Bearing Type for Rotary Application

[KB P]

I need to select a bearing type for a rotary table. The table will be an aluminum plate, 48 inch dia 75 lbs, and will need to rotate at 60rpm max. I would like the plate to be supported by just the bearing. would a slewing ring be best or can I use an angular contact bearing or even just a regular large ball bearing? There won't be much load on the table top, maybe 10 lbs max static load.

 

[Tmoose]

What is the purpose of the table ?

I suggested we build an encoder table a little smaller diameter with parts like this -

https://www.northerntool.com/shop/tools/product_200365090_200365090

 

[MikeHalloran]

We can't see what you are trying to do, so we don't know why you wouldn't use, e.g. a small radial bearing in a flanged pillow block and a polar array of inverted casters.

If you need a very precise trajectory, then any of the bearings you propose might work. If you have an overturning moment, the slewing ring, or a Kaydon 'X' bearing would be indicated. If your environment is dusty or wet, you might want a sealed bearing.

There are no 'regular' large bearings. In sizes larger than truck wheel bearings, they start getting expensive in money and in time.

What causes the table to rotate? Some ways of doing that will put a radial force on the bearings; you have to account for stuff like that.






Mike Halloran
Pembroke Pines, FL, USA

 

[KB P]

The purpose of the table is an accumulation table for small pill bottles, not high accuracy. Ideally the plate would be only supported in the center by a bearing. This shouldn't be a problem since there is hardly and overturning moment force.

The table would be directly connected to a drive shaft on a DC motor. I am trying to improve upon a current design that once used casters and now uses a glide ring. I would like to remove these extra supports to reduce cost and parts.

 

[MikeHalloran]

If you could reduce the weight of the table, you could rigidly connect it to the DC motor and use the motor's bearings to support the whole table and its load.

Caution: Motor bearings are usually sized for zero axial load, so a motor that could support an axial load would be a special; but it's not impossible.



Mike Halloran
Pembroke Pines, FL, USA

 

[KB P]

Mike,

Unfortunately the diameter of the plate is fixed. The thickness is currently at 3/8" and I'd be concerned about a thinner plate running flat. I am going to test the system with a slewing ring.

Thanks

 

[Tmoose]

Some rear engine rear wheel drive cars drive the speedometer off a front wheel. VW and Corvair and probably early Pontiac Tempest come to mind. The non rotating axle has a hole bored thru it for the speedo drive cable to pass thru. The cable engages a square socket etc in the cap that seals the rotating hub.

http://repairguide.autozone.com/zne...0c152/80/26/75/fc/medium/0900c152802675fc.gif

I'd use the high capacity COTS axle and hub from Northern Tool, and drill the axle for a small drive spindle/shaft to pass thru, like the automotive.
You have not mentioned the power and rpm requ8irements, but there are any number of small nylon spline or hex or even square drive miniature couplings that //might// make easy to couple the motor to the drive spindle, and the drive spindle to the COTS hub with minor modifications. Your DC motor would only have to drive that hub and then the table.

 

[sreid]

Lazy Susan Bearing.

https://www.amazon.com/s/?ie=UTF8&k...&hvtargid=kwd-98710532&ref=pd_sl_8l2b4k648b_e