What is the formation mechanism of the lubricating film in self-lubricating scraper bearings, and how is its stability ensured?

Ensuring the long-term stable operation of self-lubricating scraper bearings hinges on the formation mechanism of the lubricating film and the assurance of its stability. Below is a detailed analysis of these two aspects:

Formation Mechanism of the Lubricating Film
Release of Solid Lubricants:
Self-lubricating scraper bearings are embedded with solid lubricants such as graphite and molybdenum disulfide. During operation, the frictional heat generated causes these solid lubricants to gradually release and migrate to the friction surfaces.

Lubricating Film Formation:
As the solid lubricants release and migrate, they form a uniform lubricating film on the friction surfaces. The primary function of this film is to reduce the friction coefficient, minimize wear, and protect the bearing from direct contact damage.

Dynamic Balance:
During operation, the lubricating film is continuously subjected to friction and wear. However, new solid lubricants are constantly released to replenish the film, creating a dynamic balance that maintains the film's integrity.

Assurance of Lubricating Film Stability
Material Selection and Optimization:
Choosing the appropriate solid lubricant is fundamental to ensuring the stability of the lubricating film. Different solid lubricants offer varying lubricating properties and stability, and must be selected based on specific application scenarios and requirements. Additionally, optimizing the bearing materials can enhance the stability of the lubricating film, such as by improving wear resistance and corrosion resistance.

Structural Design:
A well-designed bearing structure aids in the stable formation and maintenance of the lubricating film. For instance, the scraper design should ensure an even distribution of the lubricant on the friction surfaces, preventing localized under- or over-lubrication. Furthermore, the bearing's sealing design should prevent external contaminants from entering, thereby maintaining a clean and stable internal environment.

Operating Condition Control:
The operating conditions of the bearing significantly impact the stability of the lubricating film. Excessive temperatures, for example, may cause lubricant failure and film destruction, so the operating temperature of the bearing must be controlled within a specific range. Additionally, parameters such as speed and load should be managed to prevent excessive impact and damage to the lubricating film.

Maintenance and Monitoring:
Regular maintenance and monitoring are crucial for maintaining the stability of the lubricating film. By inspecting the bearing's wear, lubricant consumption, and the state of the lubricating film, potential issues can be detected and addressed promptly. Advanced monitoring techniques, such as vibration analysis and temperature monitoring, can also be used for real-time tracking and early warning of the bearing's operational status.

The formation mechanism of the lubricating film in self-lubricating scraper bearings relies on the release and migration of solid lubricants. Meanwhile, the stability of the lubricating film is influenced by factors such as material selection, structural design, operating conditions, and maintenance and monitoring. By comprehensively considering these factors and implementing corresponding measures, the long-term stable operation of self-lubricating scraper bearings can be ensured.