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Spherical Bearing
A spherical plain bearing is a bearing that permits angular rotation about a central point in two orthogonal directions (usually within a specified angular limit based on the bearing geometry). Typically these bearings support a rotating shaft in the bore of the inner ring that must move not only rotationally, but also at an angle. Self-aligning spherical bearings were first used by James Nasmyth around 1840 to support line shaft bearings in mills and machine shops. For long shafts it was impossible to accurately align bearings, even if the shaft was perfectly straight. Nasmyth used brass bearing shells between hemispherical brass cups to align the bearings to self-align. Construction Spherical bearings can be of a hydrostatic or mechanical construction. A spherical bearing by itself consists of an outer ring and an inner ring and a locking feature that makes the inner ring captive within the outer ring in the axial direction only. The outer surface of the inner ring and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spherical Plain Bearing
A sphere () is a geometrical object that is a three-dimensional analogue to a two-dimensional circle. A sphere is the set of points that are all at the same distance from a given point in three-dimensional space.. That given point is the centre of the sphere, and is the sphere's radius. The earliest known mentions of spheres appear in the work of the ancient Greek mathematicians. The sphere is a fundamental object in many fields of mathematics. Spheres and nearly-spherical shapes also appear in nature and industry. Bubbles such as soap bubbles take a spherical shape in equilibrium. The Earth is often approximated as a sphere in geography, and the celestial sphere is an important concept in astronomy. Manufactured items including pressure vessels and most curved mirrors and lenses are based on spheres. Spheres roll smoothly in any direction, so most balls used in sports and toys are spherical, as are ball bearings. Basic terminology As mentioned earlier is the sphere's r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bearing (mechanical)
A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis; or, it may ''prevent'' a motion by controlling the vectors of normal forces that bear on the moving parts. Most bearings facilitate the desired motion by minimizing friction. Bearings are classified broadly according to the type of operation, the motions allowed, or to the directions of the loads (forces) applied to the parts. Rotary bearings hold rotating components such as shafts or axles within mechanical systems, and transfer axial and radial loads from the source of the load to the structure supporting it. The simplest form of bearing, the ''plain bearing'', consists of a shaft rotating in a hole. Lubrication is used to reduce friction. In the ''ball bearing'' and ''roller bearing'', to reduce sliding ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bore
Bore or Bores often refer to: *Boredom * Drill Relating to holes * Boring (manufacturing), a machining process that enlarges a hole ** Bore (engine), the diameter of a cylinder in a piston engine or a steam locomotive ** Bore (wind instruments), the interior chamber of a wind instrument ** Gauge (firearms), the inner diameter of the barrel of a firearm ** Nominal bore, a pipe size standard ** Water well, known as a bore in Australia Places * Bore (woreda), a district of Ethiopia that includes the town of Bore * Bore, Emilia-Romagna, a commune in Emilia-Romagna, Italy * Boré, Mali, a village in Dangol Boré commune in the Mopti Region of Mali * Bore, Norway, a small village in Klepp municipality in Rogaland county, Norway * Bore Track, a track in the South Australian outback * Bore Valley, South Georgia, Antarctica People * Bore (surname) * Francisco Bores (1898–1972), Spanish artist Maritime shipping * Steamship Company Bore, a Finnish company that operated for a time within ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
James Nasmyth
James Hall Nasmyth (sometimes spelled Naesmyth, Nasmith, or Nesmyth) (19 August 1808 – 7 May 1890) was a Scottish engineer, philosopher, artist and inventor famous for his development of the steam hammer. He was the co-founder of Nasmyth, Gaskell and Company manufacturers of machine tools. He retired at the age of 48, and moved to Penshurst, Kent where he developed his hobbies of astronomy and photography. Early life Nasmyth was born at 47 York Place, Edinburgh where his father Alexander Nasmyth was a landscape and portrait painter. One of Alexander's hobbies was mechanics and he employed nearly all his spare time in his workshop where he encouraged his youngest son to work with him in all sorts of materials. James was sent to the Royal High School where he had as a friend, Jimmy Patterson, the son of a local iron founder. Being already interested in mechanics he spent much of his time at the foundry and there he gradually learned to work and turn in wood, brass, iron ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Line Shaft
A line shaft is a power-driven rotating shaft for power transmission that was used extensively from the Industrial Revolution until the early 20th century. Prior to the widespread use of electric motors small enough to be connected directly to each piece of machinery, line shafting was used to distribute power from a large central power source to machinery throughout a workshop or an industrial complex. The central power source could be a water wheel, turbine, windmill, animal power or a steam engine. Power was distributed from the shaft to the machinery by a system of belts, pulleys and gears known as ''millwork''. Operation A typical line shaft would be suspended from the ceiling of one area and would run the length of that area. One pulley on the shaft would receive the power from a parent line shaft elsewhere in the building. The other pulleys would supply power to pulleys on each individual machine or to subsequent line shafts. In manufacturing where there were a lar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Statics
