Speed Mode Research Articles

Modern successful global solutions in environmentally friendly urban delivery and their application in Ukraine

Nowadays the issue of reducing environmental pollution is on the agenda of all countries. Among the areas that have huge negative consequences for nature, logistics and supply chains take their place. Today, there are many concepts and scientific currents that recognize the need to account for the environmental component in urban logistics. Environmental aspects are used when evaluating the efficiency of investment projects, developing new models of vehicles, calculating taxes and insurance payments, and when searching for the best delivery schemes. The goal of the work. Taking into account the world experience in research on the chosen topic, the purpose of this study is to consolidate the world's successful experience in environmentally friendly urban delivery and assess their applicability in Ukraine. Technologies and methods that allow reducing the negative impact of motor vehicles on the environment include: The technology of off-peak delivery, which allows you to improve the speed mode of the car. With off-peak delivery, the probability of traffic jams is minimized, which makes the speed of movement the maximum permissible in the city (and, accordingly, the most environmentally friendly). Although night delivery is currently not possible in Ukraine due to the curfew, late and early delivery is still available, allowing you to successfully bypass traffic jams. Use of consolidation centers. The economic idea of consolidation of freight transportation is to use the effect of scale - the greater the carrying capacity of the vehicle, the lower the specific costs for transportation of a unit of production. Currently, the construction of the consolidation center is being evaluated from the point of view of the impact of the supply chain on the environment. At the same time, the existence of a consolidation center near or within the city allows to organize delivery by vehicles with zero or low level of environmental pollution. Use of Parcel Delivery Lockers. Delivery lockers are usually installed in places where the maximum flow of residents is concentrated, which makes it possible to create additional comfort for users due to the possibility of choosing the point closest to their own home or place of work. This method eliminates up to two thirds of harmful emissions into the air. The number of post machines and the area covered by them increases year by year, which allows us to talk about the success of this technology. According to the results of 2022, such major players of express delivery as "Nova Poshta" (now “Nova”), "Ukrposhta" and "Meest" will continue to work with post delivery lockers in Ukraine. Use of more environmentally friendly types of transport. The use of hybrid, electric or non-motorized vehicles is increasingly used in last-mile logistics. Electric vehicles, mopeds, two- or three-wheeled bicycles with a large trunk or cargo body can be considered environmentally friendly types of urban logistics. Such vehicles have practically zero emissions of harmful substances, they are much more maneuverable and do not require a lot of space for unloading, loading and parking. Implementation of zones with low (zero) air pollution. Zones with zero or low emissions have long been used in developed countries. There are no generally accepted technologies for calculating the territory that requires restrictions on the movement of transport, as well as for calculating the cost of such movement. Usually it depends on the will of the local authorities, the wishes of the residents and the well-being of the region. Prohibition on the use of motor vehicles. Some local authorities introduce a complete ban on the use of motor vehicles within certain parts of the city. Usually these are historical centers with dense buildings and a large number of tourists. Sometimes such drastic measures are combined with night delivery technology. If this is not possible, the only alternative is delivery by small, usually two- or three-wheeled, zero-emission vehicles. Improvement of traffic management. Competently designed organization of road traffic can reduce the pressure on the environment. The use of an intelligent transport system in smart cities allows you to perform important tasks like detection of transport accidents; automated control of the ramp, traffic lights and parking, etc. Improvement of road conditions. This refers to the quality of the road surface, markings, cleanliness of the road surface, etc. Improvement of road conditions indirectly affects the improvement of environment of the region. Summing up the results of the research, successful global practices in environmental friendly urban logistics are highlighted, which are applied and have prospects for application in Ukraine. It was concluded that there is a huge potential of using world experience in urban logistics of Ukraine. This will bring Ukrainian logistics and urban supply chains to a new level, increasing the level of health and general satisfaction of the citizens.

Effects of fuel and driving conditions on particle number emissions of China-VI gasoline vehicles: based on corrections to test results.

