Torque Transmission Research Articles

Research on the calculation and evaluation method of transmission efficiency of noncircular planetary gear

The torque fluctuation characteristics of noncircular planetary gear (NPG) systems are difficult to obtain, and there is no clear analysis method and evaluation method for transmission efficiency, which seriously affects their service performance. Given that, this article establishes a torque fluctuation model for NPG systems based on the principle of gear meshing and differential geometry theory and methods, taking into account factors such as actual working conditions and speed loads. And proposed, the comprehensive transmission rate, a new method for evaluating the efficiency of NPG systems. By analyzing the actual working conditions of NPG systems, the influence mechanism of alternating load and speed on torque fluctuation and transmission efficiency was explored. The research results indicate that the alternating load can cause an increase in system impact and vibration. The comprehensive transmission rate of NPG systems decreases with increasing rotational speed and increases with increasing load, and is more sensitive to changes in rotational speed. The trend of comprehensive transmission rate and transmission efficiency of NPG systems is basically consistent, indicating that the proposed method of using comprehensive transmission rate to evaluate transmission efficiency is a practical and feasible analysis method. The research results can provide a new method for dynamic measurement and evaluation of torque and transmission efficiency of non-circular gear transmission systems.

Liquid Vortex Formation in a Swirling Container Considering Fractional Time Derivative of Caputo

This paper applies fractional calculus to a practical example in fluid mechanics, illustrating its impact beyond traditional integer order calculus. We focus on the classic problem of a rigid body rotating within a uniformly rotating container, which generates a liquid vortex from an undisturbed initial state. Our aim is to compare the time evolutions of the physical system in fractional and integer order models by examining the torque transmission from the rotating body to the surrounding liquid. This is achieved through closed-form, time-developing solutions expressed in terms of Mittag–Leffler and Bessel functions. Analysis reveals that the rotational velocity and, consequently, the vortex structure of the liquid are influenced by three distinct time zones that differ between integer and noninteger models. Anomalous diffusion, favoring noninteger fractions, dominates at early times but gradually gives way to the integer derivative model behavior as time progresses through a transitional regime. Our derived vortex formula clearly demonstrates how the liquid vortex is regulated in time for each considered fractional model.

Online adaptive identification of clutch torque transmissibility for the drivability consistency of high-performance production vehicles

Drivability in vehicles with a wet-type dual-clutch transmission (DCT) relies heavily on the precise torque transfer control of the clutch to efficiently distribute the engine torque to the wheels. However, the large variation in the clutch torque transmissibility caused by temperature and wear and the lack of torque sensors for the driveline in production vehicles are the two significant challenges that hinder accurate clutch control in wet DCT vehicles. Therefore, knowledge regarding clutch torque transmissibility is crucial for realizing the demanded clutch torque because it can help determine the required clutch pressure. Thus, in this study, an online adaptive identification algorithm for clutch torque characteristics is developed for high-performance vehicles with wet-type DCTs. The proposed algorithm estimates each clutch torque characteristic using the extended Kalman filter (EKF) based on a parameterizable model for the torque transmissibility curve, making it applicable to production vehicles. Further, the algorithm incorporates an adaptation law based on the Lyapunov stability theorem to compensate for uncertainties in the engine torque, thereby ensuring a robust identification performance regardless of the installed engine type. The estimation performance and effectiveness of the adaptive identification algorithm are experimentally validated using test vehicles with wet DCT.

Development of Quasi-Passive Back-Support Exoskeleton with Compact Variable Gravity Compensation Module and Bio-Inspired Hip Joint Mechanism.

The back support exoskeletons have garnered significant attention to alleviate musculoskeletal injuries, prevalent in industrial settings. In this paper, we propose AeBS, a quasi-passive back-support exoskeleton developed to provide variable assistive torque across the entire range of hip joint motion, for tasks with frequent load changes. AeBS can adjust the assistive torque levels while minimizing energy for the torque variation without constraining the range of motion of the hip joint. To match the requisite assistance levels for back support, a compact variable gravity compensation module with reinforced elastic elements is applied to AeBS. Additionally, we devised a bio-inspired hip joint mechanism that mimics the configuration of the human hip axis to ensure the free body motion of the wearer, significantly affecting assistive torque transmission and wearing comfort. Benchtop testing showed that AeBS has a variable assistive torque range of 5.81 Nm (ranging from 1.23 to 7.04 Nm) across a targeted hip flexion range of 135°. Furthermore, a questionnaire survey revealed that the bio-inspired hip joint mechanism effectively facilitates the transmission of the intended assistive torque while enhancing wearer comfort.

