I would like to briefly discuss some thoughts on ball bearing efficiency specifically in terms of applied load and resulting stress. I don’t want to trivialize this subject; there are textbooks written on the subjects of electrohydrodynamic lubrication (EHL), octahedral subsurface shear stress and friction losses due to elastic hysteresis. This is a just a high-level discussion on the importance of individual bearing stress on efficiency. 

Randy Stott, publisher of Power Transmission Engineering and Gear Technology magazines, recently sat down with Norm Parker, technical fellow and technical manager for Torque Transfer Systems at Stellantis, to discuss bearing technology during the Motion + Power Technology Expo in Detroit.

It seems like everyone is jumping into the electric gearbox market. Even Schaeffler is in the electric drive module (EDM) market now with their own 800v system. With all these new entries, some companies are satisfied with following traditional bearing arrangements while some want new and unique solutions or some combination of both. There is heavy debate over which styles are the best. In this article, we will talk about the different types of 2-bearing arrangements for each shaft with the pros and cons of each for a simple three shaft, single speed parallel axis gearbox (ala Tesla style).

Welcome back to Part 2 of our inner ring and creep discussion. We left off with our creep calculation resulting in a 10.5 µm minimum inner ring fit to avoid creep. For the sake of making clean dimensions, let’s call it 10 µm on the lower end and the upper end is simply whatever your manufacturer can hold.

I think I spend more time talking about ball bearings today than at any other time in my career. Ball bearings have always had a large place in automotive, but not typically in high demand positions—other than a few niche areas. High demand positions, such as axles and planetaries, were typically reserved for tapers, needles and cylindricals. The landscape is changing quickly.

In everyday life and in the technical fields we often discover that certain decisions are based on “scientific data” when, in fact, they are often founded on historic conclusions that have not been challenged or re-evaluated in a long time. One such common myth is that for a stable and well-tuned drive you should match the motor’s inertia to the load inertia, which is typically done using a gearbox. Two factors lead to that conclusion: a. there is an optimization formula using the time constant of the motor and the load torque that shows that the best acceleration will be achieved if the reflected load inertia matches the rotor inertia; and b. a PID controller, which was commonly used when electric servos entered the marketplace, tend to perform best and appear to be most stable when the inertia are close or matched.

In the past, we designed motors and drives separately from the mechanical system, and then we integrated suitable components to make a system work. Increasingly, though, the design focuses more on the overall system aspect and system integration, which makes the design of customized components more challenging. In this article, we will use examples of specific software tools, and it should be noted that these are just that: examples. For many of these tools, multiple similar and good software packages exist that can be used.

Coverage of IMTS and MINExpo International will continue on the PTE website through the end of the year and into 2025. We're excited to share the stories and new technologies discussed at both trade shows in September.

Our next legacy entry is maxon, a global leading provider of electric drive systems. The company provides single-source DC and BLDC motors, gearheads, sensors, control electronics, mechatronic drive systems and more-from individual prototypes to large-scale production. The history of maxon begins with Interelectric AG in Frankfurt.

Dual loop control is often used to improve the performance of a motion control system. Although this appears more complex at first look, the overall system cost and complexity needed to reach the desired level of precision may often be significantly reduced. In the example system, mechanical stiffness was improved by a factor of approximately 100 by the use of a secondary feedback device.In the case of a single loop lead screw system, the feedback is usually located on the back of the motor. 

Mitsubishi Electric Corporation recently announced that it had been awarded a Guinness World Records title on May 21, 2024, for the fastest robot to solve a puzzle cube using the TOKUI Fast Accurate Synchronized Motion Testing Robot (TOKUFASTbot). The previous record of 0.38 seconds was trumped by TOKUFASTbot's time of 0.305 seconds. 

The manufacturing industry often sets the trends for technology adoption in industrial settings. For example, the automation journey began a half-century ago with the first industrial robot — a 2,700-pound behemoth Unimate prototype — installed in a GM factory in 1959. Since then, robotics technology has significantly evolved and expanded beyond traditional manufacturing. Today, robots are integral to various industries, undertaking tasks like automated bricklaying in construction, efficient goods handling in logistics and warehousing and critical functions such as dispensing medication within hospitals.