chainflex cables supply KESSLER spindles with energy and signals

Cable guidance to the swivelling spindle heads ensures a long service life and reduces failures

The "system technology" business area of the renowned spindle manufacturer FRANZ KESSLER, develops and produces swivelling spindle heads and rotary pivoting tables, which enable a very precise processing of metal and increasingly also composite workpieces. Kessler uses igus chainflex solutions for the energy and signal supply as they meet the very high demands regarding service life and reliability.

Profile

  • What was needed: pre-assembled readychain system consisting of energy chains and chainflex cables (twistable CFROBOT4 cables, motor cables from the CF310 product range, CFPE cables as earth core)
  • Requirements: compact and wear-resistant energy and signal supply, resistance against cooling lubricants
  • Industry: machine tool manufacturing
  • Success for the customer: use of igus e-chains and chainflex solutions since 2003 without notification of a failure
Other products for machine tools
Pivoting spindle head If the housing of the pivoting spindle head is opened, the chainflex cables can be seen. From left to right: igus Sales Consultant Oliver Seibold, Florian Gehrmann, Product Manager Motor Spindles & Pivoting Systems at Kessler, and Markus Kogelmann, igus Industry Manager Machine Tools.

Problem

The spindle manufacturer FRANZ KESSLER in Bad Buchau has developed the company name into a brand that is known for the highest performance and quality. The main competence of electric motor manufacturing: development and production of electromotive (direct) drives for various applications within machine tools, but also for use in forming technology.
In addition to spindle and drive technology, the system technology division offers compact and rigid swivelling spindle heads and two-axis rotary pivoting tables. They create the precondition for processing medium-sized and large workpieces in gantries. The five-axis processing allows for very efficient and precise turning and milling processes in one clamping. The CoolMotion® torque motors in these systems stand for high dynamics, high torque and compact installation height. The direct drive in all axes enables accelerations and a high degree of precision, both of which would not be possible with mechanical drives.
The fact that KESSLER takes great care in selecting products for the supply of energy and signals to workpiece axes and rotary pivoting tables goes without saying. The heads and axes are very compact, so that there is not much space left for the cables. This means that the cables, which are continuously and frequently being moved at short intervals, must be all the more wear-resistant. Resistance to cooling lubricants is yet another requirement.

Solution

Energy chains from igus are now being used for the outer cables of pivoting tables - for example, at the travel axes of large gantries for aerospace applications. Today, an igus delivery usually contains the complete and harnessed movable cable systems under the name readychain. This was also the case with the spindle manufacturer FRANZ KESSLER.
The igus chains have proven successful in the application even under inconvenient circumstances - for example, in combination with flying swarf or when the machines process composite materials instead of metals, which is occurring more and more often. In these cases, the fibres have an abrasive effect, which does not affect the service life of the igus chains and cables. Basically, igus cables from the chainflex product range are also installed in areas that are not visible, in the housings of the swivelling spindle heads and rotary pivoting tables. Here, different types are used. At the customer interface above the head, which rotates through ±360°, twistable CFROBOT4 cables are used. They transmit the signals for the incremental and absolute encoders in the spindle. The motor cables in use are from the CF310 product range, and the earth cores are CFPE cables. Here, the cables often have a lower bend radii than stated. In these cases, igus has tested the application conditions and granted special releases.
"For us, what counts is fail-safety. Our customers expect high-performance systems with a very long service life. According to these criteria, all components - especially the ones for moving applications - have to be carefully selected."
 
Florian Gehrmann, Product Manager for Spindles & Pivoting Systems at KESSLER
Kessler spindle The compact dimensions of the swivelling spindle heads from Kessler are mainly due to the torque motors from their own development and manufacturing.
Rotary pivoting table The rotary pivoting tables from the KESSLER system technology product range, enable the highly precise five-axis processing of medium-sized and large workpieces in one clamping.

No problems since 2003

KESSLER has been using igus chainflex cables since 2003. In that entire time, no problems or failures have ever been reported to the design engineers responsible. This is even more remarkable as the cables in the system technology components carry out heavy-duty tasks with intense, short and quick rotating and linear movements, during which the cables are exposed to cooling lubricants and swarf. The high wear resistance of the TPE jacket ensures that the outer jacket does not wear, and the special cores wound in bundles prevent deformations in the core structures, which would lead to corkscrews and core ruptures.
 
This is why KESSLER always uses chainflex cables - even in non-moving applications. Florian Gehrmann: "For us, what counts is fail-safety. Our customers expect high-performance systems with a very long service life. According to these criteria, all components - especially the ones for moving applications - have to be carefully selected. " Under these circumstances, the chainflex cables and also the igus energy chains have proven successful for use in swivelling spindle heads and rotary pivoting tables from KESSLER for thirteen years.