Study on the Speed Control and Heat Dissipation Performance of Cone-tube Permanent Magnet Governor

The speed regulation range, output torque, and heat dissipation performance are important performance indicators of permanent magnet speed regulators. Enhancing the speed regulation range and output torque, and reducing the heat generation power are of significant importance for expanding the application range of permanent magnet speed regulators. To address the issues of a single adjustment process, insufficient heat dissipation space, and inadequate torque transmission capability of the traditional straight-barrel permanent magnet speed regulator, a cone-barrel permanent magnet speed regulator with a magnetic rotor assembly structure was designed through the analysis of the structure and transmission characteristics of the traditional straight-barrel permanent magnet speed regulator. Using the ANSYS Maxwell finite element analysis software, the output torque characteristics of the cone-barrel structure were studied. Considering the effect of eddy current heating, a conjugate heat transfer model for the permanent magnet speed regulator was developed, and the heat dissipation performance of the cone-barrel structure was explored through ANSYS Fluent simulation analysis. The results indicate that compared to the traditional straight-barrel permanent magnet speed regulator, the cone-barrel regulator can provide greater output torque when fully coupled; at maximum power consumption, the air velocity over the surface of the cone-barrel permanent magnet speed regulator conductor is higher, resulting in better heat dissipation and thus a lower operating temperature.

Experimental measurement of a multi-pole magnetorheological fluid clutch under air cooling.

Thermal characteristics have a profound effect on the allowable slip power and torque transmission stability of magnetorheological (MR) fluid devices. This paper investigates the thermal properties of a multi-pole MR clutch under different heat dissipation methods. First, the structure of the clutch is described, and heat generation and heat dissipation of the designed clutch are studied theoretically. Then, a numerical model is established, and several simulations are conducted on steady-state and transient temperatures under various operation conditions. After that, a temperature testing platform for the MR clutch is built, and several temperature experiments are carried out. The results show that the allowable steady-state slip power of the clutch under natural air cooling is about 147W. Under forced air cooling, the allowable steady-state slip powers are 1.295, 1.555, and 1.790 kW, respectively, when the wind speeds are 3.5, 7.0, and 10.5m/s. Furthermore, it turned out that the transmission torque of the MR clutch decreases with the increase in temperature. The experimental and simulated values of temperature are in good agreement in terms of numerical values and trends, indicating that the established temperature field simulation model can better reflect the temperature characteristics of the actual operation of the proposed multi-pole MR clutch. This research achievement can provide support for research on heat dissipation technology for MR devices with multiple excitation sources.

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.

Devising a technique for measuring torque of electric motors using machine vision

The object of research is the technique for measuring torques of electric motors. The main problem to be solved is the need to expand the range of informative parameters used in transmission torque converters of electric motors. This need arises from the design complications of placing the measuring devices directly on the motor shaft. As part of the study, a system was designed for determining the torques of electric motors, which combines the procedure for assessing the load on the shaft and software tools for visually determining the quantitative characteristics of such a load using machine vision. In order to acquire visual characteristics of the twisting of the shaft, a special coupling with an insert containing a liquid was designed. This coupling is able to change its shape in proportion to the load on electric motor shaft. The proposed visual control system, based on video information processing techniques, makes it possible to analyze changes in the shape of the coupling caused by the action of the torque. Features of the application of the proposed measurement technique are that there is no need to place electronic components of the measuring transducer directly on the shaft. Due to the specified features, the proposed procedure provides a solution to the problems of torque measurement in aggressive environments, which is of crucial importance for the efficiency of some specific production processes. Analysis of the visual characteristics of torque showed that the proposed approach could be applied in measuring transducers. At the same time, the results of testing the procedure confirmed that it requires the use of high-precision video recording equipment. This paves the way for the design of new, more modern, and reliable measurement systems that could be used in a wide range of industrial solutions

