Program design of an online dynamic balancing system for grinding-wheel and spindle
For unbalance of grinding wheel and spindle system in high-speed grinding process, an online dynamic balancing program is proposed. Firstly unbalance factors during grinding process are analyzed, and vibration features excited by these centrifugal forces are defined. Based on these works, technologies on wheel-spindle online dynamic balancing are introduced, including sensor selection and setting, vibration signal and phase angle measurement, signal amplification and analog filtering, A/D conversion, digital filtering, unbalance solution, dynamic balancing device and its drive and control. Finally, a wheel-spindle online dynamic balancing program is designed, which will have a good engineering application prospect in CNC machine spindle system.
ADAMS-based vibration analysis of GyroWheel rotor with flex-gimbal suspension
GyroWheel is an innovative device that combines the actuating capabilities of the control moment gyro with the rate sensing capabilities of the tuned rotor gyro by using a spinning flex-gimbal system. For a 3-DOF GyroWheel rotor with high spinning velocity, the uneven mass distribution, called unbalance, is inevitable which leads to unexpected vibration. In order to analyze the properties of vibration caused by this uneven mass distribution, the dynamical model of the GyroWheel system with flex-gimbal suspension is established with ADAMS software. Some theoretical analyses and simulation illustrations are developed in this paper, which provide helpful guidance for further experimental studies.
Paul, Jules, and Marie Tannery (With a Note on Grégoire Wyrouboff)
T Marie Tannery, whose life and work ended on 27 January I945, but it is impossible to speak of her without speaking of her husband, to whom the whole of her mature life was devoted though she survived him forty-one years. An elaborate biography of Paul Tannery appeared in Osir's 4 (1938); there is no need of repeating here all the details, it will suffice to recall the main facts for the reader's guidance.