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The screw pump is the oldest positive displacement pump. [1] The first records of a water screw, or screw pump, date back to Hellenistic Egypt before the 3rd century BC. [1] [3] The Egyptian screw, used to lift water from the Nile, was composed of tubes wound round a cylinder; as the entire unit rotates, water is lifted within the spiral tube to the higher elevation.
A screw turbine at a small hydro power plant in Goryn, Poland. The Archimedean screw is an ancient invention, attributed to Archimedes of Syracuse (287–212 BC.), and commonly used to raise water from a watercourse for irrigation purposes.
The first type of screw conveyor was the Archimedes' screw, used since ancient times to pump irrigation water. [1] They usually consist of a trough or tube containing either a spiral blade coiled around a shaft, driven at one end and held at the other, or a "shaftless spiral", driven at one end and free at the other. The rate of volume transfer ...
Archimedes wrote the earliest theoretical study of the screw as a machine, [13] and is considered to have introduced the screw in Ancient Greece. [9] [14] By the first century BC, the screw was used in the form of the screw press and the Archimedes' screw. [10]
Instead of the central pin and string of the string compass, this device uses a non-rotating shaft (column) with helical threads (screw; see Archimedes’ screw) to which are attached two slotted arms: one horizontal arm is affixed to (travels up) the screw threads of the vertical shaft at one end, and holds a drawing tool at the other end ...
The tightening screw's worm thread engages with the slots on the clamp band. Occasionally a worm drive is designed to run in reverse, resulting in the worm shaft turning much faster than the input. Examples of this may be seen in some hand-cranked centrifuges, blacksmithing forge blower, or the wind governor in a musical box.
Scientists were expecting the octopus to work on problem-solving solutions by understanding how the screw top lid works and opening it with its arms. But the octopus bypassed the screw top completely.
Archimedes' principle states that the upward buoyant force that is exerted on a body immersed in a fluid, whether fully or partially, is equal to the weight of the fluid that the body displaces. [1] Archimedes' principle is a law of physics fundamental to fluid mechanics .