Why does the bearing temperature increase after filling with grease?

The impact of grease filling on bearing temperature is complex and multifaceted. It involves not only the amount of grease, but also the type, distribution, and use environment of the grease. Correct addition of grease can effectively reduce friction and wear during bearing operation, thereby maintaining a reasonable temperature level. However, improper addition method or amount may cause the temperature to rise, which not only affects the performance of the bearing, but may also shorten its service life. The following will provide a detailed analysis of the impact of grease filling on the increase in bearing temperature:

1. Adding too much will cause the temperature to rise

(1) Increase rotational resistance: When too much grease is added, it will stir violently inside the bearing, increase rotational resistance, and cause the temperature to rise.

(2) Accelerate the deterioration of grease: The increase in temperature will accelerate the oxidation rate of grease, causing it to deteriorate in advance and shorten its service life. The precipitation of base oil accelerates, causing the grease to dry out and harden, further deteriorating the lubrication conditions and forming a vicious cycle.

2. Improper filling amount affects bearing performance

(1) Increase in friction torque: When the grease filling amount increases, the friction torque increases, causing the bearing temperature to increase.

(2) Sealing problem: Too much grease will also increase the pressure on the seal, which may cause the seal to rupture or fail, introduce impurities or moisture, and cause damage to the bearing.

3. Uneven distribution of grease leads to local overheating

(1) New grease integration problem: The newly added grease fails to melt quickly and distribute evenly, resulting in excessive local friction and an increase in temperature.

(2) Running-in period: There should be a running-in period after new grease is added, and the rotation speed is reduced to 30~60% of standard operation to avoid overheating problems caused by uneven distribution.

4. Improper grease type affects lubrication effect

(1) Wrong grade selection: Using a grease grade that does not match the bearing requirements may lead to poor lubrication effect and increased temperature.

(2) Grease deterioration or contamination: If the grease is contaminated or deteriorated, it will lose its normal lubrication function, increase the friction resistance of the bearing operation, and then cause the temperature to rise.

5. Assembly quality and environmental issues

(1) Improper assembly: Improper assembly of the bearing, such as too loose or too tight fit with the end cover, can also cause abnormal temperature rise.

(2) Environmental impact: Insufficient cleanliness of the bearing and its surrounding environment will also cause adverse effects on the bearing, including an increase in temperature.

6. Improper operation and maintenance

(1) Improper refueling technology: Improper operation when adding grease, such as improper pressure control of the grease gun, may also lead to excessive or uneven addition of grease, causing the temperature to rise.

(2) Insufficient maintenance monitoring: Lack of proper monitoring and maintenance of the operating status of the bearing may result in the inability to detect and deal with problems that cause temperature rise in time.

In addition to the above, you also need to pay attention to the following aspects:

(1) Determine the appropriate grease filling amount to avoid too much or too little.

(2) Select the appropriate grease type to ensure it matches the bearing requirements.

(3) When adding grease, pay attention to the operation method to avoid problems caused by improper technical operation.

(4) Regularly inspect and maintain bearings to ensure the cleanliness of the bearings and their surrounding environment.

Summary: Factors such as the amount, type, distribution and usage environment of grease all have an important impact on the temperature of the bearing. Correct grease filling and maintenance methods can effectively control the temperature of the bearing and ensure its normal operation and long-term durability.