# Torque requirement

1. Jan 2, 2009

### Analysis

Dear all,

I need clarification regarding torque requirement in the following arrangement.
Imagine a shaft 25mm diameter 600mm length simply supported and one end
gear is attached to drive the shaft.
Load is externally applied via lever arm and different material(polymer) same
diameter is in contact.
My query is what is the torque required to drive this shaft arrangement.
Load,shaft geometries,speed are the known values.

My approach is assumed that at static condition load is applied over shaft, finding
the reaction force at each bearing end and from this force multiplied by bearing
mean radius with co efficient of friction of bearing which is normally(0.0025max).

Is the approach is correct?

1)My suspect is when applying force to the bearing, friction coefficient will

increase how to change of friction is accommodated?
2)Rollers in contact with pressure to overcome frictional resistance will be less

only i.e. shaft in contact assume that 100 N is acting,to overcome this force we

will multiply with friction coefficient of two materials say 0.3 and the calculation is

100 x 0.30=30N is enough to overcome the force of 100 N
3)To find reaction force at the ends can i use of 30N instead of 100N?

4)Suppose reaction force will changes in each end,say one end is 50 N and
another end is 35N can i take higher value?

5)Above is that running torque what will the empirically starting torque to select
induction motor or servo drive motor specification.can i take say 1.5 times
running torque for both? Can i use T=IxAlpha approach?

6)In this gear is going to drive the shaft gear PCD has any influences?bcoz gear
radius is used to drive the shaft torque?

Prakash

2. Jan 6, 2009

### Dr.D

Hello, Prakash. You continue to try to get someone else to do your work, don't you? I have to say, I am amazed at your persistence!

3. Jan 11, 2009

### Analysis

Dearsirs,
Sorry in the case of wrong ,whatever my clarifications /doubts only posting i am not the person getting my work done thro others.Also my posts are narrating the approaches of my work and seeking others comments thats all.This is to enhance my theoretical knowledge.From ur point of view what are the questions can we post?

From the above In the torque requirement querey my suspect is while rotating we can easily overcome the load applied by top roller,comparitevely taking total load used to finding reactions from that am calculating the torque....?

Thanks for ur comment

Prakash