Water motor
The water motor is a motor that is driven by flowing water. The main types of water motors are water wheels , water turbines, and water column machines . In this fundamental, general sense, the term water motor is synonymous with water power machine . Specifically, in the 19th and early 20th centuries, water motors in particular were small water column machines that generated a rotating movement and are hardly used today.
Water wheels
The water wheel is the oldest form of a water motor, it was built in the 4th / 3rd centuries. Century BC Invented by the Greeks. A waterwheel is a wheel with blades that is rotated by flowing water. If the water falls onto the wheel from above, one speaks of an overshot waterwheel; if the wheel is suspended in a flowing body of water, it is an undershot one. Working waterwheels can almost only be found in developing countries; in industrialized countries they are no longer of any economic importance.
Water turbines
From the 19th century onwards, water wheels were increasingly being replaced by water turbines , as they are more efficient. Either only the kinetic energy of the water is transferred to the turbine, as in the Pelton turbine and the flow-through turbine , or the potential energy, as in the Francis turbine and the Kaplan turbine .
Water column machines
Possibly the largest design of a water motor is the direct acting water column machine . It was developed in 1748 by G. Winterschmidt in Clausthal for the Upper Harz mining industry and used there until the beginning of the 20th century. In contrast to a water wheel, which also required correspondingly large wheel diameters for large heads, the water column machine managed with a compact design thanks to pressure pipes even with large heads. In addition, it was able to achieve a somewhat more favorable degree of efficiency.
The water column machine works similarly to a steam engine, except that instead of the steam pressure, the pressure of the cold water from the pressure pipe was used. Because of the considerable masses that were in motion in the form of water with constant changes of direction, the water column machines were allowed to run very slowly.
Similar to the function of a hydraulic ram , a different medium was usually conveyed with the acting water. The different-sized pistons of the water column machine run on a single axis, the control is remotely like a steam engine . Water column machines came u. a. as brine hoisting machine and used in Freiberg and Upper Harz mining. There were also uses for driving machines or driving skills ; the largest had an output of 97 kW.
Freiberg water column machine (1900)
Reichenbach's water column machine in the Klaushäusl Museum
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Schmid's water motor
The Swiss mechanical engineer Albert Schmid from Zurich developed a small water motor in the 1870s that worked like a steam engine. A piston in a cylinder was alternately charged with pressurized water so that it moved back and forth in the cylinder, a crankshaft converted this movement into a rotary movement. A flywheel ensured that the machine ran evenly. The control of the flow was achieved by designing the crank drive without a crosshead , the piston rod acting directly on the crank and the cylinder oscillating. This pivoting movement of the cylinder opened the inlet and outlet channels alternately. In order to absorb the resulting pressure peaks of the water in the phase when both inlet ducts were temporarily closed, an air chamber was attached to the engine . A simple device made it possible to precisely adjust the sealing gap between the stationary and moving part by raising or lowering the axis of rotation of the piston, so that the contact surfaces did not touch, but neither did too much leakage water escape.
The Schmid engine was presented at the World Exhibition in Vienna in 1873 and was then used in pressurized water networks such as that of the Usine des Forces Motrices in Geneva , but also for mobile circular saws for chopping firewood in Zurich and other applications. Many Schmid's water motors were no longer needed with the advent of electrical energy supply and were scrapped during the First World War , especially because of the many brass parts that provided raw material for the manufacture of ammunition . Few examples have survived, such as the motor that drives the Rothenberg water supply pump .
Water motors in washing machines
The water motor has also been used successfully in washing machines , e.g. B. from 1914 by the manufacturer Miele . These washing machines, which were in use until the 1960s, consisted of a wooden tub with a turnstile built into the lid. This turnstile was set in steady right-left movements by two pistons connected to the water supply. The washing effect came about through the constant movement of the laundry in the wash tub filled with lye and / or water.
The high water consumption usually played less of a role, as service water was often plentiful and correspondingly cheap. In addition, in the economical country house holdings, the "drive water" was often used for other purposes and was used on the washing day anyway.
A major advantage of the water motor was that the machine equipped with it worked without a power connection. At that time, especially in rural areas, there was not yet a power connection in every house, and even if there was one, the power was often insufficient to run an electric motor.
A prerequisite for the correct function of the water motor was a corresponding pressure in the water pipe. In times of increased water consumption (before or after work) the water pressure was often insufficient. In the more severe winters, when the water pipes often froze, the water motor was also unusable. For these reasons, these washing machines always had a device to move them with muscle power.
With the invention of the Constructa fully automatic washing machine and the increasing spread of sufficiently powerful power connections, washing machines with water motors disappeared from the market.
literature
- Alfred Musil: The engines for trade and industry. 3rd edition, Vieweg, Braunschweig 1897.
Web links
- Function of a water column machine (Java applet)
Individual evidence
- ^ Torsten Schröpfer: Treasure trove, interesting facts about the West Harz mining and metallurgy. Series of publications by the Oberharzer Geschichts- und Museumsverein e. V., Clausthal-Zellerfeld, 2000.
- ↑ a b c Nekrolog A. Schmid . In: Schweizerische Bauzeitung . tape 65 , no. 4 , 1915, pp. 42-43 ( E-Periodicals ).
- ↑ a b Old Rothenberg water supply. In: www.morr-siedelsbrunn.de. Retrieved September 5, 2015 .
- ↑ André Ducluzaux: Transportation l'énergie hydraulique à distance, avant l'électricité (1830-1890) . In: La Houille Blanche . No. 4-5 , 2002, doi : 10.1051 / lhb / 2002054 .
- ^ Photo of Schmid Water engine. (No longer available online.) In: www.panoramio.com. Formerly in the original ; Retrieved September 5, 2015 . ( Page no longer available , search in web archives )