DESENHO TÉCNICO CAIXA DE DIREÇÃO
In automotive engineering, the drivetrain (also frequently spelled as "drive train" or
sometimes "drive-train") is the group of components of a motor vehicle that deliver power to
the drive wheels.[1] This excludes the engine or motor that generates the power.
In contrast, the powertrain is considered to include both the engine and/or motor(s) as well
as the drivetrain.
In marine applications, the drive shaft will drive a propeller rather than a drive axle, while the
actual engine might be highly similar to an automotive engine.
The function of the drivetrain is to couple the engine that produces the power to the driving
wheels that use this mechanical power to rotate the axle. This connection involves physically
linking the two components, which may be at opposite ends of the vehicle and so requiring a
long propeller shaft or drive shaft. The operating speed of the engine and wheels are also
different and must be matched by the correct gear ratio. As the vehicle speed changes, the
ideal engine speed must remain approximately constant for efficient operation and so this
gearbox ratio must also be changed, either manually, automatically or by an automatic
continuous variation.