将扭簧中心支架、尼龙胶圈、固定法兰、与门体重量相匹配的扭簧、锁紧法兰、绕线轮、轴承支架按顺序（分清左右侧）套在镀锌钢管上，并注意各零部件是否安装正确。用M8×41㎜的方头螺钉将扭簧中心支架固定到洞口上部中间位置的短木板上，并注意避开链盒的安装位置。用M8×40㎜的螺栓将扭簧中心支架、尼龙胶圈、固定法兰和扭簧连接，再将扭簧和锁紧法兰连接。然后将轴承支架的下端用M9.5×19㎜的大帽螺丝和螺帽与水平轨连接件连接固定，轴承支架的上端用M8×41㎜的方头螺钉固定到侧木框上。
The center bracket of torsion spring, nylon rubber ring, fixed flange, torsion spring matching the weight of door, locking flange, winding wheel and bearing bracket are sleeved on galvanized steel pipe in sequence (distinguishing left and right sides), and attention should be paid to whether the parts are installed correctly. The center bracket of the torsion spring is fixed to the short board at the middle position of the upper part of the hole with the square head screw of M8 *41, and the installation position of the chain box is avoided. The center bracket of torsion spring, nylon rubber ring, fixed flange and torsion spring are connected with M8 *40_bolts, and then the torsion spring and locking flange are connected. Then the lower end of the bearing bracket is connected and fixed with the horizontal rail connector with the big cap screw and nut of M9.5 *19. The upper end of the bearing bracket is fixed to the side timber frame with the square head screw of M8 *41.