Proper installation of bearings can prevent premature failure of bearings

Proper installation of bearings can prevent premature failure of bearings

1. End of bearing fatigue caused by touch

Touch fatigue effect refers to the effect of alternating stress on the nominal bearing operation. Touching fatigue detachment occurs in the name of bearing operation, often accompanied by fatigue cracks. Firstly, it occurs at a greater alternating shear stress below the touch name, and then expands to form different detachment shapes under the name, such as pitting or pitting detachment, and shallow detachment refers to small flakes after detachment. Due to the gradual expansion of the detachment surface, it often extends towards deeper layers, forming deep detachment. Deep detachment is the source of fatigue that results from touch fatigue.

2. Effect of bearing wear

Wear and tear effect refers to the effect caused by sliding conflicts between nominal metals, resulting in continuous wear and tear of the nominal metal during operation. A rolling bearing composed of two or more bearing structures simultaneously within a set of bearings. Such as needle roller and thrust cylindrical roller combination bearings, needle roller and thrust ball combination bearings, needle roller and angular contact ball combination bearings, etc. Continuous wear and tear will cause gradual damage to the entire bearing, leading to loss of bearing scale accuracy and other related issues. Wear and tear may affect changes in appearance, increase in cooperative gaps, and alter the nominal description of the operation. It may also affect the lubricant or cause it to become infected to a certain level, resulting in a complete loss of lubrication function, and thus causing the bearing to lose rotational accuracy and even prevent abnormal operation. Wear effectiveness is one of the common forms of bearing effectiveness, which can be divided into more common types of abrasive wear and adhesive wear according to the form of wear.

Abrasive wear refers to the wear caused by the squeezing of foreign hard particles, hard foreign objects, or metal debris between the nominal operation of bearings and the movement of the nominal contact, often forming plow like abrasions in the nominal operation of bearings. Hard particles or foreign objects may come from inside the host or from other adjacent machines in the host system, which are fed into the bearings by lubricating media. Adhesive wear refers to the uneven force distribution on the conflicting surface caused by micro protrusions or foreign objects in the conflicting name. When the lubrication condition deteriorates severely, heat is generated due to partial conflicts, which can easily lead to partial deformation and micro welding of the conflicting surface. In severe cases, the nominal metal may partially melt, and the contact surface exerts force to tear off some conflicting welding points from the substrate, increasing plastic deformation. This cycle of adhesion tearing adhesion constitutes adhesive wear, with slight adhesive wear referred to as abrasion and severe adhesive wear referred to as bite.

3. Effect of bearing cracking

The main reasons for the effectiveness of bearing cracking are defects and overload. When the external load exceeds the strength limit of the data and causes complete machine cracking, it is called overload cracking. The important cause of overload is the sudden malfunction of the host or improper installation. Defects such as micro cracks, shrinkage holes, bubbles, large foreign objects, overheating arrangements, and partial burns in the entire bearing can also cause cracking at the defect site during impact overload or intense oscillation, which is called defect cracking. It should be pointed out that during the manufacturing process of bearings, the presence of the above-mentioned defects can be correctly analyzed through instruments in the re inspection of raw materials, quality control of casting and heat treatment, and processing process control. In the future, it is still necessary to strengthen the control. But individually, most of the common bearing cracking results in overload.

The reasons for high bearing temperature include: the quality of lubricating oil does not meet the requirements or deteriorates, and the viscosity of lubricating oil is too high; Tight organizational installation (lack of gaps); Bearing installation is too tight; The bearing race rolls on the shaft or inside the shell; Excessive load; Cracking of the bearing holder or rolling element.

1) The roundness of the shaft and seat hole, as well as the verticality of the shoulder, should be determined according to the corresponding accuracy of the bearing. The bearing industry in China has developed rapidly with the import of bearings. The types of bearings have increased from few to many, the production quality and technical level have increased from low to high, and the industry planning has grown from small to large. It has now formed a professional production system with completely complete product categories and a relatively reasonable production layout.

2) It is necessary to correctly plan the interference amount of the rotating ring cooperation, as well as the suitable amount of the fixed ring cooperation. It is also advisable to achieve a relatively small amount of thermal interference in the rotating ring. As long as the thermal expansion effect at the operating temperature and the centrifugal force effect at higher speeds are effectively guaranteed, it is not possible to form tight cooperative nominal creep or sliding. The fixed ring is selected with extremely small gaps or interference fit based on the size of the working load and the bearing scale. Excessive looseness or tightness is not conducive to maintaining the original correct shape.

3) If the bearing operates at high speed and operates at high temperatures, special attention should be paid to the cooperation of the rotating ring not being too loose to prevent eccentric oscillation, and the cooperation of the fixed ring not having gaps to prevent deformation and oscillation of the ring under load.

Rolling bearings allow for slight operating noise during operation. If the noise is too loud or there is abnormal noise or impact sound, it indicates that the bearing is faulty. The bearing industry in China has developed rapidly with the import of bearings. The types of bearings have increased from few to many, the production quality and technical level have increased from low to high, and the industry planning has grown from small to large. It has now formed a professional production system with completely complete product categories and a relatively reasonable production layout.

The reasons for noise in rolling bearings are quite complex, one of which is nominal wear of the inner and outer rings of the bearing. Due to this type of wear and tear, the cooperative relationship between the bearings and the housing, as well as between the bearings and the shaft, has been damaged, resulting in the axis deviating from the correct orientation and producing abnormal noises during high-speed movement of the shaft. When the bearing is tired, its nominal metal will fall off, which will also cause the radial clearance of the bearing to increase and produce abnormal noise.