The Development Of New-type Vertical Dynamic Balancing Machine And The Measurement Of Amount Of Dynamic Unbalance Of Work-piece

This dissertation is based on the project 'the modal analysis of vibration structure with multi-degrees of freedom and the measurement for dynamic unbalance of work-piece' which is supported by the National Natural Science Foundation of China (NO.10176011). The primary task is to develop new-type swing frame of vertical dynamic balancing machine with static-couple separation character, and to measure the amount of dynamic unbalance at low rotation velocity. Therefore, various new-type swing frames are designed out. Their translation stiffness are assort with their torsion stiffness, the translation natural frequencies are closed to the torsion natural frequencies. The positions of the vibration centers of new-type swing frame systems are improved. To improve the measurement precision, the circuit is amended and the disturbing signals and measurement errors are reduced.The mathematics model of general vertical-dynamic-balancing-machine is set up firstly. The vibration properties of the vertical-dynamic-balancing-machine are analyzed. The relationship between the vibration center and working frequency is discussed and the relationship between the property of static-couple separation and working frequency is obtained also. The reason why the general vertical dynamic balancing machines can't separate the static unbalance from couple unbalance effectively is clarified. The scopes of the translation natural frequencies and torsion natural frequencies of various vertical dynamic balancing machines can provide theoretic instruction for designing new types of vertical dynamic balancing machines.To separate the static unbalance and couple unbalance effectively, the HVB1-30, HMVB2 and HVB3-30 types of hard bearing vertical dynamic balancing machines are designed and their vibration structures are analyzed in detail in this dissertation. There are many variational-section spring boards in the new swing frames. The translation stiffness is assort with the torsion stiffness. Furthermore, there are several sensors on the measurement points, fixed vertically and horizontally respectively. Therefore, the new dynamic balancing machines can measure static unbalance and couple unbalance directly, and the influence between them is faint. The new vertical dynamic balancing machines are suitable for inertial measurement of flying objects, and can overcome the shortcomings of traditional vertical dynamic balancing machines, in which the effect of plane-separation is inferior. The vertical dynamic balancing machines with the new vibration structures can be widely used in the future applications.The modals and harmonic responses of the HVB1-30 and HMVB2 type vibration structures are analyzed by using the ANSYS7.0. By comparing the finite element modal analysis with the experimental modal analysis, the natural frequencies and vibration modes are found out. The result indicates that the translation natural frequencies are near to the torsion natural frequencies, and they are in the same rank, which ensure that the static unbalance and couple unbalance can measured respectively. The positions of the vibration center are higher than those of the general vertical dynamic balancing machines, which indicates that the plane-separation effects are better. In the modal analysis of HVB1-30 type swing frame, the effect that the pivotal geometric sizes act on the vibration modal is analyzed, and the transfer functions at the pivotal measurement points are analyzed too. The result indicates that the static-couple separation effects of the new swing frames are better. The dynamic simulation for the HVB1-30 type vertical dynamic balancing machine is carried into execution on the MATLAB platform. The amplitude frequency characteristics and phase frequency characteristics of static unbalance measurement and couple unbalance measurement are analyzed respectively. The effects on the vibration property caused by some pivotal geometrical sizes are discussed through giving the stiffness calculation formulas. The optimum mathematics model of the...