Tractor Transmission Research Articles

Vegetable-based Oil as UTTO Fluid for Agricultural Tractors Application

HighlightsLubricants are commonly used in agricultural activities involving machines.To reduce lubricants impact on the environment, a process has been started for replacing them with products obtained from vegetable oils.Tests have been carried out to explore the possibility of introducing vegetable-based UTTO in tractors.Results encourage to deepen the behavior of vegetable-based oils and develop specific test bench and methods.Abstract. To reduce the impact of mineral and synthesis lubricants on the environment, a process has been started for replacing them with lubricants and hydraulic fluids obtained from high-oleic vegetable oils, with good tribological properties, high biodegradability, and low toxicity. Test have been carried out at Research Center for Engineering and Agro-Food Processing of Monterotondo, Rome, Italy, with the aim of comparing the performances provided by a standard agricultural tractor supplied with conventional Universal Tractor Transmission Oil (UTTO) fluid and with a vegetable-based oil in their transmission-hydraulic system group. The research aimed at assessing differences, if any, in tractor’s performances attributable to the fluids in comparison. For a better comparison, the tests were carried out under controlled conditions, connecting the tractor, at first to a dynamometric brake used in engine and transmission tests, then to a test rig for hydraulic lifts. The results, although non generalizable, were encouraging, indicating that the tractor’s performances with the two fluids, after 30 h work cycles, were similar both for transmission and hydraulic lift. On the other hand, the reduction observed in the viscosity of the biofluid requires the deepening of the aspects related to its durability. The results also allowed to focus some basic aspects of the evaluation of biofluids and to identify some methodological approaches mainly based on the comparation of fluids performance during repeatable work cycles and on the assessment of how their physical properties evolve overtime. Keywords: Biolubricant, Engine performance, High-oleic sunflower oil, Hydraulic lift, Lifting force, Power transmission.

Wheel wear analysis of motor and unpowered car of a high-speed train

The wheel-wear characteristics of the motor and unpowered car of a high-speed train were investigated, for the first time, by a wheel-wear prediction model comprising a wheel-wear sub-model, an unpowered car dynamics sub-model, and a novel motor-car dynamics sub-model. The motor-car dynamics model considers the detailed structural characteristics and working mechanics of the traction transmission system. Assuming the real track parameters and track irregularities, it handles the nonlinear factors such as the traction characteristics, gear backlash, time-varying mesh stiffness, gear friction and wheel–rail contact. This study assessed the wheel-wear characteristics of a high-speed train by suitable performance indices (wheel-wear depth and contact patch energy). Finally, the model was validated by comparing the simulation results with those of field tests. The predicted and measured wheel wear were in good agreement. Both the wheel wear depth and contact energy were higher for the motor car than the unpowered car, because the traction torque on the wheelsets of the motor car increased the longitudinal creepage. During one re-profiling cycle, the transmission stability of the gear transmission system worsened with continuous wheel-wear. Furthermore, the proposed methods can assess the wheel wear and working status of the traction transmission system in the vehicle vibration environment of any rail vehicle.

Possibilities of modernization of wheel motor blocks of locomotives

The task of modernizing the wheel-motor blocks of locomotives with a wheel diameter of 1050 mm with asynchronous and collector traction motors is considered. As a result of the analysis, it was found that the design of the traverse suspension of the collector engines is outdated and contains wearing surfaces that are difficult to protect from contamination, while due to the limited dimensions the attempt to use a hinged suspension of the “Earring” type, the silent blocks on the axes were stuck. For drives with asynchronous motors, an increase in the rotational speed is limited by the cantilever location of the gear, at which the gear rotates and the end of the motor shaft can be turned. An engine suspension design with three spherical silent blocks, a liquid with ferromagnetic nanoparticles and a permanent magnet is proposed. It eliminates jamming of the silent blocks on the axes during transverse movements of the engine and ensures interchangeability of the wheel-motor blocks for upgraded and non-upgraded trolleys. To improve the reliability of traction transmission, it is proposed to position the gear between the rotary bearings. To reduce the wear of traction gear teeth, the design of an elastic gear wheel with chevron teeth was proposed. A patent for an invention and a patent for a utility model have been obtained for the proposed technical solutions.

