دیکشنری تخصصی مهندسی نفت - نسخه آنلاین

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: The compounding transmiting and variable speed driving rig whose power package uses multi-line roller chain.

the hydraulic powered chain driven unit that snubs or strips coiled tubing into or out of a well.

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

n: a chain drive powered by the draw works that drives the rotary table assembly;it runs from the drawworks sprocket to a drive-shaft sprocket. The driveshaft sprocket turns the drive-shaft assembly that drives the rotary table.

n: in a roller chain drive, an amount of stretching that causes the chain to engage improperly with the sprockets. wear pad n: a flat metal protrusion of a downhole tool that is usually hardfaced and that protects the rotating tool from wear.