Driving torque model of the bionic soft arm’s hyperelastic bellows

ABSTRACT The technology of soft continuum robots represents an advance in the field of robotics to benefit a wide range of industries such as healthcare, manufacturing or environmental exploration. Soft continuum robots can be driven pneumatically by bellows as the soft continuum manipulator presented in this article. A driving torque model of the bellows considering hyperelastic material properties, friction and restoring torques is derived, whose purpose is suitability for model-based control design and subsequent trajectory generation. Hence, the driving torque model must be real-time capable. This is realized by an iterative algorithm calculating the bellows’ torque transmission by assuming a two-dimensional no-slip membrane contact. Nonlinear strain behaviours and hysteresis effects of the bellows are considered by the Ogden material model. The driving torque model’s performance is validated experimentally by measuring the external torques of the bellows.

Automotive wheel torque control systems

The approaches of foreign specialists to improving electronic control systems for the dynamic state of vehicles (traction, directional stability, rollover resistance) to improve their safe operation are analyzed. The three main components of the Active Transmission Torque Management (ADTM) system are considered: the center clutch, the electronic limited slip differential (ELSD), and the torque vectoring system. The possibilities and limitations of using active torque control systems to ensure vehicle safety are shown. Keywords: electronic control, vehicle dynamics, wheel torque, torque vectoring, active safety. alexey.scherbin@nami.ru

Comparing Torque Transmission of Different Bracket Systems in Combination with Various Archwires Considering Play in the Bracket Slot: An In Vitro Study.

This study aims to examine the play between various archwires and bracket systems, exploring potential variations in angle values for specific torque and torque values for a given angle along different bracket systems. Therefore, seven brackets systems were evaluated in conjunction with different stainless steel archwires of varying dimensions (0.016″ × 0.022″, 0.018″ × 0.025″, and 0.019″ × 0.025″). Biomechanical behavior during torque development and transmission was assessed using a six-component force/torque sensor. Torque angles (5-45°) were specified with subsequent torque measurement, and the sequence was reversed by setting the torque (5-30 Nmm) and measuring the angle. A reference measurement with 0 Nmm torque served to evaluate bracket slot play. Bracket play (0 Nmm) during palatal load ranged between 20.06° and 32.50° for 0.016″ × 0.022″ wire, 12.83° and 21.11° for 0.018″ × 0.025″ wire, and 8.39° and 18.73° for 0.019″ × 0.025″ wire. The BioQuick® bracket exhibited the highest play, while Wave SL® and Damon® Q brackets demonstrated the lowest play (p < 0.001). Significant differences (p < 0.001) between the brackets were observed in the torque angles required to achieve torques of 5-20 Nmm. In summary, each bracket system has a different torque transmission, which is of great clinical importance in order to achieve correct torque transmission and avoid complications such as root resorption.

Design, modeling, and control of a novel soft-rigid knee joint robot for assisting motion

AbstractThis paper presents the design, modeling, and control of a novel soft-rigid knee joint robot (SR-KR) for assisting motion. SR-KR is proposed to assist patients with knee joint injuries conducting gait training and completing walking movements. SR-KR consists of a novel soft-rigid bidirectional curl actuator, a thigh clamping structure, and a crus clamping structure. The actuating part of SR-KR is composed of soft materials, which ensures the wearing comfort and safety, while the wearing parts contain rigid structure, which ensures the efficient transmission of torque. The bending deformation model of SR-KR is established, which reveal the relationship among SR-KR’s bending curvature, working pressure, and output torque. Experiments show that SR-KR can provide more than 26.3 Nm torque for knee joint motion in human gait range. A double closed loop servo control system including attitude servo and pressure servo is built to better apply SR-KR. Mechanical property test, trajectory-driven test, and lower limb wearing test have been conducted, which show that SR-KR has ability to assist in lower limb motion and has potential in the fields of rehabilitation and human enhancement.

