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Cam Follower
In mechanical engineering, a cam follower, also known as a track follower, is a specialized type of roller or needle bearing designed to follow cam lobe profiles. Cam followers come in a vast array of different configurations, however the most defining characteristic is how the cam follower mounts to its mating part; ''stud'' style cam followers use a stud while the ''yoke'' style has a hole through the middle. Construction The modern stud type follower was invented and patented in 1937 by Thomas L. Robinson of the McGill Manufacturing Company. It replaced using a standard bearing and bolt. The new cam followers were easier to use because the stud was already included and they could also handle higher loads. While roller cam followers are similar to roller bearings, there are quite a few differences. Standard ball and roller bearings are designed to be pressed into a rigid housing, which provides circumferential support. This keeps the outer race from deforming, so the race cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tappet
A tappet is most commonly a component in an internal combustion engine which converts the rotating motion of the camshaft into linear motion of the valves, either directly or indirectly. An earlier use of the term was for part of the valve gear in beam engines beginning in 1715. The term is also used for components in pneumatic cylinders and weaving loom. __TOC__ Beam engines The first recorded use of the term tappet is as part of the valve gear in the 1715 Newcomen engine, an early form of steam engine. Early versions of the Newcomen engines from 1712 had manually operated valves, but by 1715 this repetitive task had been automated through the use of tappets. The beam of the engine had a vertical 'plug rod' hung from it, alongside the cylinder. Adjustable blocks or 'tappets' were attached to this rod and as the beam moved up and down, the tappets pressed against long levers or 'horns' attached to the engine's valves, working the cycle of steam and injection water valves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Needle Roller
A needle roller bearing is a special type of roller bearing which uses long, thin cylindrical rollers resembling needles. Ordinary roller bearings' rollers are only slightly longer than their diameter, but needle bearings typically have rollers that are at least four times longer than their diameter. Like all bearings, they are used to reduce the friction of a rotating surface. Compared to ball bearings and ordinary roller bearings, needle bearings have a greater surface area in contact with the races, so they can support a greater load. They are also thinner, so they require less clearance between the axle and the surrounding structure. Needle bearings are heavily used in automobile components such as rocker arm pivots, pumps, compressors, and transmissions. The drive shaft of a rear-wheel drive vehicle typically has at least eight needle bearings (four in each U joint) and often more if it is particularly long, or operates on steep slopes. See also * Race (bearing) * Tap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tappet
A tappet is most commonly a component in an internal combustion engine which converts the rotating motion of the camshaft into linear motion of the valves, either directly or indirectly. An earlier use of the term was for part of the valve gear in beam engines beginning in 1715. The term is also used for components in pneumatic cylinders and weaving loom. __TOC__ Beam engines The first recorded use of the term tappet is as part of the valve gear in the 1715 Newcomen engine, an early form of steam engine. Early versions of the Newcomen engines from 1712 had manually operated valves, but by 1715 this repetitive task had been automated through the use of tappets. The beam of the engine had a vertical 'plug rod' hung from it, alongside the cylinder. Adjustable blocks or 'tappets' were attached to this rod and as the beam moved up and down, the tappets pressed against long levers or 'horns' attached to the engine's valves, working the cycle of steam and injection water valves ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tapered Roller Bearing
Tapered roller bearings are rolling element bearings that can support axial forces (i.e., they are good thrust bearings) as well as radial forces. Description The inner and outer ring raceways are segments of cones and the rollers are tapered so that the conical surfaces of the raceways, and the roller axes, if projected, would all meet at a common point on the main axis of the bearing. This geometry makes the motion of the cones remain coaxial, with no sliding motion between the raceways and the outside diameter of the rollers. This conical geometry creates a linear contact patch which permits greater loads to be carried than with spherical (ball) bearings, which have point contact. The geometry means that the tangential speeds of the surfaces of each of the rollers are the same as their raceways along the whole length of the contact patch and no differential scrubbing occurs. The rollers are stabilized and restrained by a flange on the inner ring, against which their la ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearing Ball
Bearing balls are special highly spherical and smooth balls, most commonly used in ball bearings, but also used as components in things like freewheel mechanisms. The balls come in many different ''grades''. These grades are defined by bodies such as the American Bearing Manufacturers Association (ABMA), a body which sets standards for the precision of bearing balls. They are manufactured in machines designed specially for the job. In 2008, the United States produced 5.778 billion bearing balls. Grade Bearing balls are manufactured to a specific grade, which defines its geometric tolerances. The grades range from 2000 to 3, where the smaller the number the higher the precision. Grades are written "GXXXX", i.e. grade 100 would be "G100". Lower grades also have fewer defects, such as flats, pits, soft spots, and cuts. The surface smoothness is measured in two ways: surface roughness and waviness. Size refers to the farthest possible distance between two points on the ball's surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backlash (engineering)
