دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

n: one type of misalignment in a chain-and-sprocket drive. The shafts are not parallel to each other (they form an angle) in either the horizontal or the vertical plane. This pulls the link plates on one side tighter than those on the other side;thus, one side of the chain and sprockets wears faster than the other. Link plates on only one side of the chain break because of fatigue.

n: in a chain-and-sprocket drive, the distance between the centres of the two sprockets or the shafts they fit on.

n: see chain drive. chain-and-sprocket drive n: a type of drive that consists of a loop of chain that goes around two shafts with sprockets fitted on the shafts. The driving shaft provides power and the driven shaft receives power. When the sprocket on the driving shaft turns, the chain moves and turns the driven sprocket. chainand- sprocket transmission n: a selective transmission made up primarily of chain-andsprocket drives. There are three two-strand chain-and-sprocket drives and a pair of gears for reversing, located between the input shaft coming from the compound, and the output shaft on a mechanically driven drawworks. Each of these chain-and- sprocket drives has a different sprocket ratio to provide three speeds to the high-drum drive and three to the low-drum drive. Com- pare gear transmission.

n: a mechanical drive using a driving chain and chain gears to transmit power. Power transmissions use a roller chain, in which each link is made of side bars, transverse pins, and rollers on the pins. A double roller chain is made of two connected rows of links, a triple roller chain of three, and so forth. chain guard n: in a chain-and-sprocket drive, a case that protects workers from the moving drive. It also protects die drive from dirt and is part of the cooling and lubrication systems. Some enclose only one drive and some enclose several drives. May be made of sheet metal or plate metal. Heavier guards also support the shafts on bearings. Both types have access panels for inspection and maintenance.

n: I. a mechanism used to transmit power from the engines to the pump, the drawworks, and other machinery on a drilling rig. It is composed of clutches, chains and sprockets, belts and pulleys, and a number of shafts, both driven and driving. 2. a substance formed by the chemical union of two or more elements in definite proportions;the smallest particle of a chemical compound is a molecule. v: to connect two or more power-producing de- vices, such as engines, to run driven equipment, such as the drawworks.

n: a method of lubricating a chain-and-sprocket drive in which a reservoir drips oil onto the chain at 4 to 20 drops per minute, depending on the speed of the drive. A drip lubricator for a multistrand drive has a pipe to distrioote the oil to all strands.

n: in a chain-and-sprocket drive, the shaft that receives the power. Compare driving shaft.

n: in a chain-and-sprocket drive, the shaft that provides the power. Compare driven shaft.

n: one of the limitations on chain-and-sprocket life. This limitation on the strength of the metal the chains and sprockets are made of may cause the metal to wear even though it is lubricated because of a heavy load or a high speed.

n: a pulley or sprocket used with belt or chain drives on machinery to maintain desired tension on the belt or chain.