Lignum vitae is a wood, also called guayacan or guaiacum, and in parts of Europe known as Pockholz or pokhout, from trees of the genus Guaiacum. The trees are indigenous to the Caribbean and the northern coast of South America and have been an important export crop to Europe since the beginning of the 16th century. The wood was once very important for applications requiring a material with its extraordinary combination of strength, toughness, and density. It is also the national tree of the Bahamas, and the Jamaican national flower.
A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.
Fluid bearings are bearings in which the load is supported by a thin layer of rapidly moving pressurized liquid or gas between the bearing surfaces. Since there is no contact between the moving parts, there is no sliding friction, allowing fluid bearings to have lower friction, wear and vibration than many other types of bearings. Thus, it is possible for some fluid bearings to have near-zero wear if operated correctly.
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 the directions of the loads (forces) applied to the parts.
A plain bearing, or more commonly sliding contact bearing and slide bearing, is the simplest type of bearing, comprising just a bearing surface and no rolling elements. Therefore, the journal 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.
In mechanical engineering, a rolling-element bearing, also known as a rolling bearing, is a bearing which carries a load by placing rolling elements between two concentric, grooved rings called races. The relative motion of the races causes the rolling elements to roll with very little rolling resistance and with little sliding.
A constant-velocity joint is a mechanical coupling which allows the shafts to rotate freely and compensates for the angle between the two shafts, within a certain range, to maintain the same velocity.
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.
A pillow block bearing is a pedestal used to support a rotating shaft with the help of compatible bearings and various accessories. The assembly consists of a mounting block which houses a bearing. The block is mounted to a foundation, and a shaft is inserted, allowing the inner part of the bearing/shaft to rotate. The inside of the bearing is typically 0.025 millimetres (0.001 in) larger diameter than the shaft to ensure a tight fit. Set screws, locking collars, or set collars are commonly used to secure the shaft. Housing material for a pillow block is typically made of cast iron or cast steel.
A stuffing box or gland package is an assembly which is used to house a gland seal. It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements.
A linear-motion bearing or linear slide is a bearing designed to provide free motion in one direction. There are many different types of linear motion bearings.
A reduction drive is a mechanical device to shift rotational speed. A planetary reduction drive is a small scale version using ball bearings in an epicyclic arrangement instead of toothed gears.
Novotext is a trade name for cotton textile-phenolic resin, essentially cotton-reinforced Bakelite. It was often used in car engines for gear wheels used to provide a direct drive to the camshaft as it is flexible and quiet-running. One of the first luxury cars to use this material for its camshaft drive gears was the Maybach Zeppelin of 1928. The material is known under various other names such as Turbax, Resitex, Celeron and Textolit. In bar form it is also known as Cartatextiel and Ferrozell and in sheet form as Harex, Tufnol and Micarta.
Rotary feeders, also known as rotary airlocks or rotary valves, are commonly used in industrial and agricultural applications as a component in a bulk or specialty material handling system. Rotary feeders are primarily used for discharge of bulk solid material from hoppers/bins, receivers, and cyclones into a pressure or vacuum-driven pneumatic conveying system. Components of a rotary feeder include a rotor shaft, housing, head plates, and packing seals and bearings. Rotors have large vanes cast or welded on and are typically driven by small internal combustion engines or electric motors.
A thrust block, also known as a thrust box, is a specialised form of thrust bearing used in ships, to resist the thrust of the propeller shaft and transmit it to the hull.
Albert Kingsbury 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.
Spiral groove bearings are self-acting, or hydrodynamic bearings used to reduce friction and wear without the use of pressurized lubricants. They have this ability due to special patterns of grooves. Spiral groove bearings are self-acting because their own rotation builds up the pressure needed to separate the bearing surfaces. For this reason, they are also contactless bearings.
A rotary union is a union that allows for rotation of the united parts. It is thus a device that provides a seal between a stationary supply passage and a rotating part to permit the flow of a fluid into and/or out of the rotating part. Fluids typically used with rotary joints and rotating unions include various heat transfer media and fluid power media such as steam, water, thermal oil, hydraulic fluid, and coolants. A rotary union is sometimes referred to as a rotating union, rotary valve, swivel union,rotorseal, rotary couplings, rotary joint, rotating joints, hydraulic coupling, pneumatic rotary union, through bore rotary union, air rotary union, electrical rotary union, or vacuum rotary union
The rim-driven thruster, also known as rim-driven propulsor/propeller is a novel type of electric propulsion unit for ships. The concept was proposed by Kort around 1940, but only became commercially practical in the early 21st century due to advances in DC motor controller technology. As of 2017, commercial models of between 500 kW and 3 MW are available from manufacturers such as Rolls-Royce, Schottel, Brunvoll, Baliño, Voith, Van der Velden, etc.
A composite bearing is a bearing made from a combination of materials such as a resin reinforced with fibre and this may also include friction reducing lubricants and ingredients.
