Risk-free laser processing
During laser processing, there is a risk that the invisible laser beam will not be switched off, by mistake or due to a technical error, and will thus injure the operator during the setup operation. Due to the high power of a 2 KW processing laser, the risk of injury is considered high. The law therefore prescribes a mechanical safety element that would safely deflect the beam as soon as it is not in use. In addition, the setter wanted to see the otherwise invisible beam on the workpiece.
Robust construction with water cooling
The task was solved with a simple concept and the most robust elements possible. The unit contains a generously-dimensioned stepper motor, which drives a slider-crank gear mechanism. The pivot bearings in the crank gear are equipped with dry slide bearings. The thrust bearing has lifetime grease lubrication. A water-cooled deflection mirror that is mounted on the thrust bearing deflects the laser beam by 90° into a beam dump, which is also water-cooled. Instead of the processing beam, a pilot laser, which indicates the position of the laser on the workpiece, is coupled via another deflection mirror mounted on the thrust bearing.
Safe and reliable
Safety-certified limit switches in duplicate monitor the position of the thrust bearing with the mirrors. This achieves safety with performance level E. A controller included in the assembly activates the motor when the active signal is applied, and thus moves the deflection mirror out of the laser beam. After the signal is deactivated, the mirror automatically moves back to the closed position. The reliability of the assembly was proven in an endurance test using statistical criteria.