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This article describes the testing of oil filters on a laboratory test device designed to monitor changes in oil filter flow and pressure, depending on the level of engine oil contamination. The laboratory test device enables testing the suitability of using filters with different filtering capabilities, even with differently polluted engine oil. The measurement results can be used in the design of new filter materials, or in the design of changing replacement intervals, which would mean a benefit from an economic as well as an ecological point of view.

The article presented describes a new design of measuring chains in laboratory test equipment, which are used for testing the hydrostatic transducers and hydraulic fluids. Laboratory test equipment allows simultaneous observation of parameters of hydrostatic transducers and hydraulic fluids by simulating the operating conditions under laboratory conditions, what can significantly reduce the testing time and economic costs. The new design functionality was verified via measurement of the basic parameters of hydrostatic transducers and changing the load of hydraulic fluids. Based on the results measured, the flow efficiency of tested hydrostatic transducer UD-25R was calculated and compared with the transducer parameters specified by the manufacturer using different types of operating hydraulic fluids. Verification measurements of the unloaded hydrostatic transducer were performed at various rotation speeds: Q 250 = 5.694 dm3·rpm at speed of n 1 = 250 rpm; Q 500 = 12.286 dm3·rpm at speed of n 2 = 500 rpm; Q 750 = 18.747 dm3·rpm at speed of n 3 = 750 rpm. Based on the hydrostatic transducer flow rate, the UD-25R transducer flow efficiency was determined: at n 1 = 250 rpm, the flow efficiency was η250 = 0.8946; at n 2 = 500 rpm, the efficiency was η500 = 0.9651; at n 3 = 750 rpm, the flow efficiency was η750 = 0.9812.

Paper presented is focused on the operating measurements of a tractor wet disc brake system. Operating measurements were evaluated after tractor’s operation at 500 Mth on the 3rd, 4th and 5th gear. Reference fluid and ecological fluid were tested during operation. In addition, work results include the evaluation of the fluid samples taken during the operational tests to monitor the tractor braking performance with wet disc brakes. Fluid samples were also tested in order to determine the changes in their physico-chemical properties. Chemical analysis was performed for both oil samples by means of X-ray fluorescence analysis according to the DIN 51829 and DIN 51399-2. Observed physical properties of the tested oils – density, viscosity, acid number, water content – were within the appropriate ranges after the end of test. Further analysis was focused on an amount of abrasive metals, contaminants, additives, and other important elements. On the basis of analyses conducted, it can be concluded that majority of elements preserved their original level showed at the 0 reference hour sample. In terms of the abrasion metals, an increase in their presence was not found. Furthermore, analysis of the physical properties of tested fluids did not prove their negative impact on the tractor wet disc brake system. Results of the operating measurements suggest that neither the applied conference fluid nor the ecological fluid showed negative effect on the minimum braking value. The minimum braking deceleration was implemented in accordance with the Law no. 106/2018.

By simulating the operating conditions, it is possible to verify and evaluate the technical properties of motor vehicle oil filters and the functionality of the designed equipment. Contaminated engine oil from operation was used with MANN W950/26 oil filter and a CNH Industrial 2992242 oil filter in the test circuit. Before use, the level of engine oil contamination in the test circuit was determined by evaluating the physicochemical properties. The laboratory test equipment also allows monitoring the technical life of oil filters, with variously contaminated engine oil, with the possibility of extending engine oil change service intervals depending on changes in the physicochemical properties of engine oil and filter efficiency. These laboratory tests can be performed in parallel in two hydraulic circuits, which can significantly reduce the testing time of the filter capabilities of oil filters, without the risk of engine damage, provided that the tests were performed under operating conditions. The results of the evaluation of the filtration capacity of oil filters can be used in the design of new filter materials, but also with a suitably determined methodology of oil filter replacement and engine oil change interval, it is possible to extend replacement intervals, which has a significant benefit not only from an economic but also ecological point of view. The result of the measurements is the confirmation of the functionality of the device with the possibility of simulating the operating conditions, at different degrees of oil contamination, at different operating temperatures and using different oil filters.

