Quiet, low-vibration energy supply system for a dynamic machining center

Profile

• What was needed: E6 series energy chains
• Requirements: detailed technical advice due to the demanding system, low space requirement, sensible arrangement of the cables within the chain, high travel speeds and accelerations
• Industry: machine tool manufacturing
• Success for the customer: detailed and individual advice led to the use of the E6 series, which impresses with its exceptionally long service life, extremely quiet and low-vibration operation and modular design; so far, no incidents have occurred despite heavy loads and high travel speeds

"We designed this machining centre especially for aluminium and light metal machining, for smaller batches", explains Dipl.-Ing. Torsten Keller, a Design Engineer at Saalfelder Werkzeugmaschinen GmbH (Samag-Group), Saalfeld, Germany, since 1995. The two-spindle horizontal machining centre with linear drives 'MFZ 500 - 2 linear' in the 3-axis unit, additionally equipped with independent Z and A/B axes for 5-axis machining, is characterised by reduced non-productive times, increased accuracies, a generous clamping area for larger workpieces and multiple clamping solutions, as well as fast job changeover and high flexibility, thanks to the double pallet changing system. It is mainly used in the automotive supply industry for machining cubic parts.
"With our complex machines, it basically comes down to technical advice on the one hand to find the best solution. On the other hand, the lowest possible space requirement is a priority for the machines, so we are happy to take advantage of application support in the run-up to the design", says Torsten Keller. "It is also a question, amongst other things, of achieving a sensible arrangement of all the cables within the energy supply system. The multitude of electrical, hydraulic and pneumatic as well as data cables must be accommodated systematically, logically and in a space-saving manner."
Further requirements for the energy supply systems: they must be able to safely handle axis speeds of 100 or 120 m/min, accelerations of 1 to 1.5 g, spindle speed ranges of 50 to 15 000 min-1 and travels of 450 to 630 mm at all times. Lastly, a wide variety of coolants must be taken into account, which are used in the system and can corrode the individual components.

Energy supply systems from igus have been used for many years in almost all of the company's horizontal machining centres and special machines, precisely matched to the respective design requirements.
In the case of the linear machine, igus recommended the undefined. It displays its special strength especially with high-speed axles. Since 2005, it has been used in the two-spindle horizontal machining centre with linear drives and has been convincing right from the start. Despite the high stress in everyday operation, no failures of the energy supply system have been recorded.
In addition to its long service life, it also offers numerous other advantages. It is characterised by extremely quiet, low-vibration operation. It minimises the polygon effect which can occur during the rolling motion of an e-chain®. The extremely low noise emission (confirmed by an expert assessment report from TÜV Rheinland) is only 46 dB(A).
Another advantage is the modular design of the E6 energy chains: The energy supply system can be shortened and lengthened as desired. A characteristic feature is the elastic spring element made of plastic, which connects the individual side parts to form a very robust energy supply system. The scalable crossbar shows no signs of wear even after 220 million strokes in the endurance test. The absence of the usual pin/bore connection results in low-vibration and quiet operation.
The quiet and low-vibration energy supply system is matched to the high speed and acceleration values in direct drive technology and ensures a continuous and reliable supply of all necessary media - from energy and compressed air to control information - even over longer distances if required. "The technical advice was worthwhile for us in the overall concept right from the start," Torsten Keller concludes.