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A pinwheel calculator is a class of mechanical calculator described as early as 1685, and popular in the 19th and 20th century, calculating via wheels whose number of teeth were adjustable. These wheels, also called pinwheels, could be set by using a side lever which could expose anywhere from 0 to 9 teeth, and therefore when coupled to a ...
A wheel power divided by the initial jet power, is the turbine efficiency, η = 4u(V i − u)/V i 2. It is zero for u = 0 and for u = V i. As the equations indicate, when a real Pelton wheel is working close to maximum efficiency, the fluid flows off the wheel with very little residual velocity. [11]
The stepped reckoner was based on a gear mechanism that Leibniz invented and that is now called the Leibniz wheel. It is unclear how many different variants of the calculator were made. Some sources, such as the drawing to the right, show a 12-digit version. [5] This section describes the surviving 16-digit prototype in Hanover. Leibniz wheel
In the position shown, the counting wheel meshes with three of the nine teeth of the Leibniz wheel. A Leibniz wheel or stepped drum is a cylinder with a set of teeth of incremental lengths which, when coupled to a counting wheel, can be used in the calculating engine of a class of mechanical calculators .
A water wheel in Erlangen, Germany The reversible water wheel powering a mine hoist in De re metallica (Georgius Agricola, 1566) The sound of the Otley waterwheel, at Manchester Museum of Science and Industry. A water wheel is a machine for converting the kinetic energy of flowing or falling water into useful forms of power, often in a watermill.
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.
The wheel was 12 feet (3.7 m) ... Hydraulic horsepower can represent the power available within ... This formula may also be used to calculate the power of a jet ...
Early hydraulic dynamometer, with dead-weight torque measurement. An absorbing dynamometer acts as a load that is driven by the prime mover that is under test (e.g. Pelton wheel). The dynamometer must be able to operate at any speed and load to any level of torque that the test requires.