The problems of the bobbin capacity and the high speed unwinding yarn taking off the ring or not during the winding of the ring spinning machine were dealt with. The mathematical model of the ring winding machine moti...The problems of the bobbin capacity and the high speed unwinding yarn taking off the ring or not during the winding of the ring spinning machine were dealt with. The mathematical model of the ring winding machine motion law was analyzed and optimized.Through the analysis and study of the movement rule of bottom bobbins and the ring spinning frame spool forming, the mathematical model of active bottom bobbins forming movement was established. Also,the mathematical model of bobbins formation was simulated and optimized. The concept of "controlled nail"was put forward. On this basis,the mathematical model of the current tube forming motion was optimized. The experimental results demonstrated that the theory of"controlled nail"met the high-speed spinning winding theory. The theory of "controlled nail "not only did the capacity of the bobbin increase,but also the spinning speed and efficiency are both improved,reducing the high-speed winder winding off. This research could provide a theoretical basis for the development of a new ring spinning frame.展开更多
Traditional ring spinning system is associated with the several limitations, one of which is yarn hairiness. The awareness has been vibrantly growing among the spinning mills for reducing staple yarn hairiness because...Traditional ring spinning system is associated with the several limitations, one of which is yarn hairiness. The awareness has been vibrantly growing among the spinning mills for reducing staple yarn hairiness because of its detrimental effects on the subsequent processes (i.e., weaving, knitting, dyeing etc.) and the quality of resultant textile products. As a result, modified form of ring frame has attracted a lot of attention among the researchers for making yarn with the lower level of hairiness value. Besides the raw material parameters and some processing variables, spinning triangle (ST) is the most critical region that has decisive influence on the distribution of fiber tensions and their spatial orientations and shapes in staple yarn body. Thus, using appropriate methods to control the spinning triangle geometry actively has been a vital issue in the field of yarn hairiness reduction. In this paper, it is attempted to make an overview on the spinning triangle based modifications of ring frame that have been designed and destined to reduce hairiness. However, agent aided ring spinning system has also been briefly discussed in this paper as well.展开更多
In this paper, we have made a study on the noise of ring spinning frame by analysing the noise radiating mechanism and the frequency spectrum of its main noise sources, such as the spindle system and the transmission ...In this paper, we have made a study on the noise of ring spinning frame by analysing the noise radiating mechanism and the frequency spectrum of its main noise sources, such as the spindle system and the transmission gear trains of the ring frame. Finally, three measures for reducing its noise are suggested: (1) using upper elastic bearing for the spindle structure, (2) using vibration isolating washers for the spindle support, and (3) improving the gear transmission structure design in the headstock of the frame.展开更多
We investigate the role of extended intrinsic mean spin tensor introduced in this work for turbulence modelling in a non-inertial frame of reference. It is described by the Euclidean group of transformations and, in p...We investigate the role of extended intrinsic mean spin tensor introduced in this work for turbulence modelling in a non-inertial frame of reference. It is described by the Euclidean group of transformations and, in particular, its significance and importance in the approach of the algebraic Reynolds stress modelling, such as in a nonlinear K-ε model. To this end and for illustration of the effect of extended intrinsic spin tensor on turbulence modelling, we examine several recently developed nonlinear K-ε models and compare their performance in predicting the homogeneous turbulent shear flow in a rotating frame of reference with LES data. Our results and analysis indicate that, only if the deficiencies of these models and the like be well understood and properly corrected, may in the near future, more sophisticated nonlinear K-ε models be developed to better predict complex turbulent flows in a non-inertial frame of reference.展开更多
