Torque from Electric Winch

[smb4050]

I'm fastening an electric winch to a rectangular HSS and I want to verify if I am correct on the amount of torque the winch will develop. Take the line load x the distance from the center of the winch to the line? For example 2,000lbs x 8" = 16,000in-lbs of torque from the winch. What about overcoming initial inertial forces? I'm not asking about the torsional stresses in the HSS. Thanks!

 

[Bribyk]

I don't think the winch torque matters for your application. All you have is a 2000lb force at some distance, X, from your HSS. From there its a simple moment-resisting, presumably bolted, connection with normal and shear forces reacted by friction and bolt tension (my assumption, again). Unless your winch is exceptionally fast you can ignore acceleration and inertial forces of the winch internals and load.

 

[SlideRuleEra]

smb4050 - Your calculation for the winch torque is correct. More often the problem would be: "How much force can a winch that develops 16,000 in-lbs of torque exert if the winch drum radius (to the cable) is 8 inches?" The answer would be 2000 lb. Whether or not the HSS can withstand a 2000 lb. force is another question.

Overcoming initial inertia is not a problem - a direct current motor, as used on a winch, has maximum torque at zero revolutions (stall torque). The full rating of the winch (16,000 in-lb) is available at the "flip of the switch".

http://www.SlideRuleEra.net

http://www.VacuumTubeEra.net

 

[smb4050]

Thanks, I appreciate the comments and advise.