## 5 Parametric Analysis of the Amplitude of VC Vibration in Rolling Bearings
### Loaded Rolling Bearing the Influence of Internal Radial Clearance and External Load
This is also shown by the contour lines that are parallel to the axis that marks the value of the internal radial clearance (\(e\)). This area is characterized by a relatively low intensity of the external radial load. The increase of external radial load significantly increases the level of the vibration amplitude due to the contact deformations. In the case of a boundary load that will cause the boundary deflection of bearing, the bearing support system will move from _support systems 1-2_ to _support systems 2-3_. This phenomenon is explained in Section 4.2 and more comprehensively in the papers under the ordinal number [21, 22]. Further increase in load will result in a negative gradient of the amplitude \(\Delta_{2}\). In the second area, the high level of the external load results in a bigger number of rolling elements into contact with bearing rings. Hence, the load distribution between the rolling elements is fairly more uniform in this area. This results in the reduction of the vibration amplitude due to the contact deformations (\(\Delta_{2}\)). The increase of the external radial load will reduce the amplitude level (\(\Delta_{2}\)) until the point when an inner ring begins to support on a maximal possible number of active rolling elements. After this point, the amplitude will increase again. Figure 9: Three-dimensional dependence of the total amplitude of VC vibration (\(\Delta\)) on the size of internal radial clearance (\(e\)) and level of external load (\(Q\)) for the 6206-single-row ball bearing. The diagram of the total amplitude of VC vibrations in a rolling bearing has been presented in Figure 9. Unlike the vibration amplitude due to the contact deformations, the total amplitude of the VC vibrations can have both positive and negative values. The total amplitude has most values in the areas of the lower intensity of external radial load and the bigger values of internal radial clearance. These are the areas where, because of a low level of contact deformations, the load transfer is mostly based on _support systems 1-2_. The biggest influence on the rotor vibrations in this area has the size of the internal radial clearance. For the smaller values of clearance, the level of the total vibration amplitude is also smaller. The external radial load has a favorable influence on the rotor vibrations only in the areas where the total vibration amplitude is positive. Namely, in the areas where emerges an unfavorable load distribution, i.e., in the areas where inner ring support on a smaller number of rolling elements, the level of the contact deformations can be very high so that the vibration amplitude due to contact deformations is bigger than amplitude \(\Delta_{1}\). In these areas, the value of the total amplitude is negative. In the areas where the total amplitude has a negative value, a bigger influence on rotor vibrations has contact deformations than the size of internal radial clearance. In the fields where the total amplitude is positive, a bigger influence on the rotor vibrations has the clearance in a bearing than the size of the external radial load.