YOU WILL WANT TO to Use Worm Gears
There is one particularly glaring reason why one would not choose a worm gear over a standard gear: lubrication. The motion between the worm and the wheel equipment faces is entirely sliding. There is absolutely no rolling element of the tooth get in touch with or conversation. This makes them fairly difficult to lubricate.
The lubricants required are usually very high viscosity (ISO 320 and greater) and thus are hard to filter, and the lubricants required are usually specialized in what they perform, requiring something to be on-site specifically for that type of equipment.
Worm Gear Lubrication
The primary problem with a worm gear is how it transfers power. It really is a boon and a curse simultaneously. The spiral motion allows huge amounts of reduction in a comparatively small amount of space for what’s required if a typical helical equipment were used.
This spiral motion also causes an incredibly problematic condition to be the primary mode of power transfer. This is commonly known as sliding friction or sliding wear.
With an average gear set the energy is transferred at the peak load stage on the tooth (known as the apex or pitchline), at least in a rolling wear condition. Sliding takes place on either part of the apex, however the velocity is relatively low.
With a worm gear, sliding motion is the only transfer of power. As the worm slides over the tooth of the wheel, it slowly rubs off the lubricant film, until there is absolutely no lubricant film remaining, and as a result, the worm rubs at the metal of the wheel in a boundary lubrication regime. When the worm surface area leaves the wheel surface, it picks up more lubricant, and begins the process over again on the next revolution.
The rolling friction on a typical gear tooth requires little in the form of lubricant film to complete the spaces and separate the two components. Because sliding happens on either aspect of the gear tooth apex, a somewhat worm drive shaft higher viscosity of lubricant than is strictly necessary for rolling wear must overcome that load. The sliding happens at a relatively low velocity.
The worm on a worm set gear turns, and while turning, it crushes against the strain that is imposed on the wheel. The only way to avoid the worm from touching the wheel is to possess a film thickness huge enough never to have the whole tooth surface area wiped off before that part of the worm has gone out of the strain zone.
This scenario takes a special kind of lubricant. Not just will it will have to be a comparatively high viscosity lubricant (and the higher the strain or temperature, the bigger the viscosity should be), it will need to have some way to help conquer the sliding condition present.
Read The Right Way to Lubricate Worm Gears to find out more on this topic.
Custom Worm Gears
Worm Gears are right angle drives providing large speed ratios on comparatively short center distances from 1/4” to 11”. When correctly installed and lubricated they function as quietist and smoothest running type of gearing. Because of the high ratios possible with worm gearing, maximum speed reduction could be accomplished in less space than a great many other types of gearing. Worm and worm gears are powered by non-intersecting shafts at 90° angles.
EFFICIENCY of worm gear drives depends to a huge extent on the helix angle 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 generates a sliding action causing considerable friction and better loss of efficiency beyond other styles of gearing. The usage of hardened and floor worm swith bronze worm gears increases efficiency.
LUBRICATION is an essential factor to improve efficiency in worm gearing. Worm equipment action generates considerable heat, decreasing efficiency. The amount of power transmitted at a given temperature boosts as the effectiveness of the gearing increases. Proper lubrication enhances effectiveness by reducing friction and high temperature.
RATIOS of worm equipment sets are dependant on dividing the amount of teeth in the gear by the amount of threads. Thus one threads yield higher ratios than multiple threads. All Ever-Power. worm gear models can be found with either left or right hand threads. Ever-Power. worm equipment sets can be found with Single, Double, Triple and Qua-druple Threads.
Basic safety PROVISION: Worm gearing shouldn’t be used as a locking mechanism to carry weighty weights where reversing actions could cause harm or damage. In applications where potential damage 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 equipment drive against backward rotation.
Materials recommended for worms can be hardened steel and bronze for worm gears. Nevertheless, depending on the application unhardened steel worms operate adequately and more economically with cast iron worm gears at 50% horsepower ratings. In addition to metal and hardenedsteel, worms can be found in stainless, aluminium, bronze and nylon; worm gears can be found in steel, hardened metal, stainless, aluminium, nylon and nonmetallic (phenolic).
Ever-Power also sells equipment tooth measuring products called Ever-Power! Gear Gages decrease mistakes, save time and money when identifying and ordering gears. These pitch templates can be found in nine sets to recognize all the standard pitch sizes: Diametral Pitch “DP”, Circular Pitch “CP”, Exterior Involute Splines, Metric Module “MOD”, Stub Tooth, Fine Pitches, Coarse Pitches and Uncommon Pitches. Refer to the section on GEAR GAGES for catalog quantities when ordering.
YOU WILL WANT TO to Use Worm Gears