A recent Design News article about packless rotary valves prompted a reminder about this bent-bellows, rotary-valve seal design. In it, a bellows encapsulates the stem to prevent leakage. With one end fixed to the valve bonnet, the other end of the bellows rotates around the stem axis as the valve is opened or closed. An external housing over the stem and bellows protects and preloads the assembly to allow controlled rotation and acts as a secondary seal. Quarter-turn, half-turn, and fully rotating models are available.
Richard Conley, P.E., Kerotest Manufacturing Corp., 2525 Liberty Ave., Pittsburgh, PA 15222-4680, (412) 392-4230.
A flexible magnetic material enclosed within a thin stainless steel jacket lets the Speed Sense(TM) system monitor shaft rotation and direction without the toothed wheels normally used in Hall-effect sensing. Originally developed to reduce turbulence in hydraulic pumps, the system should also reduce losses in transmissions and compressors. The patented ring is available separately for custom applications.
Allen Anderson, Temper Corp., Fonda, NY 12068, (518) 853-3467.
Plastic components on heavy equipment may come as a surprise, but Case Corp. says the polyurethane reaction-injection molded (RIM) fenders on its L-Series(TM) backhoes outperform steel in the application. The 24-lb, 61x21x28-inch fenders can support a 50-lb corner load and rebound from impacts in temperatures from 180 degrees F to -20 degrees F.
Made from 18% glass-filled Bayflex(TM) 110-50 elastomeric polyurethane RIM system, the fenders feature molded-in tool trays and thermos-bottle holders. Their design eliminates ten separate parts and can be molded with nickel-shell tooling, cutting molding costs by 50% compared to steel tools.
Craig Snyder, Bayer Corp. (formerly Miles, Inc.), Mobay Rd., Pittsburgh, PA 15205-9741, (412) 777-7454.