The Bulk Metallic Glass Gears project is an example of a new kind of gear. Unlike conventional gears, BMGs are cold-resistant and run smoothly without any lubricant. Moreover, BMG gears are resistant to extreme cold, even at -328 degrees Fahrenheit or -200 degrees Celsius. That makes them an excellent choice for robots working in such environments. NASA’s Mars Curiosity rover expends energy on heating up its grease lubricant, so the BMG gear is a great way to save power.
The Nugear structure is equivalent to two Wolform PGTs. Both have a carrier and are similar in terms of torque-to-weight ratios. Although they are less robust under changes in operating conditions, the gearheads have a significant advantage over RG350. In addition, they have low no-load starting torques and have higher efficiencies. However, the NuGear structure is not yet commercially available, and more research is needed.
Another type of wearable high-tech gear is the exoskeleton, a mechanical device that mimics the human skeleton and helps workers avoid the aches and pains of repetitive motion. Currently, exoskeleton technology is only reaching the factory floor, but many startups are developing high-tech gear that can be worn while performing manual work. For instance, the EksoVest suit, developed by Ekso Bionics, is already being tested in assembly plants of Ford. It not only reduces the wear and tear of repetitive motion, but also provides lift assistance without batteries. It is also intended to help people suffering from neurorehabilitation.
Another important consideration for selecting a gearbox is its efficiency. While it has been a long-standing concern in other fields, gearbox efficiency is only recently becoming a key decision parameter in robotics. The higher the efficiency of a gearbox, the lower its energy consumption and environmental footprint. Higher efficiencies also result in smaller weight and autonomies. And, of course, improved efficiency is always a desirable outcome. While these factors may not be quantifiable, they are all important for a gearbox’s efficiency.
The Strain Wave Gear was introduced by GAM in 2001. A Strain Wave Gear is similar, but it is designed for a linear guidance of a single tooth. A Poligon Shaft is the wave generator in the Strain Wave Gear. An integrated spline connects the multiple teeth, resulting in a cycloid-like movement. The Strain Wave Gear is an example of a new kinematic approach to gear design.
While Harmonic Drives dominate the robotic gearbox market in the 90s, improvements in cycloid technology have enabled the cycloid gearbox to gain ground. They have gained ground, first in Japan and then elsewhere. According to NABTESCO, the cycloid hybrid gearbox can now cover more than 60% of the robotic gearbox market. This new dominant technology can be especially useful for proximal joints subjected to greater loads and lower weight restrictions.
