Use journal with ball bearing

[Hesam267]

Hi guys
I saw a multistage centrefugal pump yesterday and two things surprised me.
1- one side of pump has radial journal sleeve and other side has two angular contact bearing with also radial journal sleeve too. Is it correct? As you know anti friction bearings don't have axial clearance and in this case journal clearance is about 0.15mm.
2- there wasn't any seat in housing for keep outer ring of angular contact bearings! So apparently These two bearings don't bear any radial force, why designer didn't puts trust bearing? Forexample 52220 ball bearing

 

[Tmoose]

Two angular contact bearings can be a very effective dual direction thrust bearing.

A comparison of Price and speed rating might be interesting.

I envision added complexity of the installed arrangement in securing the "shaft washer to the shaft and then applying proper axial/height dimensions for the bearing assembly in the housing.
With a pair of angular contact bearing it can as simple as tightening the shaft lock nut and confirming the housing cover has "pinch" .
Tighten and done.

 

[Daren Samy]

Hesam ! There is lack of information in your post. Kindly tell the bearing arrangement w.r.t Drive End and Non-Drive End. I would be in better position to give you opinion. Moreover, tell about how your technician has adjusted float (if you have info/knowledge. For general information, these comments are being recorded for your help.

1. Two angular contact bearing arrangement is good to accommodate axial thrust on either side. It is generally accepted & mostly used practice in our industry. (Kindly share pump drawing if you have have). Angular contact ball bearing is ball bearing too. I don't understand how are you creating distinction between two types of ball bearing. It will good to read O and X arrangement of thrust bearing. Radial bearing in combination with thrust bearing takes up the radial load only and permit the thrust bearing to take up the axial load to maximum.

 

[JJPellin]

We call this arrangement ball/sleeve. It is common and has worked very well for us on many pumps. This arrangement allows for the advantage of a sleeve bearing without use of a circulating oil system. This combination can be lubricated with oil rings and constant level oilers. Upgrading to a hydrodynamic thrust bearing (Kingsbury) would normally require a pressurized, circulating oil system.

Johnny Pellin