Three-dimensional yarn path and bearing dynamics of the high-speed ring spinning process with a superconducting magnetic bearing twisting system including transient operation modes

超导磁力轴承(SMB)作为环锭纺纱的创新加捻元件，与传统的钢领/钢丝圈系统相比，可以将这项技术的生产率提高到50000 rpm的角主轴速度，而传统的钢领/钢丝圈系统的最高速度可能达到25000 rpm。然而，非均匀环轨运动产生的非定常过程力、纱线动力学和轴承特性之间的复杂相互作用以及旋转纱线气球的亚音速气动流型对环锭纺纱过程在如此高的转角主轴速度下起着特别重要的作用，因此需要进行广泛的研究。为了了解新系统的复杂行为，需要对SMB加捻元件和整个纱线路径进行基于模型的分析和计量研究。这个跨学科联合项目的主要目的是建立和验证一个新的纱线力学数学模型，该模型考虑了三维纱线路径和SMB轴承在所有过程状态下的动力学，即加速、同步纺纱和停止，包括不均匀的环轨运动、纱线气球的空气动力学以及轴承负荷随固有频率的变化，从而充分发挥无摩擦SMB系统的潜力。此外，还将开发高效假捻元件的概念，以显著提高在较高角主轴速度下的纺纱稳定性。在这些工作的同时，还将进行先进的计量研究，以确定3D气球形状、沿纱线路径的加捻传播以及纱线和气球控制环之间的摩擦。所有计量结果将被用作模拟和验证SMB纺纱过程的非平稳数学模型的输入参数。预计拟议项目的研究和结果将对纺织技术中最先进的过程建模以及基于SMB的部件在高速机器上的应用做出重大贡献。

The application of a superconducting magnetic bearing (SMB) as an innovative ring-twisting element for ring spinning allows to increase the productivity of this technology up to an angular spindle speed of 50,000 rpm in comparison to the conventional ring/traveler system, where a maximum speed of 25,000 rpm is possible. However, non-stationary process forces originating from a non-uniform ring rail movement, complex interactions between the yarn dynamics and the bearing properties as well as aerodynamical subsonic flow regimes of the rotating yarn balloon are playing a particularly important role for the ring spinning process at such high angular spindle speeds and thus necessitates extensive research efforts. In order to understand the complex behavior of the new system, model-based analysis and metrological investigations on the SMB twist element and the complete yarn path is required. The main objective of this interdisciplinary joint project is to develop and to validate a new mathematical model of the yarn mechanics considering the three-dimensional yarn path and the SMB bearing dynamics for all process states, i.e. acceleration, synchronous spinning and stopping, including the non-uniform ring rail movement, the aerodynamics of the yarn balloon as well as the variation of bearing load due to natural frequency, so that the potential of the frictional free SMB system can be fully utilized. Additionally, the concept for highly efficient false twist element will be developed to improve spinning stability significantly at higher angular spindle speed. These efforts will be accompanied by advanced metrological investigations to identify the 3D balloon form, the twist propagation along the yarn path as well as the friction between the yarn and balloon control rings. All the metrological results will be used both as input parameters for the simulation and for the validation of the non-stationary mathematical model of the SMB spinning process.It is expected that the investigation and results of the proposed project will have a significant contribution to the modelling of state-of-the-art processes in textile technology as well as for the application of SMB based component for high speed machines.