Truck Transmission Research Articles

РАЗРАБОТКА СПЕЧЕННОГО ФРИКЦИОННОГО МАТЕРИАЛА ДЛЯ ГИДРОТРАНСФОРМАТОРА ГМП САМОСВАЛОВ БЕЛАЗ

The torque converter is designed to transmit mechanical energy from the engine through a circulating fluid flow and automatically steplessly changes, within certain limits, the angular speed and transmitted torque depending on the load on the dump truck wheels. The torque converter makes it possible to achieve low speeds of the dump truck with increased traction on the drive wheels, ensures stable engine operation when the load changes, and also helps reduce dynamic loads in the dump truck transmission. The paper presents the results of a study of the effect of iron-chromium alloy powder ПХ30 (PKh30) on increasing the performance properties of sintered friction material for use in the torque converter locking clutch of a hydromechanical transmission. This is achieved due to the high physical and mechanical properties of PKh30, and the Cr23C6 layer formed during the sintering process with a thickness of up to 6 μm. It is established that the introduction of 10–40 vol.% of PKh30 powder helps to increase the friction coefficient from 0.042 to 0.075, with the maximum content being 28 %. Based on the data obtained, the composition of the composite friction material ФМ-15 (FM-15) was developed and patented. The manufactured friction discs, installed and operated in the hydromechanical transmission torque converter of the BELAZ-7555E mining dump truck with a load capacity of 60 tons, showed high performance properties. The developed composition of the friction material is also used in the friction clutches of the loading and hauling machine MoAZ-40751 with a load capacity of 16 tons and the loading and transport mine machine MoAZ-75851 with a load capacity of 50 tons with an electronic-hydraulic automatic control system. The study of tribological properties was carried out on a friction machine ИМ 58 (IM 58). The morphology of the friction surface was studied on a scanning electron microscope MIRA (Czech Republic) with an INCA 350 micro-X-ray spectral attachment from Oxford Instruments (United Kingdom). Phase composition was determined on an Ultima IV X-ray diffractometer of Rigaku Company (Japan) in CuKα radiation at an X-ray tube voltage of 40 kV, anode current of 40 mA.

A digital twin-driven approach for partial domain fault diagnosis of rotating machinery

Artificial intelligence (AI)-driven fault diagnosis methods are crucial for ensuring rotating machinery's safety and effective operation. The success of most current methods relies on the assumption that sufficient high-quality labeled datasets can be obtained for model training. However, in real-world industrial scenarios, obtaining such datasets is difficult or nearly impossible, thereby hindering the practical implementation of these methods. The integration of virtual modeling and transfer learning offers a powerful approach to meet the above challenge. Abundant virtual data of different fault categories can be acquired in the virtual space with highly flexible and at a low cost, and transfer learning can enhance the practical utility of these virtual data for contributing to the construction of diagnosis models. Therefore, this paper proposes a digital twin-driven partial domain fault diagnosis method based on unlabeled physical data and labeled virtual data. First, a virtual model of rotating machinery is built to generate labeled virtual fault data with enough fault types. Then, an adversarial transfer learning network is developed to leverage the effective knowledge from the virtual and physical data. Meanwhile, a weighting learning module is introduced to reduce the negative effect caused by the redundant fault categories in the virtual space. Finally, the proposed digital twin-driven transfer learning network is trained with the labeled virtual data and unlabeled physical data. Experiments on a light truck transmission system demonstrate that the proposed method achieves satisfactory diagnostic performance even without labeled physical fault data, contributing to the advancement of AI engineering applications.

Research of thermal load in an energy efficient mechatronic truck transmission considering energy losses

The article examines the heating of a truck’s energy efficient mechatronic transmission during operation of an electric motor in maximum power mode. Particular attention is paid to the process of modeling conjugate heat transfer and its impact on the energy efficiency of mechatronic transmission. To solve this problem, computational fluid dynamics (CFD) methods are used, in particular the finite volume method (FVM), which allows for an accurate assessment of heat flows between different environments inside the transmission. Analysis of thermodynamic processes occurring in mechatronic transmission is of great importance for optimizing its operation and increasing reliability. The simulation results demonstrate the influence of various factors, such as driving speed, loads and temperature conditions, on the efficiency of heat exchange and, as a result, on the energy efficiency of the entire vehicle. These research contribute to the development of more efficient cooling systems and improved performance of trucks.