Analysis of ways of increasing the energy efficiency of traction electric transmission of shunting diesel locomotive

The article is devoted to the problems of increasing the energy efficiency of traction electric transmission of a shunting diesel locomotive. In the context of rising fuel costs, to maintain the competitiveness of rail transport, the issue of energy efficiency of the traction rolling stock, which accounts for about 90% of the total consumption of hydrocarbons by rail, is quite acute. At present, a number of measures have been investigated to improve the efficiency of diesel engines of locomotives, which allows getting an increase in the efficiency at the level of 1-5%. The use of new efficient types of electromechanical transducers with static converters, in turn, also enables us to reduce fuel and lubricant consumption by a diesel locomotive. However, solving the problem of energy efficiency in traction transmission of a locomotive requires a comprehensive approach. One of such approaches is the application of new types of diesel generator sets for locomotives – free-piston combustion engines with linear generators. The application of new designs of thermal engines makes it possible to significantly extend the possible limits of increasing the efficiency of diesel traction.

Motor car–track spatial coupled dynamics model of a high-speed train with traction transmission systems

As an important component of a high-speed train motor car, the traction transmission system, which directly affects the dynamic performance and the running safety of the vehicle. The present paper establishes a comprehensive spatial coupled dynamics model of the motor car–track system. The model is based on classical vehicle–track coupled dynamics and gear dynamics theory. The coupling effects between the traction transmission subsystem and the vehicle–track system are captured by the suspension system, gear mesh, and wheel–rail interactions. Some nonlinear factors, such as the nonlinear damping characteristics, the gear time-varying mesh stiffness, and the wheel–rail contact relationship, are considered. The results of the proposed dynamics model are compared with those of experimental field tests for validation, which reveals the dynamics performance of the whole system, particularly the dynamics of the traction transmission system in vehicle-coupling vibration environments. The traction transmission exerted non-negligible effects on the wheelset vibrations and the wheel–rail interface, especially in the low-speed range. Furthermore, this dynamics model can assess the vibrational characteristics of the coupled system under the complex excitations that occur during service, such as gear cracking, wheel defects and rail local defects, particularly during the acceleration process.

Torsional vibration analysis of the gear transmission system of high-speed trains with wheel defects

The gear transmission system of a high-speed train is the key component, which delivers the traction torque from the motor to the wheelset. It couples with the vehicle system via the suspension system, gear meshing and the wheel–rail interface. The dynamic performance of the transmission system directly affects the operational reliability or even the running safety of high-speed trains. In this study, the effects of wheel polygonalisation and wheel flat on the dynamic responses of the transmission system are investigated through simulations of a novel vehicle dynamics model. This model integrates the flexible gearbox housing, the time-varying mesh stiffness and the nonlinear gear tooth backlash, and the track irregularities to obtain more realistic responses of the traction transmission systems in a vehicle vibration environment, from motors to wheelsets, under the effects of the wheel flat and polygonal wear. The field experimental tests are implemented for a vehicle running along a main high-speed railway line in China. Subsequently, the developed dynamics model is validated with good agreement between the experimental and the theoretical results. The calculated results revealed that wheel flat and wheel polygonal wear caused a high-frequency fluctuation of both the longitudinal creep force and the gear mesh force, causing a violent and complex torsional vibration of the gear transmission system. Moreover, the flexible deformation of the gearbox housing, especially its resonance due to the wheel polygonal wear, contributed to the torsional vibration of the gear transmission system.

