Ľubomír Hujo

POSSIBILITY OF HYDRAULIC FLUIDS WITH A LOW ENVIRONMENTAL IMPACT APPLICATION IN AGRICULTURE AND TRANSPORT MACHINERY

Agricultural and transport equipment is ideally suited to use hydraulic oils. After engine oils, hydraulic fluids are the second most important group of lubricants. More than 85 % of these materials are currently mineral oil-based. In view of their high ecotoxicity and low biodegradability, mineral oil-based lubricants constitute a considerable threat to the environment. In contrast, most hydraulic fluids based on plant oils have a low environmental impact and are completely biodegradable. Moreover, lubricants based on plant oils display excellent tribological properties and generally have very high viscosity indices and flash points. For this reason, therefore, particularly soybean, sunflower and rapeseed seem to possess the relevant properties as a potential hydraulic fluid. There are several tribotechnical methods how to assess the current technical state of used lubricants (viscosity, water content, flash point, acidity). One of the modern methods how to detect wear particles is LaserNet Fines, which is a suitable technique for machine condition monitoring. The ageing of test oils is analysed by the Fourier transform infrared spectroscopy (FT-IR); for determining anti-wear properties of hydraulic oils, the standard STN EN ISO 20623:2004 indicates 1 hour under an applied load of 150 N. The objective of the paper is to show the description and examples of modern tribotechnical methods used for determination of the technical state of used biolubricants utilized in agriculture and transport machinery.

RESEARCH OF NEW ECOLOGICAL SYNTHETIC OIL-BASED FLUID

This paper presents the evaluation of a newly developing synthetic-based hydraulic fluid MOL Farm UTTO Synt, developed by MOL Group, Hungary. The fluid was subjected to a laboratory test by using a gear hydrostatic pump UD 25, which is used in the latest Zetor Fortera tractors. During the test, flow values were statistically evaluated and graphically displayed in the form of flow characteristics and the loss of flow efficiency. On the basis of laboratory test results, it can be concluded that the newly developing fluid meets the specified requirements and it is possible to continue in testing under operating conditions.

RESEARCH OF LIMITED AND UNLIMITED EMISSION EFFECT ON THE ENVIRONMENT DURING THE BURNING OF ALTERNATIVE FUELS IN AGRICULTURAL TRACTORS

This work is aimed at the basic analysis of diesel oil and rapeseed methyl ester and evaluation of limited and unlimited emission produced by their combustion. Thereafter, test results are compared, and there is also done the evaluation of emission – greenhouse gases, dangerous exhaust gases and strong carcinogens and their contents during fuel combustion. These measurements were performed at the Research Station Agroscope ART in Tanikon (AAT) in Switzerland and in cooperation with the Department of Transport and Handling (DTH), Faculty of Engineering, Slovak University of Agriculture in Nitra.

EFFECT OF ECOLOGICAL ENERGY CARRIERS ON FLOW CHARACTERISTICS OF TRACTOR HYDRAULIC PUMP

This paper deals with the effect of ecological energy carrier on flow characteristics of a hydraulic pump. A hydraulic oil MOL Farm UTTO Synt was used as an ecological energy carrier. After completing 900 engine hours, the flow efficiency of the hydraulic pump decreased by Δηpr = 1.197 %. Oil samples were taken from the agricultural tractor Zetor Forterra 114 41. These samples were subjected to an IR spectroscopy analysis in an accredited laboratory WearCheck, Hungary. The following oil properties were examined: kinematic viscosity at 40 °C, viscosity index, silicium and ferrum content.

Study of the Impact of Synthetic Fluid on the Lifetime of Hydraulic Pump

This paper deals with the lifetime test of a tractor hydraulic pump. The basic indicator of hydraulic pump lifetime is flow characteristics. This paper presents the results of the performance test of ecological hydraulic fluid. These results were subjected to statistical analysis. Based on these data, it is possible to express a minimum impact of ecological hydraulic fluid on hydraulic pump lifetime. The test was carried out in cooperation between the Department of Transport and Handling (Slovak University of Agriculture in Nitra) and Slovnaft, a.s. (joint-stock company), and supported by the Scientific Grant Agency of the Ministry of Education, Science, Research and Sport of the Slovak Republic – VEGA, ref. No 1/0857/12.

Evaluation of Fuel Consumption in Road Freight Transport

Abstract This paper deals with the importance of fuel economy in road freight transport. It provides the calculation of financial savings for fuel savings of 0.5 l per 100 km. In the subsequent part, some factors that influence the fuel consumption are specified, e.g. aerodynamic resistance, rolling resistance, and tyre inflation pressure. The effect of tyre inflation pressure on fuel economy has been tested on four selected towing vehicles. Based on the results obtained, it can be stated that tyre pressure has a great impact on fuel consumption. A one-bar pressure reduction of tyres can increase the fuel consumption by 0.5 l per 100 km.

Design of Laboratory Test Device for Evaluating the Lifetime of Hydraulic Components of Tractor Three-Point Hitch

The designed laboratory device will solve the issue of test methods of tractor hydraulics, monitoring the lifetime of hydraulic components, and testing of various oil types. The results of experimental measurements of forces and pressures in the three-point hydraulic hitch of tractor with plough allow implementing the design and simulation of operational loads of the dynamic system of tractor three-point hitch (TPH) under laboratory conditions. Theoretical and experimental works were focused on tractors. The design of test device is based on load characteristics obtained from the operation of tractor with plough. Research was focused on the use of results obtained from operational measurements of the tractor with plough and their simulation by a hydrostatic simulator under laboratory conditions. The laboratory device will enable the TPH life tests while loading with forces in the horizontal and vertical direction so that it corresponds to a practical loading process

Comparison of Two Designs of Differential Planetary Gear with Differential in Output

The goal of the presented contribution is a comparison of two variants of differential mechanical planetary gearboxes. The designed variants of differential gearboxes are characterized by gear shifting under load. Reflected depending on the variable gear may be a change of gear ratios, either stepped or continuously. The results of kinematic analyses of both variants of differential planetary gearbox with differential in output are shown in tabular and graphical form

Implementation of a New Methodology of Emission Inspections in Motor Vehicles with an Advanced Emission System

Abstract This paper focuses on the implementation of a new exhaust-emission measurement system of motor vehicles equipped with a petrol engine and an advanced emission system. Our study deals with new methods of emission inspections using on-board diagnostics in order to increase the efficiency of emission inspection itself. The aim of implementing the new method of emission measurement is to eliminate vehicles that contribute to air pollution with emissions, due to an insufficient technical condition of the petrol engine fuel supply system.

Assessment of a Transport Company in Terms of Performance Utilisation of Vehicles

Abstract Our study is focused on solution opportunities of national road freight transport in a selected company in terms of performance utilisation of vehicles. The indicators of time and performance utilisation of lorries and their trailer units are used for analysing the transport company. Based on correlative assessment, it is possible to determine the effects of year-to-year performance variations of vehicles in terms of running performances, transport performances, average travel distance and average loading.