Improving the reliability of auxiliary machines of electric locomotives based on the use of vibration diagnostics data

Abstract

The article is devoted to the actual study of the array of vibration parameters of auxiliary machines of freight electric locomotives VL-85, obtained during the input vibration control by multi-channel equipment of vibration measuring units developed at the Irkutsk State Transport University. The measurements were carried out at the repair locomotive depot «Nizhneudinskoe» before the entrance of electric locomotives for current and medium repairs. Statistical processing of the data array of more than 1 300 vibration measurements of motor fans of electric locomotives VL-85 was carried out. It is established that the vibration level of most motor fans significantly exceeds the maximum permissible according to the existing State Standard ISO–10816-3-2002. The array is divided into zones of reliability by vibration velocity. It is proved that the probability distribution density of the root-mean-square values of vibration velocity and vibration acceleration obeys the lognormal law. The parameters of this law (mathematical expectation, standard deviation) are calculated. The analysis data showed that more than 50% of motor fans need repair according to the existing standards of permissible vibration. An algorithm is proposed for step-by-step reduction of vibration and increase in the inter-repair mileage of motor fans by temporarily reducing the regulatory requirements for permissible vibration, ensuring uniform loading of repair production and, at the same time, strict compliance with the requirements of the state standard for the permissible root-mean-square value of vibration velocity at the repair exit. Improving the quality of repairs is possible with a more complete use of the possibilities of input and output vibration control of bearings, balancing of the rotor, control of the windings of the fan electric motor and its external magnetic field. Numerical simulation of the proposed algorithm for reducing the vibration of the array of serviced motor fans during their repair by improving its quality was carried out, taking into account the uneven rate of wear (vibration increase) during operation of motor fans, which was adopted as obeying the normal law of probability distribution. It is determined that the degree of repair services loading will be uneven, but within acceptable limits. It is also established that after three years of repair according to the adopted algorithm, the mathematical expectation of vibration velocity will decrease to a standard level value of 2,5 mm/s. The number of motor fans exceeding the maximum permissible level of 4,5 mm/s will be within 40–45 motor fans, which will ensure uniform loading of repair production. Thus, the results of numerical simulation of the proposed algorithm for reducing vibration and increasing the inter-repair mileage of motor fans confirmed its feasibility and effectiveness.