Crushing of abrasive particles in gearbox oil of tractors operating in dusty environmental conditions

This paper investigates the factors affecting the strength of abrasive particles in tractor gearbox oil operating in dusty conditions. The study focuses on gearboxes with constant mesh gears, categorized into two types based on torque transmission. The research aims to determine the degree of activity of abrasive particles influencing gear teeth wear resistance. A methodology for calculating the possibility of crushing abrasive particles based on their concentration, size, and strength is proposed. The influence of normal force arising from friction torque, rolling bearings, and oil agitation on abrasive particles is also examined. The findings indicate that when gear transmission does not transmit torque, the normal force does not lead to abrasive particle crushing, resulting in high wear capacity in the gearbox oil. However, under the influence of normal force from the torque transmitted by the internal combustion engine, abrasive particles in the tooth contact zone are crushed, reducing their wear capacity. The study’s results contribute to understanding the factors affecting abrasive particle strength in tractor gearboxes operating in dusty conditions, providing insights into improving system design and operation for enhanced durability and efficiency.

Numerical and analytical models of the mechanism of torque and axial load transmission in a shock absorber for drilling oil, gas and geothermal wells

The paper proposes an improved design of a shock absorber used in drilling deep oil and gas and geothermal wells with polycrystalline diamond compact (PDC) bits. The proposed innovations successfully combat the dangerous phenomenon of self-excited vibrations, which can lead to malfunctions such as stick-slip and whirling of the drilling tool. Most conventional drill shock absorbers are designed to only absorb longitudinal vibrations, which was sufficient when using roller cutter bits for the drilling process. However, the design features of PDC bits and the phenomenon of interaction of their cutters with interlayered rocks during deep drilling impose new requirements on the properties of the drill shock absorber. To protect the downhole tool from abnormal torque values and torque oscillations, it is proposed to equip the shock absorber with a special torque transmission unit in the form of a fourteen-thread self-releasing screw pair. This unit is capable of transforming increases in external torque into increases in the force that loads the elastic element of the shock absorber. The numerical and analytical models of the mechanism of transferring external axial load and torque to the elastic element of the drill shock absorber are constructed. The distribution of contact pressures on the interacting surfaces of the screw pair and the distribution of equivalent stresses in the screw pair parts are analysed. The strength of the proposed drill shock absorber assembly was evaluated using the Huber-von Mises energy criterion. The dependence of the load transmitted to the elastic element of the shock absorber on changes in the external torque and external axial force is investigated. In general, it is determined that the external load is distributed evenly between all turns of the screw pair, and the limit state of the parts of the proposed assembly is not reached even under high-torque operating load. The obtained analytical dependencies will allow to effectively determine the required strength and stiffness of the elastic element of the drill shock absorber at the design stage. The obtained analytical results were verified using a finite element model.

Research on a novel water-cooling multi-cylinder magnetorheological transmission device.

Power transmission is an important application for magnetorheological (MR) fluid, and the cylinder-type power transmission device is a novel transmission form due to its high stability, higher transmission torque, and large ratio of power to mass. This work designed a novel multi-cylinder transmission device with a water-cooling channel because the MR transmission device, especially high-power MR transmission device, inevitably works in the high-temperature environment. Based on Ohm's law and electromagnetism theory, the magnetic circuit in the novel MR transmission device is designed, and the magnetoresistance was calculated. The finite element method is used to analyze the magnetic field in the device to ensure that the magnetic field in the working gap of MR fluid is strong enough for the MR effects. The temperature of the MR fluid inside the device is analyzed by the finite element method in the natural cooling state and the water-cooling state, respectively, so as to obtain the performance of water cooling. The novel MR transmission device is manufactured to verify its power transmission capability and heat-dissipation performance. The experimental results show that the novel device can transmit a maximum torque of 70 N m, consistent with the rated torque. In addition, compared with natural cooling, the water cooling makes the temperature of the MR fluid to drop by 32.7% under the same working condition. This is the first time that the cooling channel is set up in the cylinder-type MR transmission device, which will provide a solution for the higher power transmission capacity by MR fluid.

