Lubrication-free bearing technology for precise adjustment of solar trackers for mobile homes

In order to be able to supply mobile homes with electricity independently, the company CityFreighter has developed the "Solartrackr", a tracking photovoltaic module that automatically aligns itself with the sun and thus ensures maximum energy yield. Its mechanics consist of lubrication-free motion plastics from igus. They ensure precise and maintenance-free movement of the solar panel, even in adverse weather conditions.

Fact sheet

What was needed: Slewing ring bearings for the rotation, lead screws for the lifting and lowering mechanism, plain bearings for the scissor bearings
Requirements: High wear resistance, weather, UV and corrosion resistance, precise movement, freedom from lubrication and minimum maintenance requirements
Industry: Mobile homes/caravans
Success for the customer: PRT slewing rings in combination with customised plastic gears, dryspin lead screw technology and plain bearings made from our robust endurance materials: These motion plastics ensure permanently reliable and precise movement of the solar module, without a lack of lubrication and corrosion becoming a problem.

Products used

Freestanding external gear ring with a large central opening.

PRT-04 slewing ring bearing series, outer drive ring

3D-printed gears made of white material.

3D-printed gears in a special shape

iglidur flanged bearings G, J and W300 in three material versions.

Flanged bearings iglidur G, iglidur J and

iglidur W300

Compact flange with Dryspin lead screw, front view.

dryspin flanged lead screw nut with

trapezoidal lead screw

Problem

Solar panels on mobile home roofs are not uncommon these days. However, these are rigid installations that cannot catch the sunlight at the best possible angle throughout the day.

When developing the system, the design engineers were looking for durable and low-maintenance components that enable precise movement: A slewing ring for the rotation, lead screws for the lifting and lowering mechanism and plain bearings for the scissor bearings. As the tracker is used outdoors and is exposed not only to UV radiation, but also to wind, rain and, possibly, salt air, the components must be weather and corrosion resistant.

Solution

Our tribologically optimised plastic components are the ideal solution here. A slewing ring bearing from the PRT-04 the design of our slewing ring bearings is not based on metal rollers or balls, but on plastic sliding elements that require no lubrication or maintenance. Printed igus gears are used to ensure precise angular adjustment of the slewing ring bearing. This ensures that the best angle to the sun is always found, which significantly increases the energy yield.

The height of the solar module is adjusted using a robust dryspin trapezoidal lead screw made of stainless steel and a matching lead screw nut made of the material iglidur J, which work precisely even in changing weather conditions.

To optimise the scissor bearings, CityFreighter also uses various plain bearings and thrust washers made from the endurance runner materials iglidur G, iglidur J and iglidur W300. These components are characterised by their wear resistance and durability. Thanks to the solid lubricants embedded in the plastic, they are also 100% maintenance-free. Problems associated with lubricated bearings – adhering dirt that leads to increased friction and wear of the shaft and bearing, loss of lubricant and corrosion – are not an issue with our plastic bearings.

"The igus components are a decisive factor for our Solartrackr. Their freedom from lubrication, precision and durability enable us to offer a reliable and maintenance-free solution that is not only efficient but also cost-effective."