The electro-hydrostatic actuator （EHA） is a kind of power-by-wire （PBW） actuator that converts the electrical power into localized hydraulic power for flight control. By removing the central hydraulic power supply...The electro-hydrostatic actuator （EHA） is a kind of power-by-wire （PBW） actuator that converts the electrical power into localized hydraulic power for flight control. By removing the central hydraulic power supply together with hydraulic pipes, an EHA＇s reliability and efficiency are greatly improved but its frequency width and stiffness decreased. To overcome the drawback, this article proposes a novel structure of EHA associated with a power regulator. Composed of a high-pressure accumulator and a proportional valve, it can store and harness the hydraulic power flexibly according to the changing control requirements. The concept of transferred volume is put forward to estimate the capability of the power regulator. The actuator output position can be kept fixed with a hydraulic lock. The compounded control is specially developed to ensure the actuator system to operate in a correct manner. The simulation results indicate that the new-brand actuator results in efficient expanding of the system frequency width with an optimal power supply.展开更多
This paper presents a novel transient lubrication model for the analysis of the variable load failure mechanism of high-speed pump used in Load Sensing Electro-Hydrostatic Actuator（LS-EHA）. Focusing on the slipper/s...This paper presents a novel transient lubrication model for the analysis of the variable load failure mechanism of high-speed pump used in Load Sensing Electro-Hydrostatic Actuator（LS-EHA）. Focusing on the slipper/swashplate pair partial abrasion, which is considered as the dominant failure mode in the high-speed condition, slipper dynamic models are established. A forth sliding motion of the slipper on the swashplate surface is presented under the fact that the slipper center of mass will rotate around the center of piston ball when the swashplate angle is dynamically adjusted. Besides, extra inertial tilting moments will be produced for the slipper based on the theorem on translation of force, which will increase rapidly when LS-EHA pump operates under highspeed condition. Then, a dynamic lubricating model coupling with fluid film thickness field, temperature field and pressure field is proposed. The deformation effects caused by thermal deflection and hydrostatic pressure are considered. A numerical simulation model is established to validate the effectiveness and accuracy of the proposed model. Finally, based on the load spectrum of aircraft flight profile, the variable load conditions and the oil film characteristics are analyzed, and series of variable load rules of oil film thickness with variable speed/variable pressure/variable displacement are concluded.展开更多
基金National Natural Science Foundation for Distinguished Young Scholars of China （50825502）
文摘The electro-hydrostatic actuator （EHA） is a kind of power-by-wire （PBW） actuator that converts the electrical power into localized hydraulic power for flight control. By removing the central hydraulic power supply together with hydraulic pipes, an EHA＇s reliability and efficiency are greatly improved but its frequency width and stiffness decreased. To overcome the drawback, this article proposes a novel structure of EHA associated with a power regulator. Composed of a high-pressure accumulator and a proportional valve, it can store and harness the hydraulic power flexibly according to the changing control requirements. The concept of transferred volume is put forward to estimate the capability of the power regulator. The actuator output position can be kept fixed with a hydraulic lock. The compounded control is specially developed to ensure the actuator system to operate in a correct manner. The simulation results indicate that the new-brand actuator results in efficient expanding of the system frequency width with an optimal power supply.
基金supported by the National Natural Science Foundation of China(Nos.51620105010,51675019 and 51575019)the National Basic Research Program of China(No.2014CB046402)+1 种基金the ‘‘111" Projectthe Excellence Foundation of BUAA for PhD Students
文摘This paper presents a novel transient lubrication model for the analysis of the variable load failure mechanism of high-speed pump used in Load Sensing Electro-Hydrostatic Actuator（LS-EHA）. Focusing on the slipper/swashplate pair partial abrasion, which is considered as the dominant failure mode in the high-speed condition, slipper dynamic models are established. A forth sliding motion of the slipper on the swashplate surface is presented under the fact that the slipper center of mass will rotate around the center of piston ball when the swashplate angle is dynamically adjusted. Besides, extra inertial tilting moments will be produced for the slipper based on the theorem on translation of force, which will increase rapidly when LS-EHA pump operates under highspeed condition. Then, a dynamic lubricating model coupling with fluid film thickness field, temperature field and pressure field is proposed. The deformation effects caused by thermal deflection and hydrostatic pressure are considered. A numerical simulation model is established to validate the effectiveness and accuracy of the proposed model. Finally, based on the load spectrum of aircraft flight profile, the variable load conditions and the oil film characteristics are analyzed, and series of variable load rules of oil film thickness with variable speed/variable pressure/variable displacement are concluded.
