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.
INVESTIGACIÓN & DESARROLLO Vol. 19, No. 1: 73 – 93 (2019)
There is a steadily growing demand for reliable, versatile measurement rotor balancing system which can be used to determine the machine unbalances behavior. The effect of these causes are the increase of vibration amplitudes, causing damage to elements of the machines, mainly in the bearings, reduce useful life time, and increase fatigue failure in machines. The industry requires that machines have to operate continuously, efficient maintenance philosophy, and reduce down time. Therefore, this research work has the main objective to design and develop a low cost rotor balancing measurement system for industrial applications. This research study was based on the ISO 1940-1 standard. The Solidworks software was used for the designing, structural stress, and modal analysis. It was also carried out and extensive numerical analysis with Finite Element Method (FEM), of the developed measurement system, in order to identify the structure resonance frequencies to avoid with the induction motor rotation frequency. For the simplicity, precision and robustness, the single plane four runs method for rotor balancing was selected. Finally, it was developed a rotor balancing measurement system. It showed the ability, and potential to use the developed equipment in industrial environment. Moreover, it has been shown that the measurement and the applied analysis method have worked accurate for unbalance detection and reduction of vibration levels from G13 to G2.
Church, state and schools in Britain, 1800-1970
Originally published 1971, this volume unravels the complicated history of the religious question in British education. The background of the key Acts of Parliament which established the "dual" system - of Church and Local Authority school - is examined. The changing policies of different religious groupings are analyzed, and their outcome in legislation brought out.