Torque applied to a bolt for belt tension.
Torque applied to a bolt for belt tension.
(OP)
Can anyone help me on the following calculations?
I have a belt & pulley system and a mechanism to create tension (please see attached picture).
I know from the manufacturer how much tension I should apply on the belt (that's ~100Kg = 220lb).
The tension is increased by tightening the nut No1 shown on the pic, with a torque wrench, so that the plate moves right horizontally.
How much torque should be applied on the nut No1, in order to have the required tension?
(The bolt is mild steel normal, 12mm diameter).
From some online calculator the given value is ~38Nm. http://www.futek.com/boltcalc.aspx
Is that correct?
Can someone advise?
I have a belt & pulley system and a mechanism to create tension (please see attached picture).
I know from the manufacturer how much tension I should apply on the belt (that's ~100Kg = 220lb).
The tension is increased by tightening the nut No1 shown on the pic, with a torque wrench, so that the plate moves right horizontally.
How much torque should be applied on the nut No1, in order to have the required tension?
(The bolt is mild steel normal, 12mm diameter).
From some online calculator the given value is ~38Nm. http://www.futek.com/boltcalc.aspx
Is that correct?
Can someone advise?





RE: Torque applied to a bolt for belt tension.
You might investigate the following, there are multiple sources for similar products:
force-deflection-gauges
sonic-tension-meter-and-accessories
RE: Torque applied to a bolt for belt tension.
tension = 220 lbs = 980 N (note no use of stupid mass units for force here)
Torque = .2*D*(2*tension) = .2*.012m*(2*980) = 4.7 N-m
RE: Torque applied to a bolt for belt tension.
RE: Torque applied to a bolt for belt tension.
RE: Torque applied to a bolt for belt tension.
Use the screw just to retain and guide a helical compression spring, selected to apply the desired force just barely off coilbind. The force near coilbind is relatively predictable for a given spring design.
Use shoulder screws or captive features instead of clamp screws.
Better, find an appropriate spring operated tensioner that's already in production, and use that.
Mike Halloran
Pembroke Pines, FL, USA
RE: Torque applied to a bolt for belt tension.
RE: Torque applied to a bolt for belt tension.
RE: Torque applied to a bolt for belt tension.
Btrueblood, please help me understand which formula you use.
T=Kdf
T (Nm)
K=0.2
d (m)
f (N)
T= 0.2 * 0.012 * 980 = 2.352 Nm
Why do you double it?
Edit:(Ok, you mentioned 180 degrees angle
So if I will apply force on my torque wrench on 90 degrees angle, I will need half the torque.)
Is it so easy?
Regards,
Yannis
RE: Torque applied to a bolt for belt tension.
RE: Torque applied to a bolt for belt tension.
RE: Torque applied to a bolt for belt tension.
You can get reliable data only indirectly - by measuring torque and measuring tension of belt by other means like deflection until you reach torque value to get satisfactory tension, but in real maintenance life you will need to make direct tension checks if you want to make sure that you did good job (as the condition of mentioned surfaces change over time).
So, your torque data can help only in rough pre-tensioning.