Worm gear drives offer many benefits. They take up little space, offer quiet operation and have been used in many different applications. Worm gear drives provide extreme benefits where size is a problem Traditional spur gears would take up considerably more room than what can be accomplished with a simple worm gearbox. They also take advantage of all the major forms of gearing to suit almost any application.
Worm gear drives offer great operation for many different uses. You'll find them in use in use in the mining industry, in ship's rudders and all types of presses. Worm drives offer a great way to amplify a limited amount of torque, though heat can cause them to become less efficient. Worm gears are also used in a limited amount of automotive differentials, though it has fallen out of favor with many manufacturers. Hummer is one of the manufacturers that still utilizes worm gears in their differential, specifically their military vehicles, though some civilian applications have worm gears, as well.
Worm gears were replaced in open differential due to problems with reduction ratios, though many all wheel drive vehicles continue to use worm gear drives in their applications. Large trucks used for hauling very heavy loads often utilize worm gear drives in their differentials, though they require very large differential housings to accommodate the amount of differential fluid needed to dissipate the heat created by the worm gear drive itself.
A worm gear drive consists of two main parts: the worm gear itself, which looks much like a spur gear and the worm, which is a gear shaped like a screw. The benefits that a worm gear drive offers are due to the fact that each revolution of the worm turns the worm gear a whole tooth; this allows them to greatly amplify torque in their relative settings.
Possibly the single best example of a worm gear is the adjustable screw clamp, called a jubilee clamp. These are found almost everywhere and most people are familiar with their appearance. Other forms of the worm gear drive exist, but this is the single most recognizable form that they take. The best applications for a worm gear drive are those in manufacturing industries where greater torque, in a smaller package is required. Since the worm gear drive is able to be set up at right angles to the input shaft, the length of the equipment is significantly reduced. Many industries find that the non-reversible motion is a great benefit, as well. Since the worm can only drive the gear, it means that they can only be used as speed reducers, rather than speed enhancers. The gear cannot drive the worm in a worm gear drive.
Due to these factors, they are an ideal way of decreasing speed, yet increasing power in smaller equipment. While there are many different applications for worm gear drives around the world today, small electric motors are possibly the area that they benefit the most, though musical instruments have been the longest running beneficiary of these devices.