Worm Gears are right angle drives providing huge speed ratios on comparatively brief center distances from 1/4” to 11”. When properly mounted and lubricated they Nylon Gear Rack function as the quietist and smoothest operating type of gearing. Because of the high ratios feasible with worm gearing, maximum speed reduction could be accomplished in much less space than a great many other types of gearing.
EFFICIENCY of worm equipment drives depends to a large degree on the helix position of the worm. Multiple thread worms and gears with higher helix position prove 25% 
to 50% better than single thread worms. The mesh or engagement of worms with worm gears produces a sliding action leading to considerable friction and better loss of efficiency beyond other types of gearing. The usage of hardened and surface worm swith bronze worm gears improves efficiency.
LUBRICATION is an essential factor to improve efficiency in worm gearing. Worm gear action generates considerable warmth, decreasing efficiency. The amount of power transmitted at a given temperature raises as the performance of the gearing increases. Proper lubrication enhances efficiency by reducing friction and warmth.
RATIOS of worm gear sets are determined by dividing the number of teeth in the apparatus by the number of threads. Thus one threads yield higher ratios than multiple threads.
Basic safety PROVISION: Worm gearing should not be used as a locking mechanism to carry weighty weights where reversing action can cause harm or damage. In applications where potential harm is non-existent and self-locking is desired against backward rotation then use of an individual thread worm with a minimal helix angle automatically locks the worm equipment drive against backward rotation.
Materials recommended for worms is definitely hardened steel and bronze for worm gears. However, depending on the application unhardened metal worms operate adequately and more economically with cast iron worm gears at 50% horsepower ratings. In addition to steel and hardenedsteel, worms are available in stainless, aluminium, bronze and nylon; worm gears can be found in steel, hardened metal, stainless, aluminium, nylon and nonmetallic (phenolic).
Gear racks are used to convert rotating motion into linear motion. A gear rack has straight tooth cut into one surface area of a sq . or round section of rod and operates with a pinion, which is definitely a small cylindrical gear meshing with the apparatus rack. Generally, gear rack and pinion are collectively known as “rack and pinion”. There are various ways to use gears.
There are applications where the gear rack is stationary, while the pinion traverses and others where in fact the pinion rotates on a fixed axis as the gear rack moves. The former is used broadly in conveying systems as the latter can be utilized in extrusion systems and lifting/lowering applications.