As a rule, the transmission of mechanical power is dramatically altered when passed through a train of rotating gears, but why should this happen?
Picture for a moment if you will, a pack of differently sized spur gears dropped into a lubricated housing. These gearboxes employ interlocking assemblies to alter transmitted torque and speed, which means force and speed are then controllable.
Remember, kinetic energy can't be destroyed, so if the teeth of a smaller gear interact with a larger gear, one energy variable is magnified while the other is minimized, thus conserving total energy expenditure.
Torque rises and speed drops in this example as the smaller gear covers its angular circumference in a fraction of the time taken by its larger cousin. And, not surprisingly, the opposite arrangement reverses this power altering phenomenon.
Raise the concept to today's modern engineering standards and everything changes. The basic premise is still unchanged, but the performance abilities of the housings are totally different. The train of gears uses spurs to reduce speed and increase torque. Additionally, the gears offer direction changing capabilities and introduce switching abilities.
Arranged in banks, for instance, an automated mechanism will switch one set of smaller gears for a larger set and introduce the concept of ratio manipulation to the motorized energy source. The primary power shaft gains incremental speed or torque variability, in this case, a feature that's used to this day in all sorts of vehicles.
If a powerful primary engine or motor rotates its shaft at a set rate and there are few speed-altering options within the electrical domain, gearboxes provide the ultimate mechanical solution. A uniform energy source, perhaps one provided by a powerful turbine, rotates at high speed in order to maximize efficiency, which leaves the power train turning too fast to incorporate other processes.
The gearing arrangement reduces speed and uses special ratio selectors to choose a user-specified torque value, thus maximizing output load carrying features. Again, all of this mechanical alchemy is controlled by simply altering the number of teeth on each gear, a process that equates to increasing or decreasing the diameter of the gear wheel.
The mark of a quality gearing solution is in manufacturing gear-loaded housings without incurring losses. The entire package runs quietly and does not generate heat. Input energy is transmitted through spur gears and helical assemblies, worm gears and locking pinions, crossing over to the output stage as a carefully calculated energy output, one that's open to manipulation through ratio changes in the form of seamless gear switching.