Misalignment faults in gear systems lead to violent vibration and noise, shortening the life of equipment. The aim of this work is the demonstration of vibration suppression of parallel-misaligned gear shafts using an...Misalignment faults in gear systems lead to violent vibration and noise, shortening the life of equipment. The aim of this work is the demonstration of vibration suppression of parallel-misaligned gear shafts using an integral squeeze film damper(ISFD). Using a first grade spur gear in engineering for reference, an open first-grade spur gear system is built and the vibration characteristics of the gear system with rigid supports and ISFD elastic damping supports are studied under different degrees of misalignment. The experimental results show that ISFD supports have excellent damping and vibration attenuation characteristics, which have improved control of the gear system vibration in horizontal, vertical and axial directions under different degrees of misalignment. This work shows that an ISFD structure can effectively suppress vibration of characteristic frequency components and resonance modulation frequency components. The test results provide evidence for the application of ISFD in vibration control of gear shaft misalignment faults in engineering.展开更多
Aiming at the shortcomings of traditional contact measurement methods such as low measurement efficiency,high cost and low accuracy,a non-contact optical measurement method based on the laser displacement sensor is pr...Aiming at the shortcomings of traditional contact measurement methods such as low measurement efficiency,high cost and low accuracy,a non-contact optical measurement method based on the laser displacement sensor is proposed.According to the relevant regulations of the coaxiality error evaluation standard and the structural characteristics of the compound gear shaft,we have designed and built a set of supporting software system as well as a hardware test platform.In this paper,the distance difference threshold and scale threshold methods are used to eliminate outlier data.The least squares circle is selected to calculate the center of the circle and the minimum containment cylinder axis method is used as the reference axis of the composite gear shaft.Compensated by the standard step shaft calibration,the coaxiality error of the composite gear shaft can be measured to be within 0.01 mm in less than two minutes.The range value of the multi-section measurement test is 0.065 mm.The average coaxiality error is∅0.476 mm.展开更多
In order to solve fretting instability problem of gear shaft shoulder due to torsional vibration in mechanical system, the mathematical model of fretting instability vibration of gear shaft shoulder was established by...In order to solve fretting instability problem of gear shaft shoulder due to torsional vibration in mechanical system, the mathematical model of fretting instability vibration of gear shaft shoulder was established by adopting the method of combining kinematics and tribology, and the numerical analysis was applied to the fretting instability mechanism of gear shaft shoulder by introducing the friction instability damping ratio. The numerical results show that the main factors causing the unstable and vibrating gear shaft shoulder are the large tightening torque and too large static friction coefficient. The reasonable values of the static friction coefficient, the amount of interference and tightening torque can effectively mitigate the fretting instability phenomenon of gear shaft shoulder. The experimental results verify that damping plays a significant role in eliminating the vibration of gear shaft control system.展开更多
The forms of the vibration disturbances inside the epicyclic gear train are analyzed. Thefrequency equations for the inner disturbances of the epicyclic gearing with one or two degrees offreedom have been built. The l...The forms of the vibration disturbances inside the epicyclic gear train are analyzed. Thefrequency equations for the inner disturbances of the epicyclic gearing with one or two degrees offreedom have been built. The latter of them is a 3-dimension problem and the range of the disturbance frequencies covers a series of planes inside the 3-dimension coordinates. As a result, thechances to lead to the system resonance are developed. The calculating results indicate that in thedesign process of the shaft system, the chances of resonance can be reduced by tunning the dynamicparameters and the structure of the system.展开更多
<span style="font-family:Verdana;">The design of bevel gear for use in the development of revolving rostrum is presented. The pinion gear is designed to rotate at 1400 rpm for the output gear of 23 rpm...<span style="font-family:Verdana;">The design of bevel gear for use in the development of revolving rostrum is presented. The pinion gear is designed to rotate at 1400 rpm for the output gear of 23 rpm. A suitable gearmotor was selected for the design based on the bevel gear design analysis. The motion is transmitted to the rostrum via a shaft keyed to it with a gib-head key and assembled on the rostrum with a spline connector. The analysis of the bevel mesh shows that maximum deformation of about 26.552 mm occurs in the pinion due to the loading the pinion tooth. The deformation of the tooth is observed to affect considerable the performance of the system. The transmission efficiency of the mechanism </span><span style="font-family:Verdana;">was obtained as 86% though effective for the operation of the system but</span> <span style="font-family:Verdana;">could be improved by a more careful material selection for the bevel gear</span><span style="font-family:Verdana;"> mesh.</span>展开更多
基金Supported by the National Basic Research Program of China(No.2012CB026000)2015 Beijing Scientific Research and Graduate Training Project(No.0318-21510028008)Key Laboratory Fund for Ship Vibration and Noise(No.614220406020717)
文摘Misalignment faults in gear systems lead to violent vibration and noise, shortening the life of equipment. The aim of this work is the demonstration of vibration suppression of parallel-misaligned gear shafts using an integral squeeze film damper(ISFD). Using a first grade spur gear in engineering for reference, an open first-grade spur gear system is built and the vibration characteristics of the gear system with rigid supports and ISFD elastic damping supports are studied under different degrees of misalignment. The experimental results show that ISFD supports have excellent damping and vibration attenuation characteristics, which have improved control of the gear system vibration in horizontal, vertical and axial directions under different degrees of misalignment. This work shows that an ISFD structure can effectively suppress vibration of characteristic frequency components and resonance modulation frequency components. The test results provide evidence for the application of ISFD in vibration control of gear shaft misalignment faults in engineering.
