What is the relationship between bearings and temperature during rotational operation?

Nov 11, 2024

The relationship between bearings and temperature is very important for bearings during mechanical operation. The performance and life of bearings are often significantly affected by temperature changes.

1. The basic relationship between bearings and temperature

Bearings are key components in mechanical equipment. Their main functions are to support and rotate while reducing friction and wear. However, during the operation of the bearing, the temperature of the bearing will change at any time due to friction, heat accumulation and changes in lubrication conditions. This temperature change not only affects the performance of the bearing but may also cause potential risks to the operation of the entire production line.

1.1. Relationship between lubrication and temperature

Lubrication is one of the key factors for the normal operation of bearings. Choose a suitable and appropriate amount of lubricating oil or grease because the viscosity of these lubricating media is closely related to temperature. Generally, the viscosity of lubricants decreases as temperature increases. Changes in viscosity directly affect the formation and maintenance of the lubricating film, which in turn affects the friction and wear properties of the bearing.

When the temperature is lower, the viscosity of the lubricant is higher, which is beneficial for forming a stable lubricating film and reducing friction and wear. However, as temperature increases and viscosity decreases, the lubricating film may become unstable, resulting in increased friction and wear. In addition, high temperatures may accelerate the oxidation and degradation of lubricants and reduce their lubricating properties. Therefore, if you need to continue working at high temperatures, you need a special high-temperature lubricant.

1.2. Relationship between friction and temperature

During the operation of the bearing, contact friction will occur between the rolling elements and the outer ring and inner ring. This friction generates heat, causing the temperature of the bearing parts to rise. The increase in temperature will intensify friction and wear, forming a vicious cycle. When the machine is running, it is necessary to check the temperature.

In order to reduce friction and temperature, grease or oil is usually added to reduce the friction coefficient of the contact surface. However, as temperatures increase, the lubricant's effectiveness may decrease, resulting in increased friction and wear. Therefore, lubricants and lubrication methods need to be properly selected to ensure that the bearings maintain appropriate temperature and lubrication conditions during normal operation.

2. Effect of temperature on bearing performance

The influence of temperature on bearing performance is multifaceted, including lubrication performance, load-bearing capacity, clearance changes, thermal expansion, etc.

2.1. Changes in lubrication performance

As mentioned earlier, an increase in temperature will reduce the viscosity of the lubricant, thereby affecting the formation and maintenance of the lubricating film. In addition, high temperatures may accelerate the oxidation and degradation of lubricants, resulting in a decrease in lubrication performance. These changes may increase the friction and wear of the bearings and reduce the service life of the bearings.

2.2. Changes in carrying capacity

The load-carrying capacity of a bearing is closely related to the rigidity and lubrication state of its internal structure. The increase in temperature may cause the lubricating film to become unstable, thereby reducing the load-carrying capacity of the bearing. In addition, high temperatures may cause thermal expansion and softening of bearing materials, further reducing their load-bearing capacity.

2.3. Changes in clearance

The clearance of the bearing refers to the gap between the rolling elements and the inner and outer rings. Under conditions of temperature change, the inner and outer rings of the bearing may expand in different amounts, resulting in changes in clearance. Changes in clearance will affect the rotation accuracy and load-carrying capacity of the bearing. The internal clearance of the bearing with normal clearance will be too small and become stuck, which may even destroy the normal operation of the bearing.

2.4. Effect of thermal expansion

Bearings generate heat during operation, causing the temperature to rise. As the temperature increases, the bearing material will thermally expand, the fit with the shaft may become looser, and the fit with the bearing seat may become tighter. This change in fit may lead to a reduction in bearing clearance or even jamming.

3. Management and control of bearing temperature

In order to ensure the normal operation of the bearing and extend its service life, the bearing temperature needs to be managed and controlled. Here are some commonly used methods:

3.1. Choose lubricants reasonably

According to the working conditions and requirements of the bearing, the lubricant and lubrication method should be reasonably selected. In high-temperature environments, lubricants with higher viscosity index and antioxidant properties should be selected to ensure that the bearings can still maintain good lubrication conditions at high temperatures. Some working environments require low-temperature grease; that is, the bearing has normal lubrication function at low temperatures.

3.2. Strengthen lubrication management

Carry out regular lubrication inspection and maintenance on bearings to ensure the quality of the lubricant. Replace aging and deteriorated lubricants promptly to avoid damage to the bearings.

3.3. Monitor bearing temperature

Real-time monitoring of bearing temperature using temperature sensors. When the temperature exceeds the set value, an alarm signal will be sent out in time so that corresponding measures can be taken. For example, bearing temperatures can be reduced by adding cooling devices or adjusting operating parameters.

3.4. Optimize bearing design

During the bearing design process, the impact of temperature on bearing performance is fully considered. By optimizing the bearing structure, materials and lubrication methods, we can improve the high-temperature resistance and load-bearing capacity of the bearings. At the same time, mechanical equipment should be maintained and maintained regularly to ensure its normal operation and extend its service life.

In summary, the relationship between bearings and temperature is close and important. Temperature changes directly affect the bearing's lubrication performance, load-carrying capacity, clearance changes and thermal expansion. In order to ensure the normal operation of the bearing and extend its service life, the bearing temperature needs to be managed and controlled. Through reasonable selection of lubricants, strengthening lubrication management, monitoring bearing temperature, optimizing bearing design and other measures, its performance can be effectively improved. At the same time, it is also necessary to strengthen research and exploration on bearing temperature issues to provide a more powerful guarantee for the normal operation and safe production of mechanical equipment.