Reliable 3D energy-chain for a mobile laser hardening system

The centerpiece of this mobile hardening system is a high-performance diode-laser that must be guided reliably by a robot. Assembly-friendly energy supply systems are proving themselves by protecting the sensitive fiber-optic cable of the laser on the one hand, and, on the other, by providing the required mobility of the robot hand on the object to be hardened.

Advantages of laser beam hardening

ALOtec GmbH was founded in 1998 as an offshoot from the Dresden-based Fraunhofer Institute for Materials and Radiation Technology (IWS). Since then, the focus has been on the production of laser hardening systems to customer specifications. They are proving themselves in the machinery building, tooling and mold-making industries. Reference systems are located in Germany and Europe, as well as the US and India. "We also offer laser hardening as a service on our own laser hardening systems", the Managing Director explains. The company has established itself in the market with a total of twelve employees.

"The service life of an elevator must extend for several decades", Eckehard Hensel points out. "Of course, this also applies to the traction wheel. Its wear-characteristics are considerably improved by laser hardening." “

Reliable processes

The radiation source of the high-performance diode laser is guided by a 6-axes robot with correspondingly high degrees of freedom. "The fiber-coupled diode laser operates with a fiber-optic cable. This means that a corresponding cable must be brought to the robot hand, the sixth axis", the Managing Director explains. "For these and other cables, such as compressed air or signal cables, we need durable cable guidance systems that last." “

One feature in this case is that the fiber-optic cable is located separately in its own guide. "Cable damage must be prevented during insertion, and it must be installed and removed with relative ease. The cable must also never be bent", Eckehard Hensel elaborates on the requirements profile. All cables are positioned in a triflex® series TRE.70 energy supply system, a 3D chain that is particularly easily to fill from the outside. The dual chamber principle of the TRE series facilitates the option to route sensitive cables in a separate chamber with a maximum of protection. The circumferential bending radius stop and the defined torsion stop prevent the load limits of expensive cables from being exceeded – this principle increases the service life and operating reliability of the application. Cables can of course be exchanged at a later point without difficulty. "If a fiber-optic cable needs to be exchanged, it can be quickly removed and replaced by only one person. Since our systems are also located abroad, it is incumbent on us to keep the service-call effort to a minimum. In addition, the production process at the system operator should not be interrupted for an unnecessarily long time!“

An additional design feature is that the energy supply system series can be shortened and extended very easily. "This gives me the ability to quickly respond to the local installation conditions when setting up a customer's system, by adjusting the length link by link", the Managing Director elaborates. Before the decision was made in favor of these energy supply systems, a host of other systems from other suppliers were tested. However, these were unable to prove themselves under real-world conditions. "This energy supply system cannot be out-performed with respect to assembly-friendliness." “

Originally, the enclosed triflex® TRC.100 was the energy supply system of choice. But this created problems for the quick replacement of cables. "This is why we ultimately decided to go with the open energy supply system", Eckehard Hensel elaborates. Corresponding sample shipments have moved the decision forward. "The samples, the personal support, the immediate availability of all components have made a convincing case for us. In addition, all change requirements were responded to promptly. Today, we are able to provide high system reliability." “
 
Of course, selecting the smaller multi-dimensionally moving energy supply systems also has had an impact of the overall system concept. Eckehard Hensel summarizes in conclusion: "The systems are basically very compact in their design. Among other factors, this is made possible by the energy supply systems. The hardening systems must operate impeccably over time. Their engineering is mature. And we are able to prove this. In spite of the high mechanical loads, we have not experienced a single failure of a fiber-optic cable world-wide!"

Further information

Used products

Application examples: