain-driven model was developed around 1885. However, many details have been improved, especially since the advent of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saab Two-stroke
The Saab two-stroke was a two-stroke cycle, inline, two cylinder, and later three cylinder engine manufactured by Swedish automotive manufacturer Saab that was based on a design by German manufacturer DKW. Two-cylinder The first version was a displacement straight-twin that was transversally mounted in the 1950–1956 Saab 92. It had with , and a top speed of . For the 1954 model year the engine received a new Solex 32BI carburetor and a new ignition coil which raised engine output to . It had some features only found in modern cars such as one ignition coil per cylinder. Three-cylinder The second type of Saab two stroke engine was a longitudinally placed inline-three cylinder of and initially . It was used in the Saabs 93, 94 (Sonett I, with an engine tuned to ), Saab Sonett II, 95, 96, Saab GT750, the Saab Formula Junior and the Saab Quantum. The engine had a combined belt driven DC dynamo and a coolant water pump. The Saab Formula Junior used a 'bored-out' hor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V4 Engine
A V4 engine is a four-cylinder piston engine where the cylinders share a common crankshaft and are arranged in a V configuration. The V4 engine is less common compared to straight-four engines. However, V4 engines have been used in automobiles, motorcycles, and other applications. Design Most V4 engines have two crankpins that are shared by opposing cylinders. The crankshaft is usually supported by three main bearings. Compared to the more common inline-four engine layout, a V4 engine is much shorter. Although different V angles can be used, if the two pistons are at a 90° V-angle with shared crankpins, the engine offers the additional advantage of perfect primary balance that reduces vibration. The design can also result in a smaller rocking couple than an inline-four engine, and the shorter crankshaft is less susceptible to the effects of torsional vibration due to its increased stiffness. Disadvantages of V4 engines include its design being inherently wider compared to in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spring (device)
A spring is an elastic object that stores mechanical energy. In everyday use the term often refers to coil springs, but there are many different spring designs. Modern springs are typically manufactured from spring steel, although some non-metallic objects like the bow are also springs. When a conventional spring, without stiffness variability features, is compressed or stretched from its resting position, it exerts an opposing force approximately proportional to its change in length (this approximation breaks down for larger deflections). The ''rate'' or ''spring constant'' of a spring is the change in the force it exerts, divided by the change in deflection of the spring. That is, it is the gradient of the force versus deflection curve. An extension or compression spring's rate is expressed in units of force divided by distance, for example or N/m or lbf/in. A torsion spring is a spring that works by twisting; when it is twisted about its axis by an angle, it produc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saab 99
The Saab 99 is a car which was produced by Saab from 1968 to 1984; their first foray into a larger class than the 96. While considered a large family car in Scandinavia, it was marketed as a niche compact executive car in most other markets. It was manufactured both in Sweden and Finland and was succeeded by the Saab 900, although the 99 continued to be produced alongside its successor. The Saab 90, an updated, less complex version using many 900 parts took over from the 99 in late 1984. Development On 2 April 1964, Gudmund's day in Sweden, after several years of planning, the Saab board started ''Project Gudmund''. This was a project to develop a new and larger car to take the manufacturer beyond the market for the smaller Saab 96. This new car became the Saab 99, designed by Sixten Sason and unveiled in Stockholm on November 22, 1967. The first prototypes of the 99 were built by cutting a Saab 96 lengthwise and widening it by ; this created the so-called '' Paddan'' (The toa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
