Nonlinear Vibration Feature Recognition Method for Reciprocating Compressor Cylinder Based on VMD-Multifractal Spectrum

Table 1

Experimental system and structure size parameter table.

Inner diameter of cylinder block	5.08 cm
Compressor flow	0.07 m^3/s
Operation period	0.078 s
Piston ring radial early thickness	3 mm
Lubrication form	Oil free
Acceleration sensor	DH1A110E
Sampling frequency	12800 Hz
Stroke	3.81 cm
Outlet pressure	0.8 MPa
Piston ring material	PTFE
Piston ring radial end thickness	2.8 mm
Motor speed	1420 r/min
Sensitivity	5.088 mV/(m/s^2)
Sampling time	1.28 s