Influence of Piston Elastic Deformation and Structure Design on the Lubrication Characteristics of Piston Pair: Simulation Analysis

Piston pair is a key friction pair of the axial piston pump, but the influence of elastic deformation and the structure design method is not clear. To reveal the real performance of piston pair, a new fluid–solid coupling calculation method is proposed. With the method, the oil film pressure and thickness field, elastic deformation, axial viscous friction and leakage of the piston pair are studied. The influences of the elastic deformation of the piston pair on oil film pressure, axial viscous friction, and leakage were revealed. To reduce the impact brought by deformation, a new piston with hollow piston structure (piston B) is designed. Compared with the traditional structure (piston A), piston B is featured with small elastic deformation, small leakage, large peak pressure, and large viscous friction force. The new fluid–solid coupling calculation method and hollow piston structure of this paper lay the foundation for the piston pair design of the axial piston pump.