The correct application of grease is crucial for bearing temperature control; the underlying mechanisms involve a variety of variables, including the quantity, type and distribution of the grease, as well as the operating environment. When applied correctly, grease can significantly reduce friction and wear during shaft operation and maintain stable temperatures; however, if applied incorrectly, it can have the opposite effect, raising temperatures and damaging the health of the bearings. The following is an in-depth analysis of how grease application affects bearing temperature rise:

Temperature Rise Caused by Excessive Grease

Increased Rotational Resistance: Excessive grease causes excessive agitation within the bearing, increasing rotational resistance and consequently leading to a rise in temperature.

Accelerated Degradation: The rise in temperature accelerates the oxidation rate of the grease, causing it to age rapidly. The separation of the base oil causes the grease to harden, impairing lubrication performance and creating a vicious cycle.

Inappropriate Filling Levels and Bearing Performance

Increased Friction Torque: Excessive grease filling increases friction torque, driving up bearing temperatures.

Compromised Sealing: Excess grease exerts additional pressure on seals, potentially damaging them and allowing contaminants and moisture to penetrate, causing bearing damage.

Uneven Grease Distribution and Localised Overheating

New Grease Integration Issues: Newly added grease fails to mix and distribute evenly quickly, leading to increased localised friction and rising temperatures. The Necessity of a Running-in Period: New grease requires a running-in period; initial rotational speed should be limited to 30–60% of normal operating speed to prevent overheating caused by uneven distribution. Inappropriate Grease Type and Lubrication Performance

Incorrect Specification Selection: Selecting a grease type that does not meet the bearing’s requirements may result in poor lubrication and increased temperatures.

Grease Deterioration or Contamination: Contaminated or deteriorated grease loses its lubricating properties, increasing friction and causing temperatures to rise.

Assembly Quality and Environmental Factors

Assembly Defects: Improper bearing assembly, such as incorrect clearance between the bearing and the end cap, can cause abnormal temperature rises.

Environmental Contamination: Insufficient cleanliness of the bearings and their surroundings can also have a negative impact on the bearings, including increased temperatures.

Operational and maintenance negligence

Lack of lubrication technique: Improper operation during the lubrication process, such as incorrect pressure control, may result in excessive or uneven grease distribution, leading to increased temperatures.

Inadequate maintenance monitoring: A lack of effective monitoring and maintenance of bearing operating conditions may result in missed opportunities to address temperature rise issues in a timely manner.

Key considerations: Determine the appropriate grease capacity to prevent over-lubrication or under-lubrication.

Select a suitable grease grade to ensure it meets the bearing’s requirements. Pay close attention to lubrication techniques to avoid potential issues caused by improper operation. Conduct regular inspections and maintenance to ensure the cleanliness of the bearings and their surrounding environment. Conclusion: The quantity, type, distribution and operating environment of the grease have a profound impact on bearing temperature. Adhering to correct grease management strategies can effectively regulate bearing temperature, ensuring reliable operation and long-term durability.