Stand trio of rolling mid-grade mill

The stand of the working trio of mill 550 is designed for rolling ordinary and special profiles from carbonaceous, middle-alloyed and other steels. The stand is installed on the existing plate and is connected to the existing drive. The stand of the mill 550 consists of a frame assembly, a cushion assembly, upper, middle and lower rolls, an upper roll position adjustment mechanism, and a lower roll position adjustment mechanism. Bed assembly consists of two semi-stands interconnected in base by crossarms and in upper part by crossarms and cover. Support legs with holes and protrusions are made in the base of the semi-shell and mated with mounting surfaces of the plate. Clamps are installed on side surfaces of semi-shell, by means of which axial adjustment of roll position is performed. The cushion assembly consists of H-shaped cushions, upper roll cushions, cushions by means of which the upper roll is balanced, lower cushions of the lower roll and casings to protect the lower roll bearings from direct scale ingress. Texolite inserts are installed in bores of cushions and cushions, which perceive axial forces. Slots are made on side sides of cushions facing roll barrels, in which end inserts are installed in "dovetail." Upper roll position adjustment mechanism includes cylindrical reduction gears arranged in bed cover cavities, two-stage worm reduction gears, balancing devices, pressure screws and their nuts installed in cover bores. Each of the two pressure screws has an individual drive. Gear wheel of cylindrical reduction gear is installed on drive end of pressure screw and engaged with parasitic gear coupled with drive gear. Proposed device comprises two tie rods connected by checks with hanger. On upper ends of rods there installed are nuts resting on crossarms, which in turn, through spherical washer rest on plunger hydraulic cylinders, which are bolted to the bed cover. The hydraulic cylinders acting on the rod press the cushion of the upper roll to the end of the pressing screw through the spherical heel, thereby providing self-installation of the cushion by the bent rolling force of the roll axis. Each of the cushions of the lower roll has an individual mechanism for adjusting the position of the lower roll, which consists of a cylindrical reduction gear located on the cover and located in the cavities of the semi-shell and the frame assembly; pressure screw and its nut installed in the borehole of the semi-stand; two-stage worm reduction gear connected to drive coupling of cylindrical reduction gear by transmission shaft installed in brackets on semi-installations. On the bed cover there is a hydraulic system, which is necessary for creation of working pressure in plunger hydraulic cylinders and hydraulic units of spacer. Working pressure is created by means of manual hydraulic pump. The roll consists of several elements: a barrel, necks and end parts. Barrel has diameter D = 630 mm, barrel length L = 1550 mm. The roll journals with diameter d = 310 mm and length 1 = 300 mm are located on both sides of the barrel and rest on bearings.