The housingless mill stand is divided into an operation side and a transmission side, and the upper roll bearing seat and the lower roll bearing seat on each side are connected by two tie rods, and the two ends of the tie rod are provided with threads, and the thread is mechanically balanced with the roller bearing seat. The device cooperates to eliminate the gap between the thread of the tie rod and the nut that it engages.
The four tie rods are respectively fixed on four brackets, and the upper side of the bracket on the operation side and the upper part of the bracket on the transmission side are connected by a tie beam, and the lower part is connected by a guide beam. The top of the tie rod is connected with the roll gap adjusting mechanism. The thread specifications of the upper and lower ends of each tie rod are the same, but the rotation direction is opposite. This ensures that the upper and lower two roll chocks are symmetric with respect to the rolling line during the roll gap adjustment. Change without changing the rolling elevation.
Roller bearings are mounted in the upper and lower roll chocks, each roll being supported by two roll bearings. In order to avoid the influence of the bending of the roll during rolling on the stress state of the tie rod and the bearing, a spherical pad is provided at the tie rod nut.
The frame of the short-stress line non-brand rolling mill is composed of two parts: the tie rod and the roll chock. The rolling force transmission route of this structure, that is, the stress return line is only the roll chock and the tie rod, so the stress return line is better. short. Since the rack only functions as a fixed tie rod and does not withstand the rolling force, the mill is called a short-stress housingless mill stand.
1. Roll diameter: 100-500mm; roll surface length 90-600mm;
2. Roll material: roll steel, Cr12MoV;
3. Feeding thickness or wire diameter: ≤ 20mm; finished product thickness: 0.1 ~ 1mm;
4. Rolling speed: 0 ~ 20 ~ 50 ~ 100m / min;
5. The total motor power: 4 ~ 500KW;
6. The thickness accuracy of the strip: longitudinal ≤ ± 0.005 ~ ± 3% belt thickness; transverse ≤ ± 0.003mm ~ ± 1% belt thickness; lateral bending (for narrow bands) ≤ 3mm / M;
7. The winding motor power is 0.2~300KW, and the cable spacing is 0.5~20mm when narrowing the belt.
The Advantages of Housingless Mill Stand
Compared with the traditional rolling mill, the rolling force of the traditional rolling mill is tolerated by the rolling mill arch, while the rolling force of the housingless mill stand is mainly supported by the four tie rods of the rolling mill and the upper and lower roll chocks. In the case of the same roll diameter of the rolling mill, the stress line of the housingless mill stand is shorter, so the rigidity is higher.
The rolling force of the rolling mill body of the traditional rolling mill is transmitted to the pressing screw through the bearing seat. Since the pressing screw is located at the upper middle part of the bearing housing, the load generated on the bearing housing is concentrated, and the number of rolling elements bearing the bearing of the rolling bearing is less, so the bearing life is short. The rolling force of the housingless mill stand is directly transmitted to the tie rod through the bearing seat, and the distance between the tie rod and the bearing seat is small, and the width of the housingless mill stand bearing seat is wider than the conventional one, which makes the pressure distribution housingless mill roll bearings is more uniform and close to the ideal state than conventional mills.
The number of rolling elements of the housingless mill roller bearing capacity is large, and the rated dynamic load carrying capacity of the bearing is much higher than that of the conventional rolling mill. The deformation of the bearing after loading is reduced, and the bearing has a long service life. The experiment proves that the same bearing with the same load, the service life of the roller bearing installed on the housingless mill stand is 4.8 times of the service life of the roller bearing installed on the traditional rolling mill.