The oldest form of rotary friction welding, the direct drive process continually adds energy using an electric motor driving the rotating component at a fixed RPM. The direct drive process accomplishes the same increase in energy through added cycle time instead of increased energy storage, allowing the parts to receive enough heat in the center of the parts to make a quality weld.
MTI’s Model 40T Rotary Friction Direct Drive Welder for oil and gas well valves.