AN INTRODUCTION & A QUICK FORCE BASED QUESTION 1

[lsm77]

Firstly hello, I am new here and hope you folks will be able to offer me advice.
I started a job as a design engineer (more like a junior design engineer) about 3 years ago with mny current company this has been my first employ as a engineer, I studied a Bsc in Product Design at uni, so had a lot to learn when I first started! However I am now studying an open University course in Beng engineering to top myself up knowledge wise.

this might seem a little long winded please bear with me!

I am currently working on a problem for a project at work involving rolling a cylindrical mass up and out from a resting position which has it sitting in between two smaller diameter drums. for obvious reasons I cannot divulge the application etc.

The drums are positioned underneath the main cylindrical mass, and have their centres sitting on a horizontal line, they touch at their radius.the large cylindrical mass sits on top of both these drums and everything is in equilibrium.

I have calculated the reactions from the drums on the cylindrical mass based on its weight and want to apply a force from the right hand side in a straight line acting upwards at an angle of about 56 degrees from the horizontal.

this force will be applied by a second cylinder pushing the cylindrical mass out from between the two drums, it will provide a torque to the cylindrical mass about the left drum`s centre, however the line of action of the force will not pass through the centre of the large cylinder.

my question is, will a component of the applied force act from the contact point between the large cylinder and small pushing cylinder, through the centre of the large cylinder?

if I know this then I can work out what torque the component of the main pushing force will apply to the large cylinder to roll it around the left most drum.

hope some one can offer me peace of mind that i have though this through correctly!

many thanks!

lsm77

 

[zekeman]

The quick answer is yes, but obviously the left cylinder has to be restrained and the pushing cylinder, if not rolling will add additional peripheral torque in the proper direction for lifting. So you can do the problem conservatively regardless of whether the pushing cylinder is or is not rolling during the process.

 

[lsm77]

Thank you zekeman! yes the two drums are actually fixed, they are on bearings and so can only rotate, but are restrained from doing so during this process as they are driven.

the small pushing roll is actually free to rotate so as not to scuff or damage the surface of the large cylindrical roll.

again many thanks for your reply!

lsm77