Lightweight Threshing Rack under Multisource Excitation Based on Modal Optimization Method

Table 1

Working frequency of main transmission parts of combine harvester.

Working part	Rotating speed (r · min^−1)	Transmission form	Reference frequency (Hz)	Operating frequency range (Hz)
Gearbox input shaft	1068	Belt drive	17. 80	14.24∼17.80
1st gear cutting roller	790	Belt drive	13. 17	10.54∼13.17
2nd gear cutting roller	687	Belt drive	11. 45	9.16∼11.45
1st gear vertical axial flow roller	643	Gear drive	10. 72	8.578∼10.72
2nd gear vertical axial flow roller	559	Gear drive	9. 32	7.46∼9.32
Fan shaft	1206	Belt drive	20. 10	16.08∼20.10
Grain agitator shaft	820	Belt drive	13. 67	10.94∼13.67
Miscellaneous agitator shaft	1267	Chain drive	21. 12	16.9∼21.12
Vibrating screen	433	Chain drive	7. 22	5.78∼7.22
Return board	433	Chain drive	7. 22	5.78∼7.22