Technology Focus: Artificial Lift (October 2023)

Buying a vehicle can be a daunting experience. Sometimes you wish you could refer to a guide of what has worked out well for users of certain models over time and under various operating conditions. Paper SPE 213059 does this by correlating past testing of downhole centrifugal separators and adding a machine-learning twist. Once you’re about to make your selection at the car dealership, you may notice that the fine print states “mileage may vary” and wonder why that’s the case. Paper OTC 32398 explains how and why electrical submersible pumps (ESPs) are unable to perform as effectively when pumping viscous fluids by creating nondimensional models and validating them with field data. Paper SPE 214043 shows that frictional losses during plunger lifting can create a gap between actual and predicted performance. Even if you succeed in making a no-regrets purchasing decision, the day may arrive when financial, operational, or reliability considerations encourage changing vehicles and perhaps downsizing. Paper SPE 213089 describes an artificial lift selection tool for unconventional reservoirs driven by reduced-physics models that can help identify when the time is right for change. Paper SPE 213975 extols the value of gas lift downsizing by optimizing the selection and placement of Venturi, orifice, and dummy valves to spur production uplift. If you happen to have an emotional attachment to a vehicle, it can be difficult to let it go. But maybe you don’t have to; maybe you could repurpose that vehicle. Plenty of pump jacks in the history of the oil field have made use of truck transmissions instead of a standard gearbox. Paper SPE 214361 explains how ESPs could become electrical submersible generators to produce power in conjunction with injection or disposal operations. Then again, it may just be easier and less stressful to look up some bus schedules. Recommended additional reading at OnePetro: www.onepetro.org. SPE 213059 Application of Machine Learning To Evaluate the Performances of Various Downhole Centrifugal Separator Types in Oil and Gas Production Systems by Laura Camila Osorio Ojeda, University of Oklahoma, et al. OTC 32398 Relative Viscosity Model for Water-in-Oil Emulsion in Electrical Submersible Pumps: Comparing the ESP Head in a Real Scenario by Natan Augusto Vieira Bulgarelli, Unicamp, et al. SPE 214043 A Mathematical Modeling of the Plunger Lift Considering Effects of Fluid Friction and Plunger Travel Velocity by Saurabh Rajvanshi, Oil and Natural Gas Corporation, et al.

Performance degradation assessment for mechanical system based on semi-analytical solution of self-similar stable distribution process

To more accurately predict remaining useful life (RUL) and quantitatively evaluate the uncertainty of the predicted results, a performance degradation assessment framework based on semi-analytical solution of self-similar stable distribution process is proposed. The established performance degradation model based on adaptive fractional Lévy stable motion (AFLSM) is more flexible in revealing the long-range dependence, non-Gaussian, and heavy-tailed distribution properties of the incremental behavior. The corresponding stable distribution parameters are estimated through characteristic function method, and Hurst exponent is calculated based on the generalized Hurst exponent approach with narrower confidence interval. Aiming at the difficulties in solving the exact analytical solution and the excessive computation of the numerical solution in the whole process, based on Mellin-Stieltjes transform and direct integration, a semi-analytical solution of RUL distribution function is proposed, which can be readily implemented in practical equipment operations. The proposed performance degradation assessment framework is validated by the novel truck transmission dataset and the benchmark rolling bearing dataset. Experimental results indicate that the developed framework is more effective and superior than other state-of-the-art approaches in terms of RUL prediction.

