Research On Detecting Method Of Dynamic Unbalance Of Small Mass And High Speed Rolling Body

It is one of the main causes of the failure of the rotating machinery system that the wear and vibration of the high speed bearing during operation and the noise and vibration caused by the load shock.In the rotating equipment,the fault caused by the unbalance of the cylindrical roller in the high speed bearing accounts for more than60% of the vibration fault.In recent years,due to the development of electronic technology,information technology and control technology,China’s dynamic balancing technology has been greatly improved.However,research on the dynamic balancing of existing mainly for large and medium-sized rolling body,less involved in the diameter of D is less than or equal to 10 mm,small length diameter ratio close to1:1 rolling body.Compared with the conventional large and medium sized rolling bodies,the micro rolling body has the characteristics of small quality,large driving difficulty and small amount of unbalance.In foreign countries,the dynamic balance test of the micro bearing roller used in the key mechanical parts such as aero engine high speed bearings is carried out.Sort out the qualified roller.Due to technical reasons,China has not yet launched the micro rolling body dynamic balance detection.Therefore,it is of great strategic value and practical significance to explore the micro rolling body dynamic balance testing technology.In this paper,the study on the measurement of micro rolling body dynamic unbalance is carried out on the micro roller in cylindrical roller bearing.According to the characteristics of small rolling body,such as small mass,high difficulty of driving and small amount of unbalance.Based on the dynamic model of dynamic balance test system.Use Recurdyn to make the dynamic balance test system of multi body dynamics simulation.The important parameters of dynamic balance test system are analyzed.Improvement and optimization of high precision dynamic balance testing system.A dynamic balance testing system based on MEMS is designed.To solve the problems such as high quality,high cost,poor sensitivity and so on.A large number of experiments show that the test system is more conducive to the detection of small rolling body imbalance.This topic mainly completes the following work:1、The principle of dynamic balance test of micro rolling body is analyzed.Using the multi-body dynamics model of Recurdyn to establish dynamic test system.A seriesof simulation analysis is carried out on the spring stiffness,spring damping and belt pretension.Through the simulation analysis,spring stiffness,damping spring preload,belt obtained three sets of parameters of rolling body influence laws in micro dynamic balance detection.Through the simulation response analysis,and provides a theoretical basis for the design and optimization of dynamic balancing machine body small rolling.At the same time,the validity of the virtual prototype and the correctness of the simulation results are verified.2、Based on the analysis of the influence of the pendulum parameters on the vibration characteristics of the dynamic balance testing system,a dynamic balance testing system for micro rolling body based on MEMS is proposed.The MEMS acceleration sensor is symmetrically embedded on the support of the swing frame.To measure the vibration acceleration.The circuit board is directly used as the support of the frame with the punched circuit board.Connect the MEMS sensor to the data acquisition system.Converting the analog signal collected by the sensor into digital signal by data acquisition system.Finally,the signal is transmitted to the computer for signal processing.3、Design of micro rolling body dynamic balance test.To verify the feasibility of MEMS based on dynamic balance test system.