Spring System design for Auto centering of a rotating shaft

[VISHAL12]

Hi All,

I have a requirement where there is rotating shaft of 75mm dia, which need to be autocentered using Springs. The shaft can maximum rotate 4 rounds and everytime when left free should auto center to its original point.

Thus, the shaft mechanism needs to rotate 2 rounds on either side and then autocenter.
Requesting you to guide me the right direction for this.

 

[israelkk]

What is the maximum spring torque needed to return the shaft to zero rotation?

 

[VISHAL12]

The shaft is a cylindrical shaft with a total weight of 4kgs.

 

[israelkk]

4kgs is a force, it is not a torque or a moment. The shaft is probably connected to something and drives it. Therefore, when the spring returns the shaft back to zero rotation it also applies torque/moment on whatever is connected to the shaft too.

 

[VISHAL12]

Torque required is between 4-5 Nm.

 

[dgallup]

How precisely does it have to return to zero? There is going to be some hysteresis in any mechanical system.

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The Help for this program was created in Windows Help format, which depends on a feature that isn't included in this version of Windows.

 

[VISHAL12]

As close as possible to the center position.

 

[israelkk]

Your design asks for a rotation of 720 degrees to each direction. In you post you gave a torque of 4-5Nm for the 720 degree deflection. This means that if your shaft have a friction torque of 1% of full torque (0.05Nm) the residual deflection at zero spring torque will be 7.2 degrees. Actually, I find it odd that a shaft of 75mm diameter will be used for 5Nm. If you can give more information regarding your design problem with real data it will be more appropriate.