Ningbo Hengnuo Hydraulic Drive Co.,Ltd , https://www.hnhydraulic.com
How Friction, Temperature, and Lubrication are Related
When choosing bearings for your next project, there are three crucial factors to keep in mind, all of which depend on the load your equipment will handle and the speed at which it needs to run. These elements—friction, temperature, and lubrication—are central to how well your bearings perform. They influence the efficiency and longevity of your machinery, so it's vital to pick bearings that match the specific requirements of your application.
### The Role of Friction, Temperature, and Lubrication in Bearing Efficiency
#### Friction
Friction leads to wear across various components, including bearings. High friction levels can cause significant damage to machinery, resulting in costly repairs. Under normal conditions, rolling bearings tend to generate far less friction compared to sliding bearings, particularly when it comes to starting friction. This makes them a more efficient choice for many applications.
#### Temperature
Each bearing type and application has its own ideal operating temperature range. It’s essential to select bearings that can withstand the thermal conditions of your operational environment. A bearing’s temperature stability depends on balancing the heat it generates with the heat it can effectively dissipate.
Initially, the temperature around a bearing will spike rapidly once operations start. Over time, this temperature will slowly stabilize to a consistent level. The time it takes to reach this stable temperature varies depending on factors like the heat capacity of the shaft and bearing housing, the actual heat output, and the type of lubrication used. If temperatures persistently rise beyond expected levels, it could signal a malfunction that requires immediate attention.
#### Lubrication
Adequate lubrication is indispensable for reliable rolling bearing performance. Lubricants help minimize friction and wear, and in some cases, they also contribute to cooling the system. Heat generated by friction must be dispersed to prevent bearing damage. Using the correct lubricating oil can help manage this heat effectively. Systems employing recirculating oil lubrication, combined with additional cooling mechanisms, can provide excellent heat dissipation. Although grease doesn’t offer the same cooling benefits as oil, it remains the most commonly used lubricant. Therefore, the grease selected should align with the application’s operating parameters, NLGI grade, temperature tolerance, and service life expectations.
### How These Three Factors Interact in Bearing Design
Friction and grease resistance often work together to elevate bearing temperatures. At the start of operations, it’s common to see a sharp increase in internal bearing temperature. Gradually, this heat disperses into the shaft and housing, while the lubricant begins to play a role in maintaining temperature stability. However, excessive grease can cause churning, leading to increased heat. A general guideline is to fill bearings with 20%-30% grease, typically filling the spaces between the bearing balls on one side.
Persistent high temperatures can lead to reduced bearing clearance, degradation of running accuracy, and diminished lubricant effectiveness. All these factors contribute to shorter bearing lifespans, making it critical to consider temperature impacts during the selection process. For challenging environments, users might opt for higher-end technical greases that offer better temperature resistance and extended service life.
If you’re curious about identifying the best bearing type for your organization, consider downloading our eBook, Bearings 101, today. Understanding these foundational principles can make a significant difference in your equipment’s reliability and efficiency.