Vibration Analysis And Structure Optimization Of Compression Device For All-in-one Machine Of Combine Harvester And Baler

The annual output of crop straw in China is close to 7 million tons,but the comprehensive utilization rate of straw is only 33%.Usually,the straw is burned in the field,and the smoke produced by the straw will stay in the air for a long time,which will seriously affect the air quality.Therefore,it is urgent to improve the comprehensive utilization rate of straw.According the structure characteristics of WODE DC50 C wheeled combined harvester,a kind of all-in-one machine of combine harvester and baler is designed,which breaks through the traditional docking method of traditional harvester and binding device,and has the advantages of good field pass and small turning radius.In addition,due to the structure of combined machine is complex,many working parts and transmission parts,working in harsh environment,the vibration and noise of the whole machine is very obvious,and the compressing device as the core components of the combined machine,when the natural frequency and the excitation frequency is near,prone to the influence of the resonance,affecting the whole machine reliability and driver comfort,therefore,study on vibration characteristics of all-in-one machine of combine harvester and baler and compression device is necessary.The main contents of this paper are as follows:(1)The structure and working principle of the combined machine were described and analyzed,on the whole configuration,transmission system,feeding device,a compression device and other key components of structure design and parameter calculation,and the connect of combined harvester and bundling device was three speed transmission device,feeding device adopted a crank connecting rod fork mechanism,compression the device adopted the heart crank slider mechanism.The working frequency of the feeding device and compression device was 93r/min,and the kinematics simulation mechanism of crank connecting rod fork indicated that straw can be conveyed smoothly.The combined machine compared with traditional traction type strapping machine,smaller turning radius,the field through better.(2)To achieve the changing rules of the signal in time domain and frequency,testing the vibration level of the 7 measurement points of the combined machine,focusing on the compression device vibration analysis and vibration test results show that the compression device may have inherent resonance.Therefore,the compression device for the modal analysis got the first 6 modal frequencies and the corresponding vibration type compression device by finite element simulation.The results show that the first order natural frequency of the compression device is close to the vibration frequency of the vibration sieve,and the three and four order natural frequencies of the compression device are close to the excitation frequency of the engine.(3)The compression device of combined machine is carried out experimental modal analysis by PCB exciting hammer,acceleration sensor,dynamic signal acquisition instrument and modal analysis system.The first 6 modal parameters of the compression device are obtained by the parameter identification and signal analysis,and the accuracy of the finite element simulation of the compression device is verified compared with the finite element calculation results.Finally,based on the finite element model of the compression device,the structural optimization is carried out to change the natural frequency of the compression device,and the optimized model is verified by finite element method.The optimization results show that the natural frequency of the optimized compression device avoids the excitation frequency,and the feasibility of the optimization scheme is verified.(4)The field performance test of combined machine is carried out.Using regular bale rate as the evaluation index,the under feeding device can convey the straw efficiently,and the compression device has good compression effect.The bale bundling rate?regular bale rate?anti-bundling rate?bale density?bale sectional dimension?pure work hour productivity were up to the design requirements.The work of the prototype is well coordinated,the structure design and parameter selection are reasonable,and the performance indexes of the whole machine can meet the needs of production.