scholarly journals The comparison of biodegradable hydraulic fluid with mineral oil on the basis of selected parameters  

2011 ◽  
Vol 57 (Special Issue) ◽  
pp. S43-S49 ◽  
Author(s):  
R. Majdan ◽  
J. Kosiba ◽  
J. Tulík ◽  
D. Kročková ◽  
V. Šinský
Keyword(s):  
Mineral Oil ◽  
Technical State ◽  
Hydraulic Fluid ◽  
Test Results ◽  
Hydraulic Systems ◽  
Operational Conditions ◽  
Two Fluids ◽  
Working Performance ◽  
Agricultural Tractors ◽  
Agricultural Tractor

The paper presents a comparison of two fluids quality. The first one was mineral oil type UTTO which is commonly used in the transmission and hydraulic systems of agricultural tractors. The second one tested was biodegradable hydraulic fluid type ERTTO which could replace the toxic mineral oil. Both fluids were tested under the same test conditions using a special test device. The selected parameters of the hydrostatic pump were evaluated. The tests were evaluated according to the parameters describing the technical state of the hydrostatic pump as follows: flow efficiency, decrease of flow efficiency and cleanliness level of the fluid tested. This additional measurement verifies the test results. On the basis of the results achieved, we can state that the biodegradable hydraulic fluid exerts no harmful influence on the technical state of the hydrostatic pump. Therefore, the biodegradable fluid tested can be applied to the agricultural tractor. Has been demonstrated that the selected parameters are suitable for the evaluation of hydraulic fluid during its working performance. Therefore, these parameters will be used in the next examination of the fluid under operational conditions of an agricultural tractor.

Adaptive steering controller using a Kalman estimator for wheel-type agricultural tractors

Robotica ◽  
2001 ◽  
Vol 19 (5) ◽  
pp. 527-533 ◽  
Author(s):  
D. Wu ◽  
Q. Zhang ◽  
J. F. Reid
Keyword(s):  
Effective Means ◽  
Adaptive Controller ◽  
Steering System ◽  
Pid Controllers ◽  
Test Results ◽  
Steering Control ◽  
Command Signals ◽  
Agricultural Tractors ◽  
Agricultural Tractor ◽  
Performance Obstacles

This paper presents an adaptive steering controller for achieving accurate and prompt steering control with noisy steering command signals and drifting valve characteristics on an automated agricultural tractor with an electrohydraulic steering system. It is difficult to accomplish performance objectives with conventional PID controllers because of the effects of disturbances and unknown factors. The adaptive controller, consisted of an adaptive gain tuner and an adaptive nonlinearity compensator, was to overcome these performance obstacles. Test results indicated that this controller provided an effective means for achieving satisfactory steering control for automated tractor traveling on changing and unpredictable farm field courses.

Hydraulic Laboratory Devices for Testing of Hydraulic Pumps

2014 ◽  
Vol 1059 ◽  
pp. 111-117
Author(s):  
Zdenko Tkáč ◽  
Ján Kosiba ◽  
Ľubomír Hujo ◽  
Daniela Uhrinová ◽  
Ivan Štulajter
Keyword(s):  
Laboratory Test ◽  
Laboratory Tests ◽  
Flow Characteristics ◽  
Hydraulic Fluid ◽  
Hydraulic Pump ◽  
Negative Effects ◽  
Operational Conditions ◽  
Pump Flow ◽  
Agricultural Tractors ◽  
Hydraulic Circuits

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.

scholarly journals Evaluation of tractor biodegradable hydraulic fluids on the basis of hydraulic pump wear

2013 ◽  
Vol 59 (No. 3) ◽  
pp. 75-82 ◽  
Author(s):  
R. Majdan ◽  
Z. Tkáč ◽  
J. Kosiba ◽  
R. Abrahám ◽  
J. Jablonický ◽  
...  
Keyword(s):  
Test Bench ◽  
Flow Characteristics ◽  
Mineral Oil ◽  
Operating Conditions ◽  
Hydraulic Fluid ◽  
Test Results ◽  
Hydraulic Pump ◽  
Cyclic Pressure ◽  
Hydraulic Fluids ◽  
Evaluation Parameters

Two types of biodegradable hydraulic fluids (HEES and HEPR) with the mineral oil-based hydraulic fluid (HV) were compared. The tests were performed using a test bench. During the tests with a tractor hydraulic pump, the fluids were loaded by a cyclic pressure load. The tests of fluids were evaluated on the basis of wear of the pump. Evaluation parameters were the flow characteristics of the pump and the cleanliness level of tested fluids. The temperature of the fluid under which the test was performed was measured in real operating conditions of the Zetor Forterra 11441 tractor. It is possible to state upon the test results that the mineral oil-based fluid was classified in the first place, the biodegradable fluid of the HEPR type in the second place, and the biodegradable fluid of the HEES type received the last position.  

