Polymer bearing handles heavy loads

Designed to handle especially high loads between 7,250 and 14,500 psi, iglide^(R) Z is the highest temperature bearing material ever created for igus. With a maximum permissible short-term temperature of 590F, the Z bearing material is the most wear-resistant iglide material, according to Aubrey Butler, bearings division product manager. "The material is not only more pliable and chemical resistant," Aubrey says, "but it's also electrically insulating and offers low moisture absorption." Suitable for sleeve bearings, flange configurations, and thrust washers, the material is targeted at high-load applications in hydraulic cylinders, scissors lifts, trailers, and handling equipment, and can run on numerous shafting materials. igus: Enter 576

Bearings reduce power loss

Timken^(R) fuel-efficient bearings were designed for driveline applications such as axle centers (pinion and differential) in passenger cars, light trucks, and SUVs. But the concept could also be used in transmissions or other automotive applications to improve fuel economy and reliability. "Internal geometry changes allow closer bearing orientation and more stable support of the pinion stub shaft," explains VP Engineering-Automotive Russ Folger. "This decreases the pinion stub shaft's length, and consequently reduces weight of the axle center by approximately 10-15%." The shorter, more rigid design is said to improve gear contact. In addition, tighter control of certain dimensions, including surface finishes, reduces power loss due to friction. Tests indicate power consumption reductions greater than 30% compared to a typical pinion bearing. "Bearing operating temperatures as much as 30C cooler combine with reduced noise and pinion movement to prolong oil life and enhance axle reliability," Folger adds. The Timken Company: Enter 577

Caged rollers boost rigidity, reduce friction

Extrapolating its Caged Ball(TM) technology into the realm of higher rigidity roller guides, THK now offers the Type SRG. "Using a proprietary resin formulated for high flexibility, strength, and chemical resistance, the cage was designed not to break," says Manager of Corp. Engineering Yoshi Oishi. "Caged rollers maintain alignment while circulating to decrease rolling-resistance variation caused by rollers skewing when entering the block's load area," Oishi explains. "The result is stable and smooth movement at speeds up to 180 m/min." The roller cage also extends life and maintenance intervals by eliminating wear associated with the high contact pressures of roller-to-roller contact, and retains lubricant in grease pockets between adjacent rollers. While life data is still being finalized, Oishi expects more than twice the life of the company's conventional roller guides. THK America Inc.: Enter 578

Polymer wheels smooth motion, reduce friction

PW series linear guides from Bishop-Wisecarver Corp. use acetyl polymer wheels running on aluminum U-channel rails instead of the steel wheels and rails used on other UtiliTrak guides. "Probably half the applications today have lighter load parameters," says Jim Leonard, sales and marketing manager. "As a result, many design engineers are using products that are overkill. The new series lets engineers meet lighter load requirements, reduce friction and weight for smoother, quieter, and more efficient operation, and save a few bucks in the process." The carriage assembly consists of three inline guide wheels. Two engage one side of the track, and one engages the other side to provide roll-moment resistance. At a 100-km service life and mounted flat, the guide handles loads up to 50 lbs axial force. Edge mounted, it handles up to 40 lbs radial force. Two frame sizes are available, and stroke length is virtually unlimited, according to Leonard, as 12 standard length tracks can be butt-joined to achieve the desired length. Bishop-Wisecarver Corp.: Enter 579

Composite rollers target light-load applications

Producing smaller and lighter products tends to increase the number of light-load manufacturing applications. As a result, more cam followers today are oversized because engineers typically select them as an afterthought, choosing from stock metal units in catalogs. Power-Core(TM) composite roller technology lets engineers create lighter, custom sized cam followers for specific load, duty, and life without overdoing it, explains President Georg Bartosch. "The unique, stress-free crystalline structure resists flattening from compression under static loads. As a result, these rollers can replace traditional steel cam followers in demanding, load-bearing applications where noise, moisture, shock, temperature, and extraordinary rail wear present a challenging operating environment." Intech Corp.: Enter 580

Coating extends bearing life

Now available in pillow-block, two-bolt, four-bolt, and down-the-road in tap-base configurations, the heavy-duty cast iron Marathon HDi series from SKF targets food processing applications. Both the cast-iron housing and regular bearing-steel insert bearings are ZMaRC^(R) treated using a conversion coating over base plating. "The coating eliminates flaking problems associated with nickel-plated products," says Brian Dahmer, business manager for MRC bearing services. "As with all Marathon products, a patented two-part stainless steel seal design allows the unit to operate in heavy washdown environments without regreasing. And since there is no need for relubrication, continuous grease purge is never a problem." For a more sanitary design, polyurethane filler in open spaces on the bases and backs of housings eliminates areas where moisture and product can collect. SKF: Enter 581