ShopSolutions Case Histories of Manufacturing Problem Solving Helicopters Fly High on Ceramic Bearings I
80 range. These materials and processes will then be incorporated to produce ceramic bearings for testing their potential use in US military aircraft, mainly helicopters, where they can oper- ate at much higher temperatures and speeds than a steel bearing. Without sufficient lubrication, conventional steel bearings in a military helicopter might last about 10 minutes; while a ceramic bearing would provide up to 30 hours of operation after loss of lubrication. Thus in a battlefield situation where an aircraft’s lubrication system is damaged, ceramic bearings would provide ample time for the craft to safely return to a secure area for re- pairs. Plus, ceramic bearings are lighter and help reduce aircraft weight. “We aren’t a production house,” said Richard Roberts, director of cor- porate development at Reliance Tool & Manufacturing. “A big order for us is 100 pieces, with most job volumes at one or two pieces. Our true forte is conducting research and develop- ing machining processes and systems for customers, and
f Reliance Tool & Manufacturing Co.’s research and test-cut- ting operations continue to progress at their current pace, the Elgin, IL shop foresees it will soon be able to cost effectively produce an entire ceramic bearing assembly, not just rollers, but also the races. Reliance is developing optimized machining processes for extremely hard ceramic materials, such as those in the Rc
ber molds for producing oil seals. Then, in an effort to reduce part-processing time, the shop perfected hard machining techniques for its metal components in the Rc
ness range and measuring in size from 0.875 to 20" (22–508 mm) in diameter or 2 to 36" (51–914-mm) square. Typical part tolerances are around 0.0005" (0.013 mm).
Reliance Tool & Manufacturing: Rick Deleon, CNC machinist/laser systems technician (left), Jeff Staes, supervisor of technical support (center) and Richard Roberts, director of corporate development (right) discuss ceramic engine liners produced using the shop’s laser-assist machining system.
Key elements in Reliance’s efforts to develop cost-effective machining processes for ceramics are special cutting inserts developed by Seco Tools Inc. (Troy, MI), innovative use of a laser mounted on an Integrex i 200-IV ST Multi-Tasking
So far, the shop has successfully turned, milled and threaded ceramic materials such as silicon nitride, zirconium and alumina.
currently our biggest customers are private Tier I suppliers to the aerospace and defense segments.”
Reliance was established in 1948, and at that time, the company was manufacturing mostly stamping dies and rub-
machine from Mazak Corp. (Florence, KY), and research done in conjunction with Northern Illinois University. So far, the shop has successfully turned, milled and threaded ceramic materials such as silicon nitride, zirconium and alumina. Most