The technique of sirospun process is applied on a modified semi-worsted balloonless spinningframe to investigate the effect of spindle-speed,yarn-twist and strand-spacing on yarn properties.Yarn breaking strength,brea...The technique of sirospun process is applied on a modified semi-worsted balloonless spinningframe to investigate the effect of spindle-speed,yarn-twist and strand-spacing on yarn properties.Yarn breaking strength,breaking extension,evenness and imperfection are examined on the basisof CCD experimental design.Yarn hairiness is particularly concerned,being found that all spinningparameters tested have significant effects on hairiness and that the minimum number of hairs oc-curs at the strand-spacing of 14.4 mm.Compared to conventional single spun yarn,experimentshave revealed the greatest advantage of using sirospun process is that all sirospun yarns have muchless hairiness.A new sirospun yarn fault,so called“loop”,has also been examined.The most likely cause forthis yarn fault is the strand-tension unbalance between the two strands when low tension spinningis applied.Further analysis and some initial tests have been carried out in the hope of overcomingthis loop fault which is an important obstacle to the application of balloonless spinning.展开更多
In order to improve the quality of yarn,a research was carried out at ring spinning.A modifiedtraveller has been used to reduce the yarn hairiness vastly.According to the statistical analysis ofthe data,it was found t...In order to improve the quality of yarn,a research was carried out at ring spinning.A modifiedtraveller has been used to reduce the yarn hairiness vastly.According to the statistical analysis ofthe data,it was found that the geometrical shape of travellers is the key factor affecting the yarnhairiness at ring spinning.展开更多
In this paper the formulation of finite element analysis for frame casing problems of theharmonic type is described. Attention is paid to the OE spinning rotor bearing assembly (RBA)’ sdynamic model, whose harmonic p...In this paper the formulation of finite element analysis for frame casing problems of theharmonic type is described. Attention is paid to the OE spinning rotor bearing assembly (RBA)’ sdynamic model, whose harmonic parameters, such as natural frequencies and modal shapes, aresolved by means of structural analysis program using personal computer, i.e. SAP84 software. Ac-cording to orthogonal factorial design table (OFDT), the predominant sensitive influential factors(PSIF) of RBA are determined.展开更多
为了保证细纱机在卷绕的过程中纱线张力稳定,减少纱线断头率,提高成纱质量,针对永磁同步电机驱动卷绕系统调速后的转速、转矩波动等问题,采用了灰狼优化(grey wolf optimizer,GWO)算法,给出一种改进的基于增益可调扩张状态观测器与改进...为了保证细纱机在卷绕的过程中纱线张力稳定,减少纱线断头率,提高成纱质量,针对永磁同步电机驱动卷绕系统调速后的转速、转矩波动等问题,采用了灰狼优化(grey wolf optimizer,GWO)算法,给出一种改进的基于增益可调扩张状态观测器与改进型趋近率滑模控制联合改进的自抗扰控制策略。首先在传统自抗扰控制基础上引入滑模控制,有效减小了峰值问题,提高了系统鲁棒性。其次,在滑模控制的基础上通过改进趋近率,提高了滑模趋近速度,同时引入了GWO算法调整滑模控制初始参数,减小了抖振问题。对自抗扰算法、滑模自抗扰算法与GWO算法改进的滑模自抗扰算法分别进行对比研究,与传统自抗扰算法控制相比,基于GWO算法改进的滑模自抗扰算法控制下的永磁同步电机在驱动卷绕系统调速后,电机转速达到稳定的时间由180 ms缩短至40 ms,瞬时平均转矩增量由105 mN·m减小到70 mN·m,减小了约33.33%。实验结果表明:基于GWO算法优化下的滑模自抗扰算法控制,能提高永磁同步电机的调速性能,有效降低永磁同步电机控制过程中的转速、转矩波动,提高管纱质量,降低成纱断头率。展开更多
基金National Basic Research Program of China(973 Program)(No.2010CB334711)
文摘The problems of the bobbin capacity and the high speed unwinding yarn taking off the ring or not during the winding of the ring spinning machine were dealt with. The mathematical model of the ring winding machine motion law was analyzed and optimized.Through the analysis and study of the movement rule of bottom bobbins and the ring spinning frame spool forming, the mathematical model of active bottom bobbins forming movement was established. Also,the mathematical model of bobbins formation was simulated and optimized. The concept of "controlled nail"was put forward. On this basis,the mathematical model of the current tube forming motion was optimized. The experimental results demonstrated that the theory of"controlled nail"met the high-speed spinning winding theory. The theory of "controlled nail "not only did the capacity of the bobbin increase,but also the spinning speed and efficiency are both improved,reducing the high-speed winder winding off. This research could provide a theoretical basis for the development of a new ring spinning frame.
