Vaihdevaihteisto

Vaihdevaihteisto, often translated as gearbox or transmission, is a mechanical system that transmits power from an engine to the driven wheels of a vehicle. Its primary function is to alter the speed and torque of the engine to match the demands of different driving conditions. Engines typically operate most efficiently within a specific range of revolutions per minute (RPM). The vaihdevaihteisto allows the engine to maintain this optimal RPM while the vehicle's speed varies.

It achieves this by employing a series of gears of different sizes. When a lower gear is selected, the vaihdevaihteisto provides more torque (rotational force), which is beneficial for starting from a standstill or climbing hills, but at a lower speed. Conversely, when a higher gear is selected, it reduces torque but allows for higher vehicle speeds at a given engine RPM, improving fuel efficiency on open roads.

There are several types of vaihdevaihteisto. Manual transmissions require the driver to select gears using a clutch pedal and a gear shifter. Automatic transmissions, on the other hand, change gears automatically based on vehicle speed and engine load, eliminating the need for driver intervention in gear selection. Continuously Variable Transmissions (CVTs) offer an infinite range of gear ratios, providing a smooth transition between speeds without distinct gear shifts. The specific design and operation of a vaihdevaihteisto are crucial for a vehicle's performance, fuel economy, and drivability.