Dirt-resistant spherical bearings in robots for weed control

Profile

• What was needed: igubal® spherical bearings
• Requirements: use in fields required spherical bearings that are dirt and dust resistant as well as robust; at the same time, the customer was looking for a cost-effective and lightweight solution.
• Industry: agriculture
• Success for the customer: igubal® spherical bearings are resistant to media, UV rays, radioactive radiation, dirt and dust; unlike metal spherical bearings, they are able to absorb vibrations; furthermore, polymer spherical bearings are up to 80 per cent lighter than metal bearings, which also had a positive effect on energy consumption in this application

The weed robot works autonomously for up to twelve hours a day.

Problem

EcoRobotix develops, manufactures and distributes innovative agricultural machinery. The aim is to provide accurate, safe, reliable and affordable robotic solutions to simplify farmers' lives and produce healthy food. The start-up's first in-house development is a weeding robot that drives autonomously over the fields and destroys weeds in a targeted manner.
The robot weighs around 130 kilograms, moves autonomously, orients and positions itself using GPS and a camera. An image capture system detects whether and where the weeds are located.
The robot is equipped with an RTK GPS for exact positioning. It is controlled and configured entirely by a smart phone application. And the solar operation makes the robot completely self-sufficient in energy supply, even when the sky is overcast.
Once the robot has finally identified a weed, it sprays a micro-dose of herbicide on the weed with pinpoint accuracy via two robot arms. Rod end bearings are used so that the two robot arms have the desired mobility.  Due to their use in fields, they must above all be equipped appropriately and robustly against dirt and dust. In addition, the customer was looking for a lightweight and economical solution.

Solution

The spherical bearings used in the robot arms are igubal rod end bearings, which are corrosion-resistant and withstand temperatures from -40 to +200 degrees Celsius. They are also resistant to media, UV rays, radioactive radiation, dirt and dust. And in contrast to their metal counterparts, the rod ends are able to absorb vibrations. The igubal rod end bearings are ideal for this application, because they are lightweight, cost-effective and very tough.
Once they have been installed, the tribo-polymer bearings no longer need any attention – thanks to their lubrication-free properties maintenance work is a thing of the past. In contrast to lubricated metal bearings, no resin residues or paste-like mixtures are formed that attract dirt to the bearing surface. The plain bearings of the igubal bearing elements can be used without any seals, even in extremely contaminated conditions. This is true for both fine dust and coarse dirt. Apart from that, polymer spherical plain bearings are up to 80 per cent lighter than metal bearings. In this case, twelve rod end bearings are installed per robot arm, which makes 24 such rod ends for two arms. This supports the lightweight construction considerably, and at the same time reduces energy consumption, which was an important criterion for the customer in this particular case due to the solar operation.

20 times less herbicides thanks to accurate detection and targeted spraying of weeds.

The igubal rod end bearings are maintenance-free, corrosion-free, cost-effective and have a high dampening capacity.