in Vol. 2 - March Issue - Year 2001
Internal Peening of very long Engine Shafts
automated peening machine for engine shafts
view inside the cabin
The internal peening of engine shafts is a demanding application. For one reason it is simply the length of the shaft to be treated which already causes difficulties. An engine shaft for a PW 6000 for instance, has the length of about 2500mm. In order to peen such a shaft internally one has to insert a lance all the way through. That means that the nozzle has to be at least as long as the shaft. This requirement brings all sorts of mechanical problems. Depending on engine type, the smallest diameter inside a shaft can go down to about 35mm.
One can imagine that the centre run of such a long internal peening nozzle is a very critical issue. Due to that fact it has to be insisted to place the shaft and respective the nozzle, in a vertical position. The sheer weight of the lance itself would bend it to an extent not acceptable if placed in a horizontal layout.
The best solution to handle this application is to insert the shaft for a certain length into a special turn table design. This turn table will not just rotate the part, but will also give the shaft the necessary stability.
In order to peen all requested areas such as borders, radiuses, etc., inside the shaft, the right lance has to be chosen. BAIKER AG has over 100 different standard internal peening nozzles on stock. If a standard design is not suitable one still can use custom made nozzles, manufactured for a particular application.
For the more simple process of peening the shafts from the outside, a standard gantry robot is used. It can move in X and Y direction. The machine is equipped with a continuously working peening system which feeds the media to two media flow rate control units and respective nozzles. Depending on the requirement the shafts can be peened externally and internally simultaneously. A remote control, which can be taken into the cabin, makes it possible to perform an efficient programming. The programs can be stored and reactivated on demand.