The increasing number of vehicles are emitting a large amount of particles into the atmosphere, causing serious harm to the ecological environment and human health. This study conducted the Worldwide Harmonized Light Vehicles Test Cycle (WLTC) to investigate the emission characteristics of particle number (PN) of China-VI gasoline vehicles with different gasoline. The gasoline with lower aromatic hydrocarbons and olefins reduced particulate matter (PM) and PN emissions by 24% and 52% respectively. The average PN emission rate of the four vehicles during the first 300s (the cold start period) was 7.2 times that of the 300s-1800s. Additionally, because the particle transmission time and instrument response time, the test results of instantaneous emissions of PN were not synchronized with vehicle specific power (VSP). By calculating the Spearman correlation coefficient between pre-average vehicle specific power (PAVSP) and the test results of PN instantaneous emissions, the delay time was determined as 10s. After the PN emissions results were corrected, the PN emissions were found to be more related to VSP. By analyzing the influence of driving status on emission, this study found that vehicles in acceleration mode increased PN emissions by 76% compared to those in constant speed mode.

How different text display patterns affect cybersickness in augmented reality.

Cybersickness remains a pivotal factor that impacts user experience in Augmented Reality (AR). Research probing into the relationship between AR reading tasks and cybersickness, particularly focusing on text display patterns and user characteristics, has been scant. Moreover, the influence of cybersickness on searching ability and the broader spectrum of user experience has not been rigorously tested. Recent investigations have aimed to pinpoint the variables that contribute to cybersickness during AR reading sessions. In one such study, 40 participants underwent a series of controlled experiments with randomized text display patterns, including variations in text speed and text movement modes. Post-experiment, participants completed a questionnaire that helped quantify their experiences and the degree of cybersickness encountered. The data highlighted that satiety, text speed, and text movement mode are significant contributors to cybersickness. When participants experienced higher levels of cybersickness, font color stood out as a particularly influential factor, whereas gender differences seemed to affect the onset of cybersickness more noticeably at lower levels. This study also drew attention to the impact of cybersickness on search ability within AR environments. It was noted that as cybersickness intensity increased, search ability was markedly compromised. In sum, the research underscores the importance of text display patterns and user characteristics, such as past AR experience, in understanding cybersickness and its detrimental effects on user experience and search ability, particularly under conditions of intense cybersickness.

Improving a methodology for estimating the cross-country ability of all-wheel-drive vehicles

The object of this study is the cross-country ability of four-wheel drive vehicles under off-road conditions. Based on the results of analysis of known studies, it was determined that the procedures of experimental assessment of the load-bearing capacity of bearing surfaces (BS), based on the use of the cone index, are used in NATO member countries. They take into account the characteristics of the surface of the theater of operations and make it possible to determine the approximate speeds of all-wheel drive vehicles with the help of standardized computer software. In the procedures for assessing the load-bearing capacity of BSs, which use the soil deformation module E, there is no possibility for calculating the speed of the car with known axle loads. In addition, they provide for the determination of a number of parameters of the bearing surface, such as the coefficient of adhesion, the angle of internal friction in the soil, and the shear modulus during the formation of a track. This makes them much more difficult compared to the procedures used by NATO. Therefore, the problem that is solved in this work is to improve the methodology for assessing the reference cross-country ability of four-wheel drive vehicles. Based on the results of scientific research, motion modeling was carried out in the MATLAB Simulink environment to determine parameters of reference cross-country ability of four-wheel drive vehicles. In order to determine the cross-country ability of samples of wheeled military vehicles (WMV) based on the indicator of the maximum pressure value (mean measure pressure – MMP), the conducted experimental studies were analyzed. They showed a difference in the speed modes of vehicles of the same gross weight but different layout schemes, within 11–12 %. Therefore, the methodology for assessing the cross-country ability based on MMP has been improved to take into account the features of the layout of WMV samples. Specifically, taking into account the different values of loads on the front axle of vehicles with hoodless and hood layouts at the same gross weight. In general, the improved procedure makes it possible to give a quantitative assessment of the movement mobility of WMV samples with various layout schemes and an assessment of their potential cross-country ability on the basis of the proposed refinement of MMP calculation

