The excessive bearing temperature during the operation of the plate bending machine is a common and more harmful fault of rotating equipment. If the cause cannot be identified and the handling is improper, it will often reduce the service life of the bearing, increase the maintenance cost, and even burn the bearing. Therefore, quickly judging the cause of the excessive bearing temperature and taking appropriate solutions guarantee the continuous and safe operation of the equipment.
There are many reasons why the bearing temperature of the plate rolling machine is too high. The common ones are as follows.
Lubrication has an important influence on the service life of bearings and friction, wear, vibration, etc. Good lubrication is a necessary condition to ensure the normal operation of bearings. According to statistics, about 40% of bearing damage is related to poor lubrication. The role of lubrication on bearings mainly includes: preventing metal corrosion; preventing foreign matter from invading and acting as a seal; discharging friction heat to prevent the bearing temperature from rising too high; reducing friction and wear and extending bearing life.
The factors that usually cause poor bearing lubrication are: insufficient lubricating oil (grease), the lubricating oil pipe is blocked by foreign objects, etc., the quality of the lubricating oil (grease) is problematic, and the lubricating oil (grease) and lubricating oil (grease) are not added on time. Contains impurities.
As an important part, bearings are used in various large and small machinery, and some machinery (such as crushers) have a lot of dust in the working environment. When part of the fine dust enters the high-speed running bearing seat, the lubricating oil or grease in the bearing seat will deteriorate. , poor lubrication, and then the bearing wear. Bearings continue to run in a worn state, and heat increases due to increased friction, resulting in increased bearing temperatures.
Improper installation is another important cause of bearing heating. Whether the bearing is installed correctly or not has a direct impact on its life and the accuracy of the host, so the centerline of the shaft and the bearing hole must be coincident during installation. If the bearing is installed incorrectly, the accuracy is low, and the bearing has deflection, torque will be generated during rotation, causing the bearing to heat up or wear. In addition, the bearing will generate vibration, increase the noise, and increase the temperature rise.
Insufficient cooling is usually manifested as pipeline blockage, inappropriate selection of cooler, poor cooling effect, etc. The cooler of the lubrication line is fouled and blocked, which will cause the cooling effect to deteriorate, especially in a summer production, this problem is especially common. Individual manufacturers do not hesitate to increase or connect coolers in series to enhance the cooling effect. The cooler is seriously fouled, the bearing temperature is too high, and frequent alarms are encountered in many production sites. A more effective solution is to pickle the cooler before summer every year.
Check and replace not in time
If the bearing is found to be severely fatigued and peeled, oxidized and corroded, worn-out pits, cracks, or has excessive noise and cannot be adjusted, if the replacement is not timely, it will cause the bearing to generate heat, abnormal sound, vibration, etc., thus affecting the normal operation. Production. In addition, the vibration caused by improper disassembly of the bearing and loose anchor bolts of the equipment will also cause indentations in the bearing raceways and rolling elements, and cracking of the inner and outer races of the bearing. During the operation of the bearing, the inspection should be carried out according to the specified period.
Poor bearing quality
Rolling bearing parts work for a long time under high alternating contact stress in the form of point contact or line contact. The bearing largely determines the accuracy, life, and reliability of the main engine. Therefore, during the purchase and acceptance of the bearing, you must pay attention to the inspection, and use qualified and high-quality products from regular manufacturers.
How to solve it?
Improper amount of fuel
When the amount of refueling is improper and the lubricating oil is too much or too little, the bearing housing should be refueled regularly according to the requirements of the work. After the bearing is refueled, sometimes the temperature will be high, mainly due to excessive refueling. At this time, the phenomenon is that the temperature continues to rise, and after reaching a certain point (generally about 10 °C to 15 °C higher than the normal operating temperature), it will remain unchanged, and then gradually decrease.
Grease does not meet the requirements
When the added grease does not meet the requirements or is polluted: the selection of lubricating grease is not suitable, it is not easy to form a uniform lubricating oil film, and the internal friction and wear of the bearing cannot be reduced, the lubrication is insufficient, and the bearing temperature rises. When different types of grease are mixed, a chemical reaction may occur, causing the grease to deteriorate, agglomerate, and reduce the lubricating effect. Contamination of the lubricating grease will also increase the bearing temperature. Dust will fall into the grease during the process of adding grease, resulting in grease pollution, resulting in the deterioration of the grease inside the bearing housing, destroying the bearing lubrication, and increasing the temperature.
Therefore, appropriate grease should be selected, the bearing housing and bearing should be cleaned during maintenance, and the refueling pipeline should be checked and dredged. Different types of grease should not be mixed; if other types of grease are replaced, the original grease should be cleaned first; Regularly add grease, grease should be properly stored for moisture-proof and dust-proof measures.
When the cooling is insufficient, check whether the pipeline is blocked, and whether the inlet oil temperature and return water temperature exceed the standard. If the selection of the cooler is inappropriate, the cooling effect is poor, and cannot meet the requirements of use, it should be replaced in time or a new cooler should be installed in parallel. The axial flow-induced draft fan should also check the insulation and sealing of the core cylinder.