Laser cladding for the repair of York compressor rotors

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1. The outer cavity length of the York screw rotor is 396.8 mm; the actual effective compression length of the screw rotor is 396.0 mm (both the male and female screws have a length of 396 mm, with minimal axial wear). The compressor model is TDSH233L, and the unit model is RWBII222; the rotor length should be 233 * 1.7 = 396.1 mm. The difference is 0.8 mm. The exhaust gap is 15–20 silk units, while the corresponding intake gap is 60–65 silk units.

2. The female rotor was welded, and three cuts were made on its exhaust end face for dynamic balancing; the deepest cuts reached 3 mm, with lengths ranging from 3 to 4 mm. There are three damage marks on the exhaust-side rotor profile, each with a depth of 3 mm. There are two damage marks on the intake end face, similar in depth to those on the exhaust side.

3. On the male rotor’s intake side, there are three welding spots, covering a large area. One spot without welding has a damage depth of 10 mm. On the exhaust side, there is one welding spot, with multiple deep and long damage marks.

4. The customer installed a sealing sleeve on the intake side of the male rotor, which altered the original shaft diameter. The actual measured diameter is 110.0 mm, while the standard diameter should be 111.6 mm. The diameter of the corresponding part of the intake seat is 112.0 mm, resulting in a difference of 0.4 mm. There is normally a 20-silk-unit gap between the intake seat and the shaft. After replacing the intake seat, the diameter of the corresponding part of the male rotor must be increased to 111.6 mm to prevent increased oil leakage and poor bearing lubrication. Careful consideration should be given to options such as shaft plating or sleeve installation.

5. Laser repair of the rotor allows for control over its length. This is achieved by measuring the distance from the exhaust end face to the shaft shoulder or shaft head (the original exhaust end face was worn). The original shaft shoulder or shaft head remains unchanged, and the original distance is maintained after repairing the exhaust end face. On the intake side, the effective compression length of the entire rotor can be measured, allowing it to be appropriately shortened in order to increase the intake side gap. Before repair After repair