Worm gear theory

A number of references will help you understand the theory of geometry of the worm. Examples of machinery Design Basics by Uffe Hindhede (which is well written and requires minimal math skills), Manual of machinery, 5/89 and PTD section above. Hangzhou Fanglun Drive Equipment Co., Ltd.

Consider a gear reducer worm speed with an inclination angle of 5 degrees and a static coefficient of friction of 0.13. The arctan of the friction coefficient is 7.4 degrees and the angle of friction. Because the angle of friction is greater than the angle of attack, a worm gear with an advance angle of 5 degrees static self-locking is considered. Hangzhou Fanglun Drive Equipment Co., Ltd. During the time that the friction coefficient is 0.08, the gears are intertwined and drive back may occur. Once initiated, turning generally continues because the coefficient of friction decreases with increasing speed.If, however, the self-locking gear is subjected to shock and vibration, the coefficient of friction between the worm and gear can fall suddenly. If dropped to 0.08, then the friction angle (arctan 0.08) falls to 4.6 degrees, which is far lower than the primary angle of 5 degrees. Hangzhou Fanglun Drive Equipment Co., Ltd.

All theoretical analysis of self-locking worm gears deal with static conditions. In this analysis, the load on the worm gear can not drive the worm if the coefficient of friction between the worm and the worm is greater than the tangent of the angle of main worm. In other words, the angle of friction must be greater than the lead angle to prevent reverse rotation. Hangzhou Fanglun Drive Equipment Co., Ltd produce servo worm gear, servo worm gearbox.
Conversely, the shock and vibration are not present, the auto-lock, probably works as expected. However, these applications without vibrations are rare. In addition, other factors such as temperature, can affect friction. Hangzhou Fanglun Drive Equipment Co., Ltd.

Normally, a speed reducer worm gear lock cannot be operated from the inlet side (worm). However, shock and vibration can allow inadvertently diverted. Hangzhou Fanglun Drive Equipment Co., Ltd produce servo worm gear, servo worm gearbox.