| Until now,engine has been developed for 100 years.During the time,many different types of engine were invented,such as reciprocating piston engine and Wankel triangle rotor-engine.etc.In these engine,traditional reciprocating piston engine is the most successful and widely used.Although its technologies are mature,there are also some intrinsic defects: low power density,complicated valve mechanism.etc.However,as energy crisis and air pollution emerge in recent years,it is required that future engines should be designed more light-weight,high power density and high efficiency.This is the reason why twin rotor piston engine has become a new research focus.The power transmission mechanism of the novel twin rotor piston engine studied in this paper is based on a combined mechanism of wobble plate and cam.Its structure is simple and completely symmetrical,well balanced.In the constraint of it,the engine works many times while the output shaft finishes one revolution.Therefore,the power density is enhanced in a big scale while keeping the size and weight of engine nearly unchanged,which has a broad application prospect.This paper studied the key part of this engine—power transmission mechanism,and the main contents are as follow:(1)The whole structure scheme of the Novel twin rotor piston engine are designed,the structure and work principle of the power cylinder and differential drive mechanism are analyzed.Then the characteristics of power transmission of this engine in 4-stroke circle are analyzed,and the implementation of its seal system and initial design of lubricating and cooling system are introduced.(2)The kinematics model of the differential drive mechanism is established using Euler kinematical equations.At first,the rotational characteristic among the wobble plate,cam and output shaft is figured out,the motion law of the wobble plate is deduced and the motion law between the two rotors is therefore obtained,then the mutual influence between the parameters of rotors and differential drive mechanism are studied.Secondly,based on the kinematics model,the developing changes of the theoretical profile of the cam are researched,the developing model of the theoretical profile is established with the volume change law of the rotors is set.This proves that as a power transmission mechanism on a engine,it has the potential of the capacity adapting different combustion.(3)The mesh surface of cam while meshing is figured out and analyzed using envelop surface theory and coordinate transformation.The main curvatures,main direction and induced curvature of the cam and roller are calculated and their curvature interference is analyzed.Then the pressure angles of cam and roller are studied,the meshing transmission performance of them is analyzed,which offers the theoretical reference in design and manufacture of differential drive mechanism.(4)The dynamics model of the Novel twin rotor piston engine is established using Dalembert Principle and Euler's dynamics equation.The force conditions of the key components are analyzed.As the pressure changing of working substance in the cylinder simulated using Zero-dimensional combustion model is known,the dynamics model is imported into the software MATLAB and simulated,then the values of the key forces and torques are obtained and their variations are analyzed.(5)According to the making of the test system of a certain engine,a test platform fitting the Novel twin rotor piston engine is built,and the prototype model is introduced.The key parameters of the Novel twin rotor piston engine are calculated and theoretically analyzed,this is the important theoretical base and design guidelines for the experiment of engineering sample in the next phase. |
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