During bearing operation, the retainer must withstand stresses caused by friction, impact, centrifugal force, and inertial force. They may also be chemically affected by certain organic solvents or coolants, lubricants, and lubricant additives. Therefore, the cage is easily damaged. Below, Fuhai He's editor will explain the reasons for abnormal heating of the lower bearing and the damage to the cage:

(1) The coaxiality of the bearing seat hole, the stiffness of the seat hole wall, and the force and sequence of tightening the bolts can all cause deformation of the bearing seat hole and bearing, resulting in abnormal heating and vibration, irregular vibration impact, compression, uneven wear, and even fracture of the retainer.

(2) Due to the misalignment of the tape wheels, the shaft is subjected to additional axial force, while the self-aligning ball bearings installed on the optical shaft are not suitable for bearing axial force, resulting in abnormal temperature rise of the bearings and accelerated wear of the cage.

(3) During the assembly and adjustment of the inner cone sleeve, the temperature increased from 30 ℃ before replacing the tape to 43 ℃, and then decreased to below 40 ℃.

(4) The reason for the high temperature of bearings is not only related to assembly quality, but also directly related to the cleanliness, quality, variety, and viscosity of the oil (grease), especially high speed bearings are more sensitive to the viscosity of the oil. For example, the room fan has a high rotational speed, low air volume, high air pressure, and small torque. It is reasonable to use thin oil for high-speed and light load equipment and bearings, as high rotational speed can easily form a bearing oil film, reduce friction resistance of rolling elements, and facilitate cleaning and heat dissipation. However, the bearing box of the No. 1 fan has been using N320 medium load process gear oil since the beginning of production. After the problem was raised, it was changed to N22O, but the viscosity is still high. If it could be changed to HJ20HJ3012>, the result would be better, The temperature will also drop from around 60 ℃ for a long time.

(5) Due to the lack of oil drainage holes in the bearing seat, excess oil can only be squeezed out from the shaft neck, and the refueling interval is short. Although not much is injected each time, the oil chamber is quickly filled, causing a sudden increase in the working temperature of the bearing by 25-35 ℃. This is the reason for the sudden increase in bearing temperature during normal operation. This situation continued for several days and improved with the extrusion of oil. Long term repetition not only wastes and affects the bearing life, but also increases the difficulty of fault diagnosis. Due to the increase in bearing temperature, the rolling contact stress increases, the viscosity and adsorption of grease decrease, and wear increases; In addition, due to the higher temperature of the bearing ring compared to adjacent parts such as the cone sleeve, thermal expansion may cause the originally less tight fit to loosen. The temperature rise caused by excessive oil and the temperature rise caused by loose sleeve are difficult to distinguish at the beginning, and sometimes the influence of thermal expansion causes both to exist simultaneously. In short, repeated results will inevitably make the hole and shaft fit tend to loosen. This situation often occurs mainly due to inappropriate lubrication regulations, and at the same time, the operator also has the idea of "more than less" when refueling. It is not necessary to add oil frequently in a closed oil chamber, as long as there is oil in the raceway, it will not cause oil shortage faults under normal operation. In addition, oil holes can also be installed at appropriate positions on the bearing seat to allow for regular refueling and avoid the phenomenon of temperature rise for a few days each time.

(6) Too much tension on the tape can also increase the temperature of the bearings, intensify vibration, and make the tape more susceptible to damage. Due to the increase in radial load of the bearing, elastic deformation occurs at the contact between the rolling element and the raceway, increasing frictional heat and wear, which can easily cause pitting corrosion.

(7) Abnormal vibration or shaft bending of the fan often causes the bearings to rapidly heat up and be easily damaged. The abnormal operation of bearings is related to misunderstandings in understanding. For a long time, the working temperature of bearings has similar regulations in almost all equipment technical documents. Some people have misconceptions and misunderstandings about the issue of bearing temperature rise. The author has encountered this situation in several factories. In many technical documents, it is stipulated without distinction or distinction between equipment objects that the working temperature rise of bearings shall not exceed 30 ℃, 40 ℃, or 65 ℃, 75 ℃, 80 ℃, and 90 ℃, etc.

Regular maintenance is necessary during the use of the cage to extend its service life!