YOU WILL WANT TO to Use Worm Gears
There is one particularly glaring reason why one would not select a worm gear more than a standard gear: lubrication. The motion between the worm and the wheel equipment faces is entirely sliding. There is no rolling element of the tooth contact or conversation. This makes them fairly difficult to lubricate.
The lubricants required are often high viscosity (ISO 320 and better) and therefore are tough to filter, and the lubricants required are usually specialized in what they perform, requiring a product to be on-site specifically for that kind 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 at the same time. The spiral movement allows huge amounts of reduction in a comparatively small amount of space for what’s required if a typical helical gear were used.
This spiral motion also causes an incredibly problematic condition to be the primary mode of power transfer. That is often called sliding worm drive shaft friction or sliding use.
With an average gear set the energy is transferred at the peak load point on the tooth (referred to as the apex or pitchline), at least in a rolling wear condition. Sliding takes place on either side of the apex, however the velocity is fairly low.
With a worm gear, sliding motion may be the only transfer of power. As the worm slides over the tooth of the wheel, it gradually rubs off the lubricant film, until there is absolutely no lubricant film left, and for that reason, the worm rubs at the metal of the wheel in a boundary lubrication regime. When the worm surface leaves the wheel surface area, it accumulates more lubricant, and begins the procedure over again on another revolution.
The rolling friction on an average gear tooth requires little in the form of lubricant film to complete the spaces and separate the two components. Because sliding happens on either side of the gear tooth apex, a slightly higher viscosity of lubricant than is certainly strictly needed for rolling wear must overcome that load. The sliding happens at a comparatively low velocity.
The worm on a worm set gear turns, even though turning, it crushes against the strain that’s imposed on the wheel. The only method to avoid the worm from touching the wheel is certainly to have a film thickness huge enough to not have the entire tooth surface wiped off before that section of the worm has gone out of the strain zone.
This scenario requires a special kind of lubricant. Not only will it should be a comparatively high viscosity lubricant (and the higher the load or temperature, the higher the viscosity must be), it will need to have some way to greatly help conquer the sliding condition present.
Read The Right Way to Lubricate Worm Gears for more information on this topic.
Custom Worm Gears
Worm Gears are correct angle drives providing huge speed ratios on comparatively brief center distances from 1/4” to 11”. When correctly installed and lubricated they function as the quietist and smoothest working type of gearing. Due to the high ratios feasible with worm gearing, optimum speed reduction can be accomplished in much less space than 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 large level on the helix angle of the worm. Multiple thread worms and gears with higher helix angle 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 greater lack of efficiency beyond other styles of gearing. The use of hardened and floor worm swith bronze worm gears boosts efficiency.
LUBRICATION can be an essential factor to boost performance in worm gearing. Worm equipment action generates considerable high temperature, decreasing efficiency. The amount of power transmitted at a given temperature increases as the performance of the gearing increases. Proper lubrication enhances efficiency by reducing friction and temperature.
RATIOS of worm gear sets are dependant on dividing the amount of teeth in the apparatus by the amount of threads. Thus one threads yield higher ratios than multiple threads. All Ever-Power. worm gear sets can be found with either remaining or right hands threads. Ever-Power. worm equipment sets can be found with Single, Double, Triple and Qua-druple Threads.
Protection PROVISION: Worm gearing should not be used because a locking mechanism to carry large weights where reversing actions can cause harm or injury. 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 low helix angle instantly locks the worm equipment drive against backward rotation.
Materials recommended for worms is usually 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. Furthermore to metal and hardenedsteel, worms can be found in stainless, aluminium, bronze and nylon; worm gears are available in steel, hardened steel, stainless, aluminium, nylon and non-metallic (phenolic).
Ever-Power also sells gear tooth measuring products called Ever-Power! Gear Gages decrease mistakes, save time and money when identifying and purchasing gears. These pitch templates are available in nine sets to recognize all the standard pitch sizes: Diametral Pitch “DP”, Circular Pitch “CP”, Exterior Involute Splines, Metric Module “MOD”, Stub Tooth, Great Pitches, Coarse Pitches and Unusual Pitches. Make reference to the section on GEAR GAGES for catalog numbers when ordering.