Two industrial equipment designers — Thompson Friction Welding and Moog Inc. — report they have developed the world’s largest linear friction welding (LFW) machine, capable of welding a surface area of 10,000 mm² (15 in²). That size is nearly twice as large as any previously achieved, and its ability to apply more than 100 metric tons of force to a welded joint surpasses the previous record.

Thomson manufactured the E100 system at its workshops in England. Co-developer Moog provided expertise in hydraulics, servo system design, control engineering, and manufacturing.

LFW requires more complex machine architecture and control than rotary welding techniques, but it is capable of joining preformed parts of any shape. In comparison to rotary welding, LFW features a moving chuck that oscillates laterally instead of spinning, and the two surfaces being joined are in contact at a much higher velocity. This means that the two component parts must be kept under high pressure during welding.

The E100 represents the first application of friction welding technology over such a wide area of fabrication. The E100’s automatic handling systems and rapid machine open/close features cut production cycle times versus manual operations, and recharging the accumulators takes only about 30 seconds for the largest and longest welds. The machine weighs 100 metric tons, and is about 100 in. tall.

Both developers say the new machine will expand the range of applications for LFW in automotive and aerospace manufacturing, because it will be capable of producing components like vehicle flooring, or it may be used to secure the blades on jet engines. They point out that component parts that previously needed to be machined from solid metal (or cast in molds, or forged from ingots) can now be fabricated using LFW, opening new manufacturing possibilities. For example, they cite the way that jet engines are manufactured, wherein fabrication could cut production cycle-times and reduce waste of expensive materials (e.g., titanium.)

The E100 is a 100-metric ton machine co-developed by Thompson Friction Welding and Moog. The builders say it may alter the way OEMs treat large components in their manufacturing efforts.

“Thompson is well known for bringing new and innovative friction welding processes to market, mostly rotary friction welding techniques and machines,” stated managing director Alan Shilton. “Rotary techniques, however, are not suitable for all components, and we saw the opportunity to develop a machine that would not only bring cost-saving benefits to both aircraft and automotive manufacturing through improved welding techniques but also position us as the global market leader in linear friction welding for some time to come.”

“The challenge presented to us was to develop a hydraulic motion control system to drive a new machine that would break industry convention in terms of size, scale and capacity,” said Steve Darnell, Moog’s regional business manager for North West Europe.

Moog’s closed-loop hydraulic servo control system for the E100 supplies fast response at high amplitude with advanced digital control techniques, delivering precise control over the weld process. Normal servo and proportional valves have a limitation of spool speed and acceleration that prevent the simultaneous delivery of high amplitude and frequency. For the E100, Moog valve spools were made to perform 3 or 4 times faster than normal. Special precautions were necessary to ensure valve integrity over a large number of welds.

Moog also provided multiple digitally controlled Servovalves that operate together at peak flow rates of up to 4,500 lpm (1,200 gpm), and possess a high frequency range of 75 to 100 Hz for large scale welding. Multiple valves also improve accuracy when the machine is turned down for smaller, lower force welds. It added a hydraulic power plant capable of more than 2 MW of instantaneous power to drive the system; seven 400-l (105-gal) gas volume accumulators, each producing massive accumulation for the peak oil flow rate ((4,500 lpm) (1,200 gpm)) required for the weld. And, it provided the manifold and distribution pipework that routes oil to multiple active components.

“It was clear from the start that Moog and Thompson gelled and we had much in common in terms of our expertise in friction welding and hydraulics as well as our commitment to push boundaries of performance to deliver high performance machines. Now here we are, two and a half years later, with this unique machine,” Shilton observed.