A Robot for Welding Repair of Hydraulic Turbine Blade

Abstract

This paper proposed a scheme of using rail-free multifunctional robot in onsite repair of hydraulic turbine blade for large-scale axial-flow and Francis runners. The robot processes such functions as profile detection and measurement, air-gouging cleaning, grinding, welding and so on. The robot's main body is composed of an all-position rail-free mobile platform and a multiple degree-of-freedom (DOF) manipulator. The mobile platform, on which the manipulator equipped with all kinds of exchangeable operating tools is mounted, adheres to the surface of the hydraulic turbine blade to be repaired. The operator can control the robot to carry out repairing work automatically through man-machine conversation interface of a monitoring system. Simulation of the process of welding repair using the robot was conducted. And prototypes of key components of the robot system were developed. Preliminary experimental results proved the feasibility of scheme of the repairing robot.

A survey of platform designs for portable robotic welding in large scale structures

“…Most of the developed welding robot climbers make use of magnet to keep them attached to the metal surface while travelling vertically. Chen et al at the Tsinghua University, China, [32] developed a climbing robot for on-site welding repair of turbine blades ( fig. 9 top left).…”

Permanent Magnet Absorbed Repairing End Effector for Wall-climbing Robot

“…So far, the Scompirobot [1], which is a rail-guided, six-axis, multi-process robot, is the only one having been utilized to repair hydraulic turbine blades.The rail has to be installed and demounted repeatedly according to damagedpositions. In contrast, featuring the advantages of cost and time saving, rail-free permanentmagnetic absorbed wallclimbing robots (PMAWRs) can move freely on the surface of some ferromagnetic workpieces [2].…”

Robotic post-weld heat treatment for in situ repair of stainless steel turbine runners

“…A few prototype robotic systems have been investigated [2][3][4][5] to perform in situ weld repair of turbine runners, but none of those have been used in the field. Over the past 20 years, Hydro-Québec researchers have developed and tested a new technology [6][7] to robotize work on hydropower equipment such as turbine runner.…”