Precision bearing manufacturer Schaeffler and the Friedrich-Alexander University of Erlangen-Nuremberg (FAU) have developed a new rolling bearing spin test stand as part of a collaborative research project. The results of the research project will be used to optimise current rolling bearing technology with the aim of cutting fuel and energy consumption in vehicles and machines.
On the test stand, bearings are subjected to 3,000 times gravitational acceleration and tested under the resulting high loads. To date, very little research has been conducted into the friction behaviour of rolling bearings under high centrifugal forces such as those generated on the rolling bearing spin test stand.
A heavyweight among test stands
The test stand, which is located in its own 22 square meter test bunker and weighs 16 tonnes, took three years to design and build with 900 technical drawings, 1600 screws and one kilometre of cable.
“The rolling bearing spin test stand has been one of the largest projects ever carried out at the Chair and it is a perfect example of the excellent cooperation between industry and universities in the field of fundamental rolling bearing research,” emphasised Prof. Dr.-Ing. Sandro Wartzack, head of the Chair for Engineering Design.
The bearings rotate twice during testing. Thanks to an open planetary gear, each bearing rotates around its own axis while all of the bearings together rotate around a central axis. The test stand will enable investigations to be carried out concerning which factors such as temperature, coatings and geometric details, actually influence the bearings under extreme loads.
Improved simulation tools
In conjunction with the FAU, Schaeffler also improved and further developed the software required for the simulation process, which enables the simulation of the behaviour of the rolling bearings even before a prototype is built by allowing optimisations to be made to the computer model. “With this test stand, we can now gain a better understanding of the phenomena associated with rolling bearings in the centrifugal force field. In this context, it is important for us to refine our simulation tools for rolling bearings based on the test results. This will help us to transfer the findings into application-oriented conditions and further improve our product development,” stated Oliver Graf-Goller, Bearings & Components Development and project manager at Schaeffler.
The last round of tests and adjustments are now being carried out. The first measurements are planned for October 2016 and will therefore improve simulations and ensure that new bearing prototypes can be tested more quickly.