Assembly-friendly system solution for demanding machining centres

• What was needed: Ready-to-install energy supply system for the lead screw of machining centres
• Requirements: Tight bend radii, compact design, suitable chain and cables for high speed, long service life and ease of installation
• Product: readychain assembled energy chain
• Industry: Machine tools
• Success for the customer: Easy-to-install and compact complete solution from igus, which reliably guides more than 50 supply cables and can be retrofitted if required

For machining centres:
The GS series of machining centres from Alzmetall is characterised by high dynamics and precision. It is mainly used for demanding machining tasks in series production, tool and mould making, prototype construction and in the aerospace industry.

The machines require more than 50 supply cables to the spindle. This requires a compact design of the energy supply or the complete system. Alzmetall requires that no cables be visible and that no components protrude from the machine.

The spindle, which operates at up to 30,000rpm, requires a total of 50 to 60 energy and signal cables, including electric cables for servo drives, hydraulic hoses for the tool clamp, encoder and measuring system cables as well as supply cables for coolant and a compressed-air supply for blowing out the spindle. Therefore, cables are required that allow for small bend radii and are characterised by a long service life even under continuous movement stress.

Despite the compact design and the narrow bend radii, the chains and with them the cables move at high speed. In rapid motion, the spindle travels at up to 60m/sec and achieves a maximum acceleration of 10m/sec². In free space, acceleration values of as much as 17m/sec² are required: This places high demands on the quality of the cable and the energy chain.

igus was involved in the development of the GS 800 at an early stage. Says Hans Jürgen Gizler: "The question was: What do you have to consider if you want to purchase a cost-effective, durable complete system?" igus was able to answer this question satisfactorily.

It therefore made sense to repeat this procedure for the new GS 650: igus supplies ready-to-connect, pre-fitted energy chains with integrated cable packages for each machine. This saves Alzmetall assembly time - an important factor as speed is seen as a competitive advantage.

Compact design - movable in three axes 
The chain and the readychain principle allow for a very compact design: The tight bend radii are only possible with chainflex cables. In addition, the requirement that no cables be visible and no components protrude could be realised thanks to the igus e-chains.

The energy chain system of the GS 650 ensures manoeuvrability in three axes. The x-axis moves separately, while the y- and z-axes overlap. Assembly is extremely simple as all three chains end in a distribution box, which igus also supplies. The x-axis has a horizontal design and rests on the upper machine cover, on which it is supported by a bridge: a design detail that saves space and ensures optimum chain guidance.

The energy chain series used, the E 4/4 Light, is characterised by very compact external dimensions. It is 20mm narrower with the same capacity. It was precisely these 20mm that ensured that the chain remained within the machine contour during all movements.

Also ideal for maintenance and retrofitting 
Two versions were specified for the chain assignment: one for the standard versions of the GS 650, a second with additional cooling hoses for the more powerful spindle with 30,000rpm. igus delivers these variants, which are harnessed in Cologne, just in time to Altenmarkt. Of course, additional cables can be integrated into the chain if required. This is even possible after installation - an argument that also convinced the designers at Alzmetall.