Installation, installation and adjustment of high-speed bearings:

1. The matching and clearance of high-speed bearings are because high-speed bearings meet the requirements of high-precision bearings and high-temperature bearings, so the following two points should be considered when considering the matching and clearance:

(1) changes in size and hardness from room temperature to high temperature;

(2) changes in force system and shape caused by high speed centrifugal force.

In short, under the condition of high speed and high temperature, it is very difficult to maintain the accuracy and performance of the bearing by selecting the fit and clearance.

In order to ensure the small deformation of raceway after bearing installation, interference of interference fit should not be too large, high speed centrifugal force and high temperature thermal expansion may offset the normal pressure of the assembly surface.Or the mating surface is loose, the above two factors must be considered to calculate the interference, and the effective interference at room temperature and normal speed may not work on high-speed bearings.

If the calculation results are too contradictory (usually only under the condition of ultra-high speed), the dual lubrication measures of under-ring lubrication and hydrostatic lubrication should be adopted.This scheme is likely to make the DMN value of the bearing break the 3 million mark.

At high temperatures the heat expands or counteracts the normal pressure on the mating surface.Or to make the surface of the fit relaxed, so it is necessary to consider the above two factors under the premise of careful calculation of excess, effective excess at room temperature and constant speed may not be effective for high-speed bearings.

If the calculation results are too contradictory (usually only under the condition of ultra-high speed), the dual lubrication measures of under-ring lubrication and hydrostatic lubrication should be adopted.This scheme is likely to make the DMN value of the bearing break the 3 million mark.

When considering the clearance of high-speed bearing, not only the above factors should be considered, but also the influence of the thermal elongation of the shaft on the clearance.The bearing must have the best clearance under the working condition, that is, under the working temperature.The gap is formed when the center of the inner ring groove and the outer ring groove are precisely aligned.Because high speed bearings strive to reduce relative sliding and internal consumption, so it is best not to adjust the clearance of the ball bearings through the relative dislocation of the inner and outer rings on the shaft.

When considering interference and clearance of bearing, it should be noted that the material is soft and prone to deformation at high temperature, as well as the possibility of permanent deformation caused by many transitions from normal temperature to high temperature.

2. Requirements for parts related to the main engine

High-speed bearing requirements bearing precise dynamic balance of rotating system, installed on the shaft and hole of the bearing when considering these problems, it must be higher than usual size, shape and position precision accuracy, especially the alignment and the shoulder to the hole or the degree of vertical shaft neck, also note the bearing running high temperature factors at a high speed.

In order to overcome this contradiction, measures such as reducing the surface roughness and strengthening the surface can be taken to improve the supporting stiffness of the bearing system, which requires high stiffness and quality of the bearing system.Hollow axles are used to reduce the mass of the system, and so on.