International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

The driving factor is an important technical feature of dynamical loaded working machines. It is especially important to know its value for the working wheel speed reducer of the rotating excavators. In this paper is presented a concept for determining the driving factor of a concrete gearbox speed reducer. To calculate the value of the driving factor according to the specified concept, knowledge of the load regime and the carrying capacity of the gearbox is necessary. The load regime is known from the load function, which is given in the paper, and is determined on the basis of the experimental measurements carried out for this purpose. The carrying capacity of the speed reducer is calculated by theoretical analysis according to the established methodology in this paper, for the characteristic pairs of gears determined in this analysis. As the most important gear pair, from the aspect of determining the driving factor, the most loaded gear pair is taken, in which during the exploitation of the speed reducer the most interventions are made, compared to the other gear pairs of the gearbox.

This paper presents a model for determining the static load on movable spatial console lattice girder and the clamps which bounded the same one. The paper presents guidelines for theoretical determination of the static load using an appropriate software package and conducted modeling for this purpose. Also, the paper displays the methodology for experimental determining the static load by setting a model for the experimental measurement on the specific measuring points of the clams and the characteristic positions of the carrying console. The research is carried out on a concrete real object and the results are shown numerically and graphically, which enables carrying out an analysis of the load and deducing concreting conclusions about the research object.

The dynamic intensity in growth of the number of motor vehicles, and with that the high quantity of exhaust emissions, significantly contributes the air contamination and other serious problems with his quality, especially in urban places. Today, the total number of vehicles globally exceeds 800 million; from witch 300 million are loading freight vehicles. These numbers are disturbing, and the concern is that the constant growth of these vehicles and the consumption of the fossil fuels will continue to raise the negative effects on the environment through the air contamination and to cause serious health problems. In this document is given the analyses for the quality of exhaust emission of diesel engines, identification of the factors which have dominant affect, actual situation about pollution from diesel engines and conclusions about future use of diesel engines vehicles, especially in the countries which are not member of EU.

This paper investigations detail analysis of the influence the type of construction and the way of fixing seat bearers on basic bus construction and its superstructure. Before performing experimental investigations it was modeling of tension-deformation condition of across frame made by using Finite Element Methods. During experimental investigations on basis of this analysis it was founded three measuring points where deformations were measuring. According results from experimental investigations it was third type of seat bearers allowing raise of safety area of bus passenger’s.

This paper presents the directions for load and safety appreciation of carrying structures component elements and their application to a particular object respectively carrying structure of rotating excavator working wheel. Load and safety of the carrying structure and its component elements are estimated based on the calculation of load and safety factors. The estimated load is based on the calculated value of load factors, while the safety by comparison of the calculated safety factors to the values of recommended minimum safety factors obtained by examinations of such structures in practice. With these indicators we have a situation where we are providing the static strength control of the analyzed elements. The paper presents numerical values of the load and safety coefficients for the excavator SRs-630 working in the coalmine "Suvodol" Bitola, for all characteristic working regimes in its exploitation lifetime. The numerical values of load and safety coefficients relate to clamps of the working wheel carrying structure and the most loaded joint of this structure.

The gearboxes (reducing gears) built in the rotating excavators used at surface coal mines, are exposed to dynamic loads which are frequently unpredictable (stochastic) given the exploitation conditions. These gearboxes are very frequently oversized by the manufacturer. Nevertheless, the possibility of impact loads due to unpredictable working resistances the excavators run up against, can reduce the safety of the gearbox, even to the extent of breakdown of some of the constituent elements in given period till the planned overhaul. This paper presents the methodology for assessing the safety (reliability) of most unreliable gear in specific gearbox, being ascertained by the maintenance experience of the gearbox. Concerning this gearbox, the load function has been established based on experimental investigations, being presented in this paper. Regarding the most unreliable gear, the carrying capacity function has been established by means of theoretical research being displayed in the comparative diagram together with the load function. This comparative diagram helps to infer the safety of the most unreliable gear in the gearbox, i.e. the safety of the gearbox as a whole. The loading on the gearbox is a variable course of the rotating moment with the driven shaft depending on the time span during the total exploitation life of the gearbox. The carrying capacity of the gearbox is equal to the permissible temporally constant rotating moment acting on the driven shaft within a time span encompassing a number of changes in the loading on the driving shaft. The presented methodology can be applied to investigate the safety of other similar gearboxes.