Determination of the Optimum Speed Mode of the Carding Machine

Determination of the Optimum Speed Mode of the Carding Machine

СТАБИЛИЗАЦИЯ ПРОЦЕССА – УСЛОВИЕ ЕГО ОБЪЕКТИВНОГО ИССЛЕДОВАНИЯ

Research of the interrelationships between the time periods of stabilization of the technological process of trier grain cleaning from: feeding the grain mixture into the trier; its initial contamination; speed mode of operation and angular position of the output tray relative to the horizon are satisfied. They were carried out using experimental equipment that provided separate, regulated and continuous supply of grain mixture components into the trier with a looped movement of purified grain. Standard methods and instruments, as well as special instruments developed at the Federal State Budgetary Institution VNIITiN, were used to assess the physical and mechanical properties of the components of the grain mixture. It was found that with a supply of 1.2 t/h, an initial contamination of 1.3% and a lifting angle of the output tray of 55°, the speed mode of operation of 36.0 rpm is excessive, while stabilization of the process is not completed even after 15 minutes (92% ), the length of the free section of the cellular surface is 0.70 - 0.75 m, which increases the level of residual grain contamination to 0.025 - 0.04%, which does not meet the requirements for seeds of the OS category. The possibility of reducing the comparable level of process stabilization by 6 times when the operating speed is reduced to 34.6 rpm (by 3.9%) has been confirmed. Reducing the operating speed to 34.0 rpm leads to an increase in process losses to 16.85%. It has been established that with an increase in the initial contamination of the grain mixture to 2.6%, the stabilization period of the process at a speed mode of 34.6 rpm increases from 4.5 to 5.5 minutes, and technological losses reach the maximum permissible value (5%). The method for calculating the actual degree of stabilization of the process with its assessment based on the removal of impurities has been refined.

An Analysis of Sliding Mode Speed Controller for a Differential Drive Wheel Mobile Robot

In this study, we present a systematically designed Sliding Mode Speed Controller (SMSC) tailored for motors utilized in a Differential Drive Wheel Mobile Robot (DDWMR). Our analysis delves into the critical parameters of the SMSC, including convergence and reaching rates, alongside simulation configurations such as time step. We concurrently consider metrics like rising time, steady-state error, and control ripple factors to optimize performance. Through comprehensive evaluation across various case studies, we demonstrate the efficacy of the fine-tuned SMSC in enhancing the overall performance of the DDWMR. Our simulation results underscore the significance of meticulous parameter tuning, particularly emphasizing the role of time step settings. We find that a smaller time step mitigates chattering phenomena and improves performance, albeit at the cost of increased computational demands and potentially heightened hardware requirements.

Comparison of in-plane compression of additively manufactured Ti6Al4V 2D auxetic structures: Lattice design, manufacturing speed, and failure mode

The metal-based 2D auxetic lattice structures hold the potential for multifunctional tasks in aerospace applications. However, the compression response of those manufactured by powder bed fusion process is underexplored. This study proposes a comprehensive comparison of in-plane quasi-static compression performance of 2D auxetic lattice structures, utilizing three designs (anti-tetrachiral (ATC), double arrow-headed (DAH), and tree-like re-entrant (TLR)), manufactured with stiff Ti6Al4V by the electron beam powder bed fusion process (PBF-EB) with various manufacturing speeds. The results revealed unique failure patterns and superior energy absorptions among 2D lattice structures in the literature. TLR design enhanced energy absorption by overcoming failures between DAH columns and exhibited the lowest standard deviations in specific energy absorption (SEA) values (9.75 %–12.62 %). Besides, Kernel average misorientation (KAM) values followed the order of DAH, TLR, and ATC, and inversely correlated with SEA values. ATC structures with the lowest KAM outperformed DAH and TLR by 47.5 % and 6.44 %, respectively. Scan speed variations affected SEA and porosity values differently for each lattice design while exhibiting similar microstructure characteristics. The findings in this study propose a significant contribution to the development of aerospace sandwich structures where harsh environments exist and employment of 2D topologies are required.

