Robots given a helping hand

Paul Boughton

Gearing experts Harmonic Drive AG has enhanced its partnership with Danish manufacturer Universal Robots with the supply of HFUS-2SH Series Gears for use in the UR-5 six-axis flexible robot. The mechanical properties of the gear are used in the flexible lightweight UR-5's six-axis robot arm. The move is an effort by Universal Robots to optimise production processes by reducing floor space and increasing flexibility.

Traditionally, industrial robots are normally large and expensive, making them feasible only for large scale production environments. The new powerful lightweight robots are designed for agile manufacturing and can easily be set up for new processes, which now allows small and medium sized firms the option to install and move robots from multiple demanding environments, with minimum downtime.

The HFUS-2SH Series Gears, in four different sizes, provide over 100Nm of torque and weigh in at only 1kg. The zero backlash gear is used on all six axes of the robot arm, meaning that an 18kg robot, working in a radius of 850mm, can handle loads of up to 5kg. The gear's single-stage 100:1 reduction ratio provides sufficient torque capacity at the arm joints, eliminating the need to use high power, heavy motors.

In addition to the high reduction ratio, the gear output operates at high speed, allowing the robots to work extremely dynamically.

"Linear systems are used in many robot applications," explained Graham Mackrell, managing director of Harmonic Drive UK. "The problem is that they're often heavy, inflexible and take up a great deal of space. The gear we've developed for Universal Robots is built directly into the robotic arm providing the most compact and elegant solution which is particularly useful when they are deployed in small or medium companies where factory space is often at a premium.

"Fitted with special purpose grippers, these robots can now take parts directly from the machines and finish them with incredible precision. They can sort and even count different parts automatically, eliminating the need for manual labour, saving even more time.

"We've made the HFUS-2SH Series available in nine sizes from 30 to 160:1 reduction ratio, with repeatable peak torque settings between 9Nm and 1,840Nm. The tilt resistant output bearing means high working loads can be applied without requiring further support. Not only are the units compact and lightweight, they also feature a large hollow shaft and can operate between -40 and +90˚C, with custom lubricants," said Graham.

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