1. ## Chain pull calculation

Hello,
I need help in calculation of chain pull for the case shown in pictures. The chain is unsupported from below. Chain is supported on upper side(as shown with blue line). chain is made from galvenised steel but chain rollers are of delrin. Upper part of chain is supported with delrin plastic plate so as to reduce friction. This is attachment chain. and paddles are hanging freely on attachments. Paddles are free to rotate. so , I want to calculate chain pull when the chain is rotating unsupported along with paddles. Thanks in advance
data:
center distance: 60inch
number of teeth in sprocket:30
pitch dia. of sprocket:14.42inch
number of paddle hanging freely at any given point of time:3
chain pitch:1.5inch
chain ansi number:120
chain roller material: delrin
chain support plate material: delrin plate.
Capture.PNGCapture1.PNGCapture2.PNG

2. Hello,

The exact functioning of the item shown by you is not very clear because you have not described the functional aspects, purpose and the item being conveyed, etc.. However it seems the upper run is sliding / moving on some surface. The lower run is not touching anywhere and it is simply hanging along with the chain. Therefore, there is no frictional resistance by the lower run. The lower run will be a catenary curve and will create consequent chain tensions at both the ends and result in pressing of chain on the sprockets. So as it appears probably you have following frictional resistance:

- (Upper run moving mass) x (Friction coefficient between chain and runners) x g if you want in Newton. If the chain is rolling and not sliding on the upper run, then consider rolling friction coefficient which is (mue steel to steel) x (Pin diameter) Divided by (Chain roller diameter).

- Based on the chain pulls, sprocket turning resistance from bearings + Chain sprocket meshing resistance. This could be by judgement or ad-hoc say 25% of the calculated resistance.

- Drive own resistance, which would get accounted as a drive efficiency.

- The conveyor is horizontal and hence there is no lift resistance.

This is too small an item for mathematical calculation. Better option is to create device (conveyor) and make it run (move) for few seconds by a string attached to the chain and then passing over a sheave and hang the weight at the end of string to make it move. This hanging weight (force) multiplied by drive sprocket radius will give the equipment resistance torque.

Hope the information may be of some use.

Ishwar G. Mulani
Author of Book: ‘Engineering Science And Application Design For Belt Conveyors’. Conveyor design basis is ISO (thereby book is helpful to design conveyors as per national standards of most of the countries across world). New print Nov., 2012.
Author of Book: ‘Belt Feeder Design And Hopper Bin Silo’
Advisor / Consultant for Bulk Material Handling
System & Issues.
Pune, India. Tel.: 0091 (0)20 25871916
Email: conveyor.ishwar.mulani@gmail.com
Website: www.conveyor.ishwarmulani.com

3. Hello,

In my earlier reply, for rolling friction coefficient, I have mentioned 'mue steel to steel', which is an error. Please read this as 'mue steel to delrin plastic (i.e. for steel pin and delrin plastic roller)'.

Regards,
Ishwar G. Mulani

4. ## Tell Us More!

From what you have omitted to mention any meaningful replies are impossible.
If you can't adequately describe the machine it is very likely that you will have considerable difficulty building it.
There are ways to avoid chewing plastic sheets to shreds but these are subject to more details of the loading regime.
There are also far better ways to do the job which I can only assume involves carrying on the top strand.
What is the point of galvanised chain links? You need a lot more help than merely calculating the low chain tension.
Bicycle chains detach because of not existent or faulty tensioning arrangements Please consider incorporating such.
This has the potential to become a most interesting topic.