Research On Reciprocating Compressor Based On The Principle Of The Internal Cycloid

Reciprocating compressor is widely used in the engineering for its significant advantages such as good air tightness and high single compression ratio.However,because of the crank connecting rod mechanism was used in the reciprocating compressor’s main drive system,the inertia force of moving parts cannot be fully balanced.The inertia force can result greater vibration and noise when the compressor is running.There are some methods to solve the problem now such as to install the counterweight on the crankshaft,to arrange several crank connecting rod mechanism like 2D type,L type,H type,so that the inertial forces of the moving components can be cancelled each other out.But these methods can only partially eliminate the inertial force,not completely.In this paper,a new type of internal cycloidal reciprocating compressor is proposed by using the special properties of the internal cycloidal line.This scheme of the compressor is derived from eliminating the vibration source,the inertial force of the moving components can be fully balanced during the operation.When a small circle which radius is r,rounding in a big circle which radius is R for pure rolling,the trajectory of any point on the small circle is the internal cycloid.In special cases,when R = 2r,the trajectory of any point on the small circle becomes a reciprocating straight line,which can be used to convert the rotational motion into the reciprocating linear motion.Based on this principle,this paper study and develops a new type of reciprocating compressor,and discusses some important problems that must be considered in the compressor design,such as compressor movement scheme,structural design,thermodynamic calculations,dynamics calculations,and major component strength calculation.In the compressor movement scheme,the planetary gear train is used to achieve the trajectory of the internal cycloid,and proposed the movement scheme of the internal cycloidal mechanism.This kind of internal cycloidal mechanism does not cause the second-order inertia when it is running,but the reciprocating inertia force of piston and connecting rod still exists.In this paper,to arrange three identical cycloid mechanism in a circle,the angle between the mechanism is 120°,and to keep the same phase of synchronous motion to offset the reciprocal inertia force.According to the movement scheme,this paper presents a structural design scheme of the internal cycloidal compressor with vertical structure and dual power input,which solved the structural design problems such as how to achieve the motion function,avoid the structural interference,design the lubrication system,and assembly process problem.According to the technical parameters of the structural design,the thermodynamic analysis of the internal cycloidal reciprocating compressor was carried out,and determine the volume flow of cylinder,cylinder diameter,piston force,and the compressor power.The results of compressor dynamic performance analysis show that the inertial force of the internal cycloidal reciprocating compressor was perfectly balanced.At the end of this paper,the key components of the internal cycloidal compressor were carefully designed and checked for strength.Based on the study,because of the inertial force is fully balanced,the vibration source was eliminated in the internal cycloidal reciprocating compressor,so that the defects of the traditional reciprocating compressor can be avoided.This new type compressor has good application and market prospects.