Worm gear is used to transfer rotation between two shafts that intersect. At an angle of 90 degrees. Usually the transmission is from the worm to the wheel. The worm gear consists of a worm screw with a modular trapezoidal thread profile angle of 40 degrees, and a worm wheel.
The worm gear ratio is the ratio of the number of teeth of the wheel to the number of visits of the worm. Worm gears have gear ratios from 8 to 80. Worm gears have a relatively high efficiency.
Worms can be single-pass and multi-pass, performed at the same time with the shaft or attachment. The latter is made separately and attached to the shaft using dowels.
In addition to worm gears, in which the worm has a straight line forming a dividing cylinder (Archimedean worms), there are transmissions with involute worms (they have an involute profile of the turns), as well as globoid transmissions with concave worms.
The quality of the worm gear engagement, in addition to the quality of the use of individual elements, is largely dependent on the quality of the Assembly.
Non pendularity of the worm axis to the axis of the worm wheel. As well as incorrectly maintained center distance-difficult to eliminate defects. They occur in the manufacture of the transmission housing. If the bearings of the worm and worm. To eliminate these defects. It is necessary to press the bushings. Press new ones and again waste them.
Then the worm gears undergo additional heat treatment and grinding, which not only increases their strength, but also guarantees high accuracy of the part. All this allows us to provide high quality and reliability of products.
Globoid worms appeared relatively recently and due to increased load capacity are becoming more common, but in the manufacture and installation is much more difficult and very hot. Therefore, cylindrical worms with a straight profile in the axial section still have a predominant distribution.