A hybrid triboelectric-piezoelectric smart squirrel cage with self-sensing and self-powering capabilities

In aero-engines, squirrel cages are commonly used as elastic support parts for bearings, serving to adjust critical speeds and provide vibration damping. Their stable operation is critical for the safety and stability of rotor systems. In this paper, a triboelectric-piezoelectric squirrel cage (TPSC) with self-sensing and self-powering capabilities is proposed. Owing to the ingenious utilization of the supporting structure, a compact design is achieved, enabling energy harvesting from the relative motion of the rotor-stator structure and the vibration of elastic support. Based on a fabricated prototype, a series of experiments are carried out to investigate the effect of the rotating speed, imbalance mass, and contact mode on the output performance of TPSC. Under the rotating frequency of 15 Hz, a maximum power output of 100.0 μW is achieved. The TPSC is capable of sensing rotating speed and detecting rolling bearing faults. A self-powered temperature and humidity sensing system that can transmit data wirelessly every 10 minutes is also realized. The TPSC enables self-powered monitoring of rotor bearing systems with squirrel cages, providing a new option for online condition monitoring of aero-engines.

An SMC-Based Accurate and Robust Load Speed Control Method for Elastic Servo System

In this paper, a modified sliding mode speed controller is designed in order to improve the load speed control performance of an elastic motor drive system with internal and external disturbances. Firstly, based on the load speed deviation and its first-order and second-order differentials, a two-dimensional sliding surface function is presented. The parameters of the sliding surface are determined by a novel particle swarm optimization (PSO) method. The method has improved inertia weights and evaluation functions, which can improve the accuracy and efficiency of the parameter search and enhance the immunity and robustness of the system. Secondly, on the basis of the integral of time-weighted absolute error (ITAE) criterion, the parameters of the exponential approach law are determined, which improves the tracking accuracy. Finally, the designed sliding mode control (SMC) with high tracking accuracy, fast dynamics, and strong robustness is verified by both simulations and experiments.

Management strategy to mitigate voltage sags effects of a multi-motors system using ADALINE algorithm and cascade sliding mode control

Multi-motor systems (MMS) find widespread use in various industrial applications, including plastic, paper, textiles, and steel rolling mills, where synchronized speeds are crucial for optimal operation. However, a significant limitation of these systems is their susceptibility to voltage sags, resulting in speed and synchronization loss, along with peak currents and torques during voltage recovery. This paper presents a comprehensive multi-motors management strategy aimed at attenuating the adverse effects of voltage sags. The proposed technique is based on principles that involve recovering the system’s kinetic energy and leveraging the current reversibility of the converters. The control scheme comprises two main strategies: an adaptive linear neuron or later adaptive linear element (ADALINE)-based voltage sag detection algorithm utilizing least mean square (LMS) adaptation for rapid convergence using artificial neural networks, and a control scheme incorporating sliding mode speed controllers and indirect rotor field-oriented control (IRFOC). Additionally, a logic-based strategy for voltage sag attenuation completes the control framework. The effectiveness and efficiency of the proposed strategy are demonstrated through simulation results obtained using MATLAB/Simulink/SimPowerSystems.

