Typical motor motion, at the end of a shaft mounted drive, should be less than 5mm on a drive size of 500 kW and higher. Palabora, at 2350 kW, had a swingbase precession on ~3-5mm, in all three planes. I have noted many other installations with similar or smaller motion.

I would consider 20-40mm end precession to be large, with something amiss, and indicative of poor machining, or alignment of the low speed coupling, or quill of the hollow shaft bore, or other connection. The machining and fitting tolerances are normally specified to limit the motion to the normal conditions stated.

If you take care using proper mounting bearings, there will be no torque link or torque arm wear of consequence, even with the high wobble. ■

We assume the rigid coupling is being used or the reducer has a shaft mount bore arrangement.

Specifications often control the minimum alignment of the rigid coupling by controlling the manufacturing process to wit:

1. Coupling halves have the connection bolts match bored, after the flange contact faces are machined and mated.

2. Pilot holes are drill and fitted with pins to control the bolt circle of the flange connection bolts

3. Perpendicularity is measured between the contact faces and connecting bolt circle to facilitate match boring of the main shaft diameters.

3. Main shaft diameters are then match bored with the connecting flange contact faces assembled, knowing/measuring the accuracy of the perpendicularity and concentricity of the main bore to the locating/pilot fitted pins. ■

Dear Mr.Teus,

You have posted at different thread. ( plastic beads problem in Torque arm run out )

Regards, ■

Dear Mr sganesh,

Thank you for your attention and I apologize for the mistake.

best regards

teus ■