Manufacturers can rely on a mass finishing system that is capable of completely eliminating manual operations and cutting processing times for finishing of blisks from several days to a few hours. Contributed by Walther Trowal
A condition monitoring vibratory system can help manufacturers ensure efficient surface finishing of high value work pieces like blisks for airplane and land based turbines. A reliable system allows the work pieces to receive a uniform, homogeneous high quality finish with repeatable results.
The surface finish of blisks—blade integrated disks—in aircraft and other turbines affects to a large extent the airflow characteristics and thus, the overall efficiency, fuel consumption and noise emissions.
To date, the surface finishing of blisks have been done manually with grinding disks and other manually operated tools. Due to the “human factor”, the quality of the final finish could greatly vary between work pieces. And it could even happen that certain surface areas were not finished at all.
For the consistent and high quality finishing of circular high value components, Walther Trowal has redesigned the rotary vibrator condition monitoring system in close cooperation with leading turbine manufacturers to make it more suitable for treating all kinds of turbine components. The system allows deburring and general surface improvement of components with diameters of up to 980 mm.
Single work pieces are mounted to the inner dome of the processing bowl. The height of the inner dome itself has been drastically shortened. After grinding media has been filled into the bowl, a vibratory motor causes the complete work bowl to vibrate. This causes a constant “rubbing” of the media against the fixed work piece. Since the “rubbing” action is highly homogeneous, a uniform, even finish on all surface areas of the disk and blades is achieved.
After completion of the process the surface roughness readings amount to Ra = 0.2 to 0.4 µm.
Starting with an initial surface roughness of Ra = 4 to 5 µm, the desired finishing results are achieved within approximately five to six hours. Compared to this innovative method the manual finishing of blisks can take several days.
Christoph Cruse, sales manager at Walther Trowal, explained: “Especially for the production of turbine components, any manual manufacturing operations must be viewed with great skepticism, because the quality of the work will vary greatly. With our new finishing machine we have completely eliminated the vagaries of the human factor. And we can reduce the finishing times for blisks from several days to just a few hours.”