Thrust Bearings

I am considering an electric retrofit to my existing shaft drive sailing yacht setup. This is a pretty standard 1" shaft through a cutlass bearing, stern tube and stern gland.

I'm happy with mounting the motor and reduction gears etc, but I know nothing about thrust bearings. Is there a recommended type for this application? A self aligning bearing would obviously appeal but I have no idea if that would be acceptable in this application.

 

What type of bearing you need is dependent on how much thrust you need to handle. I truly doubt that you will need a shoe type thrust bearing, A flat or tapered roller bearing will likely fit your needs. It should be mounted just outboard of the motor connection flex coupling.

 

Cheers. My back of the envelope calculation indicates that thrust is considerably lower than the rating of any tapered roller bearing which fits the shaft so I guess that works.

I have seen examples where thrust is transferred through the flexible coupling to the motor mount itself. I guess this puts an unnecessary load on the coupling, and doesn't constrain the main shaft as effectively.