Repair Methods for Wear on the Main Shaft Journal of Stainless Steel Centrifugal Fans

Repair Methods for Wear on the Main Shaft Journal of Stainless Steel Centrifugal Fans

Basic Introduction to Stainless Steel Centrifugal Fans: The main shaft of a stainless steel centrifugal fan is a critical component connecting the fan blades to the fan base. The main shaft is made of hollow stainless steel, and machining its inner bore is particularly challenging. The primary machining equipment for the fan’s main shaft is a deep-hole drilling machine. Given the characteristics of the fan’s main shaft, modifications to the head of the deep-hole drilling machine are required. The main shaft of a wind turbine experiences both radial and axial displacement. In practice, axial displacement of the main shaft is directly transmitted to the input shaft of the gearbox. Unless special measures are taken to control the radial clearance of spherical roller bearings, axial clearance, and the positioning of planetary gears, axial displacement will adversely affect the planetary gear support bearings within the gearbox. The axial displacement of the main shaft in a stainless steel centrifugal fan depends on the system’s rigidity and the internal clearance of the fixed-end bearing. After installing pre-tightened multi-row tapered roller bearings at the fixed end, the axial displacement at the right end of the main shaft is approximately one-fourth of that when using spherical roller bearings. Reducing axial displacement minimizes the risk of axial compression on the gearbox input shaft. This is of critical importance. When one end is fixed and the other is floating, the fixed-end bearing (multi-row tapered roller bearing or spherical roller bearing) can withstand both radial and axial forces, while the floating-end bearing (cylindrical roller bearing or spherical roller bearing) can only withstand radial forces. Since the direction of the axial force is from the rotating end to the gearbox end, regardless of whether multi-row tapered roller bearings or spherical roller bearings are used, only the single row of rollers near the gearbox end can bear the entire axial force. Wear Patterns and Repair Techniques for Stainless Steel Centrifugal Fans: If the retaining sleeve of a stainless steel centrifugal fan becomes loose, it can be tightened for maintenance based on any abnormal noises emitted by the fan. Generally, if the stainless steel centrifugal fan is not in use for an extended period, the locking nut securing the sleeve may come loose, causing the sleeve to slide toward its wider end. This results in the bearing inner ring directly wearing against the journal, accelerating and worsening wear. Repair Method: For slightly worn components, use an inverter-driven pulse brush to perform repair machining.