A Simple Procedure for the Prediction of the Collapse Pressure of Pipelines With Narrow and Long Corrosion Defects: Uncertainty and Sensibility Analysis

2018 ◽  
Author(s):  
Nara Oliveira ◽  
Theodoro Netto
Keyword(s):  
Simple Procedure ◽  
Experimental Tests ◽  
External Pressure ◽  
Experimental Program ◽  
Small Scale ◽  
Test Results ◽  
Collapse Pressure ◽  
Operational Conditions ◽  
Sensibility Analysis ◽  
Corrosion Defects

The collapse pressure of pipelines containing corrosion defects is usually predicted by deterministic methods, either numerically or through empirical formulations. The severity of each individual corrosion defect can be determined by comparing the differential pressure during operation with the estimated collapse pressure. A simple deterministic procedure for estimating the collapse pressure of pipes with narrow and long defects has been recently proposed by Netto (2010). This formulation was based on a combined small-scale experimental program and nonlinear numerical analyses accounting for different materials and defect geometries. However, loads and resistance parameters have uncertainties which define the basic reliability problem. These uncertainties are mailyrelated to the geometric and material parameters of the pipe and the operational conditions. This paper presents additional experimental tests on corroded pipes under external pressure. The collapse pressure calculated using the equation proposed by Netto (2010) is compared with this new set of experiments and also with test results available in open literature. These results are used to estimate the equation uncertainty. Finally, a sensitivity analysis is performed to identify how geometric parameters of the defects influence the reduction of collapse pressure.

scholarly journals Development of Control System for Automated Manual Transmission of 45-kW Agricultural Tractor

2020 ◽  
Vol 10 (8) ◽  
pp. 2930 ◽  
Author(s):  
Wan-Soo Kim ◽  
Yong-Joo Kim ◽  
Yeon-Soo Kim ◽  
Seung-Yun Baek ◽  
Seung-Min Baek ◽  
...  
Keyword(s):  
Control System ◽  
High Efficiency ◽  
Position Control ◽  
Experimental Tests ◽  
Manual Transmission ◽  
Reduction Gear ◽  
Shift Control ◽  
Automated Manual Transmission ◽  
Agricultural Tractors ◽  
Agricultural Tractor

This study aims to develop and evaluate an automated manual transmission (AMT) for agricultural tractors with high efficiency and high convenience by using electric actuators. An AMT system to control manual-type shuttle gearboxes and transmissions for tractors is developed by adding a shuttle shifting actuator, a clutch actuator, and a control system to a conventional manual transmission (MT). The clutch actuator is designed using an electric motor and a reduction gear. The AMT control system is developed and experimental tests are conducted to evaluate the performance of the AMT. The results of the performance of the actuator position control demonstrate that the shuttle shifting actuator and clutch actuator are controlled appropriately, achieving a maximum overshoot of less than 5% and 0%, a settling time of less than 0.500 s and 1.50 s, and a steady-state error of less than 1% and 1%, respectively. The performance of the automatic forward and reverse control demonstrates a shift control time of less than 2.50 s and target revolutions per minute (RPM) reaching time of less than 3.00 s. Thus, AMT systems for tractors can be easily developed by applying shuttle shifting actuators, clutch actuators, and a control system to conventional manual transmissions.

