Rolling bearings should have basic properties such as long life, low vibration, low noise, low rotational torque and high reliability. To achieve the above
Performance, must ensure the processing accuracy of the bearing parts, the processing quality of the steel ball, ferrule, cage has an impact on the bearing vibration,
The processing quality of the medium steel ball has the most obvious influence on the bearing vibration. The prominent problem is that the vibration value of the steel ball is large and the surface defects are serious.
Random quality problems such as bruises, scratches, and burns. The basic problem facing the bearing industry is to reduce the vibration and noise of the bearing.
Sound, this will improve the geometric accuracy of the steel ball and the ferrule, and reduce the roughness of the working surface. This article focuses on the various technical references of steel balls.
The impact of the standard on bearing vibration and noise.
2 The influence of various technical indexes of steel ball on bearing performance
The quality of the steel ball directly affects the bearing performance. Its technical indicators mainly include: steel ball shape error, steel ball surface roughness
Degree, surface defects of steel balls, etc.
2.1 Influence of shape error of steel ball on bearing performance
The shape error of the steel ball is one of the important reasons that affect bearing vibration and noise. Steel ball and groove surface shape during steel ball processing
Into the contact pair, subject to extrusion, friction, consumption of excess metal on the surface of the billet, and gradually rounded into a ball. In order to reduce the shape error of the steel ball,
Various technical measures have been taken in the process. The larger the shape error of the steel ball, the greater the vibration value of the bearing, so the steel ball must be reduced.
Shape error. When the bearing rotates, due to the shape error of the steel ball, the position of the ball is forced to change continuously, which causes the bearing vibration and
Noise, the shape error of the steel ball causes the bearing to produce low frequency vibration.
2.2 Influence of surface roughness of steel ball on bearing performance
The surface roughness of a steel ball generally refers to the surface microscopic unevenness on the surface of the steel ball, spherical error and waviness. Steel ball surface
Roughness has a great influence on the medium and high frequency vibration of the bearing, causing the bearing to produce noise. The influence of steel ball surface roughness on bearing vibration
It is much larger than the influence of the surface roughness of the ferrule channel on the vibration of the bearing. The larger the surface roughness value of the steel ball, the higher the vibration value of the bearing.
The surface roughness value of the steel ball must be reduced.
2.3 Influence of surface defects of steel ball on bearing performance
General term for cracks, scratches, rust, and depressions on the surface of steel balls caused by machining, rust, corrosion, or raw materials.
The quality of the surface of the surface has a great influence. Therefore, the determination of the amount of cutting and the development and design requirements of the supporting tire are basket-shaped cages.
The key to the quality of the end face.
2.4 Influence of steel ball hardness on bearing performance
The hardness of the steel ball will directly affect the bearing fatigue life and dynamic performance. The experimental results show that the hardness of the steel ball is around 62HRC.
When the contact fatigue life is the highest; when the hardness changes within the range of 57-65HRC, the higher the hardness, the better the corrosion resistance; when the hardness value is lower than
At 61 HRC, the wear resistance decreases as the hardness value decreases; when the hardness value is higher than 61 HRC, the effect on wear resistance is not significant. same
The smaller the hardness difference of the steel balls in the sleeve bearing, the better. The hardness of the steel ball also has a significant influence on the vibration value of the bearing.
When the steel balls of 63HRC and 66HRC are used, the vibration value of the former is 3dB larger than the latter. For bearings with vibration values, steel balls
The hardness is in the range of 65-67HRC, and the difference in hardness of the steel ball in the same bearing is not more than 0.5HRC.
2.5 Influence of surface grinding of steel ball on bearing performance
The surface of the steel ball is burned during the grinding process after quenching and tempering. The surface of the steel ball is abrupt due to some abnormal reason.
However, after impact, jamming, rubbing or grinding, the temperature of the metal in the area rises to the quenching or tempering temperature, and then it is cooled immediately.
The area forms a burn burn. Grinding burns can only be shown by cold pickling according to certain methods. Because the metallographic structure and hardness of the burned spot are different from the normal area, it becomes the hidden of early peeling.
Suffering, the contact fatigue strength decreased significantly. Tests have shown that burned steel balls have a 16% lower life expectancy than non-burn steel balls.
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