Precision Gearboxes for Highly Dynamic Robotic Applications

Rapid accelerations, abrupt changes in direction, short cycle times, and high start-stop frequencies, all while meeting very high requirements for repeatability and positioning accuracy: Highly dynamic applications place significant demands on the precision gearboxes used. This makes it all the more important to have a solution that is precisely tailored to the specific load conditions and motion profile. Nabtesco will show you what matters most when it comes to selection and design.

High-dynamic applications place high demands on the precision gears used. These must operate reliably even under high accelerations, short cycle times, and frequent load changes, while delivering high repeatability and transmission accuracy and enabling precise positioning.

What Requirements Do Highly Dynamic Applications Place on Precision Gearheads?

Low backlash and high torsional rigidity are particularly crucial for precise and stable positioning. A low moment of inertia also facilitates rapid acceleration and deceleration. Furthermore, the gearboxes must be able to transmit high dynamic torques and safely absorb short-term peak loads, such as those occurring during abrupt changes in direction or emergency stop procedures.

Lubrication also has a significant impact on performance and service life. The lubricant must be tailored to the gearbox design, speed, load, and operating temperature. Properly selected and optimally sized lubrication reduces friction and wear, limits heat generation, and helps maintain the gearbox’s precision and performance even under high dynamic loads.

Key Requirements:

Low backlash, ideally even zero backlash
High torsional rigidity
Low moment of inertia
High dynamic torques
High load capacity under frequent load cycles
High overload capacity
High transmission and repeatability accuracy
High efficiency
Long service life

Design Based on Motion and Load Profiles

When designing a system, it is not sufficient to consider only the rated torque. The entire motion and load profile is decisive. This includes acceleration and deceleration times, rotational speeds, peak torques, load cycles, duty cycle, and potential emergency stop or collision events. These factors determine which gearbox type, size, and reduction ratio are suitable to ensure the required dynamics, precision, and service life.

Design Challenges:

High mechanical stress due to frequent load and direction changes
Heat generation at high speeds and short cycle times
Vibrations and positional deviations resulting from elastic deformations
Short-term load peaks during acceleration, braking, and emergency stop events
Conflicting requirements between dynamics, precision, installation space, weight, efficiency, and service life

Which Drive Concepts are Suitable for Highly Dynamic Applications?

Strain wave gears, cycloidal gears and precision planetary gears are particularly well-suited for highly dynamic applications. Direct drives can also be a suitable gearless alternative. These concepts prioritize different factors in terms of dynamics, backlash, torsional rigidity, moment of inertia, load capacity, reduction ratio, efficiency, and installation space. Which solution is best suited depends on the specific load case, the available installation space, the motion profile, and the requirements for accuracy, dynamics, and service life.

Comparison: Drive Concepts for Highly Dynamic Applications

The overview shows typical characteristics of the various drive concepts. The specific properties vary depending on the series, size, reduction ratio, and installation situation.

What Advantages do Nabtesco’s Precision Gears Offer in Highly Dynamic Applications?

Nabtesco’s precision gears enable fast and precise movements even at high speeds, with rapid acceleration, under heavy loads, and with frequent load changes. Strain wave gears are characterized by zero backlash, low weight, high torque capacity, and a compact design. The virtually backlash-free cycloidal gears offer high torsional rigidity, robustness, and shock resistance, with backlash remaining extremely low even over long periods of time. Both technologies support short cycle times, precise positioning tasks, and high requirements for process reliability.

Typical applications for highly dynamic precision gears: