Siemens 1120 Frames ODP 사용자 설명서

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Sleeve Bearings 
 

Maintain proper oil level. 
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, 580, 680, and 800 frame 
motors are approximately 2 mils  per inch of bearing 
diameter.  Diametrical sleeve bearing clearances for 
the 1120  frame is in the range of 1.5mils per inch of 
bearing diameter. 
 
An accurate check of bearing clearance is obtained 
with micrometer measurements of the shaft journal 
and bearing bore.