YOU WILL WANT TO to Use Worm Gears
There is one especially glaring reason one would not choose a worm gear more than a typical gear: lubrication. The movement between your worm and the wheel equipment faces is entirely sliding. There is no rolling component to the tooth contact or conversation. This makes them fairly difficult to lubricate.
The lubricants required are usually high viscosity (ISO 320 and greater) and therefore are difficult to filter, and the lubricants required are typically specialized in what they perform, requiring a product 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 at the same time. The spiral movement allows large sums of reduction in a comparatively little bit of space for what is required if a typical helical equipment were used.
This spiral motion also causes a remarkably problematic condition to be the principal mode of power transfer. This is often called sliding friction or sliding wear.
With an average gear set the power is transferred at the peak load stage on the tooth (referred to as the apex or pitchline), at least in a rolling wear condition. Sliding occurs on either part of the apex, but 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 remaining, and as a result, the worm rubs at the metallic of the wheel in a boundary worm drive shaft Lubrication regime. When the worm surface leaves the wheel surface area, it picks up 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 fill in the spaces and separate both components. Because sliding takes place on either part of the gear tooth apex, a somewhat higher viscosity of lubricant than can be strictly necessary for rolling wear is required to overcome that load. The sliding takes place at a comparatively low velocity.
The worm on a worm set gear turns, even though turning, it crushes against the load that’s imposed on the wheel. The only way to prevent the worm from touching the wheel can be to possess a film thickness huge enough to not have the whole tooth surface wiped off before that portion of the worm has gone out of the strain zone.
This scenario takes a special sort of lubricant. Not only will it should be a relatively high viscosity lubricant (and the higher the load or temperature, the bigger the viscosity should be), it will need to have some way to help overcome 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 large rate ratios on comparatively brief center distances from 1/4” to 11”. When properly installed and lubricated they function as the quietist and smoothest running type of gearing. Due to the high ratios possible with worm gearing, maximum speed reduction can be accomplished in less space than a great many other types of gearing. Worm and worm gears are powered by nonintersecting shafts at 90° angles.
EFFICIENCY of worm gear drives depends to a huge degree on the helix position of the worm. Multiple thread worms and gears with higher helix angle prove 25% to 50% more efficient than one thread worms. The mesh or engagement of worms with worm gears generates a sliding action leading to considerable friction and higher loss of efficiency beyond other styles of gearing. The usage of hardened and ground worm swith bronze worm gears improves efficiency.
LUBRICATION can be an essential factor to improve effectiveness in worm gearing. Worm equipment action generates considerable heat, decreasing efficiency. The quantity of power transmitted at confirmed temperature increases as the effectiveness of the gearing boosts. Proper lubrication enhances efficiency by reducing friction and temperature.
RATIOS of worm gear sets are dependant on dividing the amount of teeth in the gear by the amount of threads. Thus single threads yield higher ratios than multiple threads. All Ever-Power. worm gear pieces are available with either left or right hands threads. Ever-Power. worm gear sets can be found with Single, Double, Triple and Qua-druple Threads.
Security PROVISION: Worm gearing shouldn’t be used since a locking mechanism to hold weighty weights where reversing action could cause harm or damage. In applications where potential damage is non-existent and self-locking is desired against backward rotation then use of an individual thread worm with a minimal helix angle immediately locks the worm equipment drive against backward rotation.
MATERIAL 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 are available in stainless, light weight aluminum, bronze and nylon; worm gears can be found in steel, hardened metal, stainless, aluminum, nylon and non-metallic (phenolic).
Ever-Power also sells gear tooth measuring devices called Ever-Power! Gear Gages decrease mistakes, save money and time when identifying and buying gears. These pitch templates can be found in nine sets to identify all the standard pitch sizes: Diametral Pitch “DP”, Circular Pitch “CP”, Exterior Involute Splines, Metric Module “MOD”, Stub Tooth, Fine Pitches, Coarse Pitches and Unusual Pitches. Make reference to the section on GEAR GAGES for catalog numbers when ordering.