Why does the bearing temperature rise even after lubricant has been applied?

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The effect of grease filling on bearing temperature is complex and multifaceted, involving not only the amount of grease but also factors such as the type of grease, its distribution, and the operating environment. Proper application of lubricant can effectively reduce friction and wear during bearing operation, thereby maintaining a reasonable temperature level; however, improper application methods or amounts can lead to an increase in temperature. The following analyzes the impact of grease filling on the increase in bearing temperature: Excessive amount of grease leads to an increase in temperature. 1. Increased rotational resistance: When too much grease is used, it moves vigorously inside the bearing, increasing rotational resistance and thus raising the temperature. 2. Accelerated deterioration of lubricating grease: Rising temperatures speed up the oxidation process of lubricating grease, causing it to deteriorate sooner and reducing its service life. The precipitation of the base oil accelerates, causing the grease to dry out and harden, which further deteriorates the lubrication conditions, creating a vicious cycle. Uneven distribution of grease leads to localized overheating. 1. Issue with the integration of new grease: The newly added grease fails to melt and distribute evenly, resulting in excessive local friction and thus an increase in temperature. 2. Running-in period: After new lubricant is added, a running-in period is required, with the speed reduced to 30–60% of the standard operating speed, in order to avoid overheating caused by uneven distribution. An inappropriate type of grease affects the lubrication performance. 1. Incorrect grade selection: Using a grease grade that does not meet the requirements of the bearings can result in poor lubrication and an increase in temperature. 2. Degraded or contaminated grease: If lubricating grease is contaminated or degraded, it loses its normal lubricating function, increasing the frictional resistance during bearing operation and thus leading to an increase in temperature. Assembly quality and environmental issues 1. Improper assembly: Incorrect assembly of bearings, such as too loose or too tight a fit with the end caps, can also lead to abnormally high temperatures. 2. Environmental impact: Insufficient cleanliness of the bearings and their surrounding environment can also have an adverse effect on them, including an increase in temperature. Improper operation and maintenance: 1. Incorrect greasing technique: Improper handling during the application of grease, such as inadequate control of the pressure from the grease gun, can also lead to excessive or uneven application of grease, thereby causing an increase in temperature. 2. Insufficient maintenance and monitoring: A lack of proper monitoring and maintenance of the bearing’s operating condition may result in problems that cause temperature increases not being detected and addressed in a timely manner. In addition to the above, the following aspects also need attention: 1. Determine the appropriate amount of grease to be filled, avoiding either too much or too little. 2. Select the appropriate type of grease to ensure it meets the requirements of the bearing. 3. When filling in lubricant, pay attention to the proper procedures to avoid problems caused by improper technical handling. 4. Regularly inspect and maintain the bearings to ensure that the bearings and their surrounding area remain clean.