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

Table 2

First six modal modes of the rotary table.

Order	Inherent frequency (Hz)	Mode of vibration
		Arm		Shoulder		Posterior
		Direction	Amplitude	Direction	Amplitude	Direction	Amplitude
(1)	152.399	Outward and upward	Large	None	Little	Downward	Small
(2)	166.591	Left (entirety); Upward (left arm); Downward (right arm)	Medium	Upward (left); Downward (right)	Small	Little	None
(3)	251.626	Outward and upward	Small	Downward	Small	Upward	Large
(4)	311.365	Right (entirety); Upward (left arm); Downward (right arm)	Largest in right	Downward (center section)	Small	Little	Little
(5)	321.16	Outward and downward	Right arm is larger than the left	Downward (center)	Small	Downward	Small
(6)	470.726	Outward and downward	Small	Upward (center)	Small	Downward	Larger