Sealed spherical bearing is strong
"What makes the SPW unique is the fact that it is an insert bearing with an integral heavy-duty seal and it comes with a one-piece, ductile iron housing as a standard feature," says Gerry McLean of NTN Bearing Corp. Seals in open bearing/sealed housing designs typically consist of a triple labyrinth seal ring that offers no contact at all, or a light-duty lip seal whose effectiveness can be compromised by only a slight misalignment between the housing and the shaft. In contrast, in the patented SPW sealed bearing, positive contact of the heavy-duty seal is assured under a greater range of misalignment conditions. Best of all, says McLean, NTN engineers were able to add seals into the bearing without robbing space from the rollers, which otherwise would have reduced the bearing capacity. Lower capacity typically means shorter bearing life.
NTN Bearing Corp.: Product Code 4670
New coating is a rust-buster
The bane of workers who maintain equipment that operates in wet environments, corrosion can lead to premature bearing failure and spalling. At the very least, these workers spend tedious hours cleaning water etch damage off bearings. But thanks to the recent availability of a zinc coating process, Timken's Jon Smitek, application development specialist, estimates that the company's new line of AquaSpexx bearings will last at least twice as long as standard bearings in applications where water-based damage is the primary mode of failure. "In salt spray tests, AquaSpexx bearings lasted more than 100 times longer than standard product before showing signs of rust," says Smitek. The 0.0003-inch-thick plating, which is applied to only the outer race of larger rolling mill bearings and all over on smaller bearings, does wear over time. But in long-term tests to study this issue, Timken has determined that wear does not impact overall bearing life.
Timken: Product Code 4668
These studs are no duds
Up until now, plant maintenance workers had no good way to gather process and vibration data. "The problem with portable systems is that the operator should always go back to the same place to take a reading. And you know how hard that can be, especially when the detector mounts to the machine with magnets," says Roy Bannach, product line manager for sensors. SKF engineers have come up with a better mousetrap--in the way of a mechanical stud that attaches permanently to machines. SKF has applied for a patent on the novel device, which features double threads (1/4-28 or MB X 1.25) for mounting a process and vibration data collection device, allowing users to lock it into place with a quick, quarter turn. "The stud creates a solid, repeatable connection and it has a high resonant frequency so the system is very responsive to low-level machine vibrations," says Jonathan Murphy, senior product designer. Also available are "smart" studs featuring a touch memory chip that can be programmed with machine temperature and vibration alarm settings unique to a particular bearing or machine. Both studs are compatible with SKF's MARLINTM condition detector, data manager and other systems.
SKF: Product Code 4667
Housed unit keeps bearings dry, clean
Corrosion is a major enemy of bearing performance in any kind of operating environment. But it is especially harmful in food processing and related areas that see a lot of constant moisture. Corrosion can not only lead to premature bearing failure, but the onset of surface rust can require an immediate shutdown. When Torrington introduced its Fafnir SURVIVOR line of bearing housed units, this innovation met with a quick and enthusiastic acceptance, says Fafnir Product Manager Jeff Koziol. Combining a polymer housing with a special, thin-dense-chrome-coated ball bearing insert, stainless steel components and a food-grade grease created a housed unit that can stand up to tough environments and hygienic requirements.
Torrington: Product Code 4669
Pillow blocks score!
New self-aligning roller bearing pillow blocks allow higher speeds and have less rolling friction in linear motion applications. The secret, says Jim Ashworth, is the company's patented pillow block design. It incorporates a larger rolling diameter than conventional ball bushing pillow blocks, which enables it to operate at significantly higher speeds and acceleration. The fact that the individually sealed steel rollers do not require shaft seals, which generate resistance to motion, gives the product a low rolling coefficient of friction (0.004).
Lee Controls: Product Code 4673
Thomson rolls out titanium balls
Design engineers seeking the performance of titanium balls in bearings and other applications but who balked at the high price in the past, may want to take another look. Thomson Industries has recently figured out a low-cost way to mass-produce precision titanium balls, priced at a mere 19ó each in quantities of 100,000. "Titanium isn't easy to form, but we've been able to perfect our process to the point that we can make a 0.125-inch-diameter ball round to within 10 millionths of an inch," says James Peta, manager of manufacturing operations. High-performance bearings are a primary application for balls made of titanium, which is desirable for its low density, anti-corrosive properties, and high tensile and compression strength. But Peta says the company has had interest in the balls for a wide range of applications, including endings on flexible cables, check valves for pump sprayers, and--he's not kidding--body jewelry.
Thomson Inds.: Product Code 4671