The feature of the twice enveloping worm
Because the difference of forming principle, the enveloping wormshaft set compares with normal column worm shaft set. There are many differences in the features of joggle. The following features of surface worm shaft in the joggle are:
1.Many joggling teeth numbers at the same time:
The teeth of surface worm shaft along with the circle of the worm gear to encircle the teeth of worm gear. In theory, all the teeth of the worm shaft can attend to the joggle, and joggle many teeth at the same time, so every tooth's bearing load is small, the bearing of the whole worm shaft fit will enhance.
2. The teeth surface of the worm gear shows the crewel contact
In the second envelop process, just because the twice contact principle, the tooth surface of the worm gear can show appear the phenomena of crewel contact, the crewel contact has increased the length of contact line, minished the load of the length of the unit contact line.
3.The angle between the positions of opposite move and the contact line
This angle is called lubricative angle. The bigger the angle the better.
Advantage:
1.Enveloping worm set's power is 2 to 3 times of cylindrical worm gear pair with the same one center distance , under the consituation of transmission the same power,circular reducer gearbox's outline size only is 1/2 to 1/3 of common cyclindrical worm reducer
2.Because enveloping worm set and gear form dynamic pressure oil film's consituation is well,so in the process of work, to be liquid lubrication or critical liquid lubrication. There be not directly friction ,between worm gear and worm wheel ,so friction is small, transmission efficiency is high
3.The main form of invalidity for worm is abrasion, pitting corrosion and tooth breaking. These matter all be got conquered successfully, under the same condition, circular worm and gear's useful life is 5 to 10 times of common cylindrical worm gear pair.