How Gear Reducers Make Possible Modern Motoring

Gear reducers are a bit of a misnomer in and of themselves. There is not one single set of gear reducers, rather it describes the function that is performed by the gearbox. In this article we look at how gear reducers have made modern motoring possible. And if it weren’t for the gear reducer, cars would either be a lot slower or a lot less efficient.

Gear reducers are used to harness internal combustion engines’ narrow power bands and translate them into an ideal driving experiences on the road.

A gear train is used to transmit power from the power source, in the car usually the internal combustion engine or the electric motor, to the driven wheels. In such an application one must be mindful of the rotational speeds of the power source, the crankshaft in the engine, and the driven wheels. As the speed of the engine is much higher than the speed of the wheel, a series of gear reducers are used to decrease the speed at which energy is transmitted, instead increase the force that is to be applied.

Gear reducers are used at various places in a vehicles transmission. The rotation of the crankshaft is reduced to the input shaft in the gearbox (the transmission), within the transmission itself (variable gear reducers by shifting gears), the final gear and finally the differential. These all present opportunities for gear reduction, though at which points the manufacturer deploys gear reducers depends on engineering constraints and other considerations such as space utilization, complexity, cost and the performance of the vehicle.

Gear reducers are essentially means of magnifying the torque produced by the engine. The greater the reduction, the greater the torque outputted. Engaging first gear in a vehicle, therefore, takes the rotational energy of the engine and transmits it as torque: permitting the vehicle to move off from standstill.

Conversely, the top gear in the gearbox will be called overdrive, or a less than 1:1 ratio between the wheels and the engine. This can be applied only when the torque demands on the engine are low. It permits the relatively little torque transmitted to the wheels to keep the car in motion but allow the engine to function at a lower RPM as well.