Analysis of Vibration of Roadheader Rotary Table Based on Finite Element Method and Data from Underground Coalmine

Table 4

Modal experiment results of the rotary table.

Order	Inherent frequency (Hz)	Mode of vibration
		Arm		Shoulder		Posterior
		Direction	Amplitude	Direction	Direction	Amplitude	Direction
(1)	139.581	Lower right side and left upper side	Larger	None	Little	Downward	Small
(2)	170.601	Left (entirety); Upward (left arm); Downward (right arm)	Normal	Upward (left); Downward (right)	Small	Little	None
(3)	270.549	Outward and upward	Small	Downward	Small	Upward	Large
(4)	363.650	Right (entirety); Upward (left arm); Downward (right arm)	Right arm is larger than the downward	Downward (center section)	Small	Little	Little
(5)	414.087	outward and downward	right arm is larger than the left	downward (center)	small	downward	small
(6)	438.216	outward and downward	small	upward (center)	small	downward	larger