1. Single-direction bearing inlayed cemented carbide alloy which coordinates with roller bearing featuring good abrasive resistance, safety high accuracy, and long service time. Gears are processed through heating treatment hrc600 and then through high accurate grinding. 2. Roller processed through heating treatment and then through grinding; hollow structure, light in weight, weak gyration inertia casual structure, light in weight, weak gyration inertia, casual stop, and with high feeding accuracy; featuring high hardness, good resistance and long service span 3. Disk type brake (common brake device) adopted high quality clutch disk lining whose two faces interconnected completely, featuring long service span, good stability and high accuracy. 4. Reversing device (1) the structure is the same as that of single-way device. Lt controls the lower gear with high accuracy and can maintain the lower wheel a long- tinmen stability and high accuracy (2) the problem of the overrunning of the lower wheel caused by sprayed oil when pressed is avoided (3) not apt to cause high heat (4) with cemented carbide alloy and roller bearing free of abrasion (5) that the roller bearing works in a circular motion way can avoid bearing seizure (6) li has weak frictional force and needs low torque fore. Lts rotating drive is not apt to be damaged (7) the reversal devices speed can reach to 30m/min. Increasing5o%compared with common speed of 20m/min.