Research On Vibration Characteristics Of Multi-point Meshing Gear Bearing Rotor System Considering Mesh Misalignment

Gear meshing is widely used as the core part of power transmission in various rotor machinery is due to high power transmission efficiency,long working life,stable transmission ratio,reliable working performance and suitable for high speed,high power and other working conditions.In recent years,with the continuous improvement of China’s gear rotor mechanical technology,its application is more and more seen in the field of shipping,aerospace and other construction machinery.At present,domestic and foreign favor in the application of high-speed power transmission parts in the gear rotor system,according to statistics,most of the rotating machinery abnormal vibration,resulting in shaft fracture,cause bearing gear and other performance state change,resulting in the shutdown of the machine to destroy major failures,often caused by the gear mesh misalignment.Therefore,it is very important to study the vibration characteristics of the multi-point meshing gear bearing rotor system with gear mesh misalignment.It is of great significance for the rotor system design and fault diagnosis of gear mesh misalignment to analyze the influence law of gear mesh misalignment on the dynamic characteristics of the gear bearing rotor system and give the motion characteristics of the gear bearing rotor system under the condition of mesh misalignment.This article is based on the urgent problems of gear bearing rotor system mesh misalignment research needs,establish a multipoint meshing gear bearing rotor system more physical field monitoring platform,the integrated use of the finite element method and numerical analysis method and combining with experiment,study the experiment platform of gear mesh misalignment of gearing of coupling rotor system vibration characteristics.The research content is mainly divided into four parts.In the first part,based on the basic theory of finite element modeling,the meshing gear models with different mesh misalignment angles are established by Solid Works.The meshing model is divided by Hyper Mesh.The finite element software is used to analyze the contact stress changes between the teeth with mesh misalignment.In the second part,the meshing displacement of gear is extracted and the meshing stiffness is calculated by finite element method.The rationality of the calculation is verified by Ishikawa formula method and ISO standard.At the same time,the meshing stiffness curves considering different mesh misalignment angles are obtained.The third part,based on the axial element method and focus on quality standard,put forward a multipoint modeling method,the dynamic model of gear meshing bearing rotor to its inherent characteristics and dynamic response calculation method is put forward,and according to the above methods select three shaft gear rotor experiment platform for example,to complete its inherent characteristics and response analysis,the rationality of the proposed method is verified.In the fourth part,the nonlinear dynamics model of multi-point meshing gear is proposed,and the vibration effect of multi-point meshing gear bearing rotor system is studied under the coupling action of nonlinear factors such as the mesh misalignment of gearing,toothed clearance and transmission error,etc.,which is verified by experiments.The results show that the mesh misalignment angle affects the contact stress.The larger the misalignment angle is,the larger the stress concentration point is.The meshing stiffness of gear is increased due to the change of the mesh misalignment angle.Coupled with mesh misalignment and nonlinear factors,the system appears frequency doubling vibration,and the sideband frequency component appears near the rodent frequency.In the frequency domain diagram of rotating shaft,there are not only rotation frequency,rodent frequency,frequency doubling component but also natural frequency component.At the same time,with the increase of the mesh misalignment angle of the gear,the clearance of the tooth side increases,and the transmission error increases.The time domain diagram of the rotating shaft shows that the radial vibration displacement increases,while the frequency domain diagram of the gear radial meshing force shows that the peak value of each frequency component increases.The research results in this paper can provide guidance for the improvement of mechanical failure vibration with multi-point meshing gear bearing rotor as the core power transmission component.