100 machines in 20 years: The success story of the rotor grinding machine RX 59

What particular challenges did Kapp Niles face during the development of the RX 59 rotor grinding machine and how were these solved?

Axel Köhler: During the development of the new machine we faced various challenges. After all, we wanted to grind larger screw compressors and significantly increase stability at the same time. It was important to design a new grinding wheel drive with counter bearing, which has higher performance and rigidity. This meant that CBN tools with a coarser grit could be used, which in turn led to a reduction of machining times. The proven measuring control in combination with the new measuring system further improved the consistent grinding results in series production.

How does KAPP NILES ensure that the machines remain state of the art?

Axel Köhler: We consistently pursue a continuous improvement process based on customer feedback. This enables us to incorporate direct feedback into the further development of our machines. We also maintain close customer relationships through regular on-site visits in order to better understand the needs and challenges of our customers and to be able to offer optimal solutions. Regular participation in specialist conferences gives us the opportunity to follow the latest trends and developments in the industry, exchange ideas with experts and gain valuable impulses for our work.

How satisfied are you with the quality of KAPP NILES products and services?

Andreas Weiher: The KAPP NILES machines are among the most reliable and stable operating resources in our company. The grinding machines are mainly used in three-shift operation and are completely unobtrusive and stable as far as the failure rate is concerned. The responsiveness of KAPP NILES with regard to service and ordering / delivery of spare parts is at a high level. We are always supported by competent, high-quality help and expertise - both by telephone and by the service technicians deployed. In terms of electrical and mechanical maintenance, we are very satisfied with these machines and can always rely on their excellent quality. We give KAPP NILES machines a thumbs up and highly recommend them to others.

Andreas Duwe: From the user's point of view, the quality and durability are impeccable. The failure rate for all KAPP NILES machines at our plant in Aerzen is exclusively less than 1%. Mechanical overhauls (retrofits) are required at the earliest for machines that are more than ten years old in three-shift operation. The controls only had to be replaced after the manufacturer's discontinuation. The new production and also the replating of grinding wheels are of very high quality and fulfil our requirements in terms of accuracy and delivery reliability to a particularly high degree.

One component of the KAPP NILES portfolio is the modernisation of grinding machines. In addition to numerous orders for new machines, Aerzen has overhauled two rotor grinding machines in recent years as a part of the KN Retrofit programme from KAPP NILES.

Why did you decide on this modernisation?

Andreas Weiher: On the one hand, sustainability was relevant, as a certain part of the high-quality components were reused. On the other hand, we were convinced by the rapid re-availability and the cost advantage compared to a new machine. In terms of quality and cost-effectiveness, we didn't notice any disadvantages compared to a new machine.

Andreas Duwe: Assuming that the machining process is still state of the art, a retrofit is extremely interesting. The basic machine concept is proven and solidly constructed. After a complete machine overhaul, both mechanically and electrically, you get a machine that is absolutely as good as new and whose acquisition costs are around 40 % lower than the price of a new machine. These economic advantages are complemented by ecological benefits such as improved sustainability and the continued use of equipment and grinding wheels.

How do you at Aerzen see the current challenges in your industry and how do you deal with them?

Sebastian Meißler: Like many other industries, the German mechanical engineering sector is characterised by political influences and negative headlines from the world press. With a view to competitiveness, Aerzen is focussing strongly on sustainability - a keyword of our time, which is reflected in many measures, but also in the development of Aerzen products and solutions. We endeavour to generate added value for our customers through innovation and pioneering technologies.

A look into the future: What trends and challenges are we facing in rotor machining?

Axel Köhler: We see several important trends and challenges in rotor machining. Increasing accuracy requirements demand more precise machining techniques. In addition, batch sizes are becoming smaller and smaller and the demand for flexible manufacturing solutions is increasing. The coating of oil-free rotors is becoming more important and requires new machining approaches.