This article focuses on the properties of ecological energy carriers, which are used in agricultural and forestry technology. The aim of the article is to describe the degradation of the working fluid from the point of view of the atomic emission spectrometer, which is used for the purpose of monitoring contaminants and additive elements. The working fluid examined was Shell Naturelle HF-E 46, a universal ecological transmission–hydraulic fluid, which was tested on laboratory test equipment. The laboratory measurement was performed for 200 h, during which the gear hydraulic pump with external gearing was cyclically loaded according to the Vickers standard. The analysis of the transmission–hydraulic fluid was performed after every 50 working hours, where the analysis of the working fluid showed that there were no significant changes in the properties of the working fluid and fluid is suitable for work in agricultural and forestry machines operating in environmentally sensitive environments.

The presented article deals with the design of equipment for measuring and testing hydrostatic transducers. The presented design of the device is used for measuring and testing hydrostatic transducers in laboratory conditions, especially hydraulic pumps. This shortens the testing time, with a reduction in economic costs for testing the elements of the hydraulic circuit or testing the properties of pumps and hydraulic fluids. By simulating the operating conditions occurring in practice, it is possible to verify and evaluate the parameters of mobile energy means used in hydraulic mechanisms. The designed laboratory equipment is used for measuring and testing hydrostatic transducers and properties of hydraulic fluids. A verification measurement of the flow of the hydrostatic transducer was performed on the proposed laboratory equipment. The output of the measurements is a confirmation of the functionality of the designed equipment. The results of the verification measurement were compared with the data obtained during the simulations in the computer program FluidSIM 5. The output of the measurements is a confirmation of the functionality of the designed equipment. When comparing the results of the verification measurement of the flow on the laboratory equipment with the data given by the manufacturer of the transducer, we recorded a decrease in flow of 5.1% at a speed of 250 rpm in comparison. At 500 rpm we recorded an increase in flow of 2.38% and at 750 rpm there was an increase of 4.15% compared to the data from the manufacturer. The results of the verification measurements were also compared with the simulation in the computer program FluidSIM 5. The flow data obtained by the simulation showed higher values than in the verification measurement. Specifically, at 250 rpm it was an increase of 3.21%, at 500 rpm by 0.39%, and at 750 rpm by 3.14%.

The article deals with the evaluation of new universal gear hydraulic biodegradable fluid MOL Farm UTTO Synt by the accelerated durability test under laboratory conditions. The operational properties of the fluid were evaluated based on its influence on the technical state of the hydrostatic pump UD 25 during the test, specifically the flow rate and flow efficiency. From the physic-chemical properties was evaluated the viscosity of the fluid, additive depletion and contamination. The viscosity, flow rate and efficiency did not exceed the manufacturer's specifications, but the level of contamination was higher. Nevertheless, the liquid shows good performance for use, as well as FT-IR spectroscopy, where no change was observed due to temperature effects on liquids and additive degradation and depletion.

The aim of the presented article is to verify the automatic and manual operating mode of the proposed measuring device for loading the external circuit of the working hydraulics of the tractor in the simulation program FluidSim. Before starting the simulation, it is necessary to select the individual parameters of the tested hydrogenerator UD 20, which is specified by the manufacturer, and to create a simulation model of this device according to the design. The device allows measurements to be made in automated mode by means of an electro-hydraulic proportional valve and in manual mode by means of a throttle valve. In the simulations in both operating modes, the flow rates at increasing speeds and constant pressures from the simulations were compared with the data provided by the hydrogenerator manufacturer. By comparing the data, it is possible to see negligible percentage differences, which are caused by the increasing temperature of the working fluid and the internal resistance of the hydrostatic transducer and filter. From these findings it follows that the proposed electromechanical device meets all the specified requirements and during real operational tests of the tractor hydraulics, its function will be correct.

This work describes the results of changes in physical properties of transmission-hydraulic fluid during simulation of operating load of FHD 17 under laboratory conditions, while monitoring the effect of quality changes of the used fluid on the flow efficiency of the hydraulic pump. Aforementioned hydraulic pump is used in hydraulic system of agricultural machine. Laboratory testing equipment allows us to simulate the operational load of the working circuit of the agriculturemachine’s hydraulic system with the possibility of testing the operating fluids andthe main elements of the hydraulic system. Hydraulic pump flow rate changes were monitored at precisely determined intervals and the influence of the physical properties of the fluid on the flow efficiency was rewieved and consequently evaluated by mathematical – statistical analysis.

