Hydraulic press

Hydraulic press

A hydraulic press is a hydraulic mechanism for applying a large lifting or compressive force. It is the hydraulic equivalent of a mechanical lever, and is also known as a Bramah press after the inventor, Joseph Bramah, of England. He invented and was issued a patent on this press in 1795. Hydraulic presses are the most commonly-used and efficient form of modern press.

How it works

The hydraulic press depends on Pascal's principle: the pressure throughout a closed system is constant. At one end of the system is a piston with a small cross-sectional area driven by a lever to increase the force. Small-diameter tubing leads to the other end of the system.

Pascal's law: Pressure on a confined fluid is transmitted undiminished and acts with equal force on equal areas and at 90 degrees to the container wall.

A fluid, such as oil, is displaced when either piston is pushed inward. The small piston, for a given distance of movement, displaces a smaller amount of volume than the large piston, which is proportional to the ratio of areas of the heads of the pistons. Therefore, the small piston must be moved a large distance to get the large piston to move significantly. The distance the large piston will move is the distance that the small piston is moved divided by the ratio of the areas of the heads of the pistons.

For example, if the ratio of the areas is 5, a force of 100 newtons on the small piston will produce a force of 500 newtons on the large piston, and the small piston must be pushed 50 cm to get the large piston to rise 10 cm. This is how energy, in the form of work in this case, is conserved and the Law of Conservation of Energy is satisfied. Work is force times distance, and since the force is increased on the larger piston, the distance the force is applied over must be decreased. The work of the small piston, 100 newtons multiplied by 0.5 meter (50 cm) is 50 joules (J), which is the same as the work of the large piston, 500 newtons multiplied by 0.1 meter (10 cm).

ee also

* Simple machine

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Look at other dictionaries:

  • Hydraulic press — Hydraulic Hy*drau lic, a. [F. hydraulique, L. hydraulicus, fr. Gr. ?, ?, a water organ; y dwr water + ? flute, pipe. See {Hydra}.] Of or pertaining to hydraulics, or to fluids in motion; conveying, or acting by, water; as, an hydraulic clock,… …   The Collaborative International Dictionary of English

  • Hydraulic press — Hydraulic press. См. Гидравлический пресс. (Источник: «Металлы и сплавы. Справочник.» Под редакцией Ю.П. Солнцева; НПО Профессионал , НПО Мир и семья ; Санкт Петербург, 2003 г.) …   Словарь металлургических терминов

  • hydraulic press — noun press in which a force applied by a piston to a small area is transmitted through water to another piston having a large area • Hypernyms: ↑press, ↑mechanical press * * * noun : a machine in which great force with slow motion is communicated …   Useful english dictionary

  • hydraulic press — a machine permitting a small force applied to a small piston to produce, through fluid pressure, a large force on a large piston. [1850 55] * * * Machine consisting of a cylinder fitted with a piston (see piston and cylinder) that uses liquid… …   Universalium

  • hydraulic press — Hydrostatic Hy dro*stat ic, Hydrostatical Hy dro*stat ic*al, a. [Hydro , 1 + Gr. ? causing to stand: cf. F. hydrostatique. See {Static}.] Of or relating to hydrostatics; pertaining to, or in accordance with, the principles of the equilibrium of… …   The Collaborative International Dictionary of English

  • hydraulic press — hidraulinis presas statusas T sritis automatika atitikmenys: angl. hydraulic press vok. hydraulische Presse, f rus. гидравлический пресс, m pranc. presse à l huile, f; presse hydraulique, f ryšiai: sinonimas – hidraulinis slėgtuvas …   Automatikos terminų žodynas

  • hydraulic press — hidraulinis presas statusas T sritis fizika atitikmenys: angl. hydraulic press vok. hydraulische Presse, f rus. гидравлический пресс, m pranc. presse hydraulique, f …   Fizikos terminų žodynas

  • hydraulic press — Bramah press, hydrostatic press …   New dictionary of synonyms

  • Hydraulic press — Гидравлический матричный пресс …   Краткий толковый словарь по полиграфии

  • hydraulic press — Смотри гидравлический пресс …   Энциклопедический словарь по металлургии

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