Variable-displacement piston driving mechanism and design method

Abstract

The invention provides a variable-displacement piston driving mechanism and a design method. The variable-displacement piston driving mechanism comprises a machine body, a main shaft, a swash plate mounting seat, a swash plate, a swash plate adjusting mechanism, a piston and air cylinder assembly, and the like, wherein through the swash plate adjusting mechanism, the rotation of the main shaft isconverted into the three-dimensional swing of the swash plate around the center of a motion pair connected between the swash plate and the swash plate mounting seat; through a connecting rod, the piston and air cylinder assembly is driven to complete a thermotechnical cycle; meanwhile, the oblique angle of the swash plate is adjusted by the variable-displacement piston driving mechanism accordingto the position of the swash plate, so that the working volume of an air cylinder can be changed, as well as the distance from the top dead center of a piston to the top of the air cylinder and the distance from the bottom dead center of the piston to the top of the air cylinder can accord with the compression ratio of the thermotechnical cycle; and through the scheme, the working volume of the piston and that of the air cylinder can be dynamically adjusted, the piston and air cylinder matching condition can be improved, and the mechanical efficiency of a system can be improved.

Description

[0001] This application is a divisional application for a patent application filed with the Chinese Patent Office on July 27, 2016, with the application number 201610597375.X, titled "Adjustable Swashplate Type Crankshaftless Variable Displacement Engine". Technical field [0002] The invention relates to the technical field of engines, in particular to a variable displacement piston driving mechanism and a design method. Background technique [0003] In modern automobiles, shipping and various power equipment, connecting rod crankshaft engines are the most widely used. [0004] 1. The traditional crankshaft connecting rod engine is subject to a fixed crank radius and piston stroke. The engine can only reach the best working condition under fixed working conditions. [0005] For gasoline engines: it must be near the best air-fuel ratio to ensure good ignition performance, combustion efficiency, and minimum pollution emissions; at the same time, the combustion characteristics of gasol...

AI Technical Summary

Problems solved by technology

The radial force on the piston will cause the friction force of the piston and cylinder, which will reduce the mechanical efficiency of the system; it will also cause the deformation of the piston and cylinder, reduce the air tightness of the piston and cylinder combination, and put forward higher requirements for the material and technology of the cylinder and piston; the diameter of the piston Transmitting the shock to the entire engine will also form lateral vibration

In addition, when the working pressure of the cylinder is the highest, since the crank and the connecting rod are almost 180 degrees, the torque output is relatively small.

[0008] 3. The cylinder bore stroke ratio of the traditional crankshaft piston engine remains unchanged, and the engine adaptability is poor

Due to the fixed bore-to-stroke ratio, once the design parameters are set, the optimal working condition of the engine cannot be adjusted, so that the engine design can only be made according to the requirements of key working conditions

[0009] 4. The crank length of a traditional crankshaft piston engine = piston stroke / 2, a larger piston stroke will inevitably require a larger crank length, and a larger crank length will inevitably require a larger crankcase

The valve control camshaft is different from the crankshaft, which requires a complex transmission coordination structure, resulting in a large volume and complex structure of the crankshaft and valve control system, which increases the volume, weight and cost of the engine

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