In mechanical engineering, backlash, sometimes called lash, play, or slop, is a clearance or lost motion in a mechanism caused by gaps between the parts. It can be defined as "the maximum distance or angle through which any part of a mechanical system may be moved in one direction without applying appreciable force or motion to the next part in mechanical sequence."p. 1-8 An example, in the context of gears and gear trains, is the amount of clearance between mated gear teeth. It can be seen when the direction of movement is reversed and the slack or lost motion is taken up before the reversal of motion is complete. It can be heard from the railway couplings when a train reverses direction. Another example is in a valve train with mechanical tappets, where a certain range of lash is necessary for the valves to work properly. Depending on the application, backlash may or may not be desirable. Some amount of backlash is unavoidable in nearly all reversing mechanical couplings, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eccentric (mechanism)
In mechanical engineering, an eccentric is a circular disk (''eccentric sheave'') solidly fixed to a rotating axle with its centre offset from that of the axle (hence the word "eccentric", out of the center). It is used most often in steam engines, and used to convert rotary motion into linear reciprocating motion to drive a sliding valve or pump ram. To do so, an eccentric usually has a groove at its circumference closely fitted a circular collar (''eccentric strap''). An attached ''eccentric rod'' is suspended in such a way that its other end can impart the required reciprocating motion. A return crank fulfills the same function except that it can only work at the end of an axle or on the outside of a wheel whereas an eccentric can also be fitted to the body of the axle between the wheels. Unlike a cam, which also converts rotary into linear motion at almost any rate of acceleration and deceleration, an eccentric or return crank can only impart an approximation of simple harmoni ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blind Hole
A hole is an opening in or through a particular medium, usually a solid body. Holes occur through natural and artificial processes, and may be useful for various purposes, or may represent a problem needing to be addressed in many fields of engineering. Depending on the material and the placement, a hole may be an indentation in a surface (such as a hole in the ground), or may pass completely through that surface (such as a hole created by a hole puncher in a piece of paper). Types Holes can occur for a number of reasons, including natural processes and intentional actions by humans or animals. Holes in the ground that are made intentionally, such as holes made while searching for food, for replanting trees, or postholes made for securing an object, are usually made through the process of digging. Unintentional holes in an object are often a sign of damage. Potholes and sinkholes can damage human settlements. Holes can occur in a wide variety of materials, and at a wide rang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Load Capacity
Static may refer to: Places *Static Nunatak, a nunatak in Antarctica United States *Static, Kentucky and Tennessee *Static Peak, a mountain in Wyoming **Static Peak Divide, a mountain pass near the peak Science and technology Physics *Static electricity, a net charge of an object **Triboelectric effect, due to frictional contact between different materials *Static spacetime, a spacetime having a global, non-vanishing, timelike Killing vector field which is irrotational *Statics, a branch of physics concerned with physical systems in equilibrium **Fluid statics, the branch of fluid mechanics that studies fluids at rest Engineering *Static pressure, in aircraft instrumentation and fluid dynamics **Static port, a proprietary sensor used on aircraft to measure static pressure *White noise or static noise, a random signal with a flat power spectral density **Noise (radio), in radio reception **Noise (video), the random black-and-white image produced by televisions attempting to displa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stress (mechanics)
In continuum mechanics, stress is a physical quantity. It is a quantity that describes the magnitude of forces that cause deformation. Stress is defined as ''force per unit area''. When an object is pulled apart by a force it will cause elongation which is also known as deformation, like the stretching of an elastic band, it is called tensile stress. But, when the forces result in the compression of an object, it is called compressive stress. It results when forces like tension or compression act on a body. The greater this force and the smaller the cross-sectional area of the body on which it acts, the greater the stress. Therefore, stress is measured in newton per square meter (N/m2) or pascal (Pa). Stress expresses the internal forces that neighbouring particles of a continuous material exert on each other, while strain is the measure of the deformation of the material. For example, when a solid vertical bar is supporting an overhead weight, each particle in the bar pushe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Turntablism
Turntablism is the art of manipulating sounds and creating new music, sound effects, mixes and other creative sounds and beats, typically by using two or more turntables and a cross fader-equipped DJ mixer. The mixer is plugged into a PA system (for live events) and/or broadcasting equipment (if the DJ is performing on radio, TV or Internet radio) so that a wider audience can hear the turntablist's music. Turntablists atypically manipulate records on a turntable by moving the record with their hand to cue the stylus to exact points on a record, and by touching or moving the platter or record to stop, slow down, speed up or, spin the record backwards, or moving the turntable platter back and forth (the popular rhythmic "scratching" effect which is a key part of hip hop music), all while using a DJ mixer's crossfader control and the mixer's gain and equalization controls to adjust the sound and level of each turntable. Turntablists typically use two or more turntables and headphon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crown
A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, particularly in Commonwealth countries, as an abstract name for the monarchy itself, as distinct from the individual who inhabits it (that is, ''The Crown''). A specific type of crown (or coronet for lower ranks of peerage) is employed in heraldry under strict rules. Indeed, some monarchies never had a physical crown, just a heraldic representation, as in the constitutional kingdom of Belgium, where no coronation ever took place; the royal installation is done by a solemn oath in parliament, wearing a military uniform: the King is not acknowledged as by divine right, but assumes the only hereditary public office in the service of the law; so he in turn will swear in all members of "his" federal government''. Variations * Costume headgear imitati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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