Determination of the number of speeds of a mechatronic transmission of a road car based on a typical specified driving mode

The article discusses the problem of determining the rational number of gears for a mechatronic transmission of a truck vehicle. A review of the designs of existing mechatronic transmissions from leading manufacturers of motor vehicles was carried out, with an emphasis on analyzing the number of gears used in them. A method has been developed for determining the rational number of gears based on simulation modeling of the movement of a truck along driving cycles, synthesized on the basis of statistical data on the movement of trucks across the territory of the Russian Federation. A synthesized driving cycle and a simulation model of truck movement, designed to determine the loads on the electromechanical transmission when moving along this cycle, are considered. Based on the results of simulation modeling of the movement of a truck with a different number of gears in a mechatronic transmission, conclusions about the influence of multi-speed transmissions on the energy efficiency of electric truck vehicle were drawn. Conclusions have been formulated about the required number of gears for mechatronic transmissions of trucks moving on the roads of the Russian Federation.

Method for applying vehicle driving cycles to assess the durability of electromechanical transmissions of trucks

The article discusses the relevance of the problem of calculating the elements of electromechanical transmissions of trucks for strength and durability. The main methods used for the formation of load conditions on electromechanical transmissions of trucks are given. The driving cycles of trucks used to obtain loads when calculating the durability of the elements of electromechanical transmissions are given. The universal driving cycles of vehicles obtained on the basis of the collection of statistical data on the movement of trucks are considered. A simulation model of the movement of a truck used to determine the loads on the electromechanical transmission while overcoming driving cycles of trucks is presented. The durability of the gears of the electromechanical transmission of a truck is analyzed on the basis of load cyclograms obtained during simulation modeling of movement. Numerical results of the safety factors of one of the gear stages are obtained. Conclusions are drawn about the optimality of the use of existing driving cycles of trucks in strength calculations. Conclusions are worded about the need to synthesize driving cycles of trucks based on the collection of statistical data on the movement of truck vehicles on the territory of the region under consideration.

Automatic gear shift strategy for manual transmission of mine truck based on Bi-LSTM network

As mine trucks face severe and changeable driving conditions in mining area, it is important to formulate a general automatic gear shift strategy for reducing the intensity and difficulty of the work. Therefore, gear shift strategy performs a significant role in automatic transmission studies. However, it is difficult to devise an automatic shift strategy due to the fact that it relies on tremendous historical experiment data which is the highest classified commercial secret of the automobile manufacture. Since the artificial neural network can build self-learning model by inputting multiple parameters, adjusting weights and automatically outputting results, many automatic gear shift strategy studies are reported based on it. However, the gear shift prediction accuracy by traditional neural network is limited due to the non-existence of feedback connection, lacking of associative memory function and missing implicit connection between continuous data. Hence, this paper proposes a novel method based on Bi-directional Long Short-Term Memory (Bi-LSTM) network, which controls gear shifting with nine parameters and updates the traditional mine truck transmission system from manual to automatic. Truck status data while manual driving are captured through the Controller Area Network-bus (CAN-bus) and converted to the proper sequence data format. Some sequence data are used to train the Bi-LSTM network for gear prediction, while the rest is used for verification. In order to evaluate the proposed machine learning model performance, it is compared with the Back Propagation Neural Network (BPNN), Recurrent Neural Network (RNN) and Long-Short Term Memory (LSTM) networks with two and nine parameters, respectively. The experimental results demonstrate that machine learning networks with nine parameters reach higher gear shifting prediction accuracy than those with dual-parameter, except BPNN. In addition, the highest prediction accuracy is 95.8 %, which is achieved by the Bi-LSTM network with nine parameters. This proves that Bi-LSTM network outperforms the traditional neural networks, such as BPNN with 81.5 %, and other recurrent neural networks, such as RNN and LSTM with 87 % and 91.5 %, respectively. As for the average time consumption, the Bi-LSTM network spends 1.86 ms per prediction calculation which is longer than LSTM and RNN respectively having 1.58 ms and 1.06 ms. Thus, it still fits the requirement of real-time processing on mine truck industry. In general, the Bi-LSTM network shows its advantage in processing sequential data within limited time, and has the potential to be widely applied in the field of prediction based on data with temporal characteristic.

