Hardinge Announces A Major Breakthrough In Hard Turning Technology

Elmira, NY - Hardinge Inc. has introduced revolutionary new technology which reduces costly manufacturing operations and enables a wider variety of industrial segments to consider the advantages of hard turning in their manufacturing process. The new Shape Compliant Chuck (SCC) combines the company's rigid machine tools with its expertise in process applications and workholding solutions to raise the bar to a new level in hard turning capability.

"The patent pending Hardinge Shape Compliant Chuck, combined with Hardinge's expertise in hard turning and its Quest lathes, offers direct and measurable benefits to companies that turn, bore and grind thin wall hardened or out-of-round parts," said J. Patrick Ervin, Hardinge Chairman of the Board/President/CEO. "The combination can help manufacturers to lower operating costs, reduce capital investment and shorten manufacturing times. In short, they enable lean manufacturing."

One of the problems associated with boring hardened parts is that the heat treatment process often distorts a part's Inside Diameter (ID) and/or Outside Diameter (OD). Conventional workholding techniques tend to overpower the workpiece and cause it to become round while gripping. When released, the workpiece elastically springs back to an out of round condition. Previously, the only way to achieve desired roundness of the finished part was to perform additional grinding on the OD/ID, which increased cost and waste, and introduced the opportunity for error.

The new shape compliant workholding technology from Hardinge grips the part "as is" and enables machining of the ID without the part moving again when released from the workholding device. When combined with proven Hardinge hard turning machine and part process technology, the result is a hard boring and/or turning process that yields greatly improved part roundness – as much as 11 times better than previous methods, while eliminating the rough and finish grinding processes normally required in the manufacture of hardened parts.

This new technology works extremely well on parts such as bearing races and other delicate workpieces. On testing recently completed on a hardened bearing race, the initial roundness of the bore was .000913". After hard boring using the shape compliant workholding mounted on a Hardinge Quest SP51 HydroGlide turning machine, a roundness of .0000835" was achieved.

The Hardinge Shape Compliant Chuck was developed during a project sponsored by National Institute of Standards and Technology's (NIST) Advanced Technology Program (ATP) to study Lean Manufacturing of Critically Hardened Steel Applications. ATP projects are used to stimulate the development of innovative technologies that promise significant commercial payoffs and widespread benefits for the nation.

Dan Soroka, Director of Engineering – Workholding Operations, explains that the Hardinge Shape Compliant Chuck is available in configurations that support a range of sizes and versions for both ID and OD gripping. "The SCC centralizes the workpiece, provides adjustable gripping forces, and allows the operator to apply the gripping forces at multiple gripping locations that contact the workpiece," he said. "There are up to eight independent gripping locations at the radial position of the out-of-round part, with equal pressure on each leaf. Since this chucking system maintains the part shape as close as possible to the original state, the finished un-gripped part roundness is improved an average of 9 to 11 times the pre-machined values," said Soroka. The SCC also provides high levels of dampening.

According to Doug Rich, Vice President – US Machine Operations, "the development of the SCC was an accomplishment that is based on partnership – both within Hardinge, between the Workholding division and US Machine Operations, and with the other ATP team members. This combined effort helped us bring a truly differentiated hard turning solution to the market."

The Hardinge Shape Compliant Chuck will be offered only on Hardinge Quest Lathes. "The combination of these technologies provides a hard turning solution that no other provider in the world can deliver," said Rich.

"We owe much thanks to the efforts of the team and to NIST for their support in addressing the challenges faced by the industry in the hard turning of hardened, thin wall and out of round parts," concluded Ervin. "Clearly, the momentum and knowledge gained during this program will continue to serve as a springboard for the future commercialization of new Hardinge products."

SOURCE: Hardinge