Modular energy supply system for revolutionary multi-spindle lathe from DMG Mori

What was needed: Rotary energy supply in the drum and six linear energy chains; supplied as a completely pre-fitted readychain solution

Requirements: High travel speeds and accelerations with high precision; many cables had to be safely guided in a small installation space; modular and easy-to-maintain system

Industry: Mechanical Engineering; multi-spindle lathe

Success for the customer: The rotary energy supply in the drum can follow rotation angles of up to 540° and allows a reverse bend radius; the chain systems can be plugged in individually and are easy to maintain and process, thus enabling a high degree of modularity and simple maintenance

The MULTISPRINT from DMG MORI was presented as a revolution in mechanical engineering at the world's largest machine tool trade show, the EMO in Hanover. It is the first machine to combine an automatic multi-spindle lathe with SWISSTYPE technology featuring a Y-axis on each spindle position. The MULTISPRINT sets new standards in terms of productivity and efficiency. The customer enjoys maximum flexibility for the mass production of components with a diameter of up to 50 millimetres.

The heart of the machine is the spindle drum with six spindles for simultaneous machining of several workpieces. The main spindles in the drum have a travel of up to 180 millimetres. The drum moves the workpieces to the tools quickly and very precisely. It only takes 0.65 seconds for one of the six spindles to travel to the next position. For spindles to return to the starting position after machining has been completed in the six stations, the drum has to turn 300° in reverse. For this, the unit, which weighs over three metric tonnes, only needs one second. The rods are pushed out of the loader through the drum to get into position for machining.

However, when the machine manufacturer was looking for a suitable energy supply system, it was not only the travel speeds and accelerations of the drum and the high precision that mattered. As the working space for the mechanics behind the drum was kept as large as possible, the solution had to guide the large number of cables in a relatively small installation space. Most recently, the focus has been on maintenance and service. The solution had to be modular and therefore easy to maintain and adapt.

One of our rotary energy supply systems was used to accompany the rotation of the drum. These are customised systems for circular movements with energy chains, which are used in machine tools and construction machinery, among other things. The standard rotary modules consist of two circular guide elements. One part of the guide trough is attached to the static part of the system and the other part to the rotating part. The Reverse Bend Radius allows the energy chains to move in two directions. Rotation angles up to 540° in one plane can be implemented here.

The drum in the MULTISPRINT consists of two rotation systems. The hoses are located in the outer system, while 24 cables are routed in the inner circle – twelve encoder cables and twelve servo cables each. Six installed linear chains each accommodate two encoder cables and two servo cables. One of the servo cables supplies the energy for the linear movements of the main spindles in the drum and one drives the spindle motor.

During development, great importance was attached to the modularity of the individual components. The linear chain systems can be plugged in individually and are easy to maintain and machine. And the sheet metal parts designed by us for attachment to the machine are made from several parts. This makes it easier to handle the readychain at the customer's premises and to harness it in our factory. The solution therefore fulfils all the requirements for ease of assembly. Finally, the chains and cables(CF27, CF270 and CF111) of the completely pre-fitted readychain® solution also manage with the relatively small installation space of the machine.