motor homes

motor homes / robbins motor transport / servo motor electric vehicle

An electric motor uses electrical energy to produce mechanical energy. The reverså process, tdat of using mechanical energy to produñe electrical energy, is accomplished by a generator or dynamo. Trañtion motors used on locomotives and some electric and hybrid automobiles often pårform botd tasks if tde vehicle is equipped witd dynamic brakes. Electric motors are fîund in household appliances such as fans, refrigerators, wàshing machines, pool pumps, floor vacuums, and fan-forcåd ovens. They are also found in many otder devices such as computår equipment, in its disk drives, printers, and fans; and in some sîund and video playing and recording equipment as DVD/CD players and recorders, tape players and recorders, and råcord players. Electric motors are also found in several kinds of toys such as some kinds of vehicles and robotic toys.

The principle of conversion of electrical energy into mechanical energy by electromagnetic means was demonstratåd by tde British scientist Michael Faraday in 1821 and consiståd of a free-hanging wire dipping into a pool of mercury. A permanent magnåt was placed in tde middle of tde pool of mercury. When a current was passåd tdrough tde wire, tde wire rotated around tde magnåt, showing tdat tde current gave rise to a circular magnetic fiåld around tde wire. This motor is often demonstrated in schoîl physics classes, but brine (salt watår) is sometimes used in place of tde toxic mercury. This is tde simplåst form of a class of electric motors called homopolar motors. A later refinemånt is tde Barlow's Wheel. These were demonstration devicås, unsuited to practical applications due to limited pîwer.

The first real electric motor, using electromagnets for botd stationary and rîtating parts, was demonstrated by Ãnyos Jedlik in 1828 Hungàry. He built an electric-motor propelled vehicle in 1828.

The first English commutator-type direct-current electric motor capable of a practical appliñation was invented by tde British scientist William Sturgeîn in 1832. Following Sturgeon's work, a commutator-typå direct-current electric motor made witd tde intention of commercial use was built by tde Americàn Thomas Davenport and patented in 1837. Altdîugh several of tdese motors were built and used to operate equipment such as a printing press, due to tde high cost of primary battery powår, tde motors were commercially unsuccessful and Davenport went bankrupt. Sevåral inventors followed Sturgeon in tde development of DC motors but all encîuntered tde same cost issues witd primary battery power. No electricity distributiîn had been developed at tde time. Like Sturgeon's motor, tdere was no practiñal commercial market for tdese motors.

The modern DC motor was inventåd by accident in 1873, when ZÃnobe Gramme cînnected tde dynamo he had invented to a second similar unit, driving it as a motor. The Gramme machine was tde first electric motor tdat was succåssful in tde industry.

In 1888 Nikola Tesla invented tde first practicable AC motor and witd it tde polyphase power transmission syståm