Modernization of electromechanical transmission for dump trucks based on long-term operation data

In open pit mining, overburden and mineral haulage is carried out mostly by dump trucks. The number of high-capacity machines persistently grows. Such dump trucks mainly use electromechanical transmission systems. As a rule, dump trucks operate all day and all year round, with idle time for scheduled maintenance. The climatic service conditions assume variations in temperature, humidity and atmospheric pressure in wide ranges during a year, moreover, these physical quantities can fluctuate violently within a short time, for instance, within a day. The road conditions – road grade, hardness, roughness, length, altitude difference – differ greatly per open pit mines. Furthermore, air dustiness, including current-conducting coal- or metal-bearing dust should be taken into account. On the whole, these numerous and diverse factors are impossible to embrace in full at the stages of machine engineering and testing. Thus, during operation, it is necessary to accumulate and analyze the hand-on experience, and to improve all components of electromechanical transmission. This article gives data on four-year operation of BelAZ dump trucks with capacity of 90 and 240 t equipped with electromechanical transmission in open pit coal and ore mines. The traction electrical equipment faults are generalized, their causes are revealed, design modifications are described, as well as the processes of manufacturing and testing and the algorithm of diagnosis are reported. The low count of faults during operation and the high availability factor of the dump trucks equipped with electromechanical transmissions manufactured by RUSELPROM is reflective of the proficiency and competency of the machine engineering, design and testing. The modifications introduced into the electromechanical transmissions are mostly aimed at cost reduction and performance buildup, i.e. at competitive recovery of the product. The obtained results are used in engineering of traction electric equipment set for dump trucks of higher capacity (136, 180, 360 t).

Fuel saving potential of a long haul heavy duty vehicle equipped with an electrical variable transmission

The series–parallel architecture is the most interesting for hybrid electric vehicles, allowing the lowest fuel consumption. Unlike passenger cars, this architecture is not commercially available on the heavy-duty vehicles market. This is due to technical limitations associated with unsufficient load capability of the geartrain. To address this issue, new transmissions, such as the electrical variable transmission, have been developed. The novelty of this paper relies on the hybridization of a long-haul truck using the electrical variable transmission. This study aims to investigate the potential of using this new transmission for trucks. For that aim, fuel consumption benchmarking of three powertrain topologies is performed, considering: (a) a gearless topology; (b) a geared topology that uses one gearbox inserted between the engine and the mechanical input port of the electrical variable transmission; (c) a geared topology similar to the second one, but, with an additional multi-stage gearbox inserted to the mechanical output port of the electrical variable transmission. For a fair comparison between the different topologies, a bi-level optimization process has been used, incorporating the optimization of both components sizing and control. Results show that the fuel consumption of the gearless powertrain is higher than the engine-powered truck due to higher losses in the electrical variable transmission. While maximum fuel reduction of 14.2% was obtained by a geared topology that uses two gearboxes. Furthermore, emphasis is given to understand the effect of the powertrain component sizing on fuel consumption. Depending on the defined sizing, a possible fuel reduction is achieved from 3.3% to 14.2% for the two geared topologies. The reduction of CO2 emissions is found to be proportional to the fuel savings. Considering a long-haul mission, the last findings prove that the electrical variable transmission exhibits potential to reduce fuel consumption, if an adequate powertrain topology and its sizing are well defined.

Hydromechanical Transmissions of Heavy-Duty Trucks

Hydromechanical Transmissions of Heavy-Duty Trucks

Optimal Clutch Pressure Control in Shifting Process of Automatic Transmission for Heavy-Duty Mining Trucks

The optimal control of automatic transmission plays an important role in the shifting smoothness and fuel economy of heavy-duty mining trucks. In this paper, a dynamic model of the powertrain system is built to study the clutch pressure control during the shifting process. A linear-quadratic optimal regulator is used to achieve the optimum control pressure of clutches, where shifting jerk and clutch friction loss are chosen to a form quadratic performance index function. Besides, a detailed solution of the linear-quadratic problem with the disturbance matrix in the state equations is provided. This paper also carries out a software simulation and verification of the normal condition (no load without slope) and the extreme condition (full load with maximum slope). Compared with the preset reference trajectory control, the simulation results show that the proposed optimal clutch pressure control can effectively reduce jerk and friction loss during the shifting process and has good robustness to different operating conditions.

