Trouble Shooting

Bearing Performance Factors
2016-10-24 16:20:11   Likes:137

Key bearing performance factors during operation are bearing noise,vibration,temperature,and lubricant state.Please refer to Table2 If any operation irregularities are detected.

1.Bearing Noise

During operation,sound detetion instruments stethoscope can be used to investigate the volume and characteristics of the bearing rotation noise.It is possible to distinguish bearing damage such as small flaking by means of its unusual yet characteristic noise.

2.Bearing Vibration

Bearing irregularities can be analyzed by measuring the vibrations of an operating machine.A frequency spectrum analyzer is used to measure the magnitude of vibration and the distribution of the frequencies.Test results enable the determination of the likely cause of the bearing irregularity.The measured data varies depending on the operating conditions of the bearing and the location of the vibration pick-up.Therefore,the method requires the determination of evaluation standards for each measured machine. It is useful to be able to detect irregularies from the bearing vibration pattern during operation.Please refer to pamphlet CAT.No.E410(Bearing Monitor)for more information about such a device.

3.Bearing Temperature

Generally,the bearing temperature can be estimated from the temperature of the housing outside surface,but a preferable way is to obtain direct measuremetns from the bearing outer ring by a probe going through an oil hole.

4.Effects of Lubrication

The two main purposes of lubrication are to minimize friction and reduce wear inside bearings that might otherwise fail prematurely.

Lubrication provides the following advantages:

1)Reduction of Friction and Wear

Direct metallic contact between the bearing rings,rolling elements and cage,which are the basic components of a bearing,is prevented by an oil film which reduces the friction and wear in the contact areas.

2)Extension of Fatigue Life

The rolling fatigue life of bearings depends greatly upon the viscosity and film thickness between the rolling contact surfaces.A heavy film thickness prolongs the fatigue life,but it is shortened if the viscosity of the oil is too low so that the film thickness is insufficient.

3)Dissipation of Frictional Heat and Cooling

Circulation lubrication may be used t carry away either frictional heat or heat transferred from the outside to prevent the bearing from overheating and the oil from deteriorating.

4)Sealing and Rust Prevention

Adequate lubrication also helps to prevent foreign material from entering the bearings and guards against corrosion or rusting.

5.Selection of Lubrication

Bearing lubrication methods are divided into two main categories:grease lubrication and oil lubrication.A lubrication method is adopted that matches the application conditions and application purpose in order to attain best performance from the bearing.Table 4 shows a comparison between grease and oil lubrication.

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