Effects of Some Hydraulic Fluid Lubricants on the Fatigue Lives of Rolling Bearings

1968 ◽  
Vol 183 (16) ◽  
pp. 21-27 ◽  
Author(s):  
R. A. Hobbs ◽  
G. W. Mullett
Keyword(s):  
Ball Bearing ◽  
Fatigue Testing ◽  
Mineral Oil ◽  
Equipment Design ◽  
Hydraulic Fluid ◽  
Oil Lubrication ◽  
Rolling Bearings ◽  
Test Conditions ◽  
Hydraulic Equipment

Hydraulic equipment operating in potentially explosive or inflammable atmospheres (e.g. pumps in mines) has to use special fluids which are fire-resistant. Frequently the equipment design is such that the same fluid is used to lubricate rolling bearings. It is already known that some fluids, particularly those containing water, cause a serious reduction in the fatigue lives of the bearings. This paper describes a ball bearing rig and the test conditions under which several fire-resistant fluids were evaluated. It compares the fatigue lives obtained with the lives obtained when using mineral oil lubrication. Factors by which bearing capacities should be reduced when using these fluids are suggested. The fatigue testing of batches of bearings is time-consuming and the fluids are continually undergoing development. There is thus some difficulty in keeping up-to-date. However, the capacity factors given are indicative of the magnitudes of the effects that fire-resistant fluids can have on bearing lives.

Development of Conservative Form of RELAP5 Thermal Hydraulic Equations: Part I — Theory

2014 ◽  
Author(s):  
Zheng Fu ◽  
Fatih Aydogan ◽  
Richard J. Wagner
Keyword(s):  
Nuclear Power ◽  
Power Plants ◽  
Numerical Approximation ◽  
Numerical Approach ◽  
Phase System ◽  
Hydraulic Systems ◽  
Governing Equations ◽  
Two Phase ◽  
Current Form ◽  
Two Fluids

The design and analysis of the thermal/hydraulic systems of nuclear power plants necessitates system codes that can be used in the analysis of steady state and transient conditions. RELAP5 is one of the most commonly used system codes in nuclear organizations. RELAP5 is based on a two-fluid, non-equilibrium, non-homogeneous, hydrodynamic model for the transient simulation of the two-phase system behavior. This model includes six governing equations to describe the mass, energy, and momentum of the two fluids. The “non-conservative” numerical approximation form (which is the current form of RELAP5 code versions) is obtained through the manipulation of selected derivative terms in the equations including the linearization of the product terms in the time derivatives of the equations. For non-conservative technique, the truncation errors introduced in the linearization process can produce mass and energy errors for some classes of transients during time advancements, either resulting in (a) automatic reduction of time steps used in the advancement of the equations and increased run times or (b) the growth of unacceptably large errors in the transient results. To eliminate these difficulties, a new, optional numerical approach has been introduced in RELAP/SCDAPSIM/MOD4.0. This new option uses a more consistent set of the “conservative” numerical approximation to solve non-linearized mass and energy governing equations. The RELAP/SCDAPSIM/MOD4.0 code, being developed as part of the international SCDAP (Severe Core Damage Analysis Package) Development and Training Program (SDTP), is the first version of RELAP5 completely rewritten to FORTRAN 90/95/2000 standards. This paper provides an overview of the original RELAP5 numerical approximations and describes the new theoretical approach. Then the second article introduces the solution strategy of conservative approach and presents some examples of transient problems that have been run using this new approach.

Model Tests on Working Performance of Geogrid Reinforcement Influenced by Differential Settlement

2011 ◽  
Vol 255-260 ◽  
pp. 3376-3381 ◽  
Author(s):  
Yi Min Wang ◽  
Hao Yi ◽  
Qing Zheng Li
Keyword(s):  
Cross Section ◽  
Model Tests ◽  
Differential Settlement ◽  
Tension Stress ◽  
Vertical Deformation ◽  
Test Results ◽  
Reinforcement Effect ◽  
Geogrid Reinforcement ◽  
Working Performance ◽  
Settlement Distribution

Based on the designing scheme of highway widening project, a serial of model tests were conducted to simulate the performance of geogrid reinforced widening embankment influenced by subgrade differential settlement. Totally, 6 models including no-geogrid reinforcement embankment, geogrid reinforcement embankment, differential settlement of 0mm, 20mm, 30mm, and 50mm between existing subgrade and newly widening subgrade were built. The differential settlement distribution of embankment and stress performance of geogrid on each model were tested and analyzed. The test results show that geogrid reinforcement can effectively decrease the vertical deformation of embankment which with load on the top. The heavier the load, the more effective the decrease of vertical settlement. Meanwhile, the geogrid can significantly adjust the distribution of settlement along the cross-section direction of embankment to less differential. The geogrid at the connection area of existing embankment and newly widening embankment receives the biggest tension stress under the subgrade differential settlement. It is suggested that a solid connection between geogrid and the existing embankment is very important for getting a better geogrid reinforcement effect on decreasing the differential settlement between existing embankment and newly widening embankment.

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