Trendy gears

摘要

Soon after the first automobiles appeared, their originators realised that they ought to provide something better and more sophisticated than a simple belt or chains to transmit the power developed by the internal combustion engine to the road wheels. Though some of the solutions they came up with were crude and not very efficient, often fairly noisy and difficult to engage when on the move, they form the basis of most current power transmission systems. In 1889, Daimler introduced the first sliding pinion transmission. In the Panhard-Levassor automobile of 1891 the engine had moved to the front and the drive was to the rear wheels, thereby pioneering a layout that has persisted to this day, though the chain drive has long been superseded by a propeller shaft to the driven rear axle.