SCREW PAIR OF COGGING MILL Russian patent published in 2003 - IPC

FIELD: machine engineering and metallurgical industry branches, namely manufacture and exploitation of heavy rolling mills. SUBSTANCE: screw pair includes full-length screw with flat foot and safety ring in the form of funnel for collecting oil having holes open to cavity of screw; movable ring; device preventing jamming of screw in nut in upper position. Bronze part of nut is cone-like and it is joined with steel casing of nut. Casing is in the form of two (upper and lower) rings provided with membranes and mutually joined by means of shell. Bronze part of nut has two bronze sleeves: cone sleeve and cylindrical sleeve hot pressed into cone sleeve and fixed in it by pins. Cylindrical sleeve is changeable one. In order to provide lubrication of screw pair, the last has systems for supplying and discharging oil through lubricating grooves on friction surfaces of screw and nut. Lubrication system operates depending upon working mode of screw in order to provide intensive lubrication of friction surfaces of screw pair and cooling of them at rotating screw and in order to provide semidry friction in screw pair at arresting screw. Nut is non-cooled one. Invention provides significantly lowered possibility for self-unscrewing of screw and loosening of rolling rolls at guiding strip between rolls. EFFECT: enhanced strength of rolls, lowered power consumption of motors of screwdown mechanism of rolling mill, increased self-braking of screw pair at arresting screw, lowered labor consumption for making screw pair, possibility for further use of worn screw pairs for creating new screw pairs with less thread diameter. 5 dwg