What was needed:
Durable and maintenance-free components for the rear axis of a personal robot
Self-lubricating and maintenance-free plain bearings that are weather-resistant and suitable for heavy loads
Success for the customer: :
By using the PRT slewing ring bearing, the rear axis of the robot is lubrication-free and maintenance-free. In addition, the service life of the PRT for use in robots was calculated in advance and far exceeds the design requirements.
“Willow is the smartest garden robot on the market today. Other robots require a perimeter wire to stay within the desired area. Our robot can do without it and easily avoids obstacles in the garden,” explains Gary Gilmartin, Mechanical Design Engineer at EEVE. This perimeter wire is normally laid on the floor, the robot registers it and therefore only stays in the restricted area. Thanks to computer vision and artificial intelligence, Willow can navigate autonomously and thus offers space for many other applications. The robot takes care of the garden, guards the property, sweeps the patio with an extension, transports goods or plays games. It can be taught new tasks without any programming effort. This makes operating and expanding Willow easy and feasible for everyone.
The robot works come rain or shine, in cold or hot places and with a high load on its components. Willow also has to withstand salty air when used in coastal areas. Because of these environmental conditions, EEVE has decided to use igus components. They are known for their durability, even under adverse conditions. The trigger for the collaboration was a sample set of iglidur plain bearings that caught Gilmartin's attention some time ago. "I knew that I would need them in future", he says.
Originally, the EEVE company installed iglidur thrust washers on the rear axis in its robots in order to reduce friction when the rear wheel was rotated. When upgrading a customer robot, an iglidur PRT slewing ring bearing was incorporated in the axis for the first time. An iglidur PRT-02-20 is now used in the rear axis of the robot. In order to optimally meet the requirements of EEVE, igus designed a custom solution with reduced required drive torque. It ensures that the rear wheel can rotate freely even in harsh operating conditions and without any maintenance. "Our customers need a product that can stand outdoors maintenance-free for many years. Our goal is that our robots always work, without ever having to be taken to a repair service", Gary Gilmartin explains the use of PRT slewing ring bearings.
igus calculated the service life of the slewing ring bearing for EEVE in advance using a free online tool: the so-called iglidur PRT expert. All data collected in the igus test laboratory on the service life of slewing ring bearings flows into this tool and thus enables an accurate prediction of the product service life. "In our case, the service life far exceeds our design requirements," notes Gilmartin. "The PRT slewing ring bearing is the only bearing we wanted to use. It offers a clear price advantage compared to ball-bearing slewing rings," he adds. In addition, ball bearings would have to be replaced much earlier due to dirt and dust pollution and must be lubricated regularly. "Even under harsh environmental conditions, our slewing ring bearings allow for robust and maintenance-free operation for at least ten years. When using EEVE, the service life is 90 years," explains Joren Kestens, who works in the field service at igus.