Modeling and Solving the Traveling Salesman Problem with Speed Optimization for a Plug-In Hybrid Electric Vehicle

This paper investigates a variant of the traveling salesman problem (TSP) with speed optimization for a plug-in hybrid electric vehicle (PHEV), simultaneously optimizing the average speed and operation mode for each road segment in the route. Two mixed-integer nonlinear programming models are proposed for the problem: one with continuous speed decision variables and one with discretized variables. Because the models are nonlinear, we propose reformulation schemes and introduce valid inequalities to strengthen them. We also describe a branch-and-cut algorithm to solve these reformulations. Extensive numerical experiments are performed to demonstrate the algorithm’s performance in terms of computing time and energy consumption costs. Specifically, the proposed solution method can efficiently solve instances with a realistic number of customers and outperforms the benchmark approaches from the literature. Integrating speed optimization into the TSP of a PHEV can lead to significant energy savings compared with the fixed-speed TSP. In addition, the proposed model is extended to investigate the impact of the presence of charging stations, which makes the problem harder to solve but has the potential to further reduce energy consumption costs. Funding: F. Wu gratefully acknowledges the support of the National Natural Science Foundation of China [Grant 72271161]. Supplemental Material: The online appendix is available at https://doi.org/10.1287/trsc.2023.0247 .

ОЦЕНКА ЧУВСТВИТЕЛЬНОСТИ ПРОЦЕССА ТРИЕРНОЙ ОЧИСТКИ ЗЕРНА К РЕЖИМАМ РАБОТЫ

Studies of the relationship between the speed mode of operation of the wild oat trier and the quality indicators of the technological process of purifying wheat from long impurities: the inevitable technological losses of full-fledged grain of the main crop into waste and residual contamination of the purified grain have been carried out. The studies were carried out using an experimental trier, which provided separate supply of grain mixture components into a cellular cylinder in specified ratios and control of the cylinder rotation speed with an accuracy of 0.1 rpm. It has been established that the quality of the process of cleaning grain from long impurities is greatly influenced by the speed mode of operation of the trier. The optimal value of the rotational speed of the cellular cylinder, at which the entire length of the cellular surface is involved with minimal losses of grain from the main crop, exists for specific values of grain supply to the trier and the angular position of the output tray. The maximum cleaning quality in terms of residual grain contamination is achieved in this way. Reducing the cylinder rotation speed from the optimal 34.6 rpm to 34.0 rpm (by 1.7%) leads to an increase in technological losses by 3.6 times with zero initial clogging and by 15.5 times with clogging 1. 3%. The relationship between the indicator of residual contamination and the size of the free cellular surface when the rotation speed of the cellular cylinder deviates upward from the optimal one has been established. With a grain supply of 1.2 t/h, an angular position of the working edge of the output tray of 55° and a cylinder rotation speed of 36.0 rpm, the value of the free cellular surface was 70 cm, the residual contamination was 14.2 pieces/kg, and in the absence of a free cellular surface, achieved by reducing the speed mode of the trier to 34.6 rpm, the residual contamination of the cleaned grain was 1.5 pieces/kg, which is 9.5 times less.

The pre-high-level temperature modulation: gas detection strategy to improve the response speed of semiconductor sensor

With the rapid development of the Internet of Things, gas detection has become an important part of ensuring industrial process and information security. In recent years, dynamic temperature modulation mode has been widely used in semiconductor gas sensors to improve their selectivity. This mode has no definition of response time so far and is not optimized from the perspective of response speed. In fact, the response speed of dynamic temperature modulation mode is relatively slow. In the Internet of Things, there is an urgent need for efficient and fast gas detection equipment. Hereon, based on the dynamic response characteristics, the response time is divided into type response time and concentration response time. When using triangular wave heating voltage based on SnO2 sensor, it shows excellent type response speed and poor concentration response speed. Then, according to the response mechanism of the sensor, the concentration response speed of the sensor is improved by applying pre-high-level to the sensor. Finally, the response mechanism of dynamic temperature modulation is explored, and on this basis, the influence on response speed is explained about oxygen accumulation and high reactive oxygen species produced by pre-high-level heating voltage.

