Critical Speed of the Shaft

For the critical speed of the shaft, should I include the weight of the members mounted on the shaft (gears, pulleys, etc.) with the forces acting on it?

anorlunda
Staff Emeritus
For the critical speed of the shaft, should I include the weight of the members mounted on the shaft (gears, pulleys, etc.) with the forces acting on it?

I wish you would be more explicit in your questions and give the context of what you are asking about.

Do you mean the critical speed as in resonances? Ihttps://en.wikipedia.org/wiki/Critical_speed

If so, then yes. Everything mounted on the shaft changes the natural frequency.

I wish you would be more explicit in your questions and give the context of what you are asking about.

Do you mean the critical speed as in resonances? Ihttps://en.wikipedia.org/wiki/Critical_speed

If so, then yes. Everything mounted on the shaft changes the natural frequency.
Critical speed of the shaft with given deflection and weight. From the formula: nc = (30/π)(ΣWy/ΣWy2)½

You most definitely need to include all the weights mounted on the shaft inthe summations. When the shaft whirls, they must move with it.

jim hardy