Mathematical model defining volumetric losses of hydraulic oil compression in a variable capacity displacement pump

Abstract

The objective of the work is to develop the capability of evaluating the volumetric losses of hydraulic oil compression in the working chambers of high pressure variable capacity displacement pump. Volumetric losses of oil compression must be determined as functions of the same parameters, which the volumetric losses due to leakage, resulting from the quality of design solution of the pump, are evaluated as dependent on and also as function of the oil aeration coefficient ε. A mathematical model has been developed describing the hydraulic oil compressibility coefficient k_{lc|ΔpPi;bP;ε;v} as a relation to the ratio Δp_Pi/p_n of indicated increase Δp_Pi of pressure in the working chambers and the nominal pressure p_n, to the pump capacity coefficient b_P, to the oil aeration coefficient ε and to the ratio ν/ν_n of oil viscosity ν and reference viscosity ν_n. A mathematical model is presented of volumetric losses q_{PVc|ΔpPi;bP;ε;v} of hydraulic oil compression in the pump working chambers in the form allowing to use it in the model of power of losses and energy efficiency.