Every kilogram counts in aircraft design, so SKF subsidiary Sarma's announcement that its new titanium bearing with a bronze bushing will save more than 100 kg in weight per A380 landing gear over traditional bi-metal (bronze and steel) bearings is big news indeed. SKF has received a process patent on the bearing and the flanged bush construction. Six of these self-aligning, spherical plain bearings per aircraft provide a structural attachment between the landing gear and fuselage, and facilitate the rotation of the support pivot axis. In all, SKF engineers tested more than dozens of material combinations, many of which they admit were "improbable." In fact, they weren't even sure at the start that titanium would be a feasible material choice. Engineering Manager Yves Maheo says that the key to the bearing was the development of a coating to prevent galling, a common phenomenon in titanium parts because of the material's relatively high friction coefficient. "Due to its low theoretical tensile and shear strength, the dry sliding coefficient of TI-6AI-4V against steel, for example, is 0.6," Maheo says. "Making matters worse, the great affinity of titanium for oxygen results in the formation of an oxide surface layer that is transferred to the sliding surface during contact, forming wear debris." While Maheo declined to divulge the exact composition of the coating or its thickness, he says the design involves two different coatings that eliminate the galling issue and make possible titanium/titanium sliding contact for the self-aligning function. SKF will offer the bearings in a range of diameters from 20 to 155 mm, and is evaluating various applications including the pylon-to-wing attachment and aileron reaction strut rod end. For information on Sarma's line of aerospace bearings, go to http://rbi.ims.ca/3854-532.
What makes this movie stand out from the typical high school sports story is that the teenagers are undocumented immigrants, and the big game is a NASA-sponsored marine robotics competition. Like many other Hollywood movies, however, Spare Parts only tells part of the story. What the film shows -- and doesn’t show -- raises important issues affecting STEM education in the US.
Instead of sifting through huge amounts of technical data looking for answers to assembly problems, engineers can now benefit from 3M's new initiative -- 3M Assembly Solutions. The company has organized its wealth of adhesive and tape solutions into six typical application areas, making it easier to find the best products to solve their real-world assembly and bonding problems.
Load dump occurs when a discharged battery is disconnected while the alternator is generating current and other loads remain on the alternator circuit. If left alone, the electrical spikes and transients will be transmitted along the power line, leading to malfunctions in individual electronics/sensors or permanent damage to the vehicle’s electronic system. Bottom line: An uncontrolled load dump threatens the overall safety and reliability of the vehicle.
Focus on Fundamentals consists of 45-minute on-line classes that cover a host of technologies. You learn without leaving the comfort of your desk. All classes are taught by subject-matter experts and all are archived. So if you can't attend live, attend at your convenience.