What is the primary function of the APU's lubrication system?

The primary function of the APU's lubrication system is to reduce friction and wear on moving parts. The lubrication system plays a critical role in ensuring the smooth operation of the APU by providing a continuous supply of lubricant to various components such as bearings, gears, and other moving parts. This lubrication forms a protective film that minimizes direct contact between metal surfaces, which is essential for preventing wear and extending the lifespan of the engine components.

By reducing friction, the lubrication system also helps maintain optimal operating temperatures, contributing to overall efficiency and performance. While other factors, such as vibration reduction and cooling, are influenced by the lubrication system, its core purpose remains focused on minimizing friction and wear, which is crucial for the reliability and longevity of the APU.