New or expanded bars or wire rod production line is mostly used in H/V arrangement of short-stress rolling mill, it is compared with the traditional mill, this compact rolling line reduces the weight of equipment and plant construction costs.
The characteristics of the short stress rolling mill:
- The rigidity of the mill is good, and the dimensional accuracy of the rolled parts is high;
- The bearing seat is a floating mechanism, and the bearing is even;
- Four-row cylindrical bearings are adopted, with large bearing angle, high load carrying capacity and long life;
- It is equipped with thrust bearing to bear the axial force and can be adjusted axially with precision;
- The bearing seat is balanced by elastic damping damper, which eliminates the gap and reduces the piping on the machine;
- Horizontal and vertical stands are the same, which can reduce spare parts;
- The adjustment of seam of rolls is symmetrical, there is fixed rolling line, the operation is convenient.
- Adoption of oil and gas lubrication can greatly improve the life of roll bearings;
- Vertical mill adopts upper transmission, avoiding cooling water and iron oxide into the transmission system;
- It is convenient to replace the rolls and adjust the local hole pattern;
- The whole replacement of the stand can reduce the time of changing rolls.
- Roll dismantling is carried out between the rolls, which is easy to operate;
- The H/V arrangement of the rolling line achieve non-twist rolling.
The requirements of operation when disassembling the short stress rolling mill:
- Remove iron oxide and oil on the surface of rolling mill.
- Adjust the roll gap of the mill to the required position, dismantle the parts in order, and place them neatly.
- Use induction heater to take out the inner ring of the bearing, the inner ring of the bearing can not be taken out if it is intact.
- Do inspection, cleaning and replacement work carefully, and clean the oil hole pipeline.
- Roller, roll neck and parts should be carefully checked before installation.
- The lubrication of the main bearings adopts 46# anti-wear hydraulic oil, which must be injected with oil before each assembly is completed and grease must be added every time in the assembly of the mill’s.
- Hot assembly parts should be carried out in accordance with the requirements of the drawings, the size must meet the requirements of the drawings.
- Rolling bearing assembly, should be cleaned, and then coated with lubricant. When assembling, the force should be even, it is forbidden to strike the bearing body with iron chain, if it is too tight, it can be used to play gently with wood or copper rod or put the inner ring into the induction heater to reheat. The place where the bearings are stored must be kept clean and dry, and the bearings stored for more than one year should be re-oiled.
- The centre line of the length of the roll body falls on the centre line of the frame, and the centre lines of the upper and lower rolls must be on the same vertical plane.