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Lubricating
Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology. Lubrication mechanisms such as fluid-lubricated systems are designed so that the applied load is partially or completely carried by hydrodynamic or hydrostatic pressure, which reduces solid body interactions (and consequently friction and wear). Depending on the degree of surface separation, different lubrication regimes can be distinguished. Adequate lubrication allows smooth, continuous operation of machine elements, reduces the rate of wear, and prevents excessive stresses or seizures at bearings. When lubrication breaks down, components can rub destructively against each other, causing heat, local welding, destructive damage and failure. Lubrication mechanisms Fluid-lubricated systems As the load increases on the contacting surfaces, distinct situations can be observed wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plain Bearing
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, comprising just a bearing surface and no rolling elements. Therefore, the journal (i.e., the part of the 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 ways on the bed of a lathe. Plain bearings, in general, are the least expensive type of bearing. They are also compact and lightweight, and they have a high load-carrying capacity. Design The design of a plain bearing depends on the type of motion the bearing must provide. The three types of motions possible are: * ''Journal'' (''friction'', ''radial'' or ''rotary'') ''bearing'': This is the most common type of p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. There are several types of friction: *Dry friction is a force that opposes the relative lateral motion of two solid surfaces in contact. Dry friction is subdivided into ''static friction'' ("stiction") between non-moving surfaces, and ''kinetic friction'' between moving surfaces. With the exception of atomic or molecular friction, dry friction generally arises from the interaction of surface features, known as asperities (see Figure 1). *Fluid friction describes the friction between layers of a viscous fluid that are moving relative to each other. *Lubricated friction is a case of fluid friction where a lubricant fluid separates two solid surfaces. *Skin friction is a component of drag, the force resisting the motion of a fluid across the surface of a body. *Internal friction is the force resisting motion between the elements making up a so ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Pump (internal Combustion Engine)
The oil pump is an internal combustion engine part that circulates engine oil under pressure to the rotating bearings, the sliding pistons and the camshaft of the engine. This lubricates the bearings, allows the use of higher-capacity fluid bearings and also assists in cooling the engine. As well as its primary purpose for lubrication, pressurized oil is increasingly used as a hydraulic fluid to power small actuators. One of the first notable uses in this way was for hydraulic tappets in camshaft and valve actuation. Increasingly common recent uses may include the tensioner for a timing belt or variators for variable valve timing systems. Pumps The type of pump used varies. Gear pumps trochoid pumps and vane pumps are all commonly used. Plunger pumps have been used in the past, but these are now only used rarely, for small engines. To avoid the need for priming, the pump is always mounted low-down, either submerged or around the level of the oil in the sump. A short pick-up ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tribology
Tribology is the science and engineering of interacting surfaces in relative Motion (physics), motion. It includes the study and application of the principles of friction, lubrication and wear. Tribology is highly interdisciplinary, drawing on many academic fields, including physics, chemistry, materials science, mathematics, biology and engineering. People who work in the field of tribology are referred to as ''tribologists''. The fundamental objects of study in tribology are tribosystems, which are physical systems of contacting surfaces. In lubricated tribosystems, contact stress can create tribofilms. Subfields of tribology include biotribology, nanotribology, space tribology and tribotronics. Etymology The word ''tribology'' derives from the Ancient Greek, Greek root τριβ- of the verb , ''wiktionary:tribo-, tribo'', "I rub" in classic Greek, and the suffix ''-logy'' from , ''wiktionary:-logia, -logia'' "study of", "knowledge of". Peter Jost coined the word in 1966, in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lubrication
Lubrication is the process or technique of using a lubricant to reduce friction and wear and tear in a contact between two surfaces. The study of lubrication is a discipline in the field of tribology. Lubrication mechanisms such as fluid-lubricated systems are designed so that the applied load is partially or completely carried by hydrodynamic or hydrostatic pressure, which reduces solid body interactions (and consequently friction and wear). Depending on the degree of surface separation, different lubrication regimes can be distinguished. Adequate lubrication allows smooth, continuous operation of machine elements, reduces the rate of wear, and prevents excessive stresses or seizures at bearings. When lubrication breaks down, components can rub destructively against each other, causing heat, local welding, destructive damage and failure. Lubrication mechanisms Fluid-lubricated systems As the load increases on the contacting surfaces, distinct situations can be observed wi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tribology
