Calculating tension
Calculating tension
(OP)
I have a situation that requires expertize beyond my capabilities. I need to know how to calculate the individual tensions in each strand and then find the bearing loads. the setup is that I have two wheels one driven the other free, each with ten grooves (with an included angle of 45 degrees), the strand (1/2" dia) first enters the driven wheel, (under 540 lbs of tension) makes a 180 degree wrap and then enters the free wheel (see the attached file) makes a 180 degrees wrap and enters the 2nd groove of the driven makes a 180 degree wrap a then enters the 2nd groove of the free wheel. this continues until the strand leaves the 5th groove of the free wheel under tension of 18,000 lbs wraps around the turn a round wheel (wheel is free) 180 degrees and the enters the 6th groove of the free wheel. it then makes successive 180 degrees wraps of the driven and free wheel until it leaves the driven wheel at 540 lbs of tension. I would greatly appreciate any help in solving this problem.





RE: Calculating tension
Mike Halloran
Pembroke Pines, FL, USA
RE: Calculating tension
RE: Calculating tension
This is not a Belt but more like wire rope. I understand the friction part of of a pulley, T1/T2 = e(uB), but the tension cannot not be equal in each strand and do you sum the the total tensions to get the total load the bearings see.
RE: Calculating tension
I have seen only one book that has this type apparatus and I don't have a clue as to the name or author.
If there is any stretch in you line the calculations get tricky. We have a 4::1 draw ratio between our gear stands.
RE: Calculating tension
RE: Calculating tension
RE: Calculating tension
But when I get to the 5th wrap on the payoff side the tension is something like 75k not the 18k.
I would assume that the tension around the free wheeling wheel would be the same ( if it goes in at 500 lbs it must must be 500 lbs on the other strand as well because there is no friction to be accounted for). Is this assume correct?
RE: Calculating tension
Where did you get you coefficient of friction values? You probably need to conduct an experiment to determine an accurate number.
I don't have any reference texts in front of me right now, but where did you get the sin(alpha/2) term in the exponent from?
RE: Calculating tension
RE: Calculating tension