Non-circular grinding of backup rolls to reduce rolling force variation/Tugivaltside mitteumarlihvimine valtsimisjou koikumise vahendamiseks

A common structure in hot strip mill backup roll bearings is to attach the conical sleeve of the slide bearing to the roll's shaft by a key. The key groove, cut to the conical sleeve, locally causes deformation under load. This sleeve spring is observed as rolling force variation. A new method to minimize force variations, based on 3D grinding of the backup rolls, was developed. A non-circular shape was ground on the rolls. The empirical research took place at a hot strip mill. As a result, the 3D ground non-circular geometry of the backup rolls considerably reduced the rolling force variation. Key words: non-circular grinding, rolling mill, backup roll, rolling force variation. Lehtribamaterjali kuumvaltspingi tugivaltside laagrikonstruktsioonis on uldlevinud lahenduseks liugelaagri koonilise hulsi kinnitamine valtsrulli teljele kiilliitega. Koonilisse puksi loigatud kiilusoon on aga koormuse rakendumisel lokaalse deformatsiooni allikaks, kusjuures puksi labipaindel on taheldatud muutusi valtsimisjous. Jou koikumiste vahendamiseks on valja tootatud uus meetod, mis pohineb tugivaltside 3D lihvimisel. Valtsidele antakse lihvimisel mitteumar kuju. Eksperimentaalne uuring kuumvaltspingil naitab, et tugivaltside mitteumara geomeetria puhul on valtsimisjou koikumine oluliselt vahenenud.