Abstract
Reduction gears are used in the joints of the robots. While precision and efficiency are required for industrial robot gearboxes, humanoid robots are expected to become more popular in the future. Flexibility must be considered in humanoid robots, and high back drivability shall be required. In this study, we aimed at realizing high efficiency, and high-precision reduction gears with high reduction ratios by maximizing the efficiency equation, hybridizing a 3K compound planetary reduction gearbox and traction drive, experimentally determining the efficiency, backlash, and angular velocity variation, and demonstrating the effectiveness of the proposed mechanism from a control perspective. In the experiments, we achieved a maximum forward driving efficiency of 90.90%, backward driving efficiency of 90.58%, and a minimum backlash of 1.18 arcmin.
Highlights
I NDUSTRIAL ROBOTS are indispensable in agriculture [1], [2] and industry [3], [4]
While the conventional backlash removal method is the most common method [26]–[28], this study showed that accurate control can be achieved without backlash estimation
We proposed a new reduction gear with high efficiency, high accuracy, and high back drivability by realizing the hybrid structure of a traction drive and a 3K compound planetary reduction gearbox while maintaning the same structure [29]
Summary
I NDUSTRIAL ROBOTS are indispensable in agriculture [1], [2] and industry [3], [4]. Many exoskeletons and electric actuators rely on reduction ratios of 100:1 or even more [12] Various mechanisms, such as planetary gearboxes, which use involute teeth as rotary actuators, wave gears (known as harmonic drives), and cycloid pin wheel reducers, are used to meet the various demands of robots [14]. As a high-precision and high back-drivability reduction mechanism, Xiaolan [24] proposed a traction drive that uses rollers instead of gears, and its structure is mainly similar to that of a planetary mechanism. A large reduction ratio can be obtained In this complicated structure, if the number of teeth of each gear is expressed as zi, i ∈ {s, p1, p2, r1, r2}, the transmission direction of the output is same as that of the input when zp1 < zp and zr1 < zr, and is opposite to the direction of the input when zp1 > zp and zr1 > zr. Since this basic driving efficiency is determined by the number of teeth and shift coefficient, the efficiency can be maximized by the number of teeth and shift coefficient [23]
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call