Worm Gears are right angle drives providing large speed ratios on comparatively short center distances from 1/4” to 11”. When properly mounted and lubricated they function as the quietist and smoothest running type of gearing. Because of the high ratios possible with worm gearing, maximum speed reduction can be accomplished in less space than many other types of gearing. Worm and worm gears operate on non-intersecting shafts at 90° angles.
EFFICIENCY of worm gear drives depends to a large extent on the helix angle of the worm. Multiple thread worms and gears with higher helix angle prove 25% to 50% more efficient than single thread worms. The mesh or engagement of worms with worm gears produces a sliding action causing considerable friction and greater loss of efficiency beyond other types of gearing. The use of hardened and ground worm swith bronze worm gears increases efficiency.
LUBRICATION is an essential factor to improve efficiency in worm gearing. Worm gear action generates considerable heat, decreasing efficiency. The amount of power transmitted at a given temperature increases as the efficiency of the gearing increases. Proper lubrication enhances efficiency by reducing friction and heat.
RATIOS of worm gear sets are determined by dividing the number of teeth in the gear by the number of threads. Thus single threads yield higher ratios than multiple threads. All RUSH GEARS inc. worm gear sets are available with either left or right hand threads. RUSH GEARS inc. worm gear sets are offered with Single, Double, Triple and Qua-druple Threads.
SAFETY PROVISION: Worm gearing should not be used as a locking mechanism to hold heavy weights where reversing action can cause harm or injury. In applications where potential harm is non-existent and self-locking is desired against backward rotation then use of a single thread worm with a low helix angle automatically locks the worm gear drive against backward rotation.
MATERIAL recommended for worms is hardened steel and bronze for worm gears. However, depending on the application unhardened steel 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, aluminum, bronze and nylon; worm gears are available in steel, hardened steel, stainless, aluminum, nylon and non-metallic (phenolic).
RUSH GEARS also sells gear tooth measuring devices called GEAR GAGES! Gear Gages reduce mistakes, save time and money when identifying and ordering gears. These pitch templates are available in nine sets to identify all the standard pitch sizes: Diametral Pitch “DP”, Circular Pitch “CP”, External Involute Splines, Metric Module “MOD”, Stub Tooth, Fine Pitches, Coarse Pitches and Unusual Pitches. Refer to the section on GEAR GAGES for catalog numbers when ordering.