For worm gear used with circular gear for rotary reduction, see worm drive.
Three types of screw thread used in leadscrews: 3 & 4: buttress thread 5: round thread 6: square threadDVD drive with leadscrew and stepper motorFloppy disc drive with leadscrew and stepper motor
A leadscrew (or lead screw), also known as a power screw[1] or translation screw,[2] is a screw used as a linkage in a machine, to translate turning motion into linear motion. Because of the large area of sliding contact between their male and female members, screw threads have larger frictional energy losses compared to other linkages. They are not typically used to carry high power, but more for intermittent use in low power actuator and positioner mechanisms. Leadscrews are commonly used in linear actuators, machine slides (such as in machine tools), vises, presses, and jacks.[3] Leadscrews are a common component in electric linear actuators.
Leadscrews are manufactured in the same way as other thread forms: they may be rolled, cut, or ground.
A lead screw is sometimes used with a split nut (also called half nut) which allows the nut to be disengaged from the threads and moved axially, independently of the screw's rotation, when needed (such as in single-point threading on a manual lathe). A split nut can also be used to compensate for wear by compressing the parts of the nut.
A hydrostatic leadscrew overcomes many of the disadvantages of a normal leadscrew, having high positional accuracy, very low friction, and very low wear, but requires continuous supply of high-pressure fluid and high-precision manufacture, leading to significantly greater cost than most other linear motion linkages.[4]
^Ball Screws & Lead screws, retrieved 2008-12-16.
^Bhandari, p. 202.
^Shigley, p. 400.
^US 5499942, Pflager, William W., "Hydrostatic nut and lead screw assembly, and method of forming said nut", published 1996-03-19, assigned to Western Atlas Inc.
A leadscrew (or lead screw), also known as a power screw or translation screw, is a screw used as a linkage in a machine, to translate turning motion...
jackscrew, or screw jack, is a type of jack that is operated by turning a leadscrew. It is commonly used to lift moderate and heavy weights, such as vehicles;...
leadscrew to the exact position where it is needed. When a cutting tool such as a drill bit or reamer is used, the feed is done with this leadscrew....
turns the leadscrew makes. This ratio allows screwthreads to be cut on the workpiece without the aid of a die. Some lathes have only one leadscrew that serves...
which removes material from the workpiece. There may or may not be a leadscrew, which moves the cross-slide along the bed. Woodturning and metal spinning...
natural for small machines making large displacements. By means of a leadscrew, rotary motion can be adapted to function as a linear actuator (a linear...
Conversion is commonly made via a few simple types of mechanism: Screw: leadscrew, screw jack, ball screw and roller screw actuators all operate on the...
one square face and the other slanted. They are most commonly used for leadscrews where the load is principally applied in one direction. The asymmetric...
nut while the threaded shaft is the screw. In contrast to conventional leadscrews, ball screws tend to be rather bulky, due to the need to have a mechanism...
Eventually the device was superseded by a mandrel-driven device called a leadscrew, which uses a train of gears that can be altered as required for the turning...
female thread may be opened and closed over the male thread of a bolt or leadscrew. This allows the nut, when open, to move along the screw without the screw...
call a screw machine of an early and prescient sort. It made use of a leadscrew to guide the cutter to produce the desired pitch, and the slot was cut...
elements incorporate concepts of one or more simple machines. For example, a leadscrew incorporates a screw thread, which is an inclined plane wrapped around...
intuitive action as: The leadscrew of the cross slide of a lathe to cause the cross slide to move away from the operator when the leadscrew is turned clockwise...
the natural frequency of a rotating object, such as a shaft, propeller, leadscrew, or gear. As the speed of rotation approaches the object's natural frequency...
arranged leadscrew that supported an inertia wheel or more commonly, a piece made up of two radial arms with weights at the ends. The leadscrew (male) rotates...
a common screw thread profile, used in high load applications such as leadscrews and jackscrews. It gets its name from the square cross-section of the...
linear actuators use a knuckle thread to reduce the wear of the steel leadscrew against a plastic sliding nut. Firefighting respirator standard EN 148-1...
threads, multi start threads, worms as used in worm wheel reduction boxes, leadscrew with single or multistart threads. b) by the use of threading boxes fitted...
pressure and rate. Common in production saws. Screw feed saws employ a leadscrew to move the saw. Pivot saws hinge in an arc as they advance through the...
of the scissor action can be hydraulic, pneumatic or mechanical (via a leadscrew or rack and pinion system). Depending on the power system employed on...
leadscrews or toothed belt drives. It is common, owing to the differences in movement speed, to use toothed belts for the X,Y drives and a leadscrew for...
also be powered by electricity which usually consists of a motor and a leadscrew. Another common type is a mechanical linear actuator such as a rack and...
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