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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.
Water flows freely off the end of the screw into the river. The upper end of the screw is connected to a generator through a gearbox. The Archimedes screw is theoretically a reversible hydraulic machine, and there are examples of single installations where screws can be used alternately as pumps and generators.
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 Screw Pump. One of the US's oldest surviving examples of the wind-driven Archimedes screw-pump. 1890 Newark: California United States ASME brochure: 92: 1984 Stanford Linear Accelerator Center. Unique electromechanical devices and systems in the longest accelerator in the world. 1962 Menlo Park: California United States ASME brochure ...
Roman screw used to dewater mines in Spain Another device which was used widely was the Archimedean screw , and examples of such drainage machines have also been found in many old mines. Depictions show the screws being powered by a human treading on the outer casing to turn the entire apparatus as one piece.
3rd century BC – Archimedes published On Floating Bodies describing the general principle for buoyancy and hydrostatics. Archimedes develops Archimedes' screw for water extraction. [1] 2nd century BC – The aqueduct Aqua Tepula and Aqua Marcia aqueducts are completed in Rome. [1] Zhang Heng of Han dynasty designs the first known seismoscope ...
The screw pump is commonly attributed to Archimedes on the occasion of his visit to Egypt, but this tradition may reflect only that the apparatus was unknown to the Greeks before Hellenistic times and introduced in his lifetime by unknown Greek engineers.
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.