To address the problems of insufficient precision reserve, limited rotational speed, and excessive temperature rise in high-speed ultra-precision machine tool spindle bearings, the influence of frictional power loss on the thermo-mechanical behavior...
In this