基金supported by the National Natural Science Foundation of China(No.51975293)Aeronautical Science Foundation of China (No. 2019ZD052010)
文摘Aiming at the shortcomings of traditional contact measurement methods such as low measurement efficiency,high cost and low accuracy,a non-contact optical measurement method based on the laser displacement sensor is proposed.According to the relevant regulations of the coaxiality error evaluation standard and the structural characteristics of the compound gear shaft,we have designed and built a set of supporting software system as well as a hardware test platform.In this paper,the distance difference threshold and scale threshold methods are used to eliminate outlier data.The least squares circle is selected to calculate the center of the circle and the minimum containment cylinder axis method is used as the reference axis of the composite gear shaft.Compensated by the standard step shaft calibration,the coaxiality error of the composite gear shaft can be measured to be within 0.01 mm in less than two minutes.The range value of the multi-section measurement test is 0.065 mm.The average coaxiality error is∅0.476 mm.
基金Project(2008AA11A116)supported by the National High Technology Research and Development Program of ChinaProject(9140A2011QT4801)supported by advanced research of the Weapon Equipment Key Fund Program,ChinaProject(61075002)supported by the Independent Subject of State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body of Hunan University,China
文摘In order to solve fretting instability problem of gear shaft shoulder due to torsional vibration in mechanical system, the mathematical model of fretting instability vibration of gear shaft shoulder was established by adopting the method of combining kinematics and tribology, and the numerical analysis was applied to the fretting instability mechanism of gear shaft shoulder by introducing the friction instability damping ratio. The numerical results show that the main factors causing the unstable and vibrating gear shaft shoulder are the large tightening torque and too large static friction coefficient. The reasonable values of the static friction coefficient, the amount of interference and tightening torque can effectively mitigate the fretting instability phenomenon of gear shaft shoulder. The experimental results verify that damping plays a significant role in eliminating the vibration of gear shaft control system.
文摘The forms of the vibration disturbances inside the epicyclic gear train are analyzed. Thefrequency equations for the inner disturbances of the epicyclic gearing with one or two degrees offreedom have been built. The latter of them is a 3-dimension problem and the range of the disturbance frequencies covers a series of planes inside the 3-dimension coordinates. As a result, thechances to lead to the system resonance are developed. The calculating results indicate that in thedesign process of the shaft system, the chances of resonance can be reduced by tunning the dynamicparameters and the structure of the system.
文摘<span style="font-family:Verdana;">The design of bevel gear for use in the development of revolving rostrum is presented. The pinion gear is designed to rotate at 1400 rpm for the output gear of 23 rpm. A suitable gearmotor was selected for the design based on the bevel gear design analysis. The motion is transmitted to the rostrum via a shaft keyed to it with a gib-head key and assembled on the rostrum with a spline connector. The analysis of the bevel mesh shows that maximum deformation of about 26.552 mm occurs in the pinion due to the loading the pinion tooth. The deformation of the tooth is observed to affect considerable the performance of the system. The transmission efficiency of the mechanism </span><span style="font-family:Verdana;">was obtained as 86% though effective for the operation of the system but</span> <span style="font-family:Verdana;">could be improved by a more careful material selection for the bevel gear</span><span style="font-family:Verdana;"> mesh.</span>
