Why does bearing temperature increase after grease has been added?

The impact of grease addition on Angular contact ball bearing temperature is complex and multifaceted, involving not only the amount of grease but also the type, distribution, and operating environment. Properly adding grease can effectively reduce friction and wear during angular contact ball bearing operation, maintaining a reasonable temperature level. However, improper addition methods or amounts can lead to an increase in temperature.

• Reasons for Temperature Increase Due to Excessive Grease Addition

 1. Increased Rotational Resistance:  Excessive grease can cause severe churning within the Angular contact ball bearing, increasing rotational resistance and thus raising the temperature.

 2. Accelerated Grease Deterioration: Elevated temperatures accelerate the oxidation of the grease, causing it to deteriorate prematurely. This leads to the base oil seeping out faster, causing the grease to dry and harden, further worsening lubrication conditions and creating a vicious cycle.

• Uneven Grease Distribution Leading to Localized Overheating

1. Integration of New Grease: Newly added grease may not immediately melt and distribute evenly, causing excessive local friction and an increase in temperature.

2. Break-in Period: After adding new grease, a break-in period is necessary, with the rotational speed reduced to 30-60% of the standard operating speed to prevent overheating due to uneven distribution.

• Inappropriate Grease Type Affecting Lubrication Effectiveness

1. Incorrect Grade Selection: Using a grease grade that does not match the bearing’s requirements can result in poor lubrication and elevated temperatures.

2. Contaminated or Deteriorated Grease: If the grease is contaminated or has deteriorated, it loses its normal lubricating function, increasing frictional resistance and raising the temperature.

• Assembly Quality and Environmental Issues

1. Improper Assembly: Incorrect assembly, such as the Angular contact ball bearing fitting too loosely or tightly with the end cap, can also cause abnormal temperature rises.

2. Environmental Impact: Insufficient cleanliness of the bearing and its surrounding environment can negatively affect the bearing, including causing temperature increases.

• Improper Operation and Maintenance

1. Improper Operation and Maintenance: Improper techniques when applying grease, such as incorrect pressure control with a grease gun, can lead to excessive or uneven grease addition, causing temperature increases.

2. Insufficient Maintenance Monitoring: Frequent shock loads can damage the bearing. Selecting bearings with high shock load capacity can improve their lifespan.

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