High-Precision Roller Supported by Active Magnetic Bearings

Abstract

Featured Application: Printing machines, Roller conveyors, Cleanroom applications.Abstract: Magnetic bearings support rotors in a non-contact way using magnetic force. Therefore, there is no friction and it is possible to measure and control the position of a rotor in the air gap. In this study, the rotational vibration of a roller was minimized using magnetic bearings, and a precision roller capable of automatic alignment using the position control function of magnetic bearings was proposed. A rotation accuracy of approximately 4.6 µm (peak-to-peak) was observed, even under a rotation of 30 rev/min and a radial force load of 300 N. The rotor position control experiment for magnetic bearings showed that 1-µm resolution position control is possible. To further improve the accuracy, the automatic alignment algorithm was proposed using magnetic bearings for the roller misalignment condition, and it was confirmed that alignment is possible at a level that the pressing force difference between both ends of the roller is within 0.3 N. Through this study, it was confirmed that rollers with magnetic bearings can be applied to precision equipment. It is expected that the implementation of the automatic alignment function will simplify the equipment configuration and maintenance compared to conventional rollers with ball bearings.

Continuous roller nanoimprinting: next generation lithography

“…Alternatively, a high-precision roller supported by active magnetic bearings was proposed. 119 Since magnetic bearings support rotors with non-contact magnetic force, friction is eliminated, allowing measurement and control of the rotor position in the air gap. After rotational vibration of a roller is minimized, automatic alignment of the roller can be achieved through the position control function of magnetic bearings.…”

Effects of Imperfect Assembly and Magnetic Properties on the Three-Pole AMB System

“…where b 1 , b 2 , ρ, k, α and ε are positive constants. In this paper, the uncertainty is mainly due to the assembly error given by ( 7) and (8). The upper bounds of its effect can be estimated.…”

“…It can also be applied in extreme environments, such as very high or low pressure, very high or low temperature, vacuum, and zero gravity. Because of these features, AMB has found wide applications, for instance, in turbo-molecular pumps [2], high-speed air compressor [3,4], flywheel energy-storage systems [5,6], control-momentum wheels [7], printed electronics systems [8], and machine tools [9], etc.…”

The annulling of the sudden appearance of an unbalance in rotary machines by using active magnetic bearings

“…Numanoy and Srisertpol also use PID controllers to reduce vibrations of the rotor/AMB system [7]. The vibration reduction benefits of AMB were exploited by Park et al to increase the precision of rollers used in printing machines [22]. Srinivas et al presented in [23] a detailed overview of the techniques used for vibration damping using AMB systems.…”