我被三个黑人玩的不能下

Worm gear and worm gear mechanisms are commonly used to transmit motion and power between two staggered shafts. The worm gear and worm gear are equivalent to gears and racks in their middle plane, and the worm gear is similar in shape to a screw. The gear reduction ratio of the worm gear is generally 20:1, sometimes even up to 300:1 or greater.

Compared to copper worm gears, copper clad iron worm gears have better resistance and can also save material costs. The raw material ratio needs to be determined according to different needs.