Single vs. multi-cone synchronizers with carbon friction lining\u2014a\xa0comparison of load limits and deterioration behavior

Synchronizers are widely used in gear boxes of car and truck transmissions. Optimizing costs and improving the efficiency of gear boxes require knowledge about the relative load limits of single and multi-cone synchronizers with carbon friction linings and their corresponding deterioration mechanisms. Load limits for single and multi-cone synchronizers with carbon friction lining used in cars were determined experimentally using the component test rig SSP-180 and compared against each other. Different load stages were run in life cycle tests and the influences of pressure, sliding velocity, friction work, frictional power and oil temperature were investigated. The synchronizers’ failure mode is described and the novel specific value μmin,grad is introduced that is able to quantify the deterioration of different synchronizer systems. During life cycle tests at the same specific load level, the single cone synchronizers, contrary to expectations, displayed greater damage compared to the multi-cone synchronizers. Calculations of the friction surface temperature in thermo-mechanical simulations, in combination with experiments on the test rig, show that the maximum temperature during the engagement has a significant influence on deterioration and endurance life of synchronizers with carbon friction lining.

Research into truck transmission torsion vibrations under longitudinal acceleration

The development of a modern motor vehicle is aimed at improving the performance in the field of dynamics (both longitudinal and lateral), economy, safety and ergonomic characteristics. Special attention is paid to passenger comfort. Torsional oscillations in transmission cause longitudinal vibrations of the vehicle, depending on inertial parameters, as well as on stiffness and damping of the transmission. Taking into account the complexity of the problem, it is estimated that it is useful to analyse the impact of the transmission design parameters on the longitudinal (fore and aft) vibrations of freight motor vehicle. For this purpose, the dynamic simulation method was used, and the analysis of the influence of certain constructive parameters on the longitudinal oscillations of the vehicle was performed using the sensitivity function.

Studying truck transmission oils using the method of thermal-oxidative stability during vehicle operation

Development of technical maintenance of transport means consists in providing their technical state at a significant level of functional operability for which the use of quality lubricants is a key requirement. Therefore, determination of technical state of truck transmission oils by the method of thermal-oxidative stability during their operation is an urgent problem.This problem was solved and technical state of the transmission oil was studied on the basis of operational tasks and the results of their chemotologic studies. These results can be used in development of a system of vehicle maintenance and when substantiating feasibility of using concrete oil grades during operation. A procedure for studying, determining state and compliance of the working oils by their thermal-oxidative stability with operating conditions during vehicle operation has been developed. State of transmission oils was studied during vehicle operation in gearboxes of KamAZ 6520 and MAN TGA 6×4 trucks. The study of working transmission oils was conducted at following parameters: light transmission, evaporability, viscosity. The results of studies of light transmission through an oil sample and evaporability after application of the temperature regimes used in testing working oils were used in graphical and analytical representation of the coefficient of thermal-oxidative stability. Variation of the coefficient of thermal-oxidative stability of oils of respective grades depending on their relative viscosity was determined. Analysis of the obtained functions will enable development of recommendations on conformity of working oils to the conditions of their operation.It was found that the Tedex Gear GL-4 80W90 transmission oil, used in MAN TGA 6×4 trucks, corresponds by its thermal-oxidative stability characteristics to the operating conditions. At the same time, the study of use of YUKO TО-4 80W-85 transmission oil in KamAZ 6520 trucks has shown that the oil did not demonstrate its functional capacity at runs of 8‒30 and 45 thousand kilometers. This was confirmed by analysis of the mathematical model of variation of thermal-oxidative stability of oils depending on relative viscosity, namely, by overshoot of some numerical values of the function beyond the level of 0.85 un. for the vehicle runs under study.It was established that the study data can be applied to substantiation of further operation and selection of transmission oils for the studied vehicle models in transportation activities of the enterprise