Limiting Control and Accurate Observation of Transmission Torque and Its Jerk in Elastic Servo Systems

Limiting Control and Accurate Observation of Transmission Torque and Its Jerk in Elastic Servo Systems

Maximum Transmission Torque Improvement of Interior Permanent Magnet Magnetic-Geared Motor

Maximum Transmission Torque Improvement of Interior Permanent Magnet Magnetic-Geared Motor

Human-Robot Joint Misalignment, Physical Interaction, and Gait Kinematic Assessment in Ankle-Foot Orthoses.

Lower limb exoskeletons and orthoses have been increasingly used to assist the user during gait rehabilitation through torque transmission and motor stability. However, the physical human-robot interface (HRi) has not been properly addressed. Current orthoses lead to spurious forces at the HRi that cause adverse effects and high abandonment rates. This study aims to assess and compare, in a holistic approach, human-robot joint misalignment and gait kinematics in three fixation designs of ankle-foot orthoses (AFOs). These are AFOs with a frontal shin guard (F-AFO), lateral shin guard (L-AFO), and the ankle modulus of the H2 exoskeleton (H2-AFO). An experimental protocol was implemented to assess misalignment, fixation displacement, pressure interactions, user-perceived comfort, and gait kinematics during walking with the three AFOs. The F-AFO showed reduced vertical misalignment (peak of 1.37 ± 0.90 cm, p-value < 0.05), interactions (median pressures of 0.39-3.12 kPa), and higher user-perceived comfort (p-value < 0.05) when compared to H2-AFO (peak misalignment of 2.95 ± 0.64 and pressures ranging from 3.19 to 19.78 kPa). F-AFO also improves the L-AFO in pressure (median pressures ranging from 8.64 to 10.83 kPa) and comfort (p-value < 0.05). All AFOs significantly modified hip joint angle regarding control gait (p-value < 0.01), while the H2-AFO also affected knee joint angle (p-value < 0.01) and gait spatiotemporal parameters (p-value < 0.05). Overall, findings indicate that an AFO with a frontal shin guard and a sports shoe is effective at reducing misalignment and pressure at the HRI, increasing comfort with slight changes in gait kinematics.

Formulasi Analitikal untuk Pengoptimuman Ketumpatan Tork dalam Gear Magnetik

Energy efficiency is a very important consideration in vehicle design today. Minimizing weight would go a long way in this direction, as it directly contributes up to 75% of fuel consumption. Mechanical gearboxes and transmissions are components that add significantly to vehicle weight. For example, the mass of typical automotive transmissions ranges from 40 to 200 kg, depending on the size of the vehicle. In recent years, magnetic gears (MG) have gained attention as realistic alternatives to mechanical gears. MGs operate without contact, where torque amplification, reduction, and transmission are achieved through the interaction of magnetic fields, which allows for lighter designs. For practical use in automotive vehicles, MGs must be capable of transferring sufficient amounts of torque. To maintain being compact and lightweight, the torque density of the MG must be maximized. Hence, the MG needs to be designed in such a way so as to achieve high flux concentration. Torque density analysis of MGs is not trivial, and often, some trade-offs between accuracy and computational cost is required. Several methods of analysis have been used by various researchers, including Finite Element Analysis, Reluctance Network Analysis (RNA), the Quasi 3D Analytical Method, and Genetic Algorithms (GA). In this work, we examine these methods and present an analytical formulation that relates MG torque to its physical parameters. Understanding such relationships could help optimise future MG designs such that torque density can be maximised.

Exploring electrical metrics for tribology measures in oil films: System design, analysis principle and physical effects

This study investigates lubricating performances of oils through altering the working conditions in accelerated aging tests, observing the degradations on the lubricants’ performances and incorporating in-time detections for verification. To meet the aims, a new measuring system has been developed to observe alterations of the recorded viscosity index, color difference, thermal coefficient and torque transmission in the oil film under electrical discharges. To resolve the quality of lubricating oil in real time, the discharging waveforms and the acoustic indexes were applied to the marginal Hilbert spectrum for characterizing the time-frequency domain features. The Fisher score of the selected features successfully differentiated the new and used lubricants. The physical effects in association with the degradations of oil films are reported in detail.