The potential for service robotics is enormous: in kitchens and bars, in care, in the fields or in logistics, lightweight robots help to automate monotonous or non-ergonomic tasks. To ensure that such new concepts can be implemented easily and, above all, cost-effectively, Igus is presenting a new modular gearbox system for cobots at the Hannover Messe. The focus is on the fully integrated tribo-shaft gearbox with motor, absolute encoder, force control and controller.

"With our low-cost automation solutions, we enable designers to enter the future of service robotics at low cost," says Stefan Niermann, member of the extended management board and responsible for low-cost automation. "This opens up scope for completely new ideas in the field of automation: robots that can serve coffee in retail stores or empty the dishwasher at home. Cobots that are used in the care sector as well as in industry - and all made in Germany."

Gearboxes play an important role here, as they are the heart of every modern robot. Last year, Igus therefore introduced a new generation of Tribo shaft gearboxes for movement on the 5th robot axis. Friction and wear are optimized by lubrication-free tribo-polymers. The use of plastics enables a compact design and cost-effective production. The Drygear shaft gearbox can be used, for example, in the last axis of articulated arm robots, gantry robots and delta robots in front of various gripper systems.

The new modular gearbox complements the range in the field of low-cost automation and helps to quickly put exciting cobot ideas into practice without having to worry about power electronics.

Fully integrated shaft gearbox for low-cost cobot applications

The modular gearbox system consists of Tribo helical gearboxes in sizes 80 and 105 with integrated motor controller, force control electronics, absolute encoder and motor. The gearbox uses a Tribo shaft generator and Tribo flex ring with external gearing as well as an external rotor brushless DC motor. An individual robot can be constructed on the basis of the gears using connecting elements, and also as a cobot using the additional electronic components. "We see market opportunities for our lightweight plastic shaft gearboxes in robots that weigh less than 8 kg," says Alexander Mühlens, Head of Low-Cost Automation at Igus. "This is because when it comes to robotics in low-cost automation, the dead weight is always important in addition to the payload and a favorable price. This means that lightweight robots can be transported more easily and used more efficiently on driverless transport systems, on 7th robot axes or, in the near future, even on drones."

The low weight is also a clear advantage when used in cobots, as smaller masses also mean smaller forces in the event of collisions. Thanks to the electronic components in the fully integrated shaft gearbox, HRC capabilities are possible. Using absolute encoder technology, forces and torques can be determined and safely limited via the motor current. To do this, Igus uses a double encoder that measures in front of and behind the joint in order to detect and react to forces and torques.

Low-cost automation offering continues to grow

A new version of the Igus service robot ReBeL will also feature the new fully integrated shaft gearboxes this year. This will make this generation of robots slimmer and more cost-effective thanks to the integrated BLDC motors with power electronics. Alexander Mühlens emphasizes: "Our goal is to bring the ReBeL onto the market in small quantities for 2,900 euros. It should be able to carry 2 kg, have a reach of up to 650 millimeters, a dead weight of less than 10 kg and a minimum service life of 2 million cycles."

The Cobot modular gearbox system complements Igus' broad portfolio in the field of low-cost automation - from gearboxes and a wide range of robot kinematics to control systems. Low-cost automation means both low entry-level prices and only automating as much as necessary. This means that the investment pays for itself within a few months.