I found a 1000 HP sleeve bearing motor OEM manual that talks about saving the "shaft locking device" that was on the brand new motor when it left the factory.

I never got a motor that big for Christmas, so I'm not sure what the design intent of such devices might be.

I figure the locking device must provide limits for some or all of the following.
1 - limit shaft rotation
2 - limit axial motion
3 - provide radial preload at one end
4 - provide radial preload against both ends (2 devices)

Has anyone been around during the installation of a brand new motor Name Brand motor, to have first hand knowledge of what's important?


Thanks,

Dan T

I have never seen an OEM shaft locking device so no first-hand knowledge. I did get a motor 4x that big for Christmas... it arrived a little late though and I didn't look at the shipping locking device.

My non-first-hand opinion is that the shaft blocking should place an axial load on the shaft. With axial load applied, presumably (we hope) the coefficient of static friction at the thrust shoulder is high enough to prevent radial movement. Providing any form of radial preload on one end would not seem to be a practical option since you would be trying to misalign the rotor until you got point contact at the corner of the sleeve bearings to prevent further radial movement.

Actually I have recently talked to several motor shop people about blocking vertical motors and the method was as I described above... apply an axial load (equivalent to downthrust in the case of vertical motor). That much I am confident of.

I didn't get any guidance on horizontal motors but now that I think about it, my intuition tells me to try to set it up similar to vertical motor where the outboard bearing takes the axial load rather than inboard. After all if inboard bearing takes the axial load then outboard end of rotor is free to move. So for horizontal sleeve bearing motor you would need to determine which bearing contacts a shoulder in which direction. Hopefully the outboad bearing contacts in at least one direction so you can put the axial load in that direction to axially load the outboard bearing. This is just my idea and I don't have any confirmation from others on shipping horizontal motors.

There is a thread on this subject at eng-tips.com motor forum.

So much of the time a motor's shaft is only strapped down! However and dependant upon design you may find a bracket with a fairly large machine screw fitted around the bearing housing and the machine screw jammed down against the shaft (AL cushion) to lock the bearing in position.

I don't think there is a set method - totally dependant upon the design of the motor in question.