Apparatus and method for centering a laser welding probe within a tube using gas pressure

摘要

An apparatus for welding the interior surface of a tube includes a laser welding probe body configured for positioning within an interior surface of a tube. A centering mechanism relying upon fluid pressure is used to substantially center the laser welding probe body within an annular void defined between the laser welding probe body and the interior surface of the tube. In one embodiment, the centering mechanism is implemented with a set of seals. In another embodiment, the centering mechanism is implemented with a set of centering balls that respond to the fluid pressure and thereby operate to center the laser welding probe body within the annular void. The fluid pressure may be created with shielding gas used during the laser welding operation.