Method for determining the parameters of an electromechanical transmission of an industrial tractor

In this paper, authors propose a method for determining the mechanical characteristics of traction electric motors and parameters of an electromechanical transmission of an industrial tractor. To ensure maximum machine performance, the developed transmission has two mechanical ranges: transport and technological. A feature of the presented scheme is the inclusion of a «ZK» type rotation mechanism (developed by the staff of Bauman MSTU G. Zaichik, M. Kreines and M. Kristi) in its composition. This mechanism is characterized by high traction in turning. The layout of industrial tractors involves placing the transmission in a cramped space inside the frame. In this regard, when developing the unit, it was required to implement its most compact design. This was achieved by using the same planetary gears to form the «ZK» rotation mechanism and for the reduced «technological» transmission range. As part of the study, traction capabilities of the tractor in each range were evaluated. In addition, an analysis was made of the influence of the design parameter of the planetary gears of the «ZK» mechanism on the operational characteristics of the machine. Depending on the design parameter, the required torques and rotational speeds of the traction electric motor rotors were obtained to ensure a given driving mode in a turn, and the time to complete a full rotation of the machine around the center of mass and the stopped side in the «transport» and «technological» transmission ranges was determined. In conclusion, an assessment was made of the influence of tractor transmission parameters on the maximum speed of maneuvers, which made it possible to determine the required power of electric machines taking into account the comfortable work of the driver-operator.

Development of a Series Hybrid Electric Aircraft Pushback Vehicle: A Case Study

The work presented in this paper is a progression to previous research which developed an overcurrent-tolerant prediction model. This paper presents some of the modelling and development techniques used for the previous research, but more emphasis is placed on the requirements of the case study; whereby an aeroplane pushback tug is converted into a series Hybrid Electric Vehicle (HEV). An iterative design process enabled the traction motor, transmission, generator and battery pack parameters to be tailored for this vehicle’s unique duty cycle. A MATLAB/Simulink model was developed to simulate the existing internal combustion engine powertrain as well as the series HEV equivalent for comparative analysis and validation purposes. The HEV design was validated by comparing the simulation results to recorded real-world data collected from the existing vehicle (torque, speeds etc.). The HEV simulations provided greater fuel savings and reduced emissions over the daily duty cycle in comparison to the existing vehicle.

Technical evolution and reliability of trolleybus’s traction transmission

Based on the analysis of the indicators of functionality and structure of the trolleybus’s traction transmission (TT), some characteristic differences havebeen established for the classification of 4 generations of drive axles (DA) structures of known world manufacturers. The calculation models andmethods for increasing the probability of a fail-safe transmission’s and DA system work, consisting of aggregates, modules, mechanisms, parts andconnections, are analyzed. A method is proposed and example is given of predicting the parametric reliability of a planetary wheel gear (PWG) in DAsystem by two criteria: fatigue strength and vibration resistance of "criteria element" – thin-walled epicycle of "weak link" – PWG

Nonlinear model predictive energy management of hydrostatic drive transmissions

In this article, we devise a nonlinear model predictive control framework for the energy management of nonhybrid hydrostatic drive transmissions. The controller determines the optimal control commands of the actuators by minimising a cost function over a receding horizon. With our approach, the velocity-tracking error is minimised while keeping the fuel economy of the system high. The hydrostatic drive transmission system studied in this article is a typical commercial work machine, that is, there is no energy storage or alternative power source in the system (a nonhybrid hydrostatic drive transmission). We evaluate success with a validated simulation model of the hydrostatic drive transmission of a municipal tractor. In our experiments, a detailed system model is used both in the system simulation and in the prediction phase of the nonlinear model predictive control. The use of a detailed model in the nonlinear model predictive control framework places our design as a benchmark for controlling nonhybrid hydrostatic drive transmissions, when compared to solutions using simplified models or computationally less intensive control methods as in earlier work by the authors. Our nonlinear model predictive control approach enables numerically robust optimisation convergence with the utilised complex nonlinear model. Above all, this is accomplished with stabilising terminal constraints and distinctive terminal cost, both based on an optimal steady-state solution. In addition, a simple method to generate initial guesses for optimisation is introduced. When compared with the performance of a controller based on quasi-static models, our results show notable improvement in velocity tracking while maintaining high fuel economy. Furthermore, our experiments demonstrate that framing energy management as a nonlinear model predictive control provides a flexible and rigorous framework for fast velocity tracking and high energy efficiency. We also compare the results with those of an industrial baseline controller.

