A Method for Monitoring the Technical Condition of Large-Scale Bearing Nodes in the Bodies of Machines Operating for Extended Periods of Time

Abstract

Failure of systems applied in machines comprising rolling and slewing bearings usually causes downtime of the entire heavy machine. The problem of failures can be aggravated by extremely difficult operating conditions, such as significant loads or a harsh environment. The entire issue inspired us to develop a method of monitoring the condition of such units. A study was carried out for six different large-scale excavators which examined strain distributions in the tested subassemblies. In order to estimate the technical condition of wheeled bogies, we used the phenomenon of strain propagation caused by the concentrated force acting in the ring girder web. Flamant theory was utilized to describe this phenomenon. Measurements were performed using strain gauges and the obtained results were compared with the FEM model. To determine whether bearing joints were in a good or bad condition, a coefficient of variation and an impulse factor were introduced as diagnostic indicators. It turned out that by evaluating these indicators, it was possible to distinguish between these two conditions. The method was successfully validated on machines that are in operation.

Functional Surface Layer Strengthening and Wear Resistance Increasing of a Low Carbon Steel by Electrolytic-Plasma Processing

“…Experimentally determined optimal modes of steel hardening by the EPP method (t heating = 4 s, t cooling = 4 s, U = 200 V) have a good correlation with the established dependence, see Eq. (2).…”

“…Mechanical engineering development is largely related to solving the tasks of increasing machines' reliability. To increase the operational reliability of machines, it is necessary to increase the endurance and durability of their parts [1] and [2] and reduce the risk of their failures [3] and [4]. This is achieved by various methods, including strengthening the operating surfaces of component parts and creating new technological processes of highly wear-resistant materials manufacturing [5] to [7].…”

Strength analysis of welded joints in support structures of heavy machinery subjected to changeable loading conditions

“…The performed strain gauge measurements [41] showed deteriorated pin connections and uneven loads of the road wheels, and the observations of the interaction between the wheels and the rails showed an eccentric impact of the wheels on the rail.…”

“…Such a system should ensure even loads on the road wheels in a single set but because of friction in the pin joints of the rocker arms the load acting on individual wheels and, consequently, on the supporting components is uneven. The worse the condition of the pins, the greater the differences in the load on respective wheels [41]. Other disadvantages of this type of solution include the lack of a rocker arm between the less loaded sets.…”

Assessment of Suitability for Long-Term Operation of a Bucket Elevator: A Case Study

“…The most valuable indicators in the time domain include RMS, peak, mean, kurtosis, crest factor and impulse factor [7,9,[11][12][13][14][15][16][17][18].…”