Mathematical model defining volumetric losses of hydraulic oil compres-sion in a variable capacity displacement pump

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 as a relation to the ratio ΔpPi/pn of indicated increase ΔpPi of pressure in the working chambers and the nominal pressure pn, to the pump capacity coefficient bP, to the oil aeration coefficient ε and to the ratio ν/νn of oil viscosity ν and reference viscosity νn. A mathematical model is presented of volumetric losses 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.