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Capstan Equation
The capstan equation or belt friction equation, also known as Euler–Eytelwein formula (after Leonhard Euler and Johann Albert Eytelwein), relates the hold-force to the load-force if a flexible line is wound around a cylinder (a bollard, a winch or a Capstan (nautical), capstan). It also applies for fractions of one turn as occur with rope drives or band brakes. Because of the interaction of frictional forces and tension, the tension on a line wrapped around a capstan may be different on either side of the capstan. A small ''holding'' force exerted on one side can carry a much larger ''loading'' force on the other side; this is the principle by which a capstan-type device operates. A holding capstan is a ratchet device that can turn only in one direction; once a load is pulled into place in that direction, it can be held with a much smaller force. A powered capstan, also called a winch, rotates so that the applied tension is multiplied by the friction between rope and caps ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capstan Equation Diagram
Capstan may refer to: *Capstan (band), an American post-hardcore band *Capstan (cigarette), a brand of British cigarette *Capstan (nautical), a rotating machine used to control or apply force to another element *Capstan (tape recorder), rotating spindles used to move recording tape through the mechanism of a tape recorder *Capstan equation, formula to describe hold-force in relation to load-force for flexible lines around a cylinder *Horse capstan, a device similar to a windlass used in mining; also called a whim *Slingsby Capstan, a British two-seat glider of the 1960s *Capstan (software), audio restoration program by Celemony which eliminates wow and flutter * Capstan Station, a station on the Canada Line of Metro Vancouver's SkyTrain rapid transit system. See also * *Rack and pinion {{disambiguation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coefficient Of Friction
Friction is the force resisting the relative motion of solid surfaces, fluid layers, and material elements sliding against each other. Types of friction include dry, fluid, lubricated, skin, and internal -- an incomplete list. The study of the processes involved is called tribology, and has a history of more than 2000 years. Friction can have dramatic consequences, as illustrated by the use of friction created by rubbing pieces of wood together to start a fire. Another important consequence of many types of friction can be wear, which may lead to performance degradation or damage to components. It is known that frictional energy losses account for about 20% of the total energy expenditure of the world. As briefly discussed later, there are many different contributors to the retarding force in friction, ranging from asperity deformation to the generation of charges and changes in local structure. When two bodies in contact move relative to each other, due to these various ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthotropic Material
In material science and solid mechanics, orthotropic materials have material properties at a particular point which differ along three orthogonal axes, where each axis has twofold rotational symmetry. These directional differences in strength can be quantified with Hankinson's equation. They are a subset of anisotropic materials, because their properties change when measured from different directions. A familiar example of an orthotropic material is wood. In wood, one can define three mutually perpendicular directions at each point in which the properties are different. It is most stiff (and strong) along the grain (axial direction), because most cellulose fibrils are aligned that way. It is usually least stiff in the radial direction (between the growth rings), and is intermediate in the circumferential direction. This anisotropy was provided by evolution, as it best enables the tree to remain upright. Because the preferred coordinate system is cylindrical-polar, this type of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serpentine Belt
A serpentine belt (or drive belt) is a single, continuous belt used to drive multiple peripheral devices in an automotive engine, such as an alternator, power steering pump, water pump, air conditioning compressor, air pump, etc. The belt may also be guided by an idler pulley and/or a belt tensioner (which may be spring-loaded, hydraulic, or manual). To allow the belt to pass over more than three pulleys with a large enough wrap angle to avoid slipping, idler pulleys which press against the back of the belt are included, forcing the belt into a serpentine shape. To accommodate this bidirectional flexing while remaining strong enough to transfer the total force required by multiple loads, a serpentine belt is almost always of multi-groove (multi-vee, poly-v, or multi-rib) construction. Variations On some engine designs, the "back" (smooth side) of the belt may drive some accessories. This is typically limited to components requiring less torque or where a large angle of wra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
V-belt
