On a centrifugal refrigeration compressor, where is oiling required?

In a centrifugal refrigeration compressor, proper lubrication is critical for the efficient operation and longevity of the machine. Oiling is required at various critical points to ensure smooth functioning and minimize wear.

The correct answer includes lubrication at the shaft end bearings, which support the rotor and are essential for maintaining alignment and reducing friction. The stage separators also require lubrication to ensure proper operation, as they help separate the refrigerant stages, preventing mixing and ensuring efficiency. Additionally, oiling the rotor itself is necessary to aid in cooling and to maintain the efficiency of the compressor's operation by reducing friction within the rotor.

This comprehensive approach to lubrication ensures that all moving parts operate smoothly, reducing the risk of mechanical failure and prolonging the life of the compressor. The inclusion of all these components in the lubrication process addresses the needs of the entire system rather than focusing on just one area, making it critical for optimal performance.