For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machi...For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared transmission.By using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and examined.The results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining accuracy.And the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges.展开更多
为了有效抑制由刀具的质量不平衡引起的电主轴系统不平衡振动,提出了一种电主轴系统不平衡振动的主动控制方案,首先研究了双绕组感应型电主轴的结构、工作原理及径向控制力模型,借助有限元法建立了感应型柔性电主轴系统的动力学模型以...为了有效抑制由刀具的质量不平衡引起的电主轴系统不平衡振动,提出了一种电主轴系统不平衡振动的主动控制方案,首先研究了双绕组感应型电主轴的结构、工作原理及径向控制力模型,借助有限元法建立了感应型柔性电主轴系统的动力学模型以及研究了FBLMS(Fast Block Least Mean Square)自适应滤波控制算法,设计了感应型柔性电主轴-刀具系统不平衡振动的主动控制系统,通过有限元法确定了径向控制力的系数以及单边磁拉力的系数,研究了经典PID控制器以及FBLMS自适应滤波控制器对刀具端不平衡振动的控制效果,结果表明FBLMS自适应滤波控制器对抑制电主轴-刀具系统端不平衡振动具有更佳控制效果。展开更多
Mass imbalance-induced vibration affects the rotating machinery very large,especially the highspeed types.Off-line balancing techniques have been widely developed for rejecting unbalance-induced vibration but do not e...Mass imbalance-induced vibration affects the rotating machinery very large,especially the highspeed types.Off-line balancing techniques have been widely developed for rejecting unbalance-induced vibration but do not eliminate unbalanced vibration in the working state.Moreover,multiple start-stops are required in off-line balancing techniques.Therefore,research on an efficient electromagnetically-driven auto-balancer is carried out in the present work,and an internal excitation actuator is designed in this balancer.The electromagnetic characteristics of the two copper coil bobbins in the internal excitation actuator are compared and analyzed.The permanent magnets inside the actuator are simulated and analyzed with different sections of round,rectangular,and elliptical.And the results show that the elliptic type has the largest self-locking force.Finally,the dynamic balance test is performed on a test bench equipped with a designed electromagnetic balancing actuator,and the unbalance vibration is reduced from 130.23 μm to 5.98 μm.展开更多
基金Project(10033135-2009-11) supported by the Korean Ministry of Knowledge Economy (MKE) through HNK. Co,Ltd.
文摘For the purpose of analyzing the torsional vibration caused by the gravitational unbalance torque arisen in a spindle system when it is machining heavy work piece,a 10-DOF lumped parameter model was made for the machine tool spindle system with geared transmission.By using the elementary method and Runge-Kutta method in Matlab,the eigenvalue problem was solved and the pure torsional vibration responses were obtained and examined.The results show that the spindle system cannot operate in the desired constant rotating speed as far as the gravitational unbalance torque is engaged,so it may cause bad effect on machining accuracy.And the torsional vibration increases infinitely near the resonant frequencies,so the spindle system cannot operate normally during these spindle speed ranges.
文摘为了有效抑制由刀具的质量不平衡引起的电主轴系统不平衡振动,提出了一种电主轴系统不平衡振动的主动控制方案,首先研究了双绕组感应型电主轴的结构、工作原理及径向控制力模型,借助有限元法建立了感应型柔性电主轴系统的动力学模型以及研究了FBLMS(Fast Block Least Mean Square)自适应滤波控制算法,设计了感应型柔性电主轴-刀具系统不平衡振动的主动控制系统,通过有限元法确定了径向控制力的系数以及单边磁拉力的系数,研究了经典PID控制器以及FBLMS自适应滤波控制器对刀具端不平衡振动的控制效果,结果表明FBLMS自适应滤波控制器对抑制电主轴-刀具系统端不平衡振动具有更佳控制效果。
基金Supported by the National Natural Suience Foundation of China(No.51775030,91860126).
文摘Mass imbalance-induced vibration affects the rotating machinery very large,especially the highspeed types.Off-line balancing techniques have been widely developed for rejecting unbalance-induced vibration but do not eliminate unbalanced vibration in the working state.Moreover,multiple start-stops are required in off-line balancing techniques.Therefore,research on an efficient electromagnetically-driven auto-balancer is carried out in the present work,and an internal excitation actuator is designed in this balancer.The electromagnetic characteristics of the two copper coil bobbins in the internal excitation actuator are compared and analyzed.The permanent magnets inside the actuator are simulated and analyzed with different sections of round,rectangular,and elliptical.And the results show that the elliptic type has the largest self-locking force.Finally,the dynamic balance test is performed on a test bench equipped with a designed electromagnetic balancing actuator,and the unbalance vibration is reduced from 130.23 μm to 5.98 μm.
