The secondary envelope worm gear pair is a commonly used transmission mechanism, and its working principle is mainly to achieve the purpose of transmission through the meshing between the worm and the worm gear.
The secondary envelope worm gear pair is composed of a worm and a worm gear, wherein the worm is composed of a worm shaft and a worm rotating body, and the worm gear is composed of a worm shaft and a worm gear rotating body. The meshing surface of the worm and worm gear is spiral-shaped, and this structure can make the transmission ratio very large. The worm is generally a single helix, and the worm hole of the worm gear is meshed with the worm.
When the worm rotates, the worm gear produces a rotational motion due to the spiral guidance of the worm. The direction of rotation of the worm is opposite to that of the worm gear, and this is because the spiral of the worm is opposite to the direction of the spiral of the worm gear. This design can realize the direction of the transmission.
Due to the small helix angle of the worm, the transmission efficiency of the worm gear pair is low, generally between 50% and 70%. In order to improve the transmission efficiency, the secondary enveloping worm gear pair also often uses worm knurling technology, that is, knurling is processed on the surface of the worm to reduce the frictional resistance when the worm and the worm gear are meshed.
Secondary envelope worm gear pairs are widely used in various mechanical equipment, such as lifting machinery, conveying machinery, construction machinery, etc. Due to its advantages of large transmission ratio, small size and simple structure, the secondary envelope worm gear pair has become an important transmission mode.