Using and features The reducer has four kinds of center distance, 80, 120, 180, 300mm, which can be divided into different worm and worm above and below two kinds of structure types(see figure 2-7) based on worm shafts configuration,each structure has two kinds of installation types. The cooling structure of gear reducer has with wind leaf and without wind leaf. The center distance is 180, 300mm reducer with wind leaf. Gear reducer adopted closed transmission structure, worm is Archimedes solenoid Rotary gear reducer is allowed direction of positive and negative, the transmission ratio of gear reducer has 16 species according to the different kinds of center distance.