There is a great deal of development effort going toward the development of "gearless" wind turbines. The reason being that the Gearbox in wind turbines remains as one of the single largest reliability problems in the industry. On wind turbines: "Current designs can't be scaled up economically. Most of the more than 25,000 wind turbines deployed across the United States have a power rating of three megawatts or less and contain complex gearbox systems. The gearboxes match the slow speed of the turbine rotor (between 15 to 20 rotations per minute) to the 2,000 rotations per minute required by their generators. Higher speeds allow for more compact and less expensive generators, but conventional gearboxes—a complex interaction of wheels and bearings—need regular maintenance and are prone to …
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