Siemens 580 Benutzerhandbuch

- 22 - 

 
Sleeve Bearings 
 

Failure to do so may cause improper lubrication of motor 
resulting in damage to the equipment. 

Follow lubrication instructions carefully. Avoid adding oil 
while unit is running. 

 
Motors with sleeve bearings are shipped without oil.  
A rust-inhibiting film is applied at the factory to protect 
bearing and journal surfaces during shipment. 

 

Before attempting to operate any sleeve bearing 
motor, the following steps must be performed. 
 
1.  Visually inspect the bearing condition.  Oil ring 

inspection ports and drain openings in the 
housing are normally provided for this purpose. 

2.  Check for any accumulation of moisture. If 

oxidation is discovered, all traces of it must be 
removed before motor is put in service, which will 
require disassembly. 

3.  Flush all oil piping. Fill bearing reservoirs to 

normal level.  Fill to mark indicated on gauge or 
to center of gauge. See the table below for 
recommended grades of oil. 

4.  Rotate shaft several turns by hand to distribute oil 

over bearing parts. Make sure oil rings rotate 
freely. 

 

 

The oil viscosity at operating temperature is very 
important in selecting proper oil and may vary in 
different climates. 

 

It is important to maintain the correct oil level, as lack 
of lubrication is often the cause of bearing failure. 

 

Inspect oil level and oil ring operation frequently.  Oil 
ring operation can be observed through the sight 
glass mounted at the top of the bearing capsule.  Oil 
rings should be perfectly round, free of burrs or rough 
edges, turn at constant speed and carry a noticeable 
amount of oil to the top of the journal.  Failure of the 
oil ring to turn freely may be caused by: 

 

1.  Ring out of round (should be round to 0.062 inch) 
2.  Fouling on a projection of the bearing bushing. 
3.  Ring not balanced (heavy side will tend to remain 

down). 

4.  Adhesion to guide slot (trapezoidal section reduces 

adhesion). 

5.  Oil too cold or viscous, or oil level too high. 
6.  Shaft not level – oil ring tends to bind. 
 
At the first sign of oil discoloration or contamination, 
replace with new oil.  Rapid discoloration is caused by 
bearing wear, often from vibration or thrust.  Change oil 
as required to keep clean. 
 
Force Feed Lubrication 
Oil is metered through an orifice in oil inlet line to allow 
the proper amount of lubricating oil to enter the bearing.  
Conventional oil rings are also supplied with the motor 
to insure temporary bearing lubrication in the event the 
force feed oil supply should fail.  It is important to check 
oil flow frequently.  Lack of lubrication may cause 
bearing failure. 
 
Checking Sleeve Bearing Clearance 
Excessive clearance can cause rapid bearing failure, 
and decreased air gap between stator and rotor at the 
bottom of the motor.  Diametrical sleeve bearing 
clearances for the 500 and 580 frame motors are in the 
range of 1.7 to 2.7 mils per inch of bearing diameter.  
Diametrical sleeve bearing clearances for the 880, 
SH400, SH450, and SH560 frames are in the range of 
1.0 to 2.0 mils per inch of bearing diameter. 
 
An accurate check of bearing clearance is obtained with 
micrometer measurements of the shaft journal and 
bearing bore. 

 

Antifriction Bearings 
For typical antifriction bearing configuration, see Figures 
3, 4 and 5. 
 
Replacement bearings may be of a different manufacturer 
but must be equal to the originals used in the motor.  
When ordering bearings specify as follows: 
1. The complete A.F.B.M.A. (Anti-Friction Bearing 

Manufacturers’ Association) bearing number from the 
motor nameplate. 

2.  Identifying numerals and manufacturer stamped on 

the bearing. 

3.  Bearing tolerance class, i.e. - A.B.E.C.-1 (Annular 

Bearing Engineers’ Committee Tolerance Class One). 

4. Internal radial clearance, i.e. – A.F.B.M.A.-3 

(Clearance Class Three).  

5. Electric 

motor 

quality.