ROLLING STAND OF MILL FOR COLD ROLLING OF TUBES Russian patent published in 1996 - IPC

FIELD: rolled tube production. SUBSTANCE: stand has a movable housing, in which two supporting grooved strips are arranged. Two pairs of rolls with supporting trunnions and necking portions for drive pinions, engaging with racks, placed in the movable housing of the stand, and with connecting gear wheels, engaging one with another, are mounted on the above mentioned grooved strips. Upper rolls have two drive changeable pinions, engaging with stationary racks, secured to a front and to a rear surface of a frame of the mill. Using rolls, having supporting trunnions, for which ratio of tooth number of the drive pinion and tooth number of the drive changeable pinion being less, than 1, allows significantly increase stroke values of the rolls along a tube to be deformed. A distance between the pairs of the rolls, being variable in statics and dynamics, namely: upon forward stroke of the rolls the distance between the pairs of the rolls increases, upon reverse stroke decreases up to a predetermined value, had been set by groovings of the roll pairs. Two pairs of such rolls, mounted successively, provides high efficiency of the stand, enhanced rigidity of its structure and high accuracy of dimensions of tubes, had been rolled. EFFECT: enhanced structure of four-roll stand due to good surveillance of a deformation zone, possibility of rapid changing of rolls, absence of bearing assemblies and their chocks, lowered metal consumption, manufacturability of the stand. 2 dwg