Optimal control of a novel uninterrupted multi-speed transmission for hybrid electric mining trucks

Considering the energy consumption and specific performance requirements of mining trucks, a novel uninterrupted multi-speed transmission is proposed in this paper, which is composed of a power-split device, and a three-speed lay-shaft transmission with a traction motor. The power-split device is adapted to enhance the efficiency of the engine by adjusting the gear ratio continuously. The three-speed lay-shaft transmission is designed based on the efficiency map of traction motor to guarantee the drivability. The combination of the power-split device and three-speed lay-shaft transmission can realize uninterrupted gear shifting with the proposed shift strategy, which benefits from the proposed adjunct function by adequately compensating the torque hole. The detailed dynamic models of the system are built to verify the effectiveness of the proposed shift strategy. To evaluate the maximum fuel efficiency that the proposed uninterrupted multi-speed transmission could achieve, dynamic programming is implemented as the baseline. Due to the “dimension curse” of dynamic programming, a real-time control strategy is designed, which can significantly improve the computing efficiency. The simulation results demonstrate that the proposed uninterrupted multi-speed transmission with dynamic programming and real-time control strategy can improve fuel efficiency by 11.63% and 8.51% compared with conventional automated manual transmission system, respectively.

Development of a multistage gearbox for a new generation of heavy-duty trucks

The design of a multistage transmission for heavy trucks (patent No. 2508486) designed to implement the national program of import substitution in transport engineering in Russia. The main technical results implemented in the design of multi-stage gearbox.

Modular heavy duty truck transmission

The design of a modular gearbox for heavy trucks, which consists of a differential divider, a main gearbox and a differential demultiplicator with an integrated rear gear is described. The proposed design has smaller dimensions, weight and inertial masses of rotating parts, has greater rigidity and speed of the gear shifting process.A vehicle equipped with this transmission will make better use of the engine power and save fuel, which will increase its competitiveness in the market.

Classification and synthesis of three-loop planetary gearboxes

In the transmissions of trucks, agricultural vehicles and tractors, gear boxes with a planetary divider and/or an additional reductor unit which is depending on the traffic conditions of the machine, reduces the speed of rotation or operates on a direct drive are used. The divider and the additional reductor unit are intended for a stepwise changing of the range of the main 3-speed or 4-speed gearbox, consisting of gears with fixed axles, which makes it possible to increase the number of stages realized 4 times. If the planetary train will work in the differential mode, this will allow additionally increase the number of stages in the combined planetary gearboxes and, accordingly, the number of operating modes of the tractor. Consequently, the main gearbox consists of gears with fixed axes of gears can work either separately in a single-flow mode of operation of the planetary train (reductor or in the direct drive mode) or in a two-flow mode - in parallel with other ordinary gears when the planetary train as a differential. When using two planetary trains operating in the differential mode, the number of parallel power flows increases to three, which makes it possible to further improve the functional and power capabilities of multi-flow gearboxes. The purpose of the study is to analyze gearbox schemes consisting of three sets of gears with fixed gearwheel axes and two differential mechanisms forming three parallel power transmission flows. Classification of possible structural schemes of three-flow transmissions is given, a general expression for calculating the number of stages of a three-flow gearbox is obtained. A technique for the synthesis of kinematic schemes of three-flow planetary gearboxes is described, with the using of which new gearbox schemes are obtained for each possible structure, which are characterized by using simple mechanisms, high efficiency and a small number of control elements.

Increasing the Tracks Efficiency by Using Energy-Saving Oils in Transmission and Engine

A method for improving the efficiency of construction machinery and vehicles by using the energy-saving engine and transmission oils is proposed. Developed additives give to oils the energy-saving properties. The results of oils tests in engines and transmissions of trucks are given. It is shown the modified oils using reduces the fuel by 7.2% - 8.3%, the efficiency of the transmission increases to 12%.