Berend Denkena, Henning Buhl, Adrian Bergmann*
Institute of Production Engineering and Machine Tools, Leibniz Universität Hannover, An der Universität 2, Garbsen 30823, Germany.
*Corresponding author: Adrian Bergmann
This paper is funded by the Deutsche Forschungsgemeinschaft (DFG, German Research Foundation) (project number 60443824).
Abstract
Producing large, high-quality workpieces requires precise axes with accurate guidance systems, which results in a demand for tighter tolerances in the corresponding guide surfaces. However, these tight tolerances and rigid structural requirements in the surfaces lead to high manufacturing and assembly costs. This causes an increased manufacturing and adjustment effort, especially for long linear axes, because the assembly cost scales with the axis size. A novel approach to circumvent these tight tolerance requirements lies in compensating for the errors in the guide surface by actively positioning the guide carriage. For this purpose, a double-sided actuator consisting of an electromagnet and an air caster is used. The advantage of such a system is the increased flexibility since it is not necessary to build a mechanical wrap-around structure for the guide rail. The elimination of the wrap-around structure is advantageous because it also makes the parallel alignment obsolete. Existing bidirectional active guide systems are limited to micro-precision applications due to the air gap of aerostatic bearings in the single-digit micrometre range. An air caster decouples the air gap from the lifting height with an elastic bellows, resulting in a higher and broader operating range of the actuator. These properties enable the usage of the actuator in larger machine tools, for example, to manufacture wing frames for aircraft. Furthermore, the guiding system can be extended by adding further guide segments at the end to extend the axis. This paper presents this new guiding system by investigating the achievable forces and the stability towards disturbance. The air caster is capable of a levitation force of up to 7,100 N with a levitation range from 250 to 280 µm, which makes ultra-precise surfaces unnecessary. The magnetic actuator provides attraction forces up to 2,300 N within this range. Induced disturbance forces of up to 250 N could be compensated by a PI controller with position errors below 1 µm.
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How to cite this paper
Bidirectional Bearing with Actively Coupled Magnetic and Pneumatic Actuator
How to cite this paper: Berend Denkena, Henning Buhl, Adrian Bergmann. (2026). Bidirectional Bearing with Actively Coupled Magnetic and Pneumatic Actuator. Engineering Advances, 6(2), 96-104.
DOI: http://dx.doi.org/10.26855/ea.2026.06.006