Why we change the roller from Rubber to PU on welding rotator?

Welding rotator is a device which uses the friction between the active roller and the workpiece to drive the workpiece to rotate in place. It is mainly used for the assembly and welding of cylindrical workpiece. If the roller interface is properly adjusted, it can also be used for the assembly and welding of cones and segments of unequal diameter rotary bodies. Its main characteristics are simple structure, convenient and flexible use, and can well adapt to all kinds of cylinder (cone)-shaped workpieces.

The welding rotator of our company ranges from 10 t to 800 t. For the consideration of electrical insulation, the outer ring of the roller is coated with rubber. And the actual load is only 1 / 3 ~ 1 / 2 of the designed data. However, the rubber wheel is easy to be torn in a short time, some from the adhesive surface of the rubber wheel and the roller wheel, and some from the inside of the rubber wheel, especially in the large load rotator.

It is considered that the tearing of the rubber wheel is mainly due to excessive tension and positive pressure. The wear is caused by the non-wear resistance of the material surface of the rubber wheel. The degumming is caused by the actual strength of the adhesive is greater than the peeling strength.

Solutions:

1) Changing the original rubber wheel into a polyurethane wheel with Shore hardness of 95°. The bonding surface between PU and metal is changed from the square groove to zigzag shape. The adhesive is selected by the polyurethane manufacturer according to the working conditions to increase the peel strength.

2)  Correcting the pulling line of the turning rolls on the spot and reinstall it to ensure the straightness of the center line of the roller.

3)  For the welding of pipe with a length of more than 55 m, a group of driven rotator is added so that the eccentricity is reduced, thus the stress condition of the roller is better improved.

4) Make some changes on the welding positioning angle of welding rotator according to the actual needs to ensure that the welding positioning angle is 80 °~ 110 °.

        Summary

According to our actual test, a set of 100 t welding rotator with rubber wheels can only work with 3 ~ 5 pieces of 30 t steel pipes before the transformation, but more than 400 pieces have been worked with after the transformation. No problems have appeared. The life of the welding rotator is extended, which not only reduces the labor intensity, but also ensures the safety and continuity of production.