World renowned for its drive trains, chassis, and automobile manufacturing equipment, the automotive division of thyssenkrupp AG significantly contributes to the technical progress and efficiency of motor vehicles. The thyssenkrupp Gerlach GmbH plant in Homburg, Germany, is a leading partner for the development of automobile engine components, offering a full-service package ranging from component design, prototype fabrication, and full-scale production.
Developing a Solution
To improve cost efficiency at its Homburg plant and to meet all customer requirements, thyssenkrupp AG installed its high-tech “production line 19” for forged crankshafts for engines with one to four cylinders in 2016. For this line, Rosler developed an innovative shot blast equipment concept known as the Rosler RKWS crankshaft shot blasting system.
At the beginning of the manufacturing sequence, bar blanks are cut to length. They are then heated in an induction oven before being shaped in a 6,500-ton press. In the last step, the crankshafts undergo a blast cleaning process in a shot blast machine.
Using a unique equipment concept for the final blast cleaning step, Rosler engineers created a system for handling different work piece sizes without time-consuming retooling of the work piece holders.
This innovation helped reduce the cycle time to less than 10 seconds, which in turn allowed the manufacturing operation to be run in a continuous flow. The result of the comprehensive cooperation between thyssenkrupp AG, Rosler, and all the other partners created the fastest, most modern crankshaft forge shop in the world capable of producing a finished component for its customers every 7.5 seconds.
Delivering Convenience & Longevity
Our innovations go beyond world records to provide long-lasting value and dependability. The RKWS system was also designed for long life and easy maintenance.
The three blast chambers and the work piece load/unload chamber are arranged in a circle around a rotary drive equipped with an asynchronous servo motor with an extremely high overload reserve. Blast media is accelerated and thrown by Rosler Gamma G blast turbines equipped with a unique Y-shaped throwing blades.
Rather than being made of chilled iron castings typically used in conventional turbines, critical wear components of the turbines are made of forged tool steel. This results in a much longer uptime of the throwing blades whose curvature produces a much higher throwing speed than straight throwing blades.
In addition, the symmetrical Y design allows the use of both blade sides. The combination of more wear resistant material and the blade geometry result in up to three times longer usable blade life.
Another feature of the Gamma G turbines is their easy maintenance. Turning the blades around or exchanging them can be done from the top of the turbine housing without having to dismount the impeller, control cage, and the media inlet tube required with conventional turbines.
The RKWS is equipped with 12 Gamma G turbines, each with an installed power of 22 kW. The turbines, evenly placed on the three blast chambers, are capable of throwing the large steel shot onto the entire surface area of the crankshafts with a speed of 80 meters per second. This results in a complete removal of forging scale and other surface contaminants.
By utilizing highly wear resistant material for all components exposed to the large cast steel shot and the removed forging scale, the RKWS shot blast system’s external workings are protected from excessive wear.
The three blast chambers are lined with wear resistant hardened steel. Media augers are made from special steel that is predominantly utilized in the mining industry. Technical characteristics of this material are its extreme toughness and its remarkable hardness of 600 Vickers providing it with a considerable structural strength.
Planning Proactive Maintenance
Thyssenkrupp AG’s “production line 19” processes the entirety of the company’s customer orders within 21 shifts per week, posing a considerable organizational challenge for the thyssenkrupp Gerlach GmbH maintenance department. In order to manage time for the equipment upkeep, the maintenance team utilizes a TBM (time-based maintenance) system.
Within a pre-determined time span, a recurring time window is defined for all inspection and maintenance activities as well as any required repairs including the replacement of spare parts. The time management allows requisitioning all repair materials in advance and facilitates the effective assignment of the maintenance personnel at thyssenkrupp Gerlach GmbH in Homburg.
Stocking Spare Parts
Planning certainty for the entire manufacturing line along with consistently high product quality is a high priority at thyssenkrupp Gerlach GmbH. For this reason, essential wear and spare parts for all machines were determined jointly with the equipment suppliers and stocked on-site in Homburg.
To define the specific requirements for the crankshaft shot blast machine, the customer relied on the experience of the Rosler service department. Based on the customer specifications, our service experts conducted a risk and wear analysis using an ultra-modern simulation of the blast media recycling process allowing them to determine the wear intensity for every single component. Based on the results of the analysis a comprehensive list of recommended spare parts was prepared including wear parts such as protective wear plates, etc.
The Rosler Way
Working with an experienced supplier is the best way to develop and maintain a shot blasting operation. From selecting the right type of machine for your needs to suggesting everyday actions to ensure repeatable results and extended uptime, Rosler develops lasting solutions. Contact us to learn how we can put our surface finishing expertise to work for you!