Fluid statics or hydrostatics is the branch of fluid mechanics that studies the condition of the equilibrium of a floating body and submerged body "fluids at hydrostatic equilibrium and the pressure in a fluid, or exerted by a fluid, on an immersed body". It encompasses the study of the conditions under which fluids are at rest in stable equilibrium as opposed to fluid dynamics, the study of fluids in motion. Hydrostatics is a subcategory of fluid statics, which is the study of all fluids, both compressible or incompressible, at rest. Hydrostatics is fundamental to hydraulics, the engineering of equipment for storing, transporting and using fluids. It is also relevant to geophysics and astrophysics (for example, in understanding plate tectonics and the anomalies of the Earth's gravitational field), to meteorology, to medicine (in the context of blood pressure), and many other fields. Hydrostatics offers physical explanations for many phenomena of everyday life, such as why ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polytetrafluoroethylene
Polytetrafluoroethylene (PTFE) is a synthetic fluoropolymer of tetrafluoroethylene that has numerous applications. It is one of the best-known and widely applied PFAS. The commonly known brand name of PTFE-based composition is Teflon by Chemours, a spin-off from DuPont, which originally discovered the compound in 1938. Polytetrafluoroethylene is a fluorocarbon solid, as it is a high-molecular-weight polymer consisting wholly of carbon and fluorine. PTFE is hydrophobic: neither water nor water-containing substances wet PTFE, as fluorocarbons exhibit only small London dispersion forces due to the low electric polarizability of fluorine. PTFE has one of the lowest coefficients of friction of any solid. Polytetrafluoroethylene is used as a non-stick coating for pans and other cookware. It is non-reactive, partly because of the strength of carbon–fluorine bonds, so it is often used in containers and pipework for reactive and corrosive chemicals. Where used as a lubricant, PTFE ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control Arm
In automotive suspension, a control arm, also known as an A-arm, is a hinged suspension link between the chassis and the suspension upright or hub that carries the wheel. In simple terms, it governs a wheel's vertical travel, allowing it to move up or down when driving over bumps, into potholes, or otherwise reacting to the irregularities of a road surface. Most control arms form the lower link of a suspension. The inboard (chassis) end of a control arm is attached by a single pivot, usually a rubber bushing. It can thus control the position of the outboard end in only a single degree of freedom, maintaining the radial distance from the inboard mount. Although not deliberately free to move, the single bushing does not control the arm from moving back and forth; this motion is constrained by a separate link or radius rod. This is in contrast to the wishbone, which are triangular and have two widely spaced inboard bearings. These constrain the outboard end of the wishbone from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constant-velocity Joint
Constant-velocity joints (also known as homokinetic or CV joints) are mechanical joints which allow a drive shaft to transmit power through a variable angle, at constant rotational speed, without an appreciable increase in friction or Backlash (engineering), play. They are mainly used in front-wheel drive vehicles. Modern rear-wheel drive cars with independent rear suspension typically use CV joints at the ends of the rear axle halfshafts and increasingly use them on the drive shaft. History The universal joint, one of the earliest means of transmitting power between two angled shafts, was invented by Gerolamo Cardano in the 16th century. The fact that it failed to maintain constant velocity during rotation was recognized by Robert Hooke in the 17th century, who proposed the first constant velocity joint, consisting of two Cardan joints offset by 90 degrees, so as to cancel out the velocity variations. This is the #Double_Cardan, "double Cardan". Many different types of consta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Car Suspension
Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/ handling and ride quality, which are at odds with each other. The tuning of suspensions involves finding the right compromise. It is important for the suspension to keep the road wheel in contact with the road surface as much as possible, because all the road or ground forces acting on the vehicle do so through the contact patches of the tires. The suspension also protects the vehicle itself and any cargo or luggage from damage and wear. The design of front and rear suspension of a car may be different. History An early form of suspension on ox-drawn carts had the platform swing on iron chains attached to the wheeled frame of the carriage. This system remained the basis for most suspension systems until the turn of the 19th century, although the iron ch ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HMSO
The Office of Public Sector Information (OPSI) is the body responsible for the operation of His Majesty's Stationery Office (HMSO) and of other public information services of the United Kingdom. The OPSI is part of the National Archives of the United Kingdom and is responsible for Crown copyright. The OPSI announced on 21 June 2006 that it was merging with the National Archives. The merger took place in October 2006. The OPSI continues to discharge its roles and responsibilities from within the structure of the National Archives. Controller of HMSO and Director of OPSI The Controller of HMSO is also the Director of OPSI. HMSO continues to operate from within the expanded remit of OPSI. The Controller of HMSO also holds the offices of Kings's Printer of Acts of Parliament, King's Printer for Scotland and Government Printer for Northern Ireland. By virtue of holding these offices OPSI publishes, through HMSO, the '' London Gazette'', ''Edinburgh Gazette'', ''Belfast Gazette'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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