Clamp pressure
Clamp pressure
(OP)
Hello
This may be simple but I am unable to calculate this.
I have a band clamp pressing a rubber seal tight. I have the torque applied on the band clamp as 5 N-m. How can I convert this torque value into a radial contact pressure acting on the seal surface? I have all the specifications of the clamp and with some friction coeff is there any straight forward formula that I can use?
Thanks for the help
This may be simple but I am unable to calculate this.
I have a band clamp pressing a rubber seal tight. I have the torque applied on the band clamp as 5 N-m. How can I convert this torque value into a radial contact pressure acting on the seal surface? I have all the specifications of the clamp and with some friction coeff is there any straight forward formula that I can use?
Thanks for the help





RE: Clamp pressure
The radial pressure on the clamp produces a hoop stress in the clamp. Multiply the hoop stress by the clamp band cross sectional area. This gives you the tangential force on the hoop that the screw has to supply. You'd need to convert the torque on the screw to clamp load provided by the screw. I'd guess this may get you to within 25% of the real answer.
RE: Clamp pressure
Cheers
Greg Locock
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RE: Clamp pressure
2piT/2=sigma/E*2pi*D*sigma*Ac/2
sigma/E*2PI*D=p
T=p*sigma*Ac
Ac=t*w
T=sigma*t*w*p
PD*w=2*sigma*t*w
P=2*sigma*t/D
P=2*T/(w*p*D)
P= radial pressure
Ac= band crossection =w*t
w band width
t band thickness
p screw pitch
sigma stress in band
D diameter of band
8d0
RE: Clamp pressure
RE: Clamp pressure
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I doubt it. It's not the same problem since the drum is not spinning, where dynamic friction is the friction force equation, but not in this case. Try writing the equation explaining this.In equilibrium there is no dynamic friction and the static friction must be distributed in some unknown fashion around the hoop.Good doctoral question
RE: Clamp pressure
The equations for spring clutch give the same exponential pressure distribution without any movement or slip. When calculating the spring clutch holding moment before slip you use the same equation with exponential pressure distribution .
The reason I think there is a friction factor is because the band strip it pulled tangent to the circle when torquing the band screw.
RE: Clamp pressure
Please let me know if my understanding does not make sense.
Thanks
FM
RE: Clamp pressure
RE: Clamp pressure
RE: Clamp pressure
Also, looking at Isaelk's comments there appears to be an exponential mu*@ falloff in stress as you go away from that point.
RE: Clamp pressure
RE: Clamp pressure