March 2021

n TECHNOLOGY March 2021 www.drivesncontrols.com 18 THE ENGINEERING PLASTICS SPECIALIST igus has developed a lightweight, low-cost gearbox with an integrated motor and controls which, it says, could cut the cost of collaborative and service robots. The modular gearbox kit consists of a tribo-polymer strainwave gear, combined with a brushless, external-rotor DC motor and controller, force control electronics, and an absolute encoder. igus plans to use the plug-and-play gearbox in a new version of its low-cost ReBel robot which will be even smaller and more cost- effective than the current version. “Our goal is to offer the ReBeL on the market for €2,900, even for small order quantities,” says igus’ head of low-cost automation, Alexander Mühlens. “It should be able to carry 2kg, have a range of up to 650mm, as well as a self-weight of less than 10kg, and a minimum running time of 2 million cycles.” The company also sees great potential for the gear-motor for robotic applications in areas such as agriculture, logistics, nursing and automated kitchens and bars. “We see market opportunities in robots whose total weight is less than 8kg,” says Mühlens. “This is because, where robotics in low-cost automation is concerned, the self-weight is always important – not just the payload and a low price. Lightweight robots are easier to transport and can be used more efficiently on driverless transport systems, on seventh robot axes or, in the near future, even on drones.” Low weight is also a significant advantage in cobots because smaller masses mean that the forces are lower if collisions occur. The new gear-motor’s built-in double absolute encoders can be used to determine forces as well as torque, and to limit the forces safely via the motor current. The encoders take measurements in front of and behind a joint to detect forces and torque levels and react accordingly. Last year, igus introduced a new generation of tribo strainwave gearboxes for the fifth axis of robots. The lubrication-free polymers reduce friction and wear, and result in compact, cost-effective designs. The strainwave gears can be used on the last axis of articulated arm, linear or delta robots – in front of grippers, for example. The new modular gearbox extends the portfolio, and igus says that its plug-and-play capabilities will allow “exciting” cobot ideas to be implemented quickly, without having to worry about the power electronics. The modular gearbox, which will be available in sizes 80 and 105, will make its public debut at the virtual version of the Hannover Fair taking place in April. The system will also be available on the RBTX.com online market, where users can combine robot kinematics with vision, safety or gripper components. “With our low-cost automation solutions, we enable design engineers to cost-effectively take part in the future of service robotics,” says Stefan Niermann, igus’ vice-president for low-cost automation. “This opens up space for new ideas in the area of automation: robots that can dispense coffee in retail shops or clear out the dishwasher at home. Cobots, that can be used in the area of nursing as well as in industry.” www.igus.de Lightweight gear-motor kit could slash robot costs PEPPERL+FUCHS HAS announced an ultrasonic safety sensor which, it claims, is the first in the world to be certified in accordance with EN ISO 13849, Cat 3, PL d. P+F has acquired the technology from the German Mayser group, which specialises in safety technology, moulded parts and headwear. The USi sensor can be used for non-contact detection of persons and objects, as well as for measuring distances in harsh environments. It is said to be unaffected by dirt, ambient noise, air flow or moisture, and can detect objects in a wide variety of materials, regardless of shape, transparency or colour. The two-channel sensor consists of a pair of transducers connected to a controller. Objects can be detected independently on each channel via an elliptical ultrasound beam with a range of up to 2.5m. The sensors can be freely positioned and installed separately from the controller in tight spaces. Signal outputs are provided via two safe OSSD outputs. A teach-in function allows the device to learn the measuring environment, including objects located in the detection field. The operating parameters can be adjusted via user-friendly software. “The USi is the perfect complement to our broad portfolio of ultrasonic sensors and extends our range of products in the strategic target sectors of intralogistics and mobile machines to include an intelligent and highly reliable solution for safety applications,” says Reiner Müller, president of Pepperl+Fuchs’factory automation division. www.pepperl-fuchs.com “We see market opportunities in robots whose total weight is less than 8kg” igus’ integrated strainwave gear-motor (top) and an exploded view (below) n Ultrasonic safety sensor is ‘the first with PL d certification’