The system that I'm working on has a rotating cylinder (cleaning head). It needs to rotate vertically between two arms, much like a cleaning brush in a car wash.

Note: I have not considered how the shafts of the cleaning head will be connected to the motor exactly but it would either be directly connected to a coupler or with a right-angled gearbox.

I have added some illustrations just in case.

rough sketch of system

Specifications of cleaning head:

Weight : 4~5kg

Length : 1.5 m

Rpm : 100 RPM MAX

I have done a bit of research and I know that the shafts need to be shouldered but how do I make one end of the shaft fixed? Tapered? Have a screw on the end of the shaft and lock the bearing with a washer and a lock nut?

Also, I'm thinking of having the top arm be where the shaft is "fixed" and the bottom be "floating" and connected to the motor. Is this a good decision?

Lastly, what bearings and bearing housings should I use?

Deep groove ball bearings seems to be able to handle the load but since there will be axial and radial loading(the cleaning head will need to tilt about 15 degrees at all times), so roller bearings maybe more suitable. I'm not certain.

There are split plummer (pillow) block housings and flanged housings, which is better for my use?

  • $\begingroup$ If I interpreted your intended application correctly, tapered bearings, or the more expensive barrel bearing are the best options to support your loading case. Barrel bearings additionally allow you more freedom to maneuver the arms holding the cleaning head. $\endgroup$
    – Bart
    Commented Jan 26, 2018 at 21:01
  • $\begingroup$ I see. I guess I will go with tapered bearings since they are slight cheaper and easily available for where I am. How about "fixing" and "floating" the shaft's ends (hope I word that correctly)? Is there some kind of design guidelines that I could refer to? $\endgroup$ Commented Jan 27, 2018 at 0:43

1 Answer 1


Since the 5 kg axial weight is small I would suggest pillow block bearings, probably base mount. If you go to McMaster, search pillow block bearings, bearing pictures and ratings will be shown. I think cleaning fluids is involved in this application, so sealed bearings, preferably stainless, and minimize water going into the area of bearing. Motor on top so it doesn't get wet.


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