Have you ever wondered how four-wheel drive works?

Earlier this week I covered how helical gears are found in the latest video game equipment. Today, I found a post on Pitchcare Magazine's website about how the new Kubota tractor is gaining traction from its bevel gear-driven 4WD system,

The operator can enjoy many hours of use without fatigue, as Kubota have, as always, put a lot of emphasis on driver comfort. The full hydrostatic power steering, matched with Kubota's bevel gear 4WD system means light, responsive, tighter turning for maximum productivity.

Really, bevel gears are ideal for applications like this. In a four-wheel drive system, all four wheels need to be driven simultaneously (obviously). Therefore, the drivetrain needs to turn both axles. The way a bevel gear works is by connecting shafts at 90 degree angles (generally, although they can connect shafts at different angles). Therefore, since the driveshaft is perpendicular to the wheel axles, all four wheels can be turned simultaneously. The same principle applies to four-wheel drive automobiles.


I hope this post helped illustrate how something we take for granted--four-wheel drive--is actually the result of a fairly elegant engineering element.