Abstract
To study the oil film performance, a multi-physical coupling model considering the elastohydrodynamic lubrication effect of the piston–cylinder interface is established and verified. The oil film thickness is obtained by solving geometric formulae, and the dynamic pressure model is derived by solving the Reynolds equation. Considering the oil film thickness and pressure distribution of the piston–cylinder interface, the elastic deformation model is solved. Both theoretical and experimental results show that the oil film morphology is influenced by the elastic deformation of the piston surface. The impact of the minimum fluid film thickness and its influence on the piston surface are well analyzed and discussed. When taking elastic deformation into account, the viscous friction reduces greatly, especially during the oil discharging process. Based on the theoretical research, a unique test rig was designed and established for testing and measuring the oil film thickness and the viscous friction of the piston.
Highlights
The axial piston pump is in widespread use for its compactness and high efficiency
Xu et al.5,6 discovered the effect of surface roughness and elastic deformation on the lubrication performance, and the results revealed that the leakage loss and viscous friction force could be reduced by decreasing the clearance between the piston and cylinder
Because the description of the simulation model and the experiment in these studies are generally relatively simple and the variables covered are not comprehensive, this paper considers the elastohydrodynamic lubrication (EHL) effect and studies the influence of displacement chamber pressure on the oil film thickness and viscous friction force in detail
Summary
The axial piston pump is in widespread use for its compactness and high efficiency. The lifetime of a piston pump is highly determined by the three friction pairs: the piston–cylinder pair, the slipper–swash plate pair, and the valve plate–cylinder pair. Bergada et al. established an instantaneous pressure and flow model of the piston– cylinder interface and predicted the leakage flow rate and the oil film thickness successfully. Li et al. proposed a sensor distribution method and verified the simulation model of the oil film thickness and pressure in the piston–cylinder interface. Recent studies are mainly focused on the friction and wear characteristics, oil film characteristics, and the EHL effect of the piston–cylinder interface considering temperature, pressure, and other influencing factors. Because the description of the simulation model and the experiment in these studies are generally relatively simple and the variables covered are not comprehensive, this paper considers the EHL effect and studies the influence of displacement chamber pressure on the oil film thickness and viscous friction force in detail.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
