1. After the installation of bearings, it is important to neglect the debugging of bearings that cannot be ignored After the installation of the bearings, add the specified lubricant and conduct a trial run to check for any noise and bearing temperature. The trial operation should be carried out under partial load conditions, and in the case of a large speed range, it should be operated at medium to low speeds. Under no circumstances should self-aligning roller bearings be started and accelerated to high speed under no-load conditions, as rolling components may slide on the bearing raceway, damage the raceway, and the cage may also be subjected to unacceptable pressure. Under normal circumstances, bearings will make a uniform "gurgling" sound. The bearing makes a whistling or sharp and piercing sound, indicating insufficient lubrication. The uneven rumbling or hammering sound of bearings is mostly due to the presence of debris in the bearings or damage to the bearings during installation. After starting, the temperature of the bearing immediately increases, which is a normal phenomenon. For example, in the case of grease lubrication, the bearing temperature will not decrease until the grease is evenly distributed inside the bearing, after which the equilibrium temperature will be reached. Abnormal high temperature or continuous significant increase in temperature indicate that there may be too much lubricant inside the bearing, or that the bearing has undergone radial or axial deformation, or that the clearance is too small. Other reasons include improper manufacturing or installation of related components, or excessive friction of seals. During or immediately after the trial operation, the seals should be checked to ensure proper functioning, and the lubrication equipment and oil level in the oil tank should also be checked. It may also be necessary to take lubricant samples to determine whether the interior of the bearing is contaminated or whether the components inside the bearing are worn.
2. Factors and intrinsic factors affecting the service life of bearings There may be many factors that affect the service life of self-aligning roller bearings, which can be further explained from both usage and intrinsic factors. The usage factors mainly refer to whether the installation, adjustment, maintenance, repair, etc. meet the technical requirements. According to the technical requirements for the installation, use, maintenance, and upkeep of self-aligning roller bearings, monitor and inspect the load, speed, working temperature, vibration, noise, and lubrication conditions that the bearings are subjected to during operation. If any abnormalities are found, immediately identify the cause and make adjustments to restore them to normal. Installation conditions are one of the primary factors in use. Improper installation of bearings often leads to changes in the stress state between various parts of the entire bearing system, causing the bearing to operate in an abnormal state and end its service life prematurely. The amount of force applied during the installation of bearings can affect their performance and lifespan, as well as cause damage to the bearings. Here are four tips to pay attention to during the force application process: 1. The magnitude of the applied force should be stable and uniform, without any impact. This requires the use of oil pressure or tools that can apply stable tension or pressure. If hammering is necessary, it should also be buffered by softer and less debris free metals such as copper sleeves, and the impact force should be as light and gentle as possible. It is best to use a copper rod or copper hammer for hammering. 2. Apply force continuously until the work is completed. For example, when installing a bearing, stop applying force when the bearing is just installed in the correct position, ensuring that the end face of the ring (washer) is pressed against the seat hole or the shoulder end face of the shaft, neither too tightly nor improperly installed. 3. The resultant force of the applied force should pass through the axis of the bearing as much as possible, which requires the application point to be uniform, symmetrical, and smooth, and applied through a spherical surface or parallel to the axis. 4. Avoid applying force through rolling elements, which requires applying force through the inner ring when installing and removing the inner ring (shaft ring), and applying force through the outer ring when installing and removing the outer ring. As long as the force applied during the installation and removal of bearings is stable and uniform, without any impact, and the force should be applied continuously until the work is completed, there will be no damage to the bearings during installation. The metallurgical quality of self-aligning roller bearing materials used to be the main factor affecting the early failure of self-aligning roller bearings. With the advancement of metallurgical technology, such as vacuum degassing of bearing steel, the quality of raw materials has been improved. The proportion of raw material quality factors in bearing failure analysis has significantly decreased, but it is still one of the main influencing factors of bearing failure. Whether the material selection is appropriate is still a factor that must be considered in bearing failure analysis. The manufacturing of self-aligning roller bearings generally involves multiple processing steps such as forging, heat treatment, turning, grinding, and assembly. The rationality, progressiveness and stability of each processing technology will also affect the service life of bearings. The heat treatment and grinding processes that affect the quality of finished bearings are often more directly related to bearing failure. In recent years, research on the deteriorated layer on the working surface of bearings has shown that the grinding process is closely related to the surface quality of bearings.
The main task of analyzing the service life of self-aligning roller bearings is to identify the main factors causing bearing failure based on a large amount of background materials, analysis data, and failure forms, in order to propose targeted improvement measures, extend the service life of bearings, and avoid sudden early failure of bearings. The vibration of self-aligning roller bearings can be divided into three types according to the direction of vibration: 1. Radial vibration. Vibration within the radial plane of the bearing ring. 2. Axial vibration. Vibration along the axis of the bearing. 3. Angular vibration. The oscillation of the radial plane of the ring relative to the diameter. The vibration of self-aligning roller bearings can be divided into the following three types according to their generation mechanism: 1. Natural vibration of bearing structure (1) Consider the outer ring as an inherent vibration caused by an elastic body. (2) Consider the outer ring as an inherent vibration caused by the steel body. (3) Consider steel balls as inherent vibrations of the steel body. 2. Forced vibration (1) The rolling elements undergo vibration, which is caused by the period of the rolling elements passing through the load line during the operation of the bearing. (2) Vibration caused by manufacturing errors in bearing components. 3. Impact vibration When there are defects such as scratches, burrs, rust spots, pitting, peeling pits, and dust on the surface of the ring raceway or rolling element, it will excite the bearing pulse type vibration. The period of the pulse is inversely proportional to the speed, and the amplitude is related to the size of the defect. The vibration of self-aligning roller bearings is often the result of the combined action of various types of vibrations mentioned above. Numerous experimental studies have shown that under normal bearing operation, the surface waviness of bearing components is the main factor causing bearing vibration.
