Innovation through automation

In our Braunschweig workshops, a robotic system that forms part of a new production line at BMA’s main site has recently taken over the manual welding of centrifugal housings and frames.

At Braunschweig, our new robot-based production line is now in operation, building large welded assemblies for centrifugals. They include the two K-series centrifugal housings and E-series centrifugal housings and frames, which BMA can now produce at the customer’s pace. The line’s heart and soul is a 2-station robotic welding system. At BMA, we believe in structuring our processes. An example: at an early stage, standard assemblies are assigned to a specific end customer, ensuring that they are available in time for the final assembly of the centrifugals. Needless to say that quality is of a consistently high level.

The new production line comprises four booths for tack welding, the 2-station robotic welding system, and two downstream welding booths for any remaining work. Thanks to the 2-station system, work can be carried out on two assemblies at the same time, with the welding robot switching automatically between the two stations. While welding work is proceeding in one station, assemblies can be, for instance, prepared for welding or welded assemblies removed from the other station. Welding times are thus maximised, throughput times for the assemblies minimised, and there are no more waiting times because of setup procedures.

Before welding starts, all supplies must be at hand and the assemblies tack welded, i.e. fixed in place with small welds. Material supplies are controlled using the Kanban principle. A predefined number of the necessary parts are kept in designated storage places. Whenever parts are removed for use, the Kanban system automatically triggers production of precisely the right number of replacements. In order to transport parts more quickly and safely, we have developed and built suitable loading devices at BMA. Proof that we use our innovative strength both for equipment and processes requested by our customers, and for continuous internal improvements.

Today, a job starts with the dispatch of a loading device carrying all individual parts to the tack welding booth. The parts have been stacked in the order they are needed for assembly: the part needed first is placed on top, the last part at the bottom. When the loading device is empty, the supply of new materials is triggered. This procedure provides high transparency, because the assembly status is visible to everybody at all times.

The robotic welding system features a pre-heating torch, three welding torches for three different welding rods, a torch cleaning unit, an offline laser sensor, a tactile sensor, an arc welding sensor, 13 synchronous axes, and just one welding power source. The welding fumes are extracted via an integrated unit, cleaned in a filter, and the clean air is then fed back into the manufacturing workshop. This minimises emissions and saves energy for heating the workshop.

Following on from our planning work in mid-2018, we ordered the robotic welding system in October of that year. The actual conversion work in the manufacturing workshop started in January 2019. Despite changes in the delivery dates of the many suppliers and individual trades, the whole production line was commissioned as scheduled, just six months after conversion work had started. A truly impressive performance by the whole planning team – particularly, since the machinery and foundations in the old manufacturing workshop had to be dismantled completely.

The new production line is just one of a range of investments in infrastructure and energy and environmental management at BMA’s main site. They include the centrifugal cycle time production line, welding fume filter systems, a vertical boring mill, a bench-type boring machine, a centre lathe, the first welding robot, two portal milling machines, and finally the robotic welding system. BMA customers will benefit from these highly efficient systems in terms of a broader range of manufacturing services. The many investments also highlight the significance of BMA’s production site in Braunschweig.