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Lead Screw
A leadscrew (or lead screw), also known as a power screw or translation screw,Bhandari, p. 202. 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.Shigley, p. 400. 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 ( ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Split Nut
A split nut is a nut that is split lengthwise into two pieces (opposed halves) so that its 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 turning (or, vice versa, to allow the screw to pass through the nut without turning). Then, when the nut is closed, it resumes the normal movement of a nut on a screw (in which axial travel is linked to rotational travel) A split nut assembly is often used in positioning systems, for example in the leadscrew of a lathe. It is one of the machine elements that makes single-point threading practical on manual (non-CNC) lathes. The very earliest screw-cutting lathes (in the late 18th and early 19th centuries) did not have them, but within a few decades, split nuts were common on lathes. The two halves of the nut have chamfered ends (60° to axis), which helps the threads to find engagement during the closing action. Usually the screw and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluid Power
Fluid power is the use of fluids under pressure to generate, control, and transmit power. Fluid power is subdivided into hydraulics using a liquid such as mineral oil or water, and pneumatics using a gas such as air or other gases. Compressed-air and water-pressure systems were once used to transmit power from a central source to industrial users over extended geographic areas; fluid power systems today are usually within a single building or mobile machine. Fluid power systems perform work by a pressurized fluid bearing directly on a piston in a cylinder or in a fluid motor. A fluid cylinder produces a force resulting in linear motion, whereas a fluid motor produces torque resulting in rotary motion. Within a fluid power system, cylinders and motors (also called actuators) do the desired work. Control components such as valves regulate the system. Elements A fluid power system has a pump driven by a prime mover (such as an electric motor or internal combustion engine) that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ball Screw
A ball screw (or ballscrew) is a mechanical linear actuator that translates rotational motion to linear motion with little friction. A threaded shaft provides a helical raceway for ball bearings which act as a precision screw. As well as being able to apply or withstand high thrust loads, they can do so with minimum internal friction. They are made to close tolerances and are therefore suitable for use in situations in which high precision is necessary. The ball assembly acts as the nut while the threaded shaft is the screw. In contrast to conventional leadscrews, ballscrews tend to be rather bulky, due to the need to have a mechanism to recirculate the balls. Another form of linear actuator based on a rotating rod is the threadless ballscrew, a.k.a. "rolling ring drive". In this design, three (or more) rolling-ring bearings are arranged symmetrically in a housing surrounding a smooth (threadless) actuator rod or shaft. The bearings are set at an angle to the rod, and this ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detail Of Raised Nose Cargo Door Of Boeing 747-8F
Detail(s) or The Detail(s) may refer to: Film and television * ''Details'' (film), a 2003 Swedish film * ''The Details'' (film), a 2011 American film * ''The Detail'', a Canadian television series * "The Detail" (''The Wire''), a television episode Music * ''Details'' (album), by Frou Frou, 2002 * Detail (record producer), Noel Fisher (born c. 1978), American music producer and performer * The Details, a Canadian rock band Periodicals * ''DETAIL'' (professional journal), an architecture and construction journal * ''Details'' (magazine), an American men's magazine See also * Auto detailing, a car-cleaning process * Level of detail (computer graphics), a 3D computer graphics concept * Security detail, a team assigned to protect an individual or group * Detaille Island Detaille Island is a small island off the northern end of the Arrowsmith Peninsula in Graham Land, Antarctica. From 1956 to 1959 it was home to "Base W" of the British Antarctic Survey and closed after the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thread Angle
The thread angle of a screw is the included angle between the thread flanks, measured in a plane containing the thread axis.. This is a defining factor for the shape of a screw thread A screw thread, often shortened to thread, is a helical structure used to convert between rotational and linear movement or force. A screw thread is a ridge wrapped around a cylinder or cone in the form of a helix, with the former being called a .... Standard values include: References Notes Bibliography *. * {{MachinerysHandbook25e Screws Metalworking terminology Threading (manufacturing) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acme Thread
