1. Reduce the number of rollers and the diameter of rollers
If the strength allows, reducing the weight of rolling body can reduce its inertia resistance, thus preventing and reducing sliding. For conventional standard bearings, the number of rolling elements is generally reduced by 50%, and the diameter is reduced by 25%. The contact fatigue life will not be significantly affected.
2. Select reasonable structure and reduce cage weight
On the premise of sufficient strength and avoiding its resonance and high-speed rotation resistance, the weight of the cage shall be reduced as much as possible. In high-speed bearings, the unbalance of the cage shall be properly controlled to change its external guidance to internal guidance, which is conducive to reducing the occurrence of slipping;
3. Under-ring oil supply
The way of oil supply under the ring can take away the temperature generated by bearing heating and reduce the additional loss caused by mixing. In addition, replacing the outer ring with the inner ring can also reduce the mixing resistance.
4. Use hollow roller preload bearing
The working speed and temperature range of turbine engine rotor bearing is wide, so the preload selection needs to be careful. The ratio of slightly outer diameter to inner diameter of typical hollow roller is 2, and the maximum hole bending stress does not exceed 25000 pounds/inch; Concentricity of inner and outer diameters is about 0.005mm.
5. Adopt elliptical bearing
Elliptical bearings generally adopt double-lobe or three-lobe structure. For example, the outer diameter of the outer ring of the double-lobe elliptical bearing is generally elliptical, and the structure of the ring raceway and the bearing seat are circular. After assembly, the raceway of the outer ring is elliptical, which can exert preload on the roller.
It can also eliminate the radial clearance between the short half-axis roller of the elliptical raceway and the raceway, and play the role of compressing the roller. However, this method will reduce the bearing fatigue life, so it needs to be carefully selected.