Structural Design And Analysis Of The Novel Spherical Engine

Spherical engine is a new type of motor which has high specific power, and the piston is not in plane motion. Combining with the characteristics of the rotary piston engine and cam engine, using the spherical transfer the movement characteristics of spherical cam mechanism, converting the piston reciprocating swing in one plane to single rotation in another plane, in this way to get power. The power transmission mechanism is the spherical cam. The pair of pistons is nested inside the cam, all parts are in the spherical shell, the engine is compact with simple structure and its operation without crank shaft and differential, thus it has high specific power. This paper design the structure of the spherical engine, makes analysis to the kinematics of the engine rotor and the piston, the cam meshing movement and rotor dynamics.(1) Structural plan design. This paper design the overall structure of the engine, choose the cam mechanism with lock structure shape, select the trigonometric function as the motion of the cam, propose the design method of the determination of spherical cam profiles and also the basic working principle of the engine are analyzed, such as the dynamics analysis and freedom analysis. Finally, the basic parameters of the engine are selected.(2) Analysis of kinetic characteristics. The kinematics model of rotor and piston of spherical engine is set up, so the displacement and velocity and acceleration of the piston are calculated; By changing the piston oscillation amplitude and geometric parameters of the rotor, kinematics parameters are analysis so as to do parameter optimization design. According to kinematics analysis, piston work process and compression ratio and cylinder capacity and cylinder pressure are analysed, the appropriate main parameters of the engine are evaluated.(3) Meshing analysis of spherical cam mechanism. Based on envelope theory and differential geometry, a general expression for the surface geometry of spherical cams with a meshing follower is presented. The contact line and pressure angle are calculated. By the use of numerical count software Matlab, the spherical cam profile and pressure angle are obtained; The curvature and axode and toothed wheel are established, one method for generating the machine setting for spherical cams is investigated.(4) Dynamics analysis. According to the theory of relative motion and the dynamic-static method, while the law of motion is known, dynamical equation of spherical engine in space motion in the non inertial systems is established. The inertial force and cue inertial force of the rotor in the non inertial systems are get. By establishing space force balance and moment balance equations of the rotor, the pressure in the cylinder and reaction force in the contact surface is get, so as to optimize the parameters of the engine. Preliminarily, the gas thermodynamic equation of the engine is established.(5) Statics Dynamics. Using software RecudDyn, the virtual prototype model of spherical engine is set up. According to the dynamic simulation, the curves of movement of the piston and the reaction force between follower and cam is get. The results of theoretical calculation and simulation are compared and analysed, simulation results show the validity of the analysis.