Sealed energy supply system for a milling and drilling machine encountering dust, dirt, and drilling oil

Profile

• What was needed: RX energy tube
• Requirements: Use under aggressive environmental conditions such as abrasive and highly lubricating materials, continuous load due to three-shift operation seven days a week, very tight bend radius of only 100 mm, taut hydraulic hoses mean high pressure on the energy chain solution.
• Industry: Machine tool manufacturing
• Success for the customer: Extremely robust energy supply system specially designed for the environmental conditions, absolute impermeability of the energy tube with simultaneous easy opening and filling, reduced maintenance and machine downtimes due to high accessibility of the cables

Problem

The company Auerbach Maschinenfabrik GmbH has been manufacturing machine tools for over 60 years. Today, the speciality encompasses the combination of conventional milling technology with modern deep drilling technology in one machine.  The resulting "AX-TLF" series is used not only in tool and mould making but also in the aerospace industry, general mechanical engineering, the solar industry, equipment manufacturing and the petroleum industry, among others. The material selection is thus broad, ranging from soft graphite to aluminium and standard steels to high-strength stainless steels and titanium alloys.  The demands on the machine and the components used are accordingly manifold.
On the one hand, dirt accumulation plays a major role. Graphite, for example, is machined dry, is extremely abrasive and smeary.  Or the topic of deep drilling, where a lot of drilling oil is used. This creeps everywhere and is extraordinarily aggressive. Another variant is, for example, minimum quantity lubrication. Here, high-pressure cooled, oiled air is used for deep drilling. Due to the atomised oil, the particles then fly through the work area before they settle everywhere.  The energy supply system is also always located in the direct swarf area when supplying the main spindle and is directly exposed to the aggressive conditions.  Depending on the volume of orders, the machines work in three shifts, seven days a week. In addition to the extreme external conditions, the bend radius is particularly tight at 100 mm. And tautly stretched hydraulic hoses, as hard as an iron bar, increase the pressure within the energy supply system.

Solution

Due to the enhanced milling performance, the machine manufacturer had looked for an even more robust energy supply solution for a customer in the course of a retrofit with newly installed pressure hoses. Since then, only RX energy tubes from igus in size 40 are used in the combination machine for milling and drilling. Enclosed polymer energy tubes from igus have already been used for twenty years in all work areas where swarf occurs. Dust, dirt, oil, aggressive environments, moisture and heat do not affect the robust energy tubes.
The "RX" energy tube with its special rounded design and smooth curved outer contour lets swarf bounce off easily.
Extensive tests were carried out on the new energy tube to ensure that it was one hundred per cent leak-proof. Despite the absolute tightness, the energy tube can be opened easily and has a large filling space with up to 52mm inner height, including cable-protecting, abrasion-optimised interior separation. The filling space can be subdivided in order to route cables and hoses separately and safely. As they remain accessible at all times after insertion into the tube, maintenance and machine downtime is reduced to a minimum.
The tube is particularly suitable for short unsupported lengths inside machine tools; applications with a reverse bend radius (RBR) can also be implemented.
Finally, the energy tubes are also delivered to the machine as readychain direct, i.e. fully harnessed with chainflex cables and hoses, including a matching guide trough.