Research On Air-suspending Dynamic Balancing Technology For Vertical Rotor

During the developing quality characteristics colligation measuring equipment for the flight equipment in Chinese Academy of Engineering Physics (CAEP), high requirements are put forward to vertical dynamic balancing measuring accuracy of the flight equipment at low rotation speed. The rotation speed must be low for the sake of safety. So far, it is still a difficult problem for accurate dynamic unbalance measuring at low rotation speed over the world. In order to solve the question in this paper, a new dynamic balancing measuring principle for vertical rotor, designing technology and a new measuring and controlling device at low rotation speed are researched and developed by supporting of the Science & Technology Foundation of CAEP.Based on the analysis of measuring principles and methods, key technologies and research tendency of vertical rotor dynamic balancing, a new measuring principle model of air-suspending vertical rotor dynamic balancing is researched and a set of experiment devices used to solve the problem of weak signal processing at low rotation speed are developed. Some key techniques are discussed, such as dynamic unbalance separation algorithm model, designing method of air-suspending dynamic balancing measuring system for vertical rotor, system frame, rotor suspending stability controlling, data transaction, etc. The main achievements and creative ideas of the paper in principle and engineering application are as follows:(1) According to vertical dynamic balancing measuring demand and characteristic of air static pressure suspending, the theoretic model for air-suspending dynamic balancing of vertical rotor is established. The rotor is suspended by an air static pressure ball bearing and drove by well-distributed air flow. Dynamic unbalance makes the rotor slant, anddynamic unbalance of the rotor can be calculated by measuring its slant displacement.(2) Algorithm of calculating dynamic unbalance on two correction planes for the new measuring principle is presented, and static unbalance and couple unbalance are separated on two correction planes. The lineal relationship function between dynamic unbalance and slant displacement is established. After the lineal parameters are determined through theoretic calculation and experiment analysis, dynamic unbalance can be calculated, so verification rotor is unnecessary. Static unbalance and couple unbalance can be measured at different status, and they are separated directly, so interference can be avoided.(3) Based on air suspending dynamic balancing principle, a set of experiment devices for vertical rotor are designed, such as supporting device, driving device, measuring device for air pressure, exactitude air pressure controlling device, displacement sensor demarcation device, etc. Designing of dual-ring slot spherical throttle is keystone. FEA software is applied to calculate spherical throttle distortion under different air pressure, which can instruct to design spherical throttle. The rotor can rotate at constant speed because it is drove by non-contact well-distributed air flow. Pressure at any point in the throttle is measured by two-dimension spherical sensor, and pressure distribution can be determined.(4) The air static pressure ball-bearing is core of the experiment devices, and its designing is a complex process with multi-parameters and multi-restrictions. Genetic algorithm is applied to optimize its structural parameters, such as spherical radius, bearing angle, air feed pressure, etc. Based on these parameters, air static press ball bearing is designed in detail. Experiment results have verified that the new optimization designing method is correct and measuring effect is satisfactory.(5) Influence of supporting air pressure variation to space attitude of the rotor is analyzed. The stability controlling techniques for vertical rotor are studied. Reasons of self oscillation are analyzed, and solutions are put forward to instruct throttle structural designing according to Laus-Holweitz stability regulation. Adaptive PID contro...