Performance and Reliable Operation of Physiological Controllers Under Various Cardiovascular Models: In Silico and In Vitro Study.

The evaluation of control schemes for left ventricular assist devices (LVADs) requires the utilization of an appropriate model of the human cardiovascular system. Given that different patients and experimental data yield varying performance of the cardiovascular models (CVMs) and their respective parameters, it becomes crucial to assess the reliable operation of controllers. This study aims to assess the performance and reliability of various LVAD controllers using two state-of-the-art CVMs, with a specific focus on the impact of interpatient variability. Extreme test cases were employed for evaluation, incorporating both in silico and in vitro experiments. The differences observed in response between the studied CVMs can be attributed to variations in their structures and parameters. Specifically, the model with smaller compartments exhibits higher overload rates, whereas the other model demonstrates increased sensitivity to changes in preload and afterload, resulting in more frequent suction events (34.2% vs. 8.5% for constant speed mode). These findings along with the varying response of the tested controllers highlight the influence of the selected CVM emphasizing the need to test each LVAD controller with multiple CVMs or, at least, a range of parameter sets. This approach ensures sufficient evaluation of the controller's efficacy in addressing interpatient variability.

An improved sliding mode speed controller for PMSM based on new terminal reaching law with generalized proportional integral observer

A compound sliding mode controller for permanent magnet synchronous motor (PMSM) based on an adaptive terminal sliding mode reaching law with generalized proportional integral observer is proposed. First, an adaptive terminal reaching law is proposed to solve the defects of large chattering in commonly used sliding mode control, which consists of a piecewise function and a terminal term of state variables. The reaching law could adjust the gain according to the distance between the system state and the equilibrium point. On the premise of reducing chattering, a higher reaching speed is guaranteed. The convergence time has an upper bound and is not concerned with the initial value of the sliding mode variable. Based on the reaching law, an adaptive sliding mode controller is established. Second, to reduce the sliding mode gain and enhance the antidisturbance ability of the PMSM, a generalized proportional integral observer is established to evaluate the perturbations in PMSM and compensate them to the speed controller in real time. Simulations and experiments verify that the new compound control method has a faster-approaching speed, smaller chattering, and stronger antidisturbance ability than other methods.

Удосконалення методики визначення нормативів тягових властивостей автомобіля skoda fabia при стендовому діагностуванні

As you know, the main output parameters characterizing the state of the power unit are the power and torque values. These parameters determine the dynamic qualities of the car, and can also affect fuel consumption and the level of harmful emissions.
 The above parameters are checked using traction roller stands. Such stands allow you to reproduce real speed and load modes. Usually, the traction force on the drive wheels is measured on the stands. It is then easy to calculate the power at a given test speed. Traction force is determined, on the one hand, by the output torque of the engine, on the other hand, by mechanical losses in the transmission. In turn, the moment is determined by the perfection of the combustion process, the complete use of the energy of combustion products, and mechanical losses in the engine itself.
 When there is no reliable, experimentally obtained external speed characteristic of an internal combustion engine, Leiderman's formula is usually used for its approximate construction.
 This technique gives a satisfactory approximation of the dependence of power on revolutions. However, the moment curve is noticeably different from the experimental one. due to the fact that it uses only one experimental point - the maximum power and the corresponding revolutions. Therefore, a refined method of building the external speed characteristic using the example of the SKODA FABIA car is proposed using additional equations that specify the values of the empirical coefficients A, B, C.
 On the basis of the refined external speed characteristics of the engine, the revolutions of the crankshaft are converted into speed, and a graph of the permissible traction force against the speed is drawn according to the derived formula. Standards for diagnostic parameters of the power unit in acceleration mode under partial load are also defined.
 The proposed method of registering engine diagnostic parameters to determine their normative values provides an individual approach to diagnosing the technical condition of cars.

