Re: Co-Efficient Of Friction Between Belts And Drive Pulleys
Hardness is a factor. So is the grooving dimension. So is the shape of the lagging to maintain compliance with the belt.
Hard belt and lagging causes a reduction in the apparent coefficient of friction. This is exacerbated with moisture.
Drive pulley slipping causes a polishing of the lagging which leads to a further reduction of interface friction.
What is the root cause? I see from another posting there is some synergy. ■
Re: Co-Efficient Of Friction Between Belts And Drive Pulleys
Larry,
thank you for your reply. Yes you are correct in that there is a drirect relation between both threads.
We are in the process of factually determining the root cause, which we believe is the corelation between the two and the reduce friction between drive and also the idlers. Is these any study that determines a range of rubber hardness verse friction co-efficient, besides Euler's equation.
What we need to prove is the point that there is an upper limit on the duro for both the lagging and the conveyor belt whereby it is no longer fit for purpose.
The age of the belts (and some lagging) is in excess on 14 years. These are positioned on stock yards but also in tunnels away from UV.
I note your comnent about maintianing the grooved profile within the lagging. ■
Re: Co-Efficient Of Friction Between Belts And Drive Pulleys
Studies have been done on the relationship between lagging rubber Shore hardness and the interface friction coefficient with belt and lagging. I do not know of a similar study with the belt. I suspect they are similar. It is less obvious of the coupled hardness conditions.
I have such studies of rubber lagging. I know it would take a while to locate. Based on my past comments to locate old files, I am not voluntering to make the search.
I would not be presumptious in recommending to toss a belt because the pulley rubber lagging has hardened. My first advice would be to lag the pulley with a ceramic. I say this without knowledge of the design. ■
Re: Co-Efficient Of Friction Between Belts And Drive Pulleys
You might try the work of Hohman and Zeddes that go beyond the concept of Euhler.
You also raise an interesting comment about the belt friction with the idlers. There is a suspicion that too small a friction can lead to idler shell failure due to belt and idler roll slippage during normal running along the return strand. This is presently under study for such a failure. ■
Re: Co-Efficient Of Friction Between Belts And Drive Pulleys
Larry, thank you for your time and thoughts. No do not go into the archieves.
We will be looking at the interaction between the lagging and pulley regarding co-efficient of friction and the hardness of the materials.
I agree with the thoughts, that the rollers if not adequately loaded up, may fail premautrely due to shell wear. As the force between the two has to overcome the rim drag, and as experienced rim drag varies greatly between manufactures.
I have also seen many installations, where by the vertical alignment of the system was very poor, and this resulted in both overloaded and underloaded return idler, and the result was the underloaded rollers suffered shell failure due to the skiding.
Again thank you for your assistance ■
Co-efficient of Friction between belts and Drive pulleys
We are seeking information on what effect. the different hardness of conveyor belt rubber and different hardness of lagging has in respect to the co-efficient of friction between the two rubbers. As we are experiencing ageing of the belt (belt duor increases) which may the root cause of the the drive slippage issue. ■