Zero backlash strain wave gears for surgical robots – High precision, compact design, large safety margin

Surgical robots pose particular challenges to drive technology. Movements must be carried out with utmost precision and exact repeatability and, at the same time, with perfect safety in the immediate vicinity of the patient. High-performance strain wave gears are ideally suited for the severe spatial constraints found in such environments thanks to their compact design and low weight. Marrying their know-how in robotics with their experience in medical engineering and their expertise in gear technology, Nabtesco realises space-saving drive solutions that thoroughly meet the high precision and safety requirements of the industry - from particularly small short gears to digital gearboxes to complete actuators.

Exact motions for precise operations

Strain wave gears made by Nabtesco are set apart by their zero backlash, excellent repeatability, and high-torque capacity and ensure transmission of the control movements to instruments and axles with no delay and with millimetre accuracy. The adjustable backdriving torque delivers controlled yielding and supports sensitive positioning. Thanks to their small dimensions and low weight, they allow for a space-saving implementation of multi-axis robot structures. Enclosed designs contribute their share to effortless cleaning and sanitary conditions.

Short gears with 120% power density and 140% life time 

Particularly interesting options for robot-assisted surgery are short gears: Compared to conventional short-build strain wave gears, they deliver 120% power density and 140% life time at identical size. This creates additional freedom for the development of compact and powerful robotics systems. Models with a hollow shaft make it possible to pass cables, hoses and power leads directly through the gear.

Compact actuators simplify system integration

Wherever applications call for a high level of integration, actuators offer crucial benefits. Combining gear, motor, encoder, and an optional brake in one finely tuned unit, they ensure high functionality, effortless handling, and maximum compactness. They thus reduce interfacing requirements and streamline the integration into complex robot systems.

High overload protection and digital gear solutions

For Emergency Stop situations, the strain wave gears are designed for torque levels of up to 500% of the rated torque and offer a safety factor against failure of up to 1,500%. In the event of a malfunction, this level of protection helps keep patients and operating personnel safe. Additional safety is provided by the digital gearbox, which captures torque variations with such precision that collisions can be detected ahead of time and movements can be stopped quickly.

Strain wave gears made in Germany

All strain wave gears are developed and produced in Limburg an der Lahn (Ovalo GmbH location) and meet high quality and process requirements. Prior to delivery, each gear is subjected to a 100% final inspection. Manufacturers of surgical robots benefit from consistently high quality, short distances and a partner with high production depth and profound engineering expertise.