Jgh Hydraulics
Mirta Dozar
Hydraulics (from Ancient Greek ὕδωρ (hdōr) 'water', and αὐλός (auls) 'pipe')[2] is a technology and applied science using engineering, chemistry, and other sciences involving the mechanical properties and use of liquids. At a very basic level, hydraulics is the liquid counterpart of pneumatics, which concerns gases. Fluid mechanics provides the theoretical foundation for hydraulics, which focuses on applied engineering using the properties of fluids. In its fluid power applications, hydraulics is used for the generation, control, and transmission of power by the use of pressurized liquids. Hydraulic topics range through some parts of science and most of engineering modules, and cover concepts such as pipe flow, dam design, fluidics and fluid control circuitry. The principles of hydraulics are in use naturally in the human body within the vascular system and erectile tissue.[3][4]
Free surface hydraulics is the branch of hydraulics dealing with free surface flow, such as occurring in rivers, canals, lakes, estuaries and seas. Its sub-field open-channel flow studies the flow in open channels.
Early uses of water power date back to Mesopotamia and ancient Egypt, where irrigation has been used since the 6th millennium BC and water clocks had been used since the early 2nd millennium BC. Other early examples of water power include the Qanat system in ancient Persia and the Turpan water system in ancient Central Asia.
In the Persian Empire or previous entities in Persia, the Persians constructed an intricate system of water mills, canals and dams known as the Shushtar Historical Hydraulic System. The project, commenced by Achaemenid king Darius the Great and finished by a group of Roman engineers captured by Sassanian king Shapur I,[5] has been referred to by UNESCO as "a masterpiece of creative genius".[5] They were also the inventors[6] of the Qanat, an underground aqueduct, around the 9th century BC.[7] Several of Iran's large, ancient gardens were irrigated thanks to Qanats.[8]
The Qanat spread to neighboring areas, including the Armenian highlands. There, starting in the early 8th century BC, the Kingdom of Urartu undertook significant hydraulic works, such as the Menua canal.[9][7][10]
The earliest evidence of water wheels and watermills date back to the ancient Near East in the 4th century BC,[11] specifically in the Persian Empire before 350 BCE, in the regions of Iraq, Iran,[12] and Egypt.[13]
In ancient Sri Lanka, hydraulics were widely used in the ancient kingdoms of Anuradhapura and Polonnaruwa.[16] The discovery of the principle of the valve tower, or valve pit, (Bisokotuwa in Sinhalese) for regulating the escape of water is credited to ingenuity more than 2,000 years ago.[17] By the first century AD, several large-scale irrigation works had been completed.[18] Macro- and micro-hydraulics to provide for domestic horticultural and agricultural needs, surface drainage and erosion control, ornamental and recreational water courses and retaining structures and also cooling systems were in place in Sigiriya, Sri Lanka. The coral on the massive rock at the site includes cisterns for collecting water. Large ancient reservoirs of Sri Lanka are Kalawewa (King Dhatusena), Parakrama Samudra (King Parakrama Bahu), Tisa Wewa (King Dutugamunu), Minneriya (King Mahasen)
In Ancient Greece, the Greeks constructed sophisticated water and hydraulic power systems. An example is a construction by Eupalinos, under a public contract, of a watering channel for Samos, the Tunnel of Eupalinos. An early example of the usage of hydraulic wheel, probably the earliest in Europe, is the Perachora wheel (3rd century BC).[19]
In the Roman Empire, different hydraulic applications were developed, including public water supplies, innumerable aqueducts, power using watermills and hydraulic mining. They were among the first to make use of the siphon to carry water across valleys, and used hushing on a large scale to prospect for and then extract metal ores. They used lead widely in plumbing systems for domestic and public supply, such as feeding thermae.[citation needed]
Hydraulic mining was used in the gold-fields of northern Spain, which was conquered by Augustus in 25 BC. The alluvial gold-mine of Las Medulas was one of the largest of their mines. At least seven long aqueducts worked it, and the water streams were used to erode the soft deposits, and then wash the tailings for the valuable gold content.[21][22]
The earliest programmable machines were water-powered devices developed in the Muslim world. A music sequencer, a programmable musical instrument, was the earliest type of programmable machine. The first music sequencer was an automated water-powered flute player invented by the Banu Musa brothers, described in their Book of Ingenious Devices, in the 9th century.[28][29] In 1206, Al-Jazari invented water-powered programmable automata/robots. He described four automaton musicians, including drummers operated by a programmable drum machine, where they could be made to play different rhythms and different drum patterns.[30]
In 1619 Benedetto Castelli, a student of Galileo Galilei, published the book Della Misura dell'Acque Correnti or "On the Measurement of Running Waters," one of the foundations of modern hydrodynamics. He served as a chief consultant to the Pope on hydraulic projects, i.e., management of rivers in the Papal States, beginning in 1626.[31]
Assuming an incompressible fluid or a "very large" ratio of compressibility to contained fluid volume, a finite rate of pressure rise requires that any net flow into the collected fluid volume create a volumetric change.
The Federal Lands Highway Hydraulics Team provides technical expertise and support in matters related to hydrology, highway drainage, culvert & bridge hydraulics, scour, and coastal highways. This involves providing services to internal FLH and FHWA staff, and external partners. The FLH Hydraulics Team has members in each FLH Division Office who perform the full range of hydrologic and hydraulic investigations, analysis, and design needed to deliver the Federal Lands Highway Program. The FLH Hydraulics Team works to establish FLH-wide policy, procedures, and standards. The Team provides assistance in interpretation of hydraulic policies, technical publications, software, and recommended guidance in solving difficult and unusual drainage problems.
Regardless of what they say, you should consider writing-up a blog post about how you use KiCad for hydraulics applications. While hydraulics is not my interest, I would be interested in how you use KiCad for that. It would also be a good way to bring more people from your neck of the woods into KiCad.
Most expensive CNC metalworking machines are purchased without fixtures to hold the workpiece(s). With today's sophisticated machines making tool changes in fractions of a second and cutting at speeds we once thought nearly impossible, the speed and quality of part clamping is the next most important opportunity for time savings and productivity improvement. VektorFlo power clamps provide the "helping hands" to present more parts to the machine spindle with less effort, more consistency, and greater productivity at a cost only modestly more than manual fixtures. Use VektorFlo because it can increase your productivity.
The selection of any single brand of hydraulic clamp, as any other important decision, must be made from an informed, intelligent point of view. Your choice should be based on many factors influenced by your specific application. Other factors can be used for general comparison and are strong indicators of the overall quality of the brand selected. Before making any decision, we ask that you take time to accurately compare product quality, product and information availability, technical support and service both before and after the sale. When you do, you'll find VektorFlo "head and shoulders" above the rest!
When we, at Vektek, made the decision to enter the Hydraulic Clamping market we knew that another "me too" product would not succeed. Only a product of outstanding quality would be successful in this competitive field. Armed with this knowledge our team of engineers began an extensive product development process. Exhaustive research, design, development and testing yielded a unified product line all of which incorporate the following appropriate features:
If you see a product on this web site, we try to have it in stock. Barring unforeseen large orders, we keep adequate shelf stock to be ready to ship small orders quickly. We can normally ship next day or same day if necessary to help you out of a difficult situation. Some VektorFlo devices are interchangeable with competitive devices to help you out of a tight spot. Please plan adequate lead times into your production schedule when ordering large quantities.
We take pride in the information we share with you, our customer. We have attempted to create a website that is easy to read, understand and use. You will find the site organized so that you can find specifications, dimensions and product specific features without a lot of useless rhetoric, but with more information than some "parts store" catalogs. Should you need information not contained in our web site, our Application Engineering Staff would be happy to answer your questions.
Successful powered workholding does not just happen. Like any other manufacturing process, it must be carefully planned. But that does not mean that you need to be a hydraulics engineer to implement a powered workholding system. Designing a system involves the common-sense application of a few basic workholding concepts and a basic understanding of fixtures.
Using power workholding does not in any way invalidate the principles of sound fixture design. The 3-2-1 concept as it relates to the location of the work piece in three planes is just as applicable when using power workholding devices as when using manual methods. Workholding devices should be positioned in such a way as to ensure firm contact between the workpiece and locating buttons, pins, or surfaces.
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