CV-Joint Test Machine to Overhaul Auto Remanufacturing; - RIT Device and Software are Patent Pending

Clunk. Click, click, click. If your car makes a clicking sound when you make a turn, your constant velocity (CV) joint probably needs to be replaced. But should that be with a brand new part or a remanufactured one? That's the dilemma consumers face, especially when it comes to remanufactured auto parts that do not always have a standardized measure of testing.

Thanks to the National Center for Remanufacturing and Resource Recovery (NCR³) at Rochester Institute of Technology, consumers can know that remanufactured CV joints have met testing requirements that show they are at a like-new condition, before they are installed in a vehicle.

This is a breakthrough for labor-intensive repairs like CV joints. To date, there have been few choices for cost-effective evaluation of remanufactured automotive parts.

To ensure that remanufactured CV joints are meeting performance standards, NCR³, a unit of the Center for Integrated Manufacturing Studies, has developed a patentable CV joint-testing machine—CV Joint Test Fixture mod II. Mod II combines scientific criteria with a low-cost machine to help remanufacturers pinpoint CV joint failures pre-sale, without tearing down the entire part.

The machine passed its first blind test on March 20. Richard Lovely, chairman of the Automotive Parts Rebuilders Association (APRA) and General Manager of Powerline Inc., brought nine CV joints to RIT to conduct the blind test. Only Lovely knew which units were defective and what type of defects they had.

"The initial results are very promising," says Lovely. Mod II recognized the defective units. It also quantified the size and location of dimple defects.

"This machine is a breakthrough for us and, ultimately, the entire remanufacturing industry," says Nabil Nasr, director of NCR³. "But making sure the machine works on a set of CV joints is only the first step. That's why this blind test was so important."

The machine evaluates the quality of remanufactured constant velocity joints by moving the CV joint the way it would move in an automobile. 'Signals' from the joint, such as changes in vibration or temperature, are picked up and analyzed. An irregular pattern in vibration, for example, could indicate a failure in one of the components.

The test machine was developed with a team of NCR³ engineers, an RIT mechanical engineering professor and a number of graduate students. Innovators on the pending patents are Kevin Kochersberger, a mechanical engineering professor, and graduate student Gregory Kacprzynski.

The information generated by the test fixture is processed by diagnostic software, also patent pending, developed by NCR³ engineers.

The software runs on a computer connected to the fixture, analyzes the data in real time, and tells the operator whether or not the joint is flawed. Engineers at NCR³ have spent several months refining the software that accompanies the test fixture.

"There are two main components that make this machine unique," says Scott Nichols, NCR³ senior staff engineer and lead developer of the CV joint test machine. "First is a patentable mechanical device that moves and applies torque to the CV joint without spinning it. And, second is the analytical software, the real strength of the system."

Remanufacturing industry members have shown interest in mod II. APRA has said that the machine "greatly enhances the ability of remanufacturers to scientifically test remanufactured CV joints."

Mod II, because it has a short cycle time and a cost-effective design, is accessible to remanufacturers as an end-of-line quality inspection tool. Developing the tools and techniques to evaluate remanufactured products is a part of NCR³'s mission, says Nasr. Such tools may help remanufacturers confirm their compliance to performance specifications.

"Remanufacturers compete in a market where 'new' is often equated with 'better'," Nasr says. "With mod II, we are answering a fundamental need for evaluation in the remanufacturing industry. This is our most versatile tool to date; it is truly advanced technology for remanufacturers."

NCR³ is now looking for a group to manufacture mod II.

"This type of test machine should add another level to rebuilders who choose to invest," says Lovely. "I believe the theory and process, which was used on this machine, will be transferable to other applications."

Technical Information

CV Joint Test Fixture mod II's design offers several testing capabilities that are new to the market. Mod II uses an accelerometer instead of a microphone to acoustically monitor the CV joint. Microphones pick up a considerable amount of background noise, making it harder to locate errors with particular rolling elements in the joint. But because NCR³'s design does not rotate the CV joint around its axis, it can use an accelerometer attached to the bearing casing to pick up a clear, accurate signal.

In the NCR³ design the CV joint and its rolling elements are exercised through their full ranges of motion, so that any race and ball defects can be detected. The result is a more complete analysis of the joint's performance than with a CV joint operating at a set angle.

Mod II applies a higher torque than ever before, using an air cylinder instead of a brake. And only a small fraction of the torque applied to the CV joint is transferred to the drive system, so that the drive motor and drive system can be kept small and inexpensive.

The final advantage is mod II's ease of operation. A CV joint can be removed and replaced in a few seconds and the articulation angle of the joint can be easily changed.

"The machine is very quiet and stable. Parts can be tested in less than two minutes. This includes mounting the unit," says Lovely.

The software uses signal-processing algorithms to compare the data against established thresholds. The result is that an operator evaluating a CV joint will get a "go" or "no-go" signal.

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NOTE TO MEDIA: Digital pictures of NCR³?s CV Joint Test Fixture mod II are available. Contact Silandara Bartlett at (716) 475-4948 or e-mail sjbcom@rit.edu for the photographs and to talk to NCR³ experts.

The National Center for Remanufacturing and Resource Recovery (NCR³) is the nation's leading center for applied research and development in remanufacturing, helping remanufacturing and resource recovery industries improve productivity, reliability and processes without harming the environment. With its advanced proven technologies and hands-on experience, NCR³ is uniquely capable of developing the innovative and concrete solutions needed to take remanufacturing and resource recovery industries to the cutting edge.

The Center for Integrated Manufacturing Studies (CIMS) at Rochester Institute of Technology is a world-class organization with a mission to increase the competitiveness of United States manufacturers through applied technology and training. Established in 1992, CIMS provides technology and workforce development solutions that strengthen industrial clients' ability to compete in the global marketplace. CIMS' business units also include Corporate Education and Training, Manufacturing Technologies, the Printing Applications Laboratory, and the Center for Excellence in Lean Enterprise. CIMS represents a dynamic collaboration of in-house technical experts, as well as academic, industry and government resources.