Design and Test of Electromagnetic Variable Frequency Excitation Sieve-cleaning Device of Seed Cleaner

The vibratory excitation of the sieve by the sieve-cleaning device is a fundamental reason for increasing the probability of material penetration, reducing seed clogging and effective sieve cleaning. Existing sieve-cleaning devices mostly use randomly bouncing rubber balls to clean the sieve, but the sieve-cleaning effect is easily restricted by the structure and operating parameters. In order to solve the problem that rubber balls' impact force is difficult to accurately control, an electromagnetic variable frequency excitation sieve-cleaning device was developed, the overall structure and operating principle was introduced, the excitation sieve-cleaning monomer and frequency conversion excitation control system was designed, and the vibration excitation mechanism was analysed; using acceleration as an indicator, the effects of spring pre-compression and excitation frequency on the vibration excitation law were studied, the results showed that both were positively related to the vibration excitation; sixteen sets of maize seed cleaning trials were carried out by using purity, screening efficiency, screening time and number of clogging seeds as indicators. The results showed that the sieve-cleaning device had a good operating effect when the spring pre-compression was 2 mm, the operating frequency was 3. 5 Hz and the sieve cleaning frequency was 50 Hz, with seed purity of 99. 1%, screening efficiency of 88.6%, screening time of 70 s, and clogging seed of 0. By setting the operating frequency and the sieve cleaning frequency in stages, the sieve-cleaning device could be precisely adjusted to meet the requirements of normal sieving and strong vibration sieve cleaning under different operating conditions. The research could provide reference for the development of intelligent sieve-cleaning equipment. © 2023 Chinese Society of Agricultural Machinery. All rights reserved.