Design And Research Of Multi-Action Internal Curve High Water Base Hydraulic Motor With Valve Distribution

Multi-action inner curve radial piston hydraulic motor is one of the main forms of low-speed and high-torque hydraulic motor.Compared with the single-action type,the multi-action inner curve hydraulic motor has the advantages of compact structure,high power density,large output torque,smooth operation at low speed and so on.Therefore,it is widely used in coal mine,engineering machinery and other fields.At present,the existing hydraulic motors with high water-based emulsion as medium are difficult to meet the requirements of high pressure,low speed,large torque and lightweight in structure principle,stator guide curve,valve distribution characteristics,output performance,etc.,especially the problems of large starting torque and large weight.In order to solve the above problems,a new type of valve-assisted multi-acting inner curve radial piston high water-based hydraulic motor is proposed in this thesis,and its key technologies are studied.The key components of the hydraulic motor are studied and analyzed through theoretical analysis and simulation,which provides theoretical basis for the design of valve-assisted multi-acting inner curve hydraulic motor.The main contents of this thesis are as follows:(1)The general scheme of the new valve-assisted multi-function internal curve radial piston hydraulic motor was designed and the basic parameters of the motor structure were determined.Leakage characteristics of motor piston-rotor sub-annular clearance in oil medium and high water-based liquid medium were compared and analyzed.Reasonable range of piston-rotor sub-annular clearance suitable for low speed,high torque and high water-based conditions was determined.In order to reduce friction,wear and leakage of contact pair and improve sealing performance,appropriate reciprocating dynamic seal form and structure were studied and designed.(2)An optimum design method of combined cam motion law curve of stator guide rail is put forward.The motion trajectory equations of curved tracks in different motion laws are established respectively.The movement state variation law,pressure angle,instantaneous contact stress and output torque of the plunger roller assembly under different types of curved tracks are compared and analyzed.The optimum amplitudeangle distribution scheme is determined and the combined cam curve without fluctuation of theoretical output torque is obtained.Based on ANSYS software,the main contact parts are simulated and analyzed to reveal the stress distribution law of key friction pairs of motor,and the rationality of stator guide curve design is verified by theoretical analysis.(3)A cartridge valve for high water-based liquid was designed,the appropriate valve aperture was determined,and the kinematic and mechanical analysis of the valve was carried out.Solidworks builds the three-dimensional model of the distribution valve.Fluent software is used to simulate and analyze the flow field inside the valve chamber with different structure forms and different openings.Pressure,velocity and vorticity profiles of different sections are obtained,and the slotted spool structure with better comprehensive performance is selected.Under this structure,the internal flow field parameters at different opening of spool are compared to verify the reliability of valve design.(4)Based on AMESSim software,the model of single-plunger distribution mechanism of valve distribution multi-function inner curve radial piston hydraulic motor was built,and the influence of diameter of spool slot,flow area and other factors on its dynamic characteristics was studied and analyzed,and the optimum structure parameters were determined,which verified the coordination position matching between distribution cam and inner curve track and the reliability of opening and closing performance of distribution valve.A virtual prototype model of hydraulic motor was built to investigate the effect of different working pressures caused by load changes on motor output torque ripple and volumetric efficiency as well as the effect of different flow inputs on motor output torque.This thesis includes 88 charts,14 tables and 73 references.