Dirt-resistant bearings in robots for weed control

Being in the agricultural sector, the components that are used need to be robust, durable and reliable. The customer was looking for parts which are cost-effective, light-weight and resistant to dirt and dust, which eliminates a lot of conventional parts such as metal bearings.

All of our parts are lubrication-free which is another requirement for the customer, to reduce the contamination onto the soil.

The robot weighs around 130 kilograms, moves independently, orientates and positions itself using GPS and a camera. An image capture system recognises whether and where the weeds are located.
The robot is equipped with an RTK GPS for exact positioning. It is fully controlled and configured using a smartphone application. And solar operation makes the robot completely self-sufficient in terms of energy supply, even when the sky is overcast.
Once the robot has identified a weed, it sprays a microdose of herbicide onto the weed with pinpoint accuracy using two robot arms. Rod ends are used to ensure that the two robot arms have the desired manoeuvrability. Because they are used in fields, they need to be protected against dirt and dust and robust. The customer was also looking for a lightweight and economical solution.

The spherical plain bearings used in the robot arm are igubal® rod ends, which are corrosion-free, lightweight, cost-effective and can withstand temperatures from -40 to +200 degrees Celsius. They are also resistant to media, UV rays, radioactive radiation, dirt and dust. Unlike their metal counterparts, the rod ends are able to absorb vibrations.
Once installed, the bearings require no further attention - thanks to their lubricant-free design. Unlike lubricated metal bearings, no resin or paste-like mixtures are formed that bind dirt to the bearing point. Even with extreme contamination, the igubal® bearing elements do not require a seal. This applies to both fine dust and coarse dirt. The polymer spherical plain bearings are up to 80 per cent lighter than metal bearings. Twelve rod ends are fitted per robot arm, which equates to 24 such rod ends for two arms. This significantly supports the lightweight constructions and at the same time reduces energy consumption.