When the mechanism is running, the part of the embedded solid lubricating bearing is allowed to have a certain temperature. When touching the shell of the mechanism by hand, it should not feel hot, otherwise it indicates that the bearing temperature is too high.

The reasons for the high temperature of the bearing are: the quality of the lubricating oil does not meet the requirements or deterioration, the viscosity of the lubricating oil is too high; Mechanism assembly is too tight (clearance is insufficient); Plane bearing assembly is too tight; The bearing ring rotates on the shaft or in the shell; Excessive load; Fracture of bearing cage or rolling body, etc.

The inlaid solid lubricating bearing is allowed to have a slight running sound in the work. If the sound is too large or there is abnormal noise or crash, it indicates that the bearing is faulty.
The reason for the noise of rolling bearings is more complex, one is the wear of the bearing inner and outer ring with the surface. As a result of this wear, the bearing and the housing, bearing and the shaft of the relationship, resulting in the axis deviated from the correct position, when the shaft at high speed movement abnormal sound. When the bearing fatigue, its surface metal peeling, will also increase the radial clearance of the bearing and produce abnormal sound. In addition, the bearing lubrication is insufficient, the formation of dry friction, and bearing breakage will produce abnormal sound. Bearing wear loose, cage loose damage, will also produce abnormal sound.

(1) Bearings with low noise requirements
In the standard bearings produced in our country, there are several varieties of ball bearings from the inner diameter φ2.5mm to φ60mm with Zl, Z2 and Z3 suffixes, corresponding to three different low noise requirements respectively, and eight models of roller bearings from N309 to N322 also have varieties manufactured according to low noise standards.
These embedded solid lubricating bearings can be fully applied to other machines with low noise requirements, and the price is cheap, such as in the type and size can meet the requirements, try to use these two types of low noise bearings.

(2) Bearings with relatively small noise are used
When the above two types of low noise bearings cannot be used, relatively low noise bearings can be used. The specific comparison basis is as follows:

1) The noise of ball bearings is lower than that of roller bearings, and the (friction) noise of bearings with relatively less sliding is lower than that of bearings with relatively more sliding;
2) The noise of the solid cage bearing is relatively lower than that of the embedded solid lubricated bearing using the stamped cage; The noise of bearings using plastic cage is lower than that of bearings using the above two kinds of cage; Those with more balls, thicker outer rings, and less noise,
3) Bearings with high precision, especially inlaid solid lubricating bearings with higher rolling body precision, have relatively less noise than low-precision bearings.
4) The noise of small bearing is relatively smaller than that of large bearing.