Research On The Balance Of The Drive Sy Stem Of Electric Compressor For Automo Bile Air Conditioning

Electric scroll compressor is the core of new energy vehicle air conditioning system,which is widely used in new energy vehicles.It is driven by the motor,and the two meshing scroll plates complete the compression of the working medium in the process of rotation.In its working process,the transmission system will be affected by the centrifugal inertia force and gas force in the rotating process of the moving scroll plate,resulting in the unstable operation of the transmission system.This instability will be transmitted to the casing,causing the vibration of the whole machine.For new energy vehicles with high requirements of stability and comfort,it is particularly important to improve the stability of the whole electric scroll compressor and reduce the vibration of the system.In this dissertation,combined with the RSE28A electric scroll compressor project of a new energy company,the scroll compressor has been deeply studied,and some work has been done on the dynamic balance and vibration of the transmission system:1.Based on the basic structure of the transmission system of the electric scroll compressor,the dynamic balance theory of the transmission system without considering the gas force is analyzed,and the gas force on the scroll plate is calculated and analyzed.2.The three-dimensional solid model of the transmission system is established and the virtual assembly is carried out.The dynamic model of the transmission system considering the gas force is established in ADAMS.Through the simulation analysis and calculation,it is found that the fluctuation range of the force on the main and auxiliary bearings is large,and a new imbalance appears in the transmission system.In this paper,the mass center of the eccentric which has a great influence on the transmission system is designed parametrically.As the optimization variable,according to the force on the auxiliary bearing as the objective function,the optimization design is carried out,and the mass center position of the eccentric is adjusted through the optimized parameters.3.The simplified model of rotor finite element analysis is established,the rotor dynamic modal analysis is carried out,the modal frequencies and corresponding vibration modes of the rotor are extracted,the critical speed of the rotor is calculated and the Campbell diagram is drawn.The results show that there is a critical speed of 10275rpm at the speed of 0～12000rpm,which is beyond our rated working speed range of 0～6000rpm,so the rotor system can run smoothly without resonance.4.The optimized eccentric wheel is assembled,and then the vibration and noise test is carried out.The vibration and noise values of the former and the latter are recorded.Through comparative analysis,noise of the optimized prototype was reduced by 2.8d BA,the vibration in the X direction was reduced by 0.9 m/s~2,the vibration in the Y direction was reduced by 0.3m/s~2,and the vibration in the Z direction was reduced by 1.0m/s~2,which proves the feasibility of the optimization,and provides some engineering value for the compressor balance solution and vibration and noise reduction.