Daily maintenance of bearings
In the daily production and life, it is necessary to check the working performance of the bearing in time to achieve early detection and early repair.
1. Perform bearing repair and assembly quality
The quality of the hinge of the bearing is ensured, and the back of the INA bearing is smooth and freck-free, and the positioning bump is intact; its own opening amount is 0.5-1.5mm, which ensures that the bearing bush fits tightly with the bearing hole by its own elastic force after assembly; When assembling, pay attention to check the machining quality of the crankshaft journal and bearing, strictly implement the repair process specification, prevent the installation from being improper due to improper loading method, and the torque unevenness or non-conformity of the bearing bolt, resulting in bending deformation and stress. Concentration, leading to early damage to the bearing.
2. Improve bearing design and manufacturing process
When designing or selecting imported bearings, the thermal balance of the bearing should be considered to control the temperature rise. Because the INA bearing works in the rubbing state, the internal friction (viscosity) of the lubricating oil causes the power consumption, which is converted into heat and causes the sliding bearing to rise. lubricating oil. When the viscosity is lowered and the gap is changed, the Babbitt alloy of the bearing is softened, and a "burning tile holding shaft" accident occurs when the temperature is severe. Therefore, in the structural design, the oil hole is opened from the top of the upper bearing bush (non-load bearing zone) of the bearing to introduce the lubricating oil from the non-load bearing zone; the oil groove is opened in the longitudinal or lateral direction with the oil inlet hole as the center on the inner surface of the bearing bush. Conducive to the average distribution of lubricating oil on the journal to control the temperature rise.
The criteria for proper lubricant selection include the type and size of the bearing, temperature, speed, load, and expected service life and relubrication cycle.
The initial radial clearance of the bearing is gradually reduced during the push-in process, and the amount of push-in determines the degree of fit. Therefore, the initial radial clearance of the roller bearing must first be measured before installation. During the push-in of the INA bearing, the radial clearance is continuously measured until the required radial clearance reduction and the desired interference fit are achieved.
Because the temperature is affected by lubrication, speed, load, and environment. Lubrication of bearing lubrication has an important influence on the fatigue life of rolling bearings and friction, wear, temperature rise, vibration, etc. Without normal lubrication, the bearings cannot work. Analysis of the cause of bearing damage indicates that about 40% of bearing damage is associated with poor lubrication. Therefore, good lubrication of the roller bearings is an effective measure to reduce bearing friction and wear. In addition, the lubrication of the sliding bearing also has various functions such as heat dissipation, rust prevention, sealing, and mitigation of impact. The effect of bearing lubrication can be briefly explained as follows:
a. forming an oil film between the two rolling surfaces or sliding surfaces that are in contact with each other to separate the two surfaces, reducing friction and wear of the contact surface.
b. When using oil lubrication, especially when using circulating oil lubrication, oil mist lubrication and fuel injection lubrication, the lubricating oil can take away most of the friction heat inside the bearing and play an effective heat dissipation effect.
c. When grease lubrication is used, it is possible to prevent foreign matter such as dust from entering the INA bearing and sealing.
d. Lubricants have the effect of preventing metal corrosion.
e. Extend the fatigue life of the roller bearing.
