Thermal management of radial bearings for high-speed pumps: the key to ensuring stable operation

Sources of heat generation
During the operation of high speed pump journal bearings, the main source of heat is friction and wear inside the bearings. The interaction between the rolling elements and raceways, between the cage and the rolling elements, and between the lubricating oil films inside the bearings will all generate friction resistance. As the speed increases, these friction effects become more intense, resulting in a large amount of mechanical energy being converted into heat energy. In addition, the bearing material will also suffer microscopic wear due to long-term high-load operation, further exacerbating the generation of heat.

Impact and challenges of heat
If this heat cannot be effectively dissipated, the bearing temperature will continue to rise, bringing about a series of chain reactions. First, high temperature will accelerate the oxidation and decomposition of the lubricant, resulting in a decrease in lubricant performance and weakened lubrication effect, thereby increasing the friction coefficient and wear rate of the bearing. Secondly, the bearing material expands due to heat, which may cause changes in the bearing clearance, affecting the accuracy and stability of the bearing. This clearance change may also intensify vibration and noise, reducing the operating efficiency of the pump. Furthermore, as the temperature continues to rise, the hardness and strength of the bearing material will also decrease, making the bearing more susceptible to plastic deformation or fatigue damage.

More seriously, a continuous high temperature environment may cause phase changes in the bearing material, such as annealing or tempering, which seriously weakens its mechanical properties. In extreme cases, the bearing may fail directly due to overheating, causing an emergency shutdown of the pump system, which not only causes production interruptions, but also may cause equipment damage and safety hazards.

Strategies and measures for thermal management
Given the importance of thermal management of high-speed pump radial bearings, it is particularly important to take effective measures to reduce bearing temperature and ensure its stable operation. The following are some commonly used thermal management strategies:

Optimize bearing design: By improving the bearing structure, such as adopting a more reasonable raceway shape, optimizing the distribution of rolling elements, etc., the friction area and friction coefficient can be reduced, thereby reducing heat generation.
Select high-performance lubricating materials: Select lubricating oil or grease with excellent oxidation resistance, high lubricity and thermal stability to improve lubrication efficiency and extend the service life of lubricating oil.
Strengthen the cooling system: Design efficient cooling channels on the bearing seat or pump housing, use circulating cooling water or air for heat exchange, and take away the heat generated by the bearing in time.
Implement temperature monitoring and early warning: Install temperature sensors to monitor bearing temperature in real time and set up an early warning system. Once the temperature exceeds the set threshold, take immediate measures, such as reducing the speed or starting a backup pump.
Regular maintenance and inspection: Clean, lubricate and inspect bearings regularly to detect and handle potential failure points in a timely manner and keep bearings in good working condition.