Automatic calibration of tractor transmission controls

Automatic calibration of tractor transmission controls

Decrease of dynamic loads in mobile energy means

The increase in the productivity of machine and tractor units is possible due to the increase in operating speeds, this leads to the emergence of increased dynamic loads in the system “engine-transmission-propulsion unit-soil”, which worsens the performance of machine-tractor aggregates. To reduce fluctuations in the “engine-transmission” system, special vibration dampers are used, which installed in close proximity to the engine and protect well the transmission from uneven engine operation; however, such dampers practically do not eliminate the oscillations of external loads. Reducing dynamic loads on the transmission and the mobile power engine (MPE) is an important issue directly related to improving the performance, reliability and durability of the tractor, as well as reducing the slippage of the drive wheels. In order to reduce effectively dynamic loads on the transmission and on the MPE, it is necessary to introduce resilient damping elements closer to the sources of oscillations, namely, to the driving wheels. At the same time, the elastic-damping element should provide accumulation of vibration energy caused by external influences and have a large energy capacity. The installation of an elastic-damping element in the final link of the tractor transmission ensures a reduction in the magnitude of external influences, thereby protecting the engine and transmission from large dynamic loads, and allows one to reduce the slippage of the propellers, which has a positive effect on the traction and energy characteristics of the tractor. Traction tests of the LTP-55 tractor on a concrete road showed that the use of an elasto-damping drive makes it possible to increase the maximum tractive power from 33.5 to 35.3 kW and to reduce the slipping of propellers by 12-30%, the specific fuel consumption by 6-10%. When driving on stubble, the use of an elastic-damping drive increases the maximum tractive power from 25 to 26 kW, reduces the skidding of propellers by 10-28%, and the specific fuel consumption by 10-12.5%.

Digital simulation of physical processes in vehicles engine power units

This article studies the issues of digital simulation of physical operating processes in vehicles transmission. Simulation of dynamic processes is carried out in power transmissions at the design stage. The procedure for using the digital packages such as MATLab – Simulink and Simscape was considered for the numerical simulation of dynamic processes in mechanical systems based on the example of the theoretical calculation of K-744 tractor transmission dynamics. A digital model of K-744 tractor transmission is constructed, its calculation scheme is given, the initial characteristics are determined. A digital model of the tractor engine was created by means of the Simulink package. A nature of change in tractor engine torqueis determined by it. The calculated analysis of normal transmission frequencies is performed. Forced torsional vibrations are calculated in the tractor change gearbox generated by the vehicle engine operation. The conditions of resonance in the transmission are analyzed. The unfavorable modes of joint operation of the engine and the gearbox are determined for K-744 tractor.

Morphology Analysis of Friction Particles Generated in Tractor Transmission Oils

Abstract The aim of the study was the examination of the morphological and compositional attributes of wear particles of tested universal tractor transmission oil (UTTO) samples by means of automatic particle counter and classifier LaserNetFinesTM-C, which is an ideal tool to establish the dynamic equilibrium concentration and hence to set the alarm limits for any type of machine. Such limits can be based on wear type and particle size ranges. The samples of two UTTO (mineral oil and biodegradable fully synthetic oil) were taken from the rear gearboxes of the wheel tractor during a long-term experiment. The measurement results showed that there was faster increase in the particle wear of mineral oil in comparison to biodegradable transmission oil. Considering the increase in the percentage of particles over 20 μm, the biodegradable oil seems to be more favourable for usage. Regardless of this, it can be concluded that the biodegradable oil is equivalent to petroleum-based oils.