Planning Speed Mode of All-Wheel Drive Autonomous Vehicles Considering Complete Constraint Set

The study aims to improve the technique of motion planning for all-wheel drive (AWD) autonomous vehicles (AVs) by including torque vectoring (TV) models and extended physical constraints. Four schemes for realizing the TV drive were considered: with braking internal wheels, using a rear-axle sport differential (SD), with braking front internal wheel and rear-axle SD, and with SDs on both axles. The mathematical model combines 2.5D vehicle dynamics model and a simplified drivetrain model with the self-locking central differential. The inverse approach implies optimizing the distribution of kinematic parameters by imposing a set of constraints. The optimization procedure uses the sequential quadratic programming (SQP) technique for the nonlinear constrained minimization. The Gaussian N-point quadrature scheme provides numerical integration. The distribution of control parameters (torque, braking moments, SDs’ friction moment) is performed by evaluating linear and nonlinear algebraic equations inside of optimization. The technique proposed demonstrates an essential difference between forecasts built with a pure kinematic model and those considering the vehicle’s drive/control features. Therefore, this approach contributes to the predictive accuracy and widening model properties by increasing the number of references, including for actuators and mechanisms.

Exploring strain rate variation in the adhesive layer during constant speed mode I fracture tests: Loading speed and test temperature effects

The existing literature primarily explores fracture energy concerning test rate. However, for numerical simulations and bonded joint design, understanding the fracture energy strain rate sensitivity is key, not test speed. Even at a constant speed in fracture tests, adhesive strain rate varies during crack propagation, complicating strain rate sensitivity analysis. The current study aims to comprehend the strain rate sensitivity of the fracture energy, as opposed to the loading rate sensitivity of two different polyurethane adhesives subjected to mode I loading conditions. The study experimentally examines strain rate variations under constant loading rates and investigates how test speed affects the strain rate in mode I fracture tests. The impact of testing temperature on the strain rate is also explored by performing tests at −30 °C and 23 °C. Digital image correlation (DIC) and tracking methods are employed to improve the understanding of strain rate characteristics in these tests. To analyse the effect of loading rate on strain rate, the tests were conducted at different speeds as well. The influence of adhesive thickness on the strain rate was also explored. It was experimentally found that the strain rate at the crack tip varies even at a constant loading rate. The variation in strain rate is mainly evident in tests performed at higher loading rates, where the strain rate range increases. The tests performed at low temperature revealed less variation of strain rate than the ones tested under the same loading rate condition at 23 °C. For the same adhesive, thicker bondlines are less likely to cause a substantial error in fracture energy results than thinner bondlines.

Test and analysis of friction torque of double-row angular contact ball bearing under vacuum environment

PurposeThe purpose of this paper is to test and analyze the friction torque of double-row angular contact ball bearings under vacuum or ordinary pressure environment, horizontal or upright installation mode, and different rotational speeds, and to provide theoretical bases for the development of aerospace equipment.Design/methodology/approachThe experiments were carried out to investigate the effects of vacuum or ordinary pressure environment, horizontal or upright installation mode and different rotational speeds on bearing friction torque. To explore the relationship between working conditions and bearing friction torque, firstly, based on the generation source of friction torque, the test principle was determined, a test system was developed and the reliability of data was verified. Secondly, the friction torque of bearing was tested, and the values under various working conditions were obtained. Finally, this paper compared and discussed the test results.FindingsThe test results show that the friction torque value of vacuum environment horizontal installation condition is the largest at different rotational speeds, and the rotational speed has the most significant influence on the friction torque.Originality/valueThe friction torque test system of double-row angular contact ball bearing under vacuum environment was designed and built. The influence rules of vacuum or ordinary pressure environment, horizontal or upright installation mode and different rotational speeds on bearing friction torque were obtained.Peer reviewThe peer review history for this article is available at: http://dx.doi.org/10.1108/ILT-08-2023-0259