Calculating Stopping Torque for Rotating Shafts

[theamalsaint]

Hey guys,

I'm new to this forum and have been watching around for some time.

I would like to accept suggestion in a design of a breaking system of a rotating shaft or something similar. The design was discussed to be a disk break but the stopping torque is needed to be calculated. I have seen the equation HP = TN/5252 lots of times but I don;t think is provides an accurate result as the area of contact and the coefficient of friction are not included. Is there a proper relationship that include the two parameters to find the stopping torque needed to stop the shaft?

Thanks in advance guys :)

 

[Unrest]

In the ideal case, the force of friction is the normal force * the friction coefficient. It's independent of contact area.

You can use this to approximate the force, and convert the force to torque with T=Fr.

 

[DickL]

There are several bits you need to know before you can start meaningfully designing a brake. How fast will it be going (e.g. rpm); how much mass are you needing to stop (e.g the mass polar moment of inertia, or equivalent mass), and how fast it needs to stopped (e.g. time for Vmax to stop, or acceleration rate, rpm/s). Once you have those you can use the rotational equivalents of F=ma to fine the necessary torque.

Once you've got the required torque the real work of brake system design begins, which is the thermal analysis of the brake during its normal duty cycling and any emergency conditions.