Shaft design
Shaft design
(OP)
Hi,
I need the help on calculating the maximum rotating mass on shaft.
Suppose I have a shaft of .5 inches diameter and Torque is 20lbf-in. How to calculate the maximum weight this shaft can rotate using given torque.
Thanks
I need the help on calculating the maximum rotating mass on shaft.
Suppose I have a shaft of .5 inches diameter and Torque is 20lbf-in. How to calculate the maximum weight this shaft can rotate using given torque.
Thanks
Bambila
Mechanical Engineer





RE: Shaft design
1)the time needed to come up to speed
2) the braking torque, if greater than T
3) the startup torque of the prime mover (could be as much as 5 times the nominal)
In any event, you get the torsional stress
stress=TR/J
T= maximum torque delivered either by prime mover or braking
R= radius of shaft
J=polar moment of inertia
RE: Shaft design
Does the 0.5 inch shaft support the weight, or merely connect to an independently supported object with this amount of weight?
What is the geometry of the object which connects to the shaft?
How is the object attached to the shaft, i.e. welded, bolted, verbally, etc.?
Does the 0.5 inch shaft have a keyway?
How is the 0.5 inch shaft supported?
RE: Shaft design
Thanks for the reply. Here I have attached the image of my problem. I hope this would help.
Thanks
Bambila
Mechanical Engineer
RE: Shaft design
That was wrong link. Image is attached in this thread. please have look.
Thanks
Bambila
Mechanical Engineer
RE: Shaft design
This is not a problem related to weight but to inertia.
If bearing friction is neglected, the momentum equation is like this: Torque = moment of inertia (shaft + disc) * angular acceleration
So the torque you have to apply, in an ideal situation, when the shaft is rotating at costant velocity (whatever its value may be), is ZERO. This is because the torque is needed to accelerate the shaft till it reaches full speed. The only thing you have to know is the acceleration needed to reach that speed. Since torque is known, you can easily calculate inertia and then the disk thickness.
The problem is obviously more complicated if a braking torque is needed to keep the shaft at costant velocity.
Regards,
Stefano
RE: Shaft design
RE: Shaft design