... structure. With the drive of the screw, the nut, the worm and the lead screw, the u ... structure. With the drive of the screw, the nut, the worm and the lead screw, the upper ... the gear of the lower rollers.3.This machine features a compact structure, and easy operation and maintenance. ... building and mining equipment, rolling functional units, shearing machine, press brake, etc. Established in 1954, we ...