DN Staff

April 23, 2001

6 Min Read
Hot Products

Got flexibility? These bearings do.

Instead of having to look through bearing catalogs to find a bearing that may work for a given design and then designing a product around the bearing, designers can now obtain bearing segments from Thomson Industries customized to conform to the shapes and envelopes required by the design. The company holds a patent for what it calls "segment technology," in which complete bearings are made of segments, each of which typically contains a plate and a retainer with a lid and balls for easy handling and storage. Until now, Thomson only provided complete bearings built on this technology. "Now, bearing segments can be configured to fit within the annulus constraints of two components, where they provide low-friction linear motion," "says Frank Dalessandro, product engineering manager for linear bearings. "Segments can also be provided with self-adjusting features to 'forgive' temperature fluctuations and material variations while maintaining a desired pre-load," he adds. So far, OEMs in the automotive, woodworking and semiconductor industries have expressed interest in customizable bearing segments, and the company believes that the technology will lead to innovation in all industries that produce sufficient volume to justify customization. "Costs will be lower in these applications than those associated with conventional bearing solutions," Dalessandro says, "but the most important aspect of customized segments will be the optimization of designs that could not otherwise be made."

Thomson Industries: Enter 610

Bear in mind this simulation software

Bearings have always been a kind of black box for engineers. Load, heat, lubrication, misalignment, and lubrication all have an impact, but up until now it has been difficult for engineers to anticipate how these factors influence a bearing's performance in an application. SKF plans to change that by sharing its bearing expertise with customers through two new bearing analysis tools, called BEAST (Bearing Simulation Tool) and Orpheus. A 3D simulation tool, BEAST analyzes minimum load or pre-loaded bearings, bearing damage due to high impact loads, cage design, and more. "A shortcoming of traditional FEA analysis is that it tends to be static. Our new tools simulate how the bearing will behave dynamically in the real world," says Dan Snyder, director of application engineering. FEA results are used as inputs to the analysis, but SKF's software takes things one step further by analyzing the dynamics of the actual application. What's the benefit to design engineers? "Better, faster designs, with less need for testing," says Snyder. "Engineers will be able to identify the correct bearing earlier and more easily, and fine tune their designs through an iterative process. And they'll be able to do it all faster." SKF plans to offer the service to all bearing customers. SKF: Enter 611

Bearings make trade-offs bearable

"When it comes to bearings, there are always trade-offs, but our F-Series self-lubricated bearings are making them more acceptable," says Charles Spungen, VP of the Engineered Materials Division of Peer Inc. The FB and FR plain bearings consist of a steel backing for mechanical strength and rigidity, a sintered bronze layer for wear resistance and heat dissipation, and a resin layer that provides anti-friction characteristics. By varying the material composition of each of these layers, explains Spungen, Peer engineers can optimize a bearing to meet the requirements of a specific application. Peer's newest addition to the line is the FR160, currently under beta test at several major OEMs. To optimize the bearing's performance in low-lubricity applications, the PTFE layer is impregnated with a tin oxide that acts as an oil magnet to maintain wetness. Applications include equipment in which the bearing operates in low-viscosity fluids with low lubricity. Peer Inc.:Enter 612

Caged ball for linear motion

Engineers everywhere are seeking to minimize downtime, and THK engineers say that their new linear family of linear motion products featuring caged ball technology does just that. "By separating the recirculating balls with a retainer, we can eliminate the heat created by ball-to-ball friction and reduce the wear-both sources of downtime and premature bearing failure," says Manufacturing Engineer Jeffrey Wick of THK America. Further, the balls themselves rotate through a pocket of lubricant, maintaining lubricity and minimizing maintenance requirements. "A decade ago design engineers weren't too concerned with maintenance issues-now they're trying to minimize or eliminate it completely," says Wick. "Our caged ball technology addresses these issues in linear motion, and does so at a cost that is competitive with standard, non-linear cage guides." The technology, which achieves micron-level accuracy, is targeted for medical device and semiconductor applications and is available in three models of THK's LM guides. THK America:Enter 613

Longer life at high temperatures

The new LH Series line of self-aligning spherical roller bearings from NTN Bearing Corporation of America reportedly offers 3.5 times the service life of industry standard bearings in normal applications as well as in such high temperature applications as steel and paper mills. A new steel treatment enables the bearings to remain stable at temperatures ranging from 250 to 492F (250C) with no reduction of hardness. "Material hardness goes down with each increase in temperature level, so in the past we had five different parts for a variety of temperature ratings. The LH Series functions well at all those temperatures, and replaces all five of the older part numbers, " says John Husemann, manager of after-market engineering. In tests, NTN reports the LH was seven times as resistant to flaking as spherical bearings made of industry standard material and 1.4 times as resistant against smearing. "The new line also demonstrated twice the fatigue-crack life under higher temperature and twice the resistance to rolling fatigue crack," Husemann says. Currently available in spherical sizes 22208 to 22218, LH bearings with outside diameters larger than 420 mm will be available later this year.

NTN Bearing Corp. of America: Enter 614

Easy-mount bearing saves time

To reduce the difficulty and time involved in installing and removing conventional bearings, Rockwell Automation offers its new Dodge metric ISN bearing featuring a patented Imperial adapter mount system, it tapers to fit a shaft, ready for lock-nut tightening. "Installation time is 15 minutes, as compared to up to two hours," says Ryan DeWachter, development engineer for Rockwell's Dodge bearings. "The assembly offers simplified mounting and dismounting, with a push-pull adapter system. Conventional bearings use screw mountings, which tend to wobble at high speed and to damage the shaft when removed." For easy removal, the lock nut that fixes the assembly in place rotates in both directions. "The sealing system provides 100% contact at 100% constant pressure, 100% of the time-protecting the bearing from dust and dirt in such applications as conveyor systems," says Application Engineer Marco De Maria. Rockwell Automation, Dodge Bearings: Enter 615

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