LTU Pinch Rollers

Posted in: , on 18. Mar. 2005 - 01:18

I am wondering if anyone has had any difficulties with the Lagging on the pinch rollers on Belt removal stations.

What it is,is 2 small 300mm diameter rollers that hyrdraulically clamp the belt and are then driven to pull slack belt out off the LTU for belt removals,clipping etc.

Because of the high torque the lagging is being sheared off. I am told this is a common problem,and am curious as to if anyone has had any experience with this also.

The lagging of the pulley has been monitored and is being done well,Cold vulcanisied. I am considering Autoclaving and wondered if anyone has tried this

Regards

Shane ■

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Re: Ltu Pinch Rollers

Posted on 18. Mar. 2005 - 01:50

Hi Shane

Autoclave method can’t be beaten and would be the way to go.

Also keep the rubber thickness down as thin as possible. ■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________

Re: Ltu Pinch Rollers

Posted on 18. Mar. 2005 - 01:51

Thanks Bruce

Why keep the rubber thickness down?

Shane ■

Re: Ltu Pinch Rollers

Posted on 18. Mar. 2005 - 02:09

Hi Shane

It reduces the elongation of the rubber under tension and therefore the stress on the rubber / bond.

Would I be correct in assuming there is no wear factor associated with this type of roller ? ■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________
Matt Croker
(not verified)

Re: Ltu Pinch Rollers

Posted on 18. Mar. 2005 - 03:31

Shane

I have come across this too. It tends to occur when high winding tensions are applied to the rolls.

I'll assume that you are you are using a Loop Take Up (LTU) with a torque contorllable winch. Are you using a clamp with the rolls? There should be a seperate belt clamp set up so that the rolls are between the LTU an the clamp. This ususaly means that you can drop your LTU tension to much less than the running tension. Two clamps locations, inbye and outbye of the LTU, may be required if the system has significant lift.

Don't go too thin with your rubber - you'll end up squashing your clips. ■

Re: Ltu Pinch Rollers

Posted on 18. Mar. 2005 - 03:51

Originally posted by Matt Croker

Shane

I have come across this too. It tends to occur when high winding tensions are applied to the rolls.

I'll assume that you are you are using a Loop Take Up (LTU) with a torque contorllable winch. Are you using a clamp with the rolls? There should be a seperate belt clamp set up so that the rolls are between the LTU an the clamp. This ususaly means that you can drop your LTU tension to much less than the running tension. Two clamps locations, inbye and outbye of the LTU, may be required if the system has significant lift.

Don't go too thin with your rubber - you'll end up squashing your clips.

Hi Matt

How did you fix the problem ?

Did you modify the lagging, if so what thickness rubber did you use and application method. ?

Or was the clamping method mentioned above enough to resolve the issue.? ■

Regards Bruce Baker Conveyor Consultants & Project Managers http://www.conveyor-services.com ________________________________________ "Professional Service" As Consultants our Customers expect and demand the right knowledge, expertise and experience and over the last 26 years we've proved we can do this time and time again, we guarantee it. "Worldwide Installations" We've worked all over the world and in all circumstances and conditions, from the Tropics of North Queensland, Australia to the Deserts of Saudi Arabia. "Expert Training" With 26 years experience, our customers bank on our extensive knowledge and expertise when they ask us to conduct training, we create a training programs customized to suit your specific requirements. ________________________________________

Re: Ltu Pinch Rollers

Posted on 18. Mar. 2005 - 03:58

Matt,

The system I am talking about uses both inbye and outbye clamps,with the pinch rollers

I guess if the LTU is full with a few hundred metres of belt,there is still a fair amount winding tension required ■

Matt Croker
(not verified)

Re: Ltu Pinch Rollers

Posted on 18. Mar. 2005 - 05:05

Shane

Having clamps both inbye and outbye is good. Does the winch technology you are using allow you to drop your LTU tension? If you are not already doing this, check that your clamps are rated for the tension differential before you rush off and change your LTU tension while clamped.

While clamped, your main tension requirement is to overcome sag. ■

Re: Ltu Pinch Rollers

Posted on 20. Mar. 2005 - 02:35

Dear Mr. Shane,

I am not very clear about the question / subject matter. But looking at the various responses, it seems that belt is being pulled to raise take-up mass. Is it so?

Generally, there has to be a hoist unit to raise the take-up mass and then belt is to be vulcanised. Sometimes people also use mobile crane to raise the take-up mass before vulcanising the belt. Please clarify.

Regards,

Ishwar G Mulani.

Author of Book : Engineering Science and Application Design for Belt Conveyors.

Advisor / Consultant for Bulk Material Handling System & Issues.

Email : parimul@pn2.vsnl.net.in

Tel.: 0091 (0)20 25882916 ■

Re: Ltu Pinch Rollers

Posted on 26. Jun. 2005 - 01:39

Out of interest we resolved this problem through the use of Poly Urethane lagging that is "cooked" on. It is handling the high stresses very well

Shane ■