In this article the next generation of robolink drive elements are showcased by igus
In order to generate accurate movement along the 5th robot axis, igus has developed a new type of strain wave gear, based on its tribo-polymer technology. As a result of using lubrication free, high-performance polymers the new gears are compact, light and require very little maintenance as they deliver what igus refers to as an especially long service life. The gearbox range is part of the growing family of low cost automation products from the Northampton-based supplier. The new gears are another area in which machine builders and automation engineers can see an improvement in performance whilst reducing costs, says the company.
One beneficial result of using iglidur high-performance polymers is that the new strain wave gears from igus require no additional lubrication, a stark contrast to metal gears. Friction and wear are also reduced through the use of lubrication-free tribo-polymers, which also lend themselves well to extremely compact designs and cost-effective methods of manufacturing. As a result of research and further development in both design and material selection, the operating smoothness, backlash and service life of the strain wave gears have all been further improved.
The primary components of the gearbox include a wave generator and a flexible gear with outer drive teeth. It also includes an outer ring gear, which is fixed in place in the housing, together with a rotary power take-off with inner teeth. A high degree of flexibility and wear resistance are achieved through the use of lubrication free igus polymers. The wave generator is elliptical and surrounding flexible gear also assumes this profile. Along the last axis of an articulated arm on a linear or delta robot, the strain wave gear can be used with different gripper systems. The current version is based on the Nema 17 stepper motor but can easily be adapted to other types and sizes of motors. The load bearing capacity of the strain wave gear has been determined in the test laboratory, and with a transmission ratio of 28:1, the gearbox has a proven service life of 1 million cycles under a load of 1.5Nm at a speed of 6rpm. Igus says that the next step is to develop a Nema 23 size gearbox.
The new gears are part of a growing portfolio of igus products designed to provide cost-effective and long-lasting automation solutions for small and medium-sized enterprises. Examples include robots that can dispense coffee or perform pick-and-place tasks in the electronics industry. A five-axis igus robolink DP costs around £3,500, due mainly to the use of polymers. Last year, igus developed, with partners, the platform RBTX.com. This makes putting together additional components to create a full robotic solution (such as the gripper, control system or pneumatic components) very straightforward. The platform brings together users and suppliers of low-cost robotic components and helps designers put together low-cost robotic solutions.