The journal bearing of aero-engine fuel gear pumps work under extreme conditions of high tem-perature,high pressure and low viscous media for a long time,which may result in lubrication failure.However,the evolution law of their lubrication performance has not been fully explored.This paper establishes and solves the fluid lubrication model of the fuel pump hydrostatic bearing.The oil film thickness test under actual operating conditions is conducted by using ultrasonic measurement principle,and the oil film thickness of the sliding bear-ing lubrication model under multiple load conditions is compared and verified.Finally,the verified sliding bear-ing lubrication model is used to study the influence mechanisms of width-to-diameter ratio,eccentricity and oil groove position on its lubrication performance.The research results show that the calculated oil film thickness changes with the working conditions and is in good agreement with the experimental measurement points,with an average calculation error of 2.3%.In addition,an increase in fuel pump load will cause the minimum thickness of the oil film to deflect towards the inlet oil groove,thereby weakening the dynamic pressure capacity.The bearing capacity of the bearing under high load conditions is mainly provided by static pressure.When the aspect ratio B/D increases from 0.4 to 1.2,it will cause the oil film temperature to decrease by 1.2℃along the circumferen-tial direction and increase by 0.5℃along the axial direction.An increase in eccentricity will lead to a decrease in the oil film thickness,and the dynamic pressure at the middle section of the mixed lubrication bearing will in-crease by 0.43 MPa.The oil groove position of the sliding bearing should be designed at the front end of the con-verging wedge structure or at the opening of the expanding wedge structure,which can improve the bearing's load-bearing performance.
AeroengineFuel gear pumpSliding bearingLubricationOil film test
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