Design of the integrated laser welding head with a continuously adjustable focus rotation radius

In this paper, the integrated laser welding head with a continuously adjustable focus rotation radius was achieved by using the output shaft (hollow shaft) of the high-frequency motor as the laser transmission tube for laser transmission, laser deflection and laser focus rotation. The continuous adjustment of the focus rotation radius was achieved by changing the relative phase angle between the two wedge prisms and using a focusing lens. And the function relationship between the focal rotation radius and the relative phase angle of two wedge prisms is verified and modified based on the measured results. The energy loss rate of the 5 kW laser through the inner diameter of the hollow shaft is less than 5% and it has little effect on weld depth. The temperature of the hollow shaft can rise to 57.4 °C only at the entrance of the hollow shaft under the long action time (120 s) of high-power (6 kW) laser. Both the weld forming and porosity defects of 5083 aluminium alloy can be effectively regulated and controlled by using the integrated laser welding head.