Experimental investigation of the abnormal vibration of the electric locomotive

This paper presents the results of a detailed experimental investigation of the abnormal vibration of the electric locomotive. A locomotive suffered from serious vibration problem was chosen for the test and its normal operations kept unchanged during the test. The wheel out-of-roundness (OOR) and vibrations of key components including the axle box, the bogie frame and the car body were measured before and after wheel re-profiling. The measured OOR results indicate that the wheels exhibit the OOR with orders 12 to 22 before re-profiling, i.e. with the center wavelengths of 200-315 mm in 1/3 octave bands. The wheel polygonal wear cannot be absolutely removed by the wheel re-profiling. The 16th-19th order OOR becomes to be dominant after re-profiling. The vibration test results show that the axle box, the bogie frame and the car body vibrate with the same dominant frequency before re-profiling. The dominant frequency of the vibration is approximately equal to the passing frequency of a polygonal wheel. The vibrations are significantly reduced after re-profiling. The wheel polygonal wear is the root cause of the abnormal vibration.