文摘Traditional ring spinning system is associated with the several limitations, one of which is yarn hairiness. The awareness has been vibrantly growing among the spinning mills for reducing staple yarn hairiness because of its detrimental effects on the subsequent processes (i.e., weaving, knitting, dyeing etc.) and the quality of resultant textile products. As a result, modified form of ring frame has attracted a lot of attention among the researchers for making yarn with the lower level of hairiness value. Besides the raw material parameters and some processing variables, spinning triangle (ST) is the most critical region that has decisive influence on the distribution of fiber tensions and their spatial orientations and shapes in staple yarn body. Thus, using appropriate methods to control the spinning triangle geometry actively has been a vital issue in the field of yarn hairiness reduction. In this paper, it is attempted to make an overview on the spinning triangle based modifications of ring frame that have been designed and destined to reduce hairiness. However, agent aided ring spinning system has also been briefly discussed in this paper as well.
文摘In this paper, we have made a study on the noise of ring spinning frame by analysing the noise radiating mechanism and the frequency spectrum of its main noise sources, such as the spindle system and the transmission gear trains of the ring frame. Finally, three measures for reducing its noise are suggested: (1) using upper elastic bearing for the spindle structure, (2) using vibration isolating washers for the spindle support, and (3) improving the gear transmission structure design in the headstock of the frame.
文摘We investigate the role of extended intrinsic mean spin tensor introduced in this work for turbulence modelling in a non-inertial frame of reference. It is described by the Euclidean group of transformations and, in particular, its significance and importance in the approach of the algebraic Reynolds stress modelling, such as in a nonlinear K-ε model. To this end and for illustration of the effect of extended intrinsic spin tensor on turbulence modelling, we examine several recently developed nonlinear K-ε models and compare their performance in predicting the homogeneous turbulent shear flow in a rotating frame of reference with LES data. Our results and analysis indicate that, only if the deficiencies of these models and the like be well understood and properly corrected, may in the near future, more sophisticated nonlinear K-ε models be developed to better predict complex turbulent flows in a non-inertial frame of reference.
文摘The technique of sirospun process is applied on a modified semi-worsted balloonless spinningframe to investigate the effect of spindle-speed,yarn-twist and strand-spacing on yarn properties.Yarn breaking strength,breaking extension,evenness and imperfection are examined on the basisof CCD experimental design.Yarn hairiness is particularly concerned,being found that all spinningparameters tested have significant effects on hairiness and that the minimum number of hairs oc-curs at the strand-spacing of 14.4 mm.Compared to conventional single spun yarn,experimentshave revealed the greatest advantage of using sirospun process is that all sirospun yarns have muchless hairiness.A new sirospun yarn fault,so called“loop”,has also been examined.The most likely cause forthis yarn fault is the strand-tension unbalance between the two strands when low tension spinningis applied.Further analysis and some initial tests have been carried out in the hope of overcomingthis loop fault which is an important obstacle to the application of balloonless spinning.
文摘In order to improve the quality of yarn,a research was carried out at ring spinning.A modifiedtraveller has been used to reduce the yarn hairiness vastly.According to the statistical analysis ofthe data,it was found that the geometrical shape of travellers is the key factor affecting the yarnhairiness at ring spinning.
文摘In this paper the formulation of finite element analysis for frame casing problems of theharmonic type is described. Attention is paid to the OE spinning rotor bearing assembly (RBA)’ sdynamic model, whose harmonic parameters, such as natural frequencies and modal shapes, aresolved by means of structural analysis program using personal computer, i.e. SAP84 software. Ac-cording to orthogonal factorial design table (OFDT), the predominant sensitive influential factors(PSIF) of RBA are determined.
