Structural characteristics and self-locking function of worm gear reducer

In many large-scale equipment, the planetary gear reducer used will use many functions. Among them, the plane double enveloping worm gear reducer is the worm gear reducer, because the worm gear and worm appear in pairs in the application of the reducer. If there is a worm in the reducer, there will be a worm gear, so the worm gear reducer is only a colloquial name for the worm gear reducer.
Structural features of worm gear reducer:
It can obtain a large transmission ratio and is more compact than the staggered shaft helical gear mechanism. The meshing tooth surfaces of the two wheels are in line contact, and its bearing capacity is much higher than that of the staggered shaft helical gear mechanism. The worm transmission is equivalent to screw transmission, which is multi tooth meshing transmission, so the transmission is stable and the noise is very small.
Self locking. When the lead angle of the worm is less than the equivalent friction angle between the meshing teeth, the mechanism has self-locking and can realize reverse self-locking, that is, the worm wheel can only be driven by the worm, but not by the worm wheel. Such as the self-locking worm mechanism used in its heavy machinery, its reverse self-locking can play a protective role.
The structural characteristics and self-locking function of worm gear reducer have low transmission efficiency and serious wear. During worm gear meshing transmission, the relative sliding speed between meshing teeth is large, so the friction loss is large and the efficiency is low. On the other hand, the relative sliding speed causes serious wear and heating of the tooth surface. In order to dissipate heat and reduce wear, expensive materials with good antifriction and wear resistance and good lubrication devices are often used, so the cost is high and the axial force of the worm is large.
Application of self-locking function of worm gear reducer:
In the transmission mode of the reducer, the worm gear transmission has the characteristics that other gear transmissions do not have, that is, the worm can easily rotate the worm gear, but the worm gear cannot rotate the worm. This is because the structure and transmission of worm gear and worm are realized through friction.
The self-locking function of worm gear transmission is very useful in mechanical applications, such as winch, conveying equipment and so on. However, also because of the friction transmission mode of worm gear, the transmission efficiency of worm gear is much lower than that of gear transmission.
Not all worm gear reducers have good self-locking function. The self-locking function of worm gear can be realized only when it reaches a certain speed ratio. This is related to the lead angle, that is, the self-locking function of worm gear and worm with small speed ratio is not so ideal.