Dear sir

welded pulley shaft is not desirable due to following reasons

1.0 shaft material is generally different EN8 /En9 compared to hub material . proper weld joint is difficult

2.0 Due to differential in thermal expension of shaft and pulley hub weld may crack

3.0 Radial weld length available is not sufficient to transmit the required torque

4.0 After welding stresses may deform pulley

I have not seen welded shafts on conveyor pulleys

A R SINGH ■

Probably does not quite fit your concept.

THere is a forged style of pulley design developed in Germany. This style was used on El Abra in Chile with up to 750 mm shafts.

Maybe a bit bigger than your reference.

This style looks like it is a ring forge upset. Each shaft has one end that is pushed into a lower end disk form making a shaft, hub and lower end disk from the shaft. This is then welded to an upper end disk form and to each end of the pulley rim. The design forms a stub shaft configuration.

We analyzed this by FEM and found the end disk circumferential weldment might be suspect if not machined inside and out. Of course this was not possible.

Many failed. ■

Sounds like they installed a live shaft design into a pulley application, too much wrap. ■

I have come across drums welded to shafts before, but only on small machines. It may not be 'best practice' they have performed without problem.

But I would hesitate to recommend this practice on a machine of significant size! ■