Stator vanes are small but essential components that convert rotational energy into static pressure through the change in flow. Thus, those little components play a vital role in the operation and efficiency of the entire power generation device. Part of high-pressure compressors, such as those found in jet engines, variable stator vanes regulate the airflow in the compressor. To do that smoothly, a bushing is inserted between each vane and spacer to reduce the friction between the two parts and prevent them from contacting the engine casing. Having a sealing function, bushings help to reduce the pressure loss from the compressor.
Technological developments increase the performance of modern engines, meaning that the compressor and its components, among which the stator vane bushings, are subject to high pressure and high temperatures. Therefore, the materials of which the bushing is fabricated, the way it is coated, and its processing are essential to ensuring the optimal performance of that segment. Part of the processing of stator vane bushings includes a multistep grinding process composed of several grinding operations: internal diameter (ID) grinding, outer diameter (OD) grinding, face- and chamfer grinding.
Expert in grinding technology, Meister Abrasives has developed the optimal solution for grinding the complex shape of a stator vane bushing. Using a High Velocity Oxygen Fuel (HVOF) coating technique, bushings are coated with tungsten carbide. The HVOF thermal coating technique is particularly suitable as it improves the properties and geometry of a component’s surface, increases wear and erosion resistance, and protects from corrosion, thus, increasing the life of the stator vane bushing.
To assure that the required process and surface parameters are achieved, Meister Abrasives’ engineers selected grinding wheels with a vitrified diamond bond (Vit DIA) technology for fine surfaces and precise geometries. Several Vit DIA wheels were selected, each matching the necessary grinding operations: ID-, OD-, face- and chamfer grinding. Due to the unique technology and structure of Meister Abrasives’ wheels, the often demanding-to-grind carbide is now smoothly processed.
A surface roughness of Ra 0.2, a cutting speed of 35m/s and a cycle time less than 180s per part were achieved – all surpassing the values that were initially requested by the customer. Due to its technology, Meister Abrasives’ Vit DIA wheel has excellent dressability and retains its shape with our matched Ceramic-bonded Dresser (cDD). Due to the high production volumes of stator vane bushings, optimizing cycle times and guaranteeing process stability is paramount – something that Meister Abrasives achieved.
See the process summary below for details. All results are achieved on a high-precision grinding machine.
