TRIZ-aided innovative design of potato-soil separating and conveying device for potato harvester

Aiming at the problems of insufficient separation of potato and soil as well as high injury rate of potato in potato-soil separating and conveying device for potato harvester,an innovative design of potato-soil separating and conveying device assisted by TRIZ theory was carried out.Based on the analysis of systematic function,the functional defects of the potato-soil separating and conveying device were identified.A set of TRIZ tools including su-field model,technical contradiction,and physical contradiction were applied to seek innovative solutions.A potato-soil separating and conveying device with a double jitter unit and downwardmotion jitter screen surface was designed.Through the mechanical analysis of the mixture of potato,soil and vine on the conveying screen surface,the angle range of tilt of sieve surface was defined to beβ≤32°．Combined with theoretical analysis and production practice,the angle of first-order ascending sieve surface was 20°while the second-order one was 16°,and the angle of descending sieve surface was 10°．The amplitude of jittering unit was 21mm,the spacing of separating sieve rod was 50mm,and the effective conveying lengths of sieve surfaces of each stage were 450mm,600mm,1 000mm and 100mm respectively.Via the kinematic analysis and comparison of the jitter screen surface including ascending as well as descending separation screen,the rationality of the innovative scheme was verified.