The first collaborative project for both partners is to set up a new testing facility at the University of Applied Sciences, which will make it possible to carry out endurance tests under environmental conditions. The aim of these tests is to experimentally examine the effects that different influencing factors have on the load carrying capacity and efficiency of magnetic and back-up bearings and to validate simulation models. The test rig will be set up by spring 2014, making the University of Applied Sciences home to the world's most modern and extensive testing facility for magnetic bearing technology.
Over the last twenty years, the University of Applied Sciences Zittau/Görlitz has become a center for magnetic bearing technology. "The new test rig will provide magnetic bearing technology with additional momentum, which will increase energy efficiency and improve climate protection technology. For the achievement of these objectives, Schaeffler is an ideal partner", says Prof. Frank Worlitz, Head of the department Mechatronic Systems at the Institute of Process Technology, Process Automation and Measuring Technology (IPM) at the University of Applied Sciences Zittau/Görlitz. Dirk Spindler, Senior Vice President R&D Schaeffler Industrial and Member of the Management Board Schaeffler Industrial, adds that in addition to basic research, the main focus is on industrial applications, following the increasing demand for innovative bearing concepts, e.g. in the field of energy technology. "Our new magnetic bearing system has received a significant response on the market. Hence, the development of energy-efficient and cost-effective systems for further areas of application are an important element of our development strategy in the field of magnetic bearing technology", says Spindler.
Magnetic bearing technology is used when the technological requirements can no longer be fulfilled by other bearing types. This especially applies to medium and large industrial machinery with very high rotational speeds and shaft weights of up to several tons. Typical application fields for magnetic bearings of this size include electric motors, gas and steam turbines, and compressors. Active electromagnetic bearing supports are based on the principle of a shaft that is levitated by means of regulated magnetic fields and can be made to rotate with practically no friction.
Sensors measure any deviations of the shaft from its reference position as an input variable for control and power electronics to set the necessary magnetic forces. The back-up bearings serve as a support for the rotor when the magnetic bearings are switched off. They also serve as a safety mechanism for the machine if, for example, a power failure occurs and causes the shaft to drop.
FAG Active Magnetic Bearing
With the FAG Active Magnetic Bearing, Schaeffler has developed a standardized unit comprising magnetic and back-up bearings as well as the relevant services. Schaeffler uses rolling bearings as back-up bearings that can be reused after a shaft drop. They are the result of many years of experience and expertise in the area of high-precision spindle bearings. At the same time, the use of standardized electronic control systems and power electronics from Siemens that have been proven and on the market for many years allows easy integration into the machine architecture. The objective is to develop and provide a comprehensive modular system with which both four and five-axis systems can be implemented from a single source.