A belt is a loop of flexible material used to link two or more rotating shafts mechanically, most often parallel. Belts may be used as a source of motion, to transmit power efficiently or to track relative movement. Belts are looped over pulleys and may have a twist between the pulleys, and the shafts need not be parallel. In a two pulley system, the belt can either drive the pulleys normally in one direction (the same if on parallel shafts), or the belt may be crossed, so that the direction of the driven shaft is reversed (the opposite direction to the driver if on parallel shafts). The belt drive can also be used to change the speed of rotation, either up or down, by using different sized pulleys. As a source of motion, a conveyor belt is one application where the belt is adapted to carry a load continuously between two points. History The mechanical belt drive, using a pulley machine, was first mentioned in the text of the ''Dictionary of Local Expressions'' by the Han Dyn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anchor
An anchor is a device, normally made of metal, used to secure a vessel to the bed of a body of water to prevent the craft from drifting due to wind or current. The word derives from Latin ', which itself comes from the Greek (). Anchors can either be temporary or permanent. Permanent anchors are used in the creation of a mooring, and are rarely moved; a specialist service is normally needed to move or maintain them. Vessels carry one or more temporary anchors, which may be of different designs and weights. A sea anchor is a drag device, not in contact with the seabed, used to minimize drift of a vessel relative to the water. A drogue is a drag device used to slow or help steer a vessel running before a storm in a following or overtaking sea, or when crossing a bar in a breaking sea. Anchoring Anchors achieve holding power either by "hooking" into the seabed, or weight, or a combination of the two. The weight of the anchor chain can be more than that of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tail
The tail is the elongated section at the rear end of a bilaterian animal's body; in general, the term refers to a distinct, flexible appendage extending backwards from the midline of the torso. In vertebrate animals that evolution, evolved to lose their tails (e.g. frogs and hominid primates), the coccyx is the homologous vestigial of the tail. While tails are primarily considered a feature of vertebrates, some invertebrates such as scorpions and springtails, as well as snails and slugs, have tail-like appendages that are also referred to as tails. Tail-shaped objects are sometimes referred to as "caudate" (e.g. lobes of liver#Caudate lobe, caudate lobe, caudate nucleus), and the body part associated with or proximal to the tail are given the adjective "caudal (anatomical term), caudal" (which is considered a more precise anatomical terminology). Function Animal tails are used in a variety of ways. They provide a source of thrust for aquatic locomotion for fish, cetaceans and cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Riding Turn
A turn is one round of rope on a pin or cleat, or one round of a coil. Turns can be made around various objects, through rings, or around the standing part of the rope itself or another rope. A turn also denotes a component of a knot. When the legs of a loop are brought together and crossed the rope has taken a turn. One distinguishes between single turn, round turn, and two round turns depending on the number of revolutions around an object. The benefit of round turns is best understood from the capstan equation. Riding turn A riding turn is a section of rope that passes on top of another section of rope, often parallel or at only a slight angle to the section below. Examples of riding turns can be seen in both the constrictor knot and the strangle knot. The second course of wrappings in some seizing knots can be referred to as riding turns. The formation of an unintentional riding turn on a sailing winch can cause it to jam. Single hitch A single hitch is a type of k ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sheet (sailing)
In sailing, a sheet is a line (rope, cable or chain) used to control the movable corner(s) (clews) of a sail. Terminology In nautical usage the term "sheet" is applied to a line or chain attached to the lower corners of a sail for the purpose of extension or change of direction. The connection in derivation with the root "shoot" is more clearly seen in "sheet-anchor", one that is kept in reserve, to be "shot" in case of emergency. Fore-and-aft rigs Fore-and-aft rigs comprise the vast majority of sailing vessels in use today, including effectively all dinghies and yachts. The sheet on a fore-and-aft sail controls the angle of the sail to the wind, and should be adjusted to keep the sail just filled. Most smaller boats use the Bermuda rig, which has two or three sets of sheets: * The mainsheet is attached to the boom, and is used to control the mainsail. In a rig with no boom on the mainsail, the mainsheet would attach directly to the mainsail clew. A mainsheet is a line con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
