| Staggered labyrinth seal device is widely used in aerospace,transportation,mining and other fields because of its advantages of high speed,reliable sealing performance and small or no friction between rotor and stator.The working principle of labyrinth seal device is complex,which can be summarized into four effects,namely,air permeability effect,friction effect,thermodynamic effect and beam contraction effect.As a standard to measure the performance of sealing device,the calculation of leakage is particularly critical.The traditional calculation of labyrinth seal leakage mainly focuses on the ideal gas in the internal medium,and only considers a single effect,so the deduced algorithm can not well describe the leakage of liquid medium lubricating oil in the staggered labyrinth seal device.And in the gearbox,with the increasing speed of the gear,the oil and gas pressure distribution in the gearbox is uneven,which affects the stability of the gearbox.Under the effect of the inlet pressure,the staggered labyrinth sealing device and the labyrinth bearing system will have different degrees of deformation at different speeds,which affects the sealing performance.The main research work of this paper is as follows:(1)According to the working principle of interleaved labyrinth seal,considering the thermodynamic effect and friction effect,the resistance loss along the way and local resistance loss of lubricating oil in interleaved labyrinth seal are discussed.At the same time,the thermodynamic effect of the lubricating oil in the sealed cavity is discussed,and the entropy and enthalpy increase of the thermodynamic system when the lubricating oil passes through the sealed cavity are analyzed.A new calculation method of leakage is proposed.(2)The flow field of lubricating oil in staggered labyrinth seal was analyzed and discussed.The inlet boundary condition was set as pressure inlet and temperature inlet,and the outlet boundary condition was set as pressure outlet.The flow of lubricating oil under different inlet total pressure,inlet total temperature,seal clearance,cavity depth,cavity width,blade inclination angle,blade thickness and spindle speed are discussed respectively,and the leakage under the above different influence factors is discussed preliminarily.(3)Based on fluid structure coupling,the deformation of staggered labyrinth seal under different conditions is analyzed and discussed.The modal analysis of labyrinth bearing system is carried out.The deformation of staggered labyrinth seal with or without prestress and the influence of different rotating speed on deformation are discussed.(4)Based on the results of fluid structure interaction,taking the leakage as the response value,different algorithms were used to optimize the structure of staggered labyrinth seal device,and the optimal combination of parameters and process was discussed.At the same time,the staggered labyrinth seal device test-bed is designed to verify the calculation method of the leakage of the staggered labyrinth seal device,and the leakage law of the staggered labyrinth seal device under different influence factors is verified. |
