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.
In a bid to boost the viability of lithium-based electric car batteries, a team at Lawrence Berkeley National Laboratory has developed a chemistry that could possibly double an EV’s driving range while cutting its battery cost in half.
Using Siemens NX software, a team of engineering students from the University of Michigan built an electric vehicle and raced in the 2013 Bridgestone World Solar Challenge. One of those students blogged for Design News throughout the race.
Robots that walk have come a long way from simple barebones walking machines or pairs of legs without an upper body and head. Much of the research these days focuses on making more humanoid robots. But they are not all created equal.
For industrial control applications, or even a simple assembly line, that machine can go almost 24/7 without a break. But what happens when the task is a little more complex? That’s where the “smart” machine would come in. The smart machine is one that has some simple (or complex in some cases) processing capability to be able to adapt to changing conditions. Such machines are suited for a host of applications, including automotive, aerospace, defense, medical, computers and electronics, telecommunications, consumer goods, and so on. This discussion will examine what’s possible with smart machines, and what tradeoffs need to be made to implement such a solution.