Foreign matter Defective sealing device, entry of foreign matter due to wear, etc., or 3) Abnormalities during bearing operation, their causes, and countermeasures that can be taken against them

In order to find the cause of a failure, it is necessary not only to investigate the bearing itself but to perform a comprehensive investigation that includes the lubricant and the mounting parts (shaft, housing, and surrounding components).

Ball bearing cagetypes

Any noise/vibration made by the bearing (monitored by means of a stethoscope, vibration measuring instrument, or equivalent; accurate detection requires both training and a lot of practice)

If bearings are operated under ideal conditions, they will last until their service life comes to an end due to rolling fatigue of the materials. But sometimes bearings can break down, or "fail," earlier than expected, and, in such a situation, it is necessary not only to investigate the bearing itself but to perform a comprehensive investigation that includes the lubricant and the mounting parts (shaft, housing, and surrounding components).

Linearball bearing cage

In this series, we will call bearing visual defects "bearing failure," and we will explain the typical bearing failure, its causes, and countermeasures that can be taken.

Table 6 shows the types of bearing failure and where they occur. The names of the various bearing components are indicated in Figures 4 a) through 4 d).

ThrustBearing Cage

Abnormal temperature rise (monitored by means of a continuous record of the temperature; this method can only in used in relatively stable operating condition)

Please note that while the JTEKT rolling bearing catalog uses the terms "bearing" and "rolling bearing" interchangeably, this column does not use the term "rolling bearing" as a general rule.

Bearingretainer types

Due to this repeated load, high pressure is generated on the raceway surfaces of the inner and outer rings that are in contact with the rolling surfaces of the rolling elements.

As shown in Table 5, "failure" is divided into a number of classification shown in the "Classification of visual defect (general term)" column, and the details of these classifications are listed in the "Term(s) for the various types of failure (technical term[s])" column.

For abnormalities that occur during bearing operation, such as noise/vibration, abnormal temperature rise, and so on, we need to sort out the cause and countermeasures, and take the appropriate countermeasures. Table 4 shows some of the abnormalities that can occur during bearing operation, their causes, and countermeasures that can be taken against them.

Bearing cagematerial

Being able to identify and predict abnormalities that occur during operation (such as abnormal temperature rise, noise, or vibration) without taking the machine apart also greatly contributes to the productivity and economic efficiency of the machine.

When a bearing that suppors a load rotates, the load is repeatedly applied to the raceway surfaces of the inner and outer rings each time rolling elements (balls or rollers) pass (see Figure 1).

Rolling fatigue in the material leads to bearing failure. If the bearing has been operated under ideal conditions, the point at which this flaking occurs is the end of the bearing's service life.

Please use this search function to find READY die set components that are equivalent to commonly used pins, bushing, ISO Springs, and Gas Springs from other manufacturers.

Ball bearingretainercage

Consequently, material flakes from the surfaces of the bearing rings or rolling elements by fatigue arising from repeated contact stress. This is called "flaking" or "spalling" (see Figures 2 and 3).

Before examining/considering the cause of the bearing breakdown, it is important first to have a proper grasp of just when the bearing breakdown occurred. As shown in Table 3, you can, to a certain extent, narrow down the cause of the bearing breakdown by determining when it occurred.

If you have selected your bearings properly and they are operated under ideal conditions, they will last until their specified service life comes to an end. But sometimes bearing failure can occur earlier than expected.