3D Printing Characteristics of Reverse Idle Gears for Tractor Transmissions

3D Printing Characteristics of Reverse Idle Gears for Tractor Transmissions

Determination of gas concentration in the lubricant of transmissions of energy-saturated agricultural tractors

Ensuring the trouble-free operation of the transmission during the operation of energy-saturated tractors is an important task. The reliability of its operation largely depends on the presence of gas in the lubrication system. The aim of the study is to develop a methodology for determining the quantitative content of gas in a gas-oil mixture. In the tractor transmissions, the composition of the gas-oil mixture can have different values, which are determined mainly by the geometric dimensions of the elements of the assembly units, the speed mode of operation, the temperature and the grade of the lubricant. The influence of these parameters can be determined by recording the composition of the gas-oil mixture during tests, both assembly units and transmissions in general, when mounted on a test bench or on a tractor. The choice of the method for recording the composition of a gas-oil mixture was carried out on the basis of an analysis of a number of studies in which various techniques for analyzing the composition of two-phase mixtures are given. Demonstrating the requirement of universality of the method, consisting in a uniform method of its application, both in bench and in object conditions, the most interesting is the method associated with sample sludge. The most successful points of the transmission lubrication system are suggested, from which it is most convenient to take samples, as well as those characterized by the largest content of gas in the oil. Also the most simple and informative method for determining the volumetric gas content in the mixture is proposed. Calculated dependences are derived, allowing to take into account the change in the volumetric ratio of oil to gas during the sampling time. The developed method allows to make an assessment of the required capacity of bilge pumps of forced lubrication systems. The technique can be used both for bench and for road tests.

Evaluation of the antiwear properties of transmission oil with nanoscale powder additives

Comprehensive pilot studies of the influence of one- and two-component nanodimensional powder additives on the operational properties of transmission TM-3-18 oil (GOST (State Standard) 23652-79 TAP-15V) are implemented. Introduction of nanopowder tin bronze and aluminum oxide additives into the base oil is found to increase the antifriction, antiwear, and antiwelding properties of the latter, as well as the cogwheel durability of units, which limits the service life of tractor transmission equipment.

Research of Biodegradable Fluid Impacts on Operation of Tractor Hydraulic System

Abstract This paper is focused on the impacts of the biodegradable hydraulic and transmission fluid (Universal Tractor Transmission Oil) on operation of tractor hydraulic and transmission systems. The fluid was used in the hydraulic and transmission systems of a Zetor Proxima 6321 tractor. Fluid samples were taken from the Zetor Proxima 6321 tractor at intervals of 250 engine hours. These samples were subjected to an infrared spectroscopy analysis in order to measure the total acid number and perform the ferrography analysis. This paper proves minimal impacts of the biodegradable hydraulic fluid on operation of the Zetor Proxima 6321 tractor. The biodegradable fluid meets the requirements for the operation of agricultural tractors in terms of low impacts on the wear of hydraulic components.

Efficiency Improvement of Agricultural Winch Machines

In this article the problems with the use of the common winch cart on very steep terrain planted with permanent crops are described, especially with regard to energy losses. A hypothesis is developed regarding the improved use of the potential energy that leads to the development of a new economical hydraulic machine. A transmission of the new agricultural tractor that can use the much bigger share of the effective potential energy is conceived in rough principles. A portable flatbed improves the total efficiency. A comparable analysis on very different sloped terrains is presented to argue for the greater efficiency of the new machine. The yearly fuel quantity saving by using the new hydraulic machine on the sloping terrain with realistic topography is 36 % in comparison to the winch cart. Decision limits about the minimum internal combustion engine power are discussed.

Power Distribution Control in Perspective Wheeled Tractor Transmission

The methodology of the power distribution mechanism parameters determination used as a part of 4th drawbar category tractor transmission is suggested. The kinematic scheme of the power distribution mechanism is provided, the prospects of mechanism application on the transport and transport technological wheeled vehicles are examined. A mathematical model, describing motion of the tractor with hinged frame, on the basis of Raus equation is suggested. The analysis of possible power distribution mechanism application solutions in the transmission of the tractor has been completed. The efficiency of mechanism, applied on the tractor with hinged frame is justified. The calculations, confirming reduction of hydraulic torque in the steering mechanism of the tractor with hinged frame are completed.