Research On Steady-State Flow Properties Of Axial Clearance In Internal Gear Grease Pump

The centralized lubrication system has the advantages of automation and intelligence,making it the preferred lubrication method for high-end mechanical equipment.The centralized lubrication system is a grease pump that distributes the grease to each lubrication point through pipes and distributors to achieve centralized grease supply of the same type or all lubrication points.However,grease is a non-Newtonian fluid with unique rheological properties.From the perspecti’ve of grease structure,grease is a structural colloidal dispersion system with certain structural strength.It requires certain stress to overcome its structural strength and flow friction resistance when flowing.This is the essence of grease different from other Newtonian fluids.Therefore,for the key components in the centralized lubrication system,the traditional fluid mechanical design method can not directly apply the component design of the centralized lubrication system,and it is necessary to carry out research on the basic theories and methods of its application.The internal gear pump is not sensitive to the viscosity of the medium,and has the advantages of high pumping pressure and low failure rate.It is used as the core component of the grease supply system(concentration lubrication system)(grease pump)and is widely used to pump grease medium.The end gap leakage is the main leakage form of the internal gear pump,which directly affects the working performance of the pump.It is important to improve the working performance of the internal gear pump.The essence of the end gap leakage of the internal gear pump is that the pressure difference between the high pressure chamber and the low pressure chamber of the pump causes the pump to generate a gap flow.In the process of pumping grease,the centralized lubrication system has low flow rate,the Reynolds number in the corresponding grease flow is low,and the flow form is laminar flow.Therefore,the form of the internal gear flow of the internal gear pump is mainly in the form of steady flow.Based on this,this paper studies the influencing factors and laws of the steady flow characteristics(leakage flow)of the end face gap of the internal gear grease pump.The main contents include the following aspects.1.The parameter analysis and structural design of the internal gear pump were carried out.The three-dimensional model of the pump was established.The principle of automatic compensation of the end face clearance of the internal gear pump was analyzed.The end gap leakage flow channel of the internal gear pump was clarified,and the subject was established.2.The rheological properties of lithium-based grease were investigated by using a rheometer.The rheological parameters of the grease were obtained by data fitting method.The rheological properties of the grease were quantified from the data point of view for lubrication.Calculation and analysis of the grease pump.The rheological properties of the grease and the experimental results of the microstructure were further synthesized,and the mechanism of the rheological properties of the grease was discussed.3.Based on the basic equation of fluid dynamics and the rheological model of grease,the mathematical model of the end face clearance of the internal gear grease pump was established.The factors affecting the end gap leakage of the internal gear grease pump were obtained.The internal gear grease was established.The mathematical model of the pump end clearance optimal value is solved,and the optimal value of the end gap is solved according to the mathematical model.4.The numerical analysis model of the leakage flow of the end face clearance grease pump is established.The numerical simulation method is used to simulate the flow field of the internal gear of the internal gear gear grease pump under different influence parameters..In this paper,the internal gear pump is taken as the research object.Based on the rheological properties of grease,the leakage law of the end face gap is explored by theoretical derivation and numerical simulation.In this paper,the research results of the end gap leakage of the internal gear grease pump have certain guiding significance for the structural design of the grease pump.