The goal of this paper is the verification measurement of the proposed laboratory testing device for operation monitoring and assessment of both the hydraulic circuit components and the energy carrier used. The goal is to test the operation of a proposed hydraulic circuit within the range of selected working pressures, flows and working fluid temperatures using the QHD-17R tractor hydraulic pump, which is used in hydraulic drive systems of agricultural and forestry tractors. By the verification measurement, we proved that the proposed laboratory testing device is suitable for testing hydraulic circuit components, as well as, potentially, for testing and monitoring the changes in physical properties of hydraulic fluids.

This paper deals with a methodology for measuring and evaluating the static characteristics of control valves, with specifying a recommended measurement chain. This method enables measuring and evaluating the dependence of pressure drop on flow and flow coefficients depending on the type of fluid, temperature and viscosity also if the measurements were made at a different temperature and viscosity. This method extends of the possibility of using of these characteristics in the design work on hydraulic components in various areas of operation.

Hujo Ľ., Tkac Z., Tulik J., Kosiba J., Uhrinova D., Janosova M. (2016): Monitoring of operation loading of three-point linkage during ploughing. Res. Agr. Eng., 62: 24–29. The research was focused on operational measurements of tractor plough tools and their subsequent utilisation and simulation under laboratory conditions by a hydrostatic simulator. In this field, theoretical and experimental works were focused on tractors, whereby the proposal of laboratory test arose out of the loading characteristics of the three-point linkage of the tractor. These characteristics were obtained from the agricultural tractor’s operation in plough aggregation. Measurements were performed with the following tools: tractor with carrier-mounted four-mouldboard plough PH1-435 and tractor with Kuhn plough manufactured by. The subject of these measurements was to obtain the time courses of forces and pressures in the hydraulic system of the three-point linkage during ploughing with carrier-mounted and semi-mounted ploughs. For objective comparison of the obtained results during experimental measurements, we determined the characteristics of measurement conditions focused on physical and mechanical properties of the soil – bulk density, moisture, penetrometer resistance and slide strength of the soil.

Hydraulic pumps are the most important components of hydraulic circuits in agricultural tractors. Their durability is influenced by flow characteristics and thus the flow efficiency. This paper presents the laboratory test of an ecological synthetic hydraulic fluid of UTTO type. This fluid is currently under development. In terms of a decrease in hydraulic pump flow efficiency, laboratory tests of these fluids did not show negative effects of its application. It can be stated that after completion of laboratory tests, it will be needed to continue with trials under operational conditions.

In this paper, there are monitored and compared the parameters of tractor three-point hitch control. Comparisons were carried out under laboratory conditions for two types of regulation. The first one was a standard mechanical and the second one was electro-hydraulic Bosch. Testing was performed on a test bench designed for the Department of Transport and Handling (Slovak University of Agriculture in Nitra). The results of measurements are evaluated statistically and shown in a graphical form.

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.

The present contribution deals with solves problem of research of testing device to monitor of hydrostatic pumps durability about dynamic loading under laboratory conditions. When carrying out the design of testing device are based on load characteristics of tractor hydraulic circuit, the individual characteristics of hydraulic components and performed calculations. Load characteristics on the tractors CASE IH Magnum 310, JOHN DEERE 8100, ZETOR FORTERRA 114 41 and Fendt 926 Vario were measured. Design of a hydraulic laboratory device is based on the need for testing new types of hydraulic pumps or various types of hydraulic fluids. When creating of hydraulic device we focused on testing hydraulic pumps used in agricultural and forestry tractors. Proportional pressure control valve is an active member of the hydraulic device, which provides change of a continuous control signal into relative pressure of operating fluid. The advantage of a designed hydraulic system is possibility of simulation of dynamic operating loading, which is obtained by measurement under real conditions, and thereby creates laboratory conditions as close to real conditions as possible. The laboratory device is constructed at the Department of Transport and Handling, Faculty of Engineering, Slovak University of Agriculture in Nitra.

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.

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

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

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.

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.

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.

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.

Kosiba J., Tka Z., Hujo Ľ., Stanik B., Stulajter I., 2013. Th e operation of agricultural tractor with universal ecological oil