Posted on May 18, 1999 at 22:01:31:

In Reply to: Conveyor Pulleys posted by K.R. Baskar on May 13, 1999 at 22:12:46:

continuation: please find the two Conveyor Dynamics, Inc. (CDI) references on pulley design.

1. Modern Pulley Design Techniques and Failure Analysis Methods - by Vinit Sethi and Lawrence Nordell SME 1993 Symposium Conveyor Belt Eng..C14

2. A New Pulley Stress Analysis Method... by Xiangjun Qiu and Vinit Sethi

Contact us for support if needed. ■

Posted on May 15, 1999 at 15:51:29:

In Reply to: Conveyor Pulleys posted by K.R. Baskar on May 13, 1999 at 22:12:46:

Dear Sir:

You requested: How to select the pulley shell thickness and the end relief distance between shell edge and end disk? Shell analysis can be very conservatively estimated by assuming the shell is a arch with a 20 degree included angle pinned at one end and horizontally free at the other with a uniform load (Roark, Omar Blodgett et al), mod. for wear, belt alignment, crown, no internal stiffner rings, wrap angle, steel belt. Proper complex analysis is $$$ better. 2nd Q none. ■

Dear Shri K R Baskar,

Pulley shell, end discs, hubs, their connection to shaft and shaft, acts as a composite body. There are design methods to decide size of these items. This cannot be described on the forum.

Some of the methods are as per Lange Germany, TJ King South Africa, D A Hills & S Baugh England, etc. as per their research / articles.

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 ■

KR,

Assuming small conveyors,

Shell width is typ. 150mm more than belt width..eg MEHA etal.

Other have advised on shell design methods.

End disc is typ. designed to Roak's - assume no contribution from shaft in stiffeness.

End disc design can vary, turbine type etc etc.

End disc is typ. 50mm or less from end of shell - to suit welding machine.

Shaft design is for infinite life, assuming shaft locking devices at end discs, the shaft size is set by both fatigue and deflection limits.

Unless U plan to do a lot of pulley design, suggest that U ask suppliers to provide either off the shelf pulleys or custion design to suit your loads/applications.

Otherwise, U will need to do some more research etc. on pulley design methods.

Cheers

James ■

Referring to the reply by Mr. James Morrish, I provide the following information for the general benefit of the readers :

1) For usual pulleys, there are routinely used standard dimensions such as bearing center distance = belt width + dimension x.

End disc distance from pulley edge = y dimension etc.

2) Basic guidelines to fix all these dimensions are related to actual accommodation of various components of the pulley, such as

- End disc should be positioned as near to the pulley edge as possible so that the bending arm for the shaft is minimum. But in doing so, it should be sufficiently away from pulley edge, so that hub projection, its key / locking rim can be removed without obstruction from plummer block. Also, it should allow tapering distance for steps in shaft diameter.

- Although there are certain norms as mentioned in serial no. 1, but it is the requirement of physical accommodation / positioning for appropriate engineering result, is governing the matter. Other issues are of secondary importance.

- The bearing center distance shall be such that the bearing alongwith the supporting member allows positioning of chute wall between bearing and pulley, with appropriate clearance.

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 ■

I believe that the "Prok" Australian website has an excel file for pulley sizing - now owned by Sandvik.

May help the initiator.

Thanks

James ■

Dear Mr. Baskar

Pulley shell thickness mainly depands upon :

-Belt tension

-Bearing center of pulley

In many design book, you will find some relation to find out the same.I have seen many articles in BULK SOLID journal.

Regards.

A.Banerjee ■