Problem solving

Machining engine blocks: extracting swarf and cooling lubricant

at John Deere, Mannheim

Surprisingly, the place with the highest number of tractors in Germany is a city - the city of Mannheim.
In 1956 John Deere took over the Lanz tractor works. Since then the John Deere Production Facility in Mannheim has become Germany's largest manufacturer and exporter of agricultural tractors. Over 50% of all the tractors produced in Germany are built in Mannheim. The Mannheim works is part of John Deere's world-wide manufacturing network and specialises in tractors in the 60 to 110 kW power range and municipal tractors.

Many tractor transmission components, such as differential gearbox housings, are made in Mannheim.
John Deere has just installed a new production line for the high-precision machining of cast components.
Nine, highly flexible machining centres mill, bore and plane differential housings in a single clamping operation.

Once the machining of a housing has been completed, the workpieces are conveyed to the next production station downstream. Before the next workpiece can be clamped in the machining centre, the worktable rotates, a safety door on the back of the machine opens and the machine operator has to extract the machining waste and cooling lubricant from the back of the machine. For this particular task John Deere, working in close collaboration with Ruwac, designed a state-of-the-art extraction system. Each machine is fitted with a 2.2 kW, AC vacuum unit and a separator silo. The solid and fluid machining wastes are separated in the silo. Two filter cartridges remove oil residues from the exhaust air. The system extracts approximately 1.5 to 2 litres of cooling lubricant for each housing and for each machining operation; this waste is collected in the separator. The bottom of the separator has a counterweighted flap.
The flap opens automatically when a preset weight is reached or when the vacuum is switched off. The collected waste drops down into a channel leading directly to the central cooling lubricant treatment system.

John Deere uses this system to clean all machining waste from the machine tools after each step in the production process. Keeping work stations clean is vital to maintaining high standards of precision during the machining of the gearbox housings.
The system also ensures that a high percentage of the used cooling lubricant is treated, recycled and returned to the production cycle. This reduces lubricant costs and is good for the environment, too.

Production engineers at John Deere did a lot of detailed design work on the system. For example, the hopper connecting the pre-separator to the channel has been optimised and designed to ensure that all the extracted cooling lubricant remains safely inside the system and cannot leak or spray out.

Before John Deere installed the new machining centres, it already had plenty of experience with various types of Ruwac industrial vacuums. Mobile Ruwac vacuum units are used to extract oil sludge and fuel wastes from the drainage channels throughout the company's production site. For the mobile extraction on machining centres, the company uses Ruwac chip/swarf vacuums. Ruwac AC vacuum units are used to extract waste during dry machining of gear wheel castings.