Friction characteristics of hydrodynamic swashplate-bearing pair in aviation hydraulic servo motors

Hydraulic servo motors are widely used in aircraft utility systems due to their high-efficiency bidirectional variable displacement drive characteristics. However, the displacement changes process leads to severe friction losses between the swashplate and the bearing, and effective solutions are currently lacking. To address this issue, a Hydrodynamic Swashplate-Bearing Pair (HSBP) structure is proposed for hydraulic servo motors, which avoids the direct contact problem of traditional structures. A numerical calculation model for the HSBP is established, the axial displacement phenomenon generated during the reciprocating motion of the swash plate is considered, and a local mobility method is introduced to solve the frictional characteristic pa-rameters of the new friction pair. The analysis and calculation results obtained the influence law of different working condition parameters and structural parameters on the friction characteristics. A quasi-actual friction test bench is developed to simulate the actual motion characteristics of the swashplate, simplifying the testing method for the friction pair. The experimental results show an error of less than 10% compared to the calculated results. Additionally, the experimental results demonstrate that the proposed hydrodynamic swashplate bearing structure can effectively reduce the friction force during the displacement adjustment process of hydraulic servo motors by more than 90% compared to traditional swashplate bearing structures.