| Rolling rotor compressor is a volumetric gas compression machine that uses working volume for rotating motion.Compressor is the core part of heat pump dryer.Its quality determines the energy consumption economy and service life of dryer.In this paper,the basic parameters of 39F0H3G rolling rotor compressor are determined by thermal calculation,and the strength checking and dynamic analysis of the compressor structure are carried out,which provides reference for product performance optimization and structural modification.Firstly,the basic principles of the overall structure design of the compressor are summarized,and the thermal parameters,volume parameters and thermal efficiency of the compressor are calculated.The performance parameters of the four refrigerants R22,R410a,R407c,and R134a were compared and analyzed.According to the safety requirements of the heat pump dryer,the R134a refrigerant was determined,and the state parameters of each cycle feature point were obtained,and the circular p-h diagram was made.The cylinder volume of the compressor is calculated and the thermal energy efficiency of the system is analyzed.Secondly,the structure and working principle of rolling rotor compressor are summarized,and the basic structural parameters are calculated.The radius of the cylinder is 20mm,the radial gap is 0.01 mm,the eccentricity is 31.6 mm,and the external diameter of the rotor is 15.8 mm.Optimize the radial position of the upper flange exhaust port and the oblique incision of the cylinder,select the exhaust port as the D-type port,and the asymmetric slide thickness is 2.5 mm.The selected crankshaft material is ductile iron QT740-3,designed with a crank pin diameter of 15mm,a spindle neck of 16.5 mm,a shaft neck length of 10mm,a crank thickness of 10.05 mm,and a width of 15.8 mm.The stress of the crankshaft is analyzed,and the minimum size of the crankshaft is 15mm,which conforms to the design requirements.Thirdly,using Solidworks software,three-dimensional drawings of parts of rolling rotor compressors are made.When drawing the model,without changing the effectiveness,the three-dimensional model is simplified as necessary,ignoring some circles and corners.Simplifying the 3D entity model is beneficial to the division of the grid in the later finite element,and the quality of the grid is improved.It can greatly simplify the computing process and improve the computing efficiency.Using the matching characteristics of the assembly ligands in the software,the parts can be easily assembled to a suitable position,and the real assembly process of the compressor can be simulated to generate the assembly effect diagram of the entire machine.Solidworks software can also complete the explosion diagram of the assembly ligand.The explosion diagram is a dynamic process of splitting a single assembly body in the assembly order.This process can also be recorded using software to form an animation for later viewing.Through computer simulation assembly,the assembly process of compressor design is clarified,the rationality of the structure design is verified,and the strong drawing function of Solidworks is used to greatly reduce the labor intensity of technicians and achieve a multiplier effect.Finally,the rolling rotor compressor and crankshaft are dynamically analyzed by Ansys software,and the modal parameters such as the natural frequency of the compressor are tested by vibration modal experimental method.The three-dimensional model of the crankshaft was established in Ansys software.Through the grid division and boundary conditions of the crankshaft,the static strength analysis of the finite element method was carried out,and the deformation and stress state of the crankshaft was analyzed.Based on the strength calculation of crankshaft in the third chapter,the results show that the strength of crankshaft meets the requirements of design and operation conditions.Based on the finite element model,the first nine free vibration modes of the crankshaft are calculated,and the mode mode and its natural frequency are analyzed.The modal frequency of the crankshaft can be used to predict the possibility of dynamic interference between the various parts of the compressor.The resonance frequency can be avoided by reasonable structural design.The optimal design of the crankshaft provides a favorable theoretical basis.The modal test experiment of the rolling rotor compressor was carried out using the modal test equipment of the compressor.The vibration test was conducted at four frequencies of 15,20,100,and 150(Hz)respectively.After testing,it was found that the compressor was operating under stable conditions.The excitation frequency value is between the first two order natural frequency values and does not cause compressor resonance.Through the finite element modal analysis of the first 6 steps of the whole machine,it is found that there is a large amplitude at the connection of the reservoir. |
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