Tribology is the science and engineering of interacting surfaces in relative Motion (physics), motion. It includes the study and application of the principles of friction, lubrication and wear. Tribology is highly interdisciplinary, drawing on many academic fields, including physics, chemistry, materials science, mathematics, biology and engineering. People who work in the field of tribology are referred to as ''tribologists''. The fundamental objects of study in tribology are tribosystems, which are physical systems of contacting surfaces. In lubricated tribosystems, contact stress can create tribofilms. Subfields of tribology include biotribology, nanotribology, space tribology and tribotronics. Etymology The word ''tribology'' derives from the Ancient Greek, Greek root τριβ- of the verb , ''wiktionary:tribo-, tribo'', "I rub" in classic Greek, and the suffix ''-logy'' from , ''wiktionary:-logia, -logia'' "study of", "knowledge of". Peter Jost coined the word in 1966, in t ... [...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] |
Ultra-high-molecular-weight Polyethylene
Ultra-high-molecular-weight polyethylene (UHMWPE, UHMW) is a subset of the thermoplastic polyethylene. Also known as high-modulus polyethylene, (HMPE), it has extremely long chains, with a molecular mass usually between 3.5 and 7.5 million amu. The longer chain serves to transfer load more effectively to the polymer backbone by strengthening intermolecular interactions. This results in a very tough material, with the highest impact strength of any thermoplastic presently made. UHMWPE is odorless, tasteless, and nontoxic. It embodies all the characteristics of high-density polyethylene (HDPE) with the added traits of being resistant to concentrated acids and alkalis, as well as numerous organic solvents. It is highly resistant to corrosive chemicals except oxidizing acids; has extremely low moisture absorption and a very low coefficient of friction; is self-lubricating (see boundary lubrication); and is highly resistant to abrasion, in some forms being 15 times more resistant to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lubricant
A lubricant (sometimes shortened to lube) is a substance that helps to reduce friction between surfaces in mutual contact, which ultimately reduces the heat generated when the surfaces move. It may also have the function of transmitting forces, transporting foreign particles, or heating or cooling the surfaces. The property of reducing friction is known as lubricity. In addition to industrial applications, lubricants are used for many other purposes. Other uses include cooking (oils and fats in use in frying pans, in baking to prevent food sticking), bioapplications on humans (e.g. lubricants for artificial joints), ultrasound examination, medical examination, and sexual intercourse. It is mainly used to reduce friction and to contribute to a better and efficient functioning of a mechanism. History Lubricants have been in some use for thousands of years. Calcium soaps have been identified on the axles of chariots dated to 1400 BC. Building stones were slid on oil-impregrated lumb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chain
A chain is a serial assembly of connected pieces, called links, typically made of metal, with an overall character similar to that of a rope in that it is flexible and curved in compression but linear, rigid, and load-bearing in tension. A chain may consist of two or more links. Chains can be classified by their design, which can be dictated by their use: * Those designed for lifting, such as when used with a hoist; for pulling; or for securing, such as with a bicycle lock, have links that are torus shaped, which make the chain flexible in two dimensions (the fixed third dimension being a chain's length). Small chains serving as jewellery are a mostly decorative analogue of such types. * Those designed for transferring power in machines have links designed to mesh with the teeth of the sprockets of the machine, and are flexible in only one dimension. They are known as roller chains, though there are also non-roller chains such as block chains. Two distinct chains can be co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oil Filter
An oil filter is a filter designed to remove contaminants from engine oil, transmission oil, lubricating oil, or hydraulic oil. Their chief use is in internal-combustion engines for motor vehicles (both on- and off-road ), powered aircraft, railway locomotives, ships and boats, and static engines such as generators and pumps. Other vehicle hydraulic systems, such as those in automatic transmissions and power steering, are often equipped with an oil filter. Gas turbine engines, such as those on jet aircraft, also require the use of oil filters. Oil filters are used in many different types of hydraulic machinery. The oil industry itself employs filters for oil production, oil pumping, and oil recycling. Modern engine oil filters tend to be "full-flow" (inline) or "bypass". History Early automobile engines did not have oil filters, having only a rudimentary mesh sieve placed at the oil pump intake. Consequently, along with the generally low quality of oil available, very freque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Piston
A piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod and/or connecting rod. In a pump, the function is reversed and force is transferred from the crankshaft to the piston for the purpose of compressing or ejecting the fluid in the cylinder. In some engines, the piston also acts as a valve by covering and uncovering ports in the cylinder. __TOC__ Piston engines Internal combustion engines An internal combustion engine is acted upon by the pressure of the expanding combustion gases in the combustion chamber space at the top of the cylinder. This force then acts downwards through the connecting rod and onto the crankshaft. The connecting rod is att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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