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Thrust Bearing
A thrust bearing is a particular type of rotary bearing. Like other bearings they permanently rotate between parts, but they are designed to support a predominantly axial load. Thrust bearings come in several varieties. *''Thrust ball bearings'', composed of bearing balls supported in a ring, can be used in low-thrust applications where there is little axial load. *''Cylindrical roller thrust bearing''s consist of small cylindrical rollers arranged flat with their axes pointing to the axis of the bearing. They give very good carrying capacity and are cheap, but tend to wear due to the differences in radial speed and friction which is higher than with ball bearings. *'' Tapered roller thrust bearings'' consist of small tapered rollers arranged so that their axes all converge at a point on the axis of the bearing. The length of the roller and the diameter of the wide and the narrow ends and the angle of rollers need to be carefully calculated to provide the correct taper so that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antenna Rotator
An antenna rotator (or antenna rotor) is a device used to change the orientation (geometry), orientation, within the horizontal plane, of a directional antenna. Most Antenna (radio), antenna rotators have two parts, the rotator unit and the controller. The controller is normally placed near the equipment which the antenna is connected to, while the rotator is mounted on the antenna mast directly below the antenna. Rotators are commonly used in amateur radio and military communications installations. They are also used with TV and FM broadcasting, FM antennas, where stations are available from multiple directions, as the cost of a rotator is often significantly less than that of installing a second antenna to receive stations from multiple directions. Rotators are manufactured for different sizes of antennas and installations. For example, a consumer TV antenna rotator has enough torque to turn a TV/FM or small amateur radio, ham antenna. These units typically cost around US$70 . ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Slewing Bearing
A slewing bearing, slew[ing] ring, or turntable bearing is a rotational rolling-element bearing that typically supports heavy, slow-turning, or slowly-oscillating loads in combination. Slewing bearings are often used in horizontal platforms, such as conventional crane (machine), cranes, swing yarders, List of amusement rides, amusement rides, and wind-facing platforms of Horizontal axis wind turbine, horizontal-axis wind turbines. In other orientations (e.g. a horizontal axis of rotation), they are used in materials handling grapples, forklift attachments, and welding turnover Jig (tool), jigs. Compared to a standard ball bearing, slewing bearing rings are quite wide, and usually have holes drilled in them to provide fixation to a structure. Seal (mechanical), Seals can be provided between the rings to protect the rolling elements. Compared to other rolling-element bearings, slewing bearings are relatively thin. Slewing bearings' thinness means that the structure they are bolted t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rolling-element Bearing
In mechanical engineering, a rolling-element bearing, also known as a rolling bearing,ISO 15 is a bearing (mechanical), bearing which carries a load by placing rolling elements (such as balls, cylinders, or cones) between two concentric, Groove (engineering), grooved rings called Race (bearing), races. The relative motion of the races causes the rolling elements to rolling, roll with very little rolling resistance and with little sliding (motion), sliding. One of the earliest and best-known rolling-element bearings is a set of logs laid on the ground with a large stone block on top. As the stone is pulled, the logs roll along the ground with little sliding friction. As each log comes out the back, it is moved to the front where the block then rolls onto it. It is possible to imitate such a bearing by placing several pens or pencils on a table and placing an item on top of them. See "bearing (mechanical), bearings" for more on the historical development of bearings. A rolling el ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plain Bearing
file:NYC 100-driving-axle-friction-bearing.jpg, Plain bearing on a 1906 S-Motor locomotive showing the axle, bearing, oil supply and oiling pad file:Linear-table with detail numbered.png, A sliding table with four cylindrical bearings file:GWR Spoked wagon wheels.jpg, A Wheelset (rail transport), wheelset from a Great Western Railway (GWR) wagon showing a plain, or journal, bearing end A plain bearing, or more commonly sliding contact bearing and slide bearing (in railroading sometimes called a solid bearing, journal bearing, or friction bearing), is the simplest type of bearing (mechanical), bearing, comprising just a bearing surface and no rolling elements. Therefore, wikt:journal#Noun, the part of the Axle, shaft in contact with the bearing slides over the bearing surface. The simplest example of a plain bearing is a shaft rotating in a hole. A simple linear bearing can be a pair of flat surfaces designed to allow motion; e.g., a drawer and the slides it rests on or the way (mac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Needle Roller Bearing
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) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
World War I
World War I or the First World War (28 July 1914 – 11 November 1918), also known as the Great War, was a World war, global conflict between two coalitions: the Allies of World War I, Allies (or Entente) and the Central Powers. Fighting took place mainly in European theatre of World War I, Europe and the Middle Eastern theatre of World War I, Middle East, as well as in parts of African theatre of World War I, Africa and the Asian and Pacific theatre of World War I, Asia-Pacific, and in Europe was characterised by trench warfare; the widespread use of Artillery of World War I, artillery, machine guns, and Chemical weapons in World War I, chemical weapons (gas); and the introductions of Tanks in World War I, tanks and Aviation in World War I, aircraft. World War I was one of the List of wars by death toll, deadliest conflicts in history, resulting in an estimated World War I casualties, 10 million military dead and more than 20 million wounded, plus some 10 million civilian de ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust Block
Thrust is a reaction force described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that system. The force applied on a surface in a direction perpendicular or normal to the surface is also called thrust. Force, and thus thrust, is measured using the International System of Units (SI) in newtons (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 meter per second per second. In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referred to as static thrust. Examples A fixed-wing aircraft propulsion system generates forward thrust when air is pushed in the direction opposite to flight. This can be done by different means such as the spinning blades of a propeller, the propelling jet of a jet engine, or by ejecting hot gases from a roc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthony Michell
Anthony George Maldon Michell FRS (21 June 1870 – 17 February 1959) was an Australian mechanical engineer of the early 20th century. Early life Michell was born in London while his parents were on a visit to England from Australia to which they had emigrated 17 years earlier. The family returned to Maldon, Victoria, in 1872, where young Anthony attended one of the state primary schools newly established in that area. He later returned to England and attended the Perse Grammar School while his elder brother, John Henry, attended Trinity College, Cambridge. On leaving school, A.G.M. Michell matriculated and spent one year as a non-collegiate student at Cambridge. In 1889, he returned to Australia and studied civil engineering at the University of Melbourne, graduating in 1895. For the next two years he obtained practical experience in structural engineering with the firm Johns and Waygood. He then returned to University, and completed a Master of Civil Engineering degree in 189 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holtwood Dam
Holtwood Dam (also Holtwood Hydroelectric Dam, Holtwood Hydroelectric Plant, McCalls Ferry Dam) is the oldest of three major dams built across the lower Susquehanna River, and the middle location of the three. It was constructed as the McCalls Ferry Dam between 1905 and 1910 by the Pennsylvania Water & Power (PW&P) Company. The dam was renamed Holtwood in honor of two company executives. PW&P merged with Pennsylvania Power & Light (PPL) in 1955. In 2015 Talen Energy took over PPL's generation and immediately sold the Holtwood plant to Brookfield Renewable Energy Partners to comply with federal antitrust requirements. Holtwood hydroelectric plant The Holtwood Hydroelectric Plant produces 252 Megawatts of power, using 14 turbine driven generators. The dam consists of a main concrete dam, which is mostly one continuous spillway, with a power house at the eastern end. The water level is raised by wooden flash boards and inflatable dam sections. The western end of the dam has th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Albert Kingsbury
Albert Kingsbury (23 December 1863 – 28 July 1943) was an American engineer, inventor and entrepreneur. He was responsible for over fifty patents obtained between the years 1902 to 1930. Kingsbury is most famous for his hydrodynamic thrust bearing which uses a thin film of oil to support weights of up to 220 tons. This bearing extended the service life of many types of machinery during the early 20th century. It was primarily outfitted on Navy ships during World War I and World War II. Personal life Albert Kingsbury was born in Morris, Illinois and graduated from Cuyahoga Falls High School, OH in 1880. Kingsbury had five daughters. In addition to his interest in tribology and bearings, Kingsbury enjoyed the world of arts, history, and letters. He devoted much time to the study of foreign languages. Kingsbury died in Greenwich, Connecticut 1943, and is buried at the Green-Wood Cemetery, Brooklyn, New York. Formal education In 1884, Kingsbury attended the University of Akron to s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Thrust Bearing
In physics, a fluid is a liquid, gas, or other material that may continuously move and deform (''flow'') under an applied shear stress, or external force. They have zero shear modulus, or, in simpler terms, are substances which cannot resist any shear force applied to them. Although the term ''fluid'' generally includes both the liquid and gas phases, its definition varies among branches of science. Definitions of ''solid'' vary as well, and depending on field, some substances can have both fluid and solid properties. Non-Newtonian fluids like Silly Putty appear to behave similar to a solid when a sudden force is applied. Substances with a very high viscosity such as pitch appear to behave like a solid (see pitch drop experiment) as well. In particle physics, the concept is extended to include fluidic matters other than liquids or gases. A fluid in medicine or biology refers to any liquid constituent of the body (body fluid), whereas "liquid" is not used in this sense. Som ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