Trapezoidal thread forms are screw thread profiles with trapezoidal outlines. They are the most common forms used for leadscrews (power screws). They offer high strength and ease of manufacture. They are typically found where large loads are required, as in a vise or the leadscrew of a lathe. Standardized variations include multiple-start threads, left-hand threads, and self-centering threads (which are less likely to bind under lateral forces). The original trapezoidal thread form, and still probably the one most commonly encountered worldwide, with a 29° thread angle, is the Acme thread form ( ). The Acme thread was developed in 1894 as a profile well suited to power screws that has various advantages over the square thread,See: * Simpson, John and Proffitt, Michael, ed.s, "acme", ''Oxford English Dictionary: Additions Series'', vol. 3 (Oxford, England: Oxford University Press, 1997)p. 10.* The Acme thread was proposed by Albert Man Powell, then president of the Powell P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mechanical Efficiency
In mechanical engineering, mechanical efficiency is a dimensionless number that measures the effectiveness of a mechanism or machine in transforming the power input to the device to power output. A machine is a mechanical linkage in which force is applied at one point, and the force does work moving a load at another point. At any instant the power input to a machine is equal to the input force multiplied by the velocity of the input point, similarly the power output is equal to the force exerted on the load multiplied by the velocity of the load. The mechanical efficiency of a machine (often represented by the Greek letter eta \eta) is a dimensionless number between 0 and 1 that is the ratio between the power output of the machine and the power input :\eta = \frac Since a machine does not contain a source of energy, nor can it store energy, from conservation of energy the power output of a machine can never be greater than its input, so the efficiency can never be greater than ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microlathe
A micro lathe (also styled micro-lathe or microlathe) is a machine tool used for the complex shaping of metal and other solid materials. Micro lathes are related to (full-sized) lathes but are distinguished by their small size and differing capabilities, application, use, and locations. Sometimes referred to as desktop lathes or table-top lathes, micro lathes can be comfortably used in areas where a full-sized lathe would be impractical. Micro lathes are well suited for use in restricted spaces where heavy machining or high accuracy are not requirements. Micro lathes find a place in homes, basements, and garages. As they are a popular tool for hobbyists, they are commonly sold through hobby catalogs and hobby websites. Micro lathes are preferred over larger lathes by some professionals, commonly locksmiths, jewelers, designers, and engineers for prototyping or fabrication work. Despite a more available price point and lower rigidity than their larger counterparts, micro lathes sti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trapezoidal Thread Form
Trapezoidal thread forms are screw thread profiles with trapezoidal outlines. They are the most common forms used for leadscrews (power screws). They offer high strength and ease of manufacture. They are typically found where large loads are required, as in a vise or the leadscrew of a lathe. Standardized variations include multiple-start threads, left-hand threads, and self-centering threads (which are less likely to bind under lateral forces). The original trapezoidal thread form, and still probably the one most commonly encountered worldwide, with a 29° thread angle, is the Acme thread form ( ). The Acme thread was developed in 1894 as a profile well suited to power screws that has various advantages over the square thread,See: * Simpson, John and Proffitt, Michael, ed.s, "acme", ''Oxford English Dictionary: Additions Series'', vol. 3 (Oxford, England: Oxford University Press, 1997)p. 10.* The Acme thread was proposed by Albert Man Powell, then president of the Powell P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Western Atlas
Western Atlas was an oilfield services company formed in 1987 through the merger of Western Geophysical (owned by Litton Industries) and Dresser Atlas. The resulting company was a joint venture of Litton and Dresser Industries until it was spun off as a publicly traded company in 1994. Background In 1998, Western Atlas was acquired by Baker Hughes. Western Atlas wireline division, Western Atlas Logging Services, became Baker Atlas, one of seven divisions of Baker Hughes. The Western Geophysical division of Western Atlas was joined with Schlumberger geophysical operations, Geco-Prakla, to form WesternGeco in 2000. WesternGeco was initially owned jointly by Baker Hughes and Schlumberger.Duey, Rhonda (2001). ''WesternGeco: A done deal'', E&P, Hart Energy Publishing, LP In 2006 Schlumberger bought Baker Hughes' interest in WesternGeco. This company went from Atlas Wireline to Western Atlas then to Baker Atlas. See also * List of oilfield service companies This is a li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
