Research On Small Wankel Pump With Integrated Drive And Executio

The Wankel pemp,based on the reverse application of the Wankel engine,which uses the rotation of the eccentric shaft to drive the triangular rotor to conduct eccentric compound rotation in the cylinder of the double-arc epicycloid,thus realizing the volume change of the chamber.Because of its simple and compact structure,high volume utilization,and the ability to integrate with other subsystems,it can be summarized that the Wankel pump is more conducive to miniaturization and integration.Wankel pumps have been explored in the fields of biomedical engineering,small cooling systems and small mixers,and have significant practical value and application prospects in the field of microfluidics.In order to improve the efficiency and performance of the Wankel pump,most of the research scholars start to study the improvement from the fluid leakage,impact and abrasion,flow field analysis and design parameter optimization,but rarely from the structural improvement to enhance its efficiency.However,the development of the field of microfluidics cannot allow the chip-scale micro-sensor and micro-actuator to have a hard connection with separation between drive and execution.It is necessary to realize miniaturization and integration of electromechanical sensors and actuators.The current traditional Wankel pumps mostly require an external drive machine,passive execution of the pump structure,in addition to the need for an external transmission device to connect the drive machine and eccentric shaft.This form of drive and execution separation not only limits the application and performance of Wankel pumps,and restricts the process of miniaturization and integration of Wankel pumps.Therefore,based on mechatronics concept,this study proposes an integrated drive and actuation structure of a small Wankel pump.The motor drive component is integrated into the execution structure of the Wankel pump,which not only has the original pumping function but also reduce the number of drive mechanisms to shorten the transmission path.The complex curve of cylinder shape line envelope of triangular rotor was replaced by simple circular arc curve and the geometric mathematical model of cylinder shape line and triangular rotor shape line was established to simplify the processing.This paper will focus on the structural design and working principle,theoretical performance analysis,finite element analysis and experimental testing of a small Wankel pump integrating the actuation component into the execution structure,as follows:(1)Based on mechatronics concept,a structure of a small Wankel pump integrating the actuation component into the execution structure is designed,describing its assembly relationship and component distribution.The creation process of the cylinder profile and the rotor profile replaced by circular arcs was revealed,and the mathematical model of the cylinder profile and rotor profile was established;The pumping cycle of the studio of the small Wankel pump with integrated drive and actuation is explained by the drive relationship and pumping principle of the pump.(2)From the kinematics and force analysis of the triangular rotor,the variation of the load on the eccentric shaft and its influencing factors are analyzed;The equation for matching the output rotational speed with the load,magnetic induction strength and other factors is derived based on the Electrical Machinery;The theoretical output flow rate of the small Wankel pump integrating the actuation component into the execution structure was derived by analyzing the volume change of the chamber,and then the matching mechanism of output speed and output flow rate with structural parameters,input voltage and magnetic field strength was obtained;A dimensionless parameter that has an important impact on its shape and working characteristics is proposed to explore the impact of this coefficient on pumping performance.(3)The finite element model of the entire pump flow field of a small Wankel pump integrating the actuation component into the execution structure is introduced,expiaining the finite element setup methods such as meshing,boundary conditions,dynamic mesh settings and user-defined settings;Through transient calculation and analysis,the velocity flow line cloud diagram and pressure change cloud diagram of the entire pump flow field working cycle were obtained,which verified the pumping function and analyzed the flow field characteristics of the pump;(4)A prototype of a small Wankel pump integrating the actuation component into the execution structure was built,and a high-speed camera experimental platform and a pumping performance experimental platform were constructed;The flow field of the chamber inside the prototype is observed and the flow field characteristics of its suction and discharge ranges are obtained,further validating the results of the simulation;The pumping performance experiments on the output speed,output flow and output pressure of the pump were conducted under different magnetic field strength and input voltage to obtain the variation pattern of its input and output parameters;The prototypes with different shape parameters were set up and fabricated,and the pumping performance of the prototypes with different shape parameters was examined separately to further refine the influence of shape parameters on the pumping performance.