The requirements for speed and flexibility of automation solutions are increasing. The Tünkers Group is a specialist in automated manufacturing processes. As a second-generation family business, the solutions originate from its own production facilities and know-how gained over decades. Tünkers provides engineers and designers worldwide with tried and tested products for common robot-related functions such as clamping, processing and transportation.

Robust, low-maintenance modules are also designed for extreme operating conditions in high-volume production in the automotive and supplier industries. The modular system has a drive, gearbox, process control and suitable interfaces and fully maps functions such as clamping or conveying.

Innovation, reliability and precision in automation technology are also of central importance for the subsidiary Expert-Tünkers. Also operating worldwide, the focus of the portfolio is on rotary tables and transport technology, whereby customer-specific solutions are increasingly being developed. The seventh axis of the company from Lorsch in Hesse is a product that combines the tried and tested with the new.

This is an additional traversing axis. The seventh axis increases mobility and reach in robotics. The solution not only enables the robots to move quickly to the respective work area, but also to guide them precisely to parallel path-controlled work steps. This means that a robot can carry out several work steps at different locations, resulting in faster processes, more economical operation and the conservation of resources.

Low-cost, current-independent end position safety device

Expert-Tünkers uses a torsion-resistant modular design for the fast, precise traversing axes, which enables high process accuracy even with a length of 30 meters. They are driven by a helical toothed rack with hardened flanks, a robust, adjustable guide system and a servo geared motor integrated into the robot's carriage.

In addition to ground-level applications, moving geo-tools are also conceivable, and thanks to the expertise in roller turntables, the seventh axis can also be designed as a curve. Whether with or without a curve, a crash in the end positions must be avoided in any case. Otherwise, in addition to repairs to robots and the overall design, there is a risk of costly downtime. For this reason, during the development phase, the design team of the traversing axis was looking for protection that works independently of electricity.

For Expert-Tünkers, only a company that meets the highest standards in terms of quality and durability could be considered as a supplier for these small and important components. At the same time, a cost-effective solution had to be found. The design engineers found that these requirements were met by ACE shock absorbers from Langenfeld: "We knew from past collaborations that, in addition to product quality, service is often the deciding factor with ACE. This was confirmed in the course of the project," says Nuno Martins, International Engineering Coordinator at Expert-Tünkers.

The design revealed that different key data had to be taken into account at the two ends of the travel path. With a maximum drive torque of around 400 Nm, 2,500 kg at 2 m/s and 4,000 kg at 1 m/s had to be successfully decelerated. For this reason, ACE TC134-146-S tube safety dampers were installed in both end positions at the start of the project.

One-way crash damper for emergency stop

Following the delivery of these components, Nuno Martins and ACE remained in contact, as he reports: "ACE informed us at an early stage that a new product series was about to be launched, which promised an even more interesting price-performance ratio for our case." We are talking about the new ACE crash dampers. In contrast to the TC dampers mentioned above, these machine elements from ACE are not reversible. This is because the new machine elements made of special aluminum or steel tubing are folded into a designated shape in the event of a crash.

As a result, they protect structures like a crumple zone with a uniform energy dissipation of 98 %. Available in ten basic types with external diameters of 87.5 mm in the aluminum and 63 and 38 mm in the steel versions, the right components for the end positions of the seventh axle were quickly found. Their maximum stroke is between 45 and 160 mm, depending on the type. Low support forces of 13,000 to 70,000 N make a decisive contribution to securing the structures.

Another decisive advantage for users of machine tools, conveyor systems or, as in this case, robotics is the range of possible energy absorption between 670 and 11,200 Nm/stroke. Secondly, after an accident, the crash event can be reconstructed from the deformation of the one-way element and, in the best case, can be avoided in the future.

As they can be replaced very quickly and easily, this application illustrates how specific customer requirements can be realized to the point by expanding ACE's range of shock absorbers. "Thanks to the cooperation with ACE, we have created an end position safety solution for the seventh axle that really fits the bill in every respect," Expert-Tünkers concludes positively.