A large-diameter hollow-shaft cryogenic motor based on a superconducting magnetic bearing for millimeter-wave polarimetry

The productivity of the conventional ring spinning process is currently limited by the frictional heat that occurs in the ring/traveler twisting system. In the framework of a fundamental research project from the German Research Foundation (DFG), the levitation principle of superconducting magnetic bearing (SMB) was implemented as a twisting element in order to eliminate the frictional problem and thus aim, at least, to double the productivity. A mathematical model of the dynamic yarn path has already been presented considering the friction free SMB system up to an angular spindle speed of 25,000 r.p.m. In this paper, the existing theoretical model, which was developed up to 25,000 r.p.m, was further modified considering the balloon control ring and yarn elasticity at a higher angular spindle speed, such as 50,000 r.p.m. The model was solved numerically using the RUNGE-KUTTA method. With this model, it is possible to estimate the yarn tension distribution and balloon form considering the above-mentioned parameters. The model established was further validated by comparing the yarn tension and balloon forms predicted with measured ones up to an angular spindle speed of 15,000 r.p.m in a ring spinning tester based on superconducting magnetic bearing.

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Mathematical modeling, simulation and validation of the dynamic yarn path in a superconducting magnet bearing (SMB) ring spinning system

Textile Research Journal ◽

10.1177/0040517516641363 ◽

2016 ◽

Vol 87 (8) ◽

pp. 1011-1022 ◽

Cited By ~ 2

Author(s):

M Hossain ◽

C Telke ◽

M Sparing ◽

A Abdkader ◽

A Nocke ◽

...

Keyword(s):

Permanent Magnet ◽

High Speed ◽

New Technology ◽

Superconducting Magnet ◽

Magnetic Bearing ◽

Ring Spinning ◽

Yarn Tension ◽

Runge Kutta Method ◽

Superconducting Ring ◽

Superconducting Magnetic Bearing

The new concept of a superconducting magnetic bearing (SMB) system can be implemented as a twisting element instead of the existing one in a ring spinning machine, thus overcoming one of its main frictional limitations. In the SMB, a permanent magnet (PM) ring rotates freely above the superconducting ring due to the levitation forces. The revolution of the PM ring imparts twists similarly to the traveler in the existing twisting system. In this paper, the forces acting on the dynamic yarn path resulting from this new technology are investigated and described with a mathematical model. The equation of yarn movement between the delivery rollers and the PM ring is integrated with the Runge-Kutta method using MATLAB. Thus, the developed model can estimate the yarn tension and balloon form according to different spindle speeds considering the dynamic behavior of the permanent magnet of the SMB system. To validate the model, the important relevant process parameters, such as the yarn tension, are measured at different regions of the yarn path, and the balloon forms are recorded during spinning with the SMB system using a high speed camera.

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