High precision worm gear
Worm gear mechanisms are often used to transmit the motion and power between two interleaved shafts. The worm wheel and the worm are equivalent to the gear and the rack in the middle plane, and the worm and the screw are similar in shape.
Features of worm gear mechanism
1. A large transmission ratio can be obtained, which is more compact than the cross-axis helical gear mechanism. 2. The meshing tooth surfaces of the two wheels are in line contact, and its carrying capacity is much higher than that of the cross-axis helical gear mechanism. 3. The worm drive is equivalent to a spiral drive and is a multi-tooth meshing drive, so the transmission is stable and the noise is small. 4. Has self-locking. When the lead angle of the worm is smaller than the equivalent friction angle between the meshing gear teeth, the mechanism is self-locking and can realize reverse self-locking, that is, only the worm can drive the worm wheel, but the worm wheel cannot drive the worm. For example, the self-locking worm mechanism used in hoisting machinery, its reverse self-locking property can play a safety protection role. 5. The transmission efficiency is low and the wear is serious. When the worm gear is engaged in transmission, the relative sliding speed between the meshing gear teeth is large, so the friction loss is large and the efficiency is low. On the other hand, the relative sliding speed means that the tooth surface wears seriously and heats up. In order to dissipate heat and reduce wear, more expensive materials with better anti-friction and anti-wear properties and good lubricating devices are often used, so the cost is higher. . 6. The axial force of the worm is large