Direct Comparison of Bearings with the Outdoor Test Rig

The new outdoor test rig from igus enables a direct comparison of several bearings subjected to high loads. Endurance tests can evaluate, for instance, life and performance of iglidur® bearings compared to metal ones.

by Alma Castiglioni

Igus commissioned a new testing system for especially high loads such as in the agricultural or building machine industry: a front loader is kept moving for twenty four hours a day outdoors, where it is exposed to all the elements.
This makes it possible to compare different bearing solutions in order to find the best products for the respective heavy-duty application. Various bearing and shaft combinations for these areas of use are tested outdoors under realistic conditions. A direct comparison of plastic and metal bushings, for example, is also possible.

High-load tests are proof of the ability to cope with stress
In the current set-up, the surface pressure is between 22 and 29.5 MPa, depending on the bearing point (29.5 MPa approximately corresponds to a load of 1.2 metric tons on a bearing with a diameter of 20 millimetres and a length of 20 millimetres). In order to find the optimum bearing and shaft combination or the most suitable iglidur Tribo polymer material, the load to be lifted can currently be increased from 250 to up to 500 kilograms. Four cycles are completed per minute, whereby the resulting speed depends on the pivoting angle of the respective bearing point. The test lasts for around two weeks. Daily visual inspections ensure that the front loader is not damaged if a bearing point fails. Thus, the test rig allows us to compare existing customer solutions (such as steel bushings, metal-rolled bearings with Teflon coating, bronze bearing, etc.) in the real application with maintenance-free iglidur® plain bearings. The results are not only important with regard to front loaders, but can also be transferred to other applications in the heavy load sector. Similar parameters can generally be found in all applications which are driven by a hydraulic cylinder.

Operation of the test rig can be followed “live”
Operation of the test rig can be followed live at the company’s web site, which provides real-time information on the bearing/shaft combinations that are currently being tested on the test rig.
On the website, there is also an overview of the test results already obtained. The results of the tests are stored in databases, on the basis of which the igus online configurators work and predict the expected service life of the selected components.
iglidur bearings are proving themselves not only in the test rig but also in use in similar applications as, for instance, in the wheeled loaders made by the company F.X.S. Sauerburger. iglidur bearings have been in use in the lifting arms of this company’s wheeled loader for more than ten years.
A surface pressure of approx. 21 MPa acts on the iglidur bearings in the lifting arm. The plastic bearings deal with this force without any problems.
The lubrication-free bearings are also impervious to wind and weather.