Analysis of leakage characteristics for bent-axis piston pump based on elastohydrodynamic deformation

Abstract

Purpose This paper aims to revel the leakage characteristics of the bent-axis piston pump considering elastohydrodynamic deformation via a dynamic leakage model. Design/methodology/approach A dynamic leakage model of bent-axis piston pump based on elastohydrodynamic lubrication theory is proposed, which is used to present the leakage characteristics of bent-axis piston pump. The model is composed of three parts. First, the dynamic gap in the piston ring-cylinder bore interface (PRCB) is described via the elastohydrodynamic lubrication equations. Then, the PRCB leakage is presented based on the dynamic gap. Finally, combined with leakage equation of the valve plate-cylinder block interface (VPCB), the total leakage model is proposed. Through the numerical simulation and experiment, the leakage characteristics of bent-axis piston pump considering elasto-hydrodynamic deformation are studied. Findings The PRCB leakage is negatively correlated with VPCB leakage under the range of 800–1400 r/min and 1–25 MPa. When the discharge pressure is less than the critical pressure, the PRCB leakage is the main factor affecting the total leakage in bent-axis piston pump. On the contrary, the VPCB leakage is the main factor. The critical pressure increases with increasing speed Originality/value The effect of operating parameters has a significant effect on the elastic deformation of piston ring without considering wear of friction pairs in bent-axis piston pump. There is a critical phenomenon in the leakage, which is related to the operating parameters, and provides a novel idea for extracting wear information from leakage and evaluating the status of bent-piston pump.

New analytical leakage models for tribological interfaces in axial piston pumps

“…The experimental results in Table 2 show that the pump's total leakage increases with the rotational speed. One may consider that the large measured leakage at high rotational speed results from the centrifugal flow that increases with the rotational speed, as shown in equations (20) and (28). However, at the same time, these two equations indicate that the centrifugal flow actually contributes little to the leakage flow.…”

“…Li et al 19 developed a nonlinear theoretical model based on Reynolds equation to predict the leakage of piston/cylinder block interface. Qing et al 20 compared the contributions of Poiseuille and Couette flows to the leakage of piston/cylinder block interface. Nie et al 21 established a fluid–structure interaction model for the piston/cylinder block interface, by which they found that the piston bush deformation increased the interface leakage due to increased gap height.…”

Lubrication and leakage characteristic research of aviation plunger pump considering plunger deflection

“…At the same time, he studied the influence of the material and structure of the valve plate on the thickness and shape of the oil film 13. Qing et al proposed a dynamic leakage model of bent-axis piston pump based on elastohydrodynamic lubrication theory, which is used to present the leakage characteristics of bent-axis piston pump 14. Deng et al analyzed the hydrodynamic lubrication characteristics of the external return spherical bearing pair of an axial piston pump/motor 15.…”