Schuler Service Modernizes Screw Press in Three Week

Production planners tend to shudder when they hear the word downtime. For example, in the time it takes to set up a machine for the next processing stage and fit the right die, production is at a temporary standstill. What happens though when the machine needs more time-consuming refit – for example, when huge components need to be exchanged as part of a major overhaul? The service team of Müller Weingarten, a subsidiary of the Schuler Group, recently demonstrated how downtime can be kept to a minimum in such cases on behalf of its customer Bifrangi. The globally operating Italian company specializes in the production of forged components for the auto industry. At Bifrangi’s UK facility, Müller Weingarten’s metalforming experts replaced the complete drive train of a screw press in record time. The machine was fully operational again after just three weeks. 

The Müller Weingarten type PZS 900 percussion press from 1981 is used to forge truck crankshafts at Bifrangi’s UK facility in Lincoln. The complexity of a service operation for such a press and the extent of the logistic challenge it represents can be illustrated by a few of the machine’s key statistics: The giant machine weighs 900 metric tons and develops a maximum press force of 16,000 metric tons. Even individual components of the machine weigh up to 180 metric tons.

When wear and tear becomes noticeable on a central component of the drive train, overhauling such a giant has to be planned very carefully. Thomas Huber, an Account Manager for Müller Weingarten’s Service division, explains: “The machine’s flywheel hub and spindle nut had reached the end of their service life and were torn. With such machines, however, it’s not possible to simply produce a new hub or spindle nut and then install it on site. The drive train’s individual components have to fit each other exactly. As a consequence, the hub and spindle nut have to be adapted to the spindle.” For Bifrangi, that would have meant dismantling the complete drive train of the screw press – including the still intact spindle – transporting it to Müller Weingarten, and then re-assembling it again on site in England after the adjustment. “In other words, downtime of at least ten weeks,” explains Thomas Huber.

Full power straight away

The fact that the actual downtime was much shorter is thanks in part to the close cooperation between Bifrangi and Müller Weingarten’s service team, but also a result of the favorable conditions at Bifrangi’s Lincoln facility. “Bifrangi had an old replacement spindle at the facility. We reconditioned the component at Müller Weingarten and adapted it to the new hub and spindle nut. The press at Bifrangi could continue operation during this time and was not affected in the least by our work. In September 2009 we then started the quick on-site exchange process. With the aid of cranes, an assembly team from Schuler Presses UK and Müller Weingarten, Germany, was able to exchange the heavy components – weighing up to 55 metric tons – in just three weeks. Straight after completing the exchange, the machine was able to reach its full operating capacity again under maximum load,” states Thomas Huber.

Focus on customer’s long-term situation

The fact that older parts are often left over following such a project is no disadvantage for Bifrangi. On the contrary: “We are currently thinking about also reconditioning these components. They can then be stored as spare parts and will help speed up maintenance work at some later date,” explains Thomas Huber with reference to the long-term planning horizon of Schuler’s service experts. The main focus is always on the customer’s processes. “In the case of repairs or servicing, we are often closely involved with the customer’s processes and have exact knowledge of the production stages and prevailing conditions. This means that we can offer tailored solutions to enable a fast pit stop,” says Thomas Huber. The entire Bifrangi project took just ten months – including planning. Not bad considering the machine’s total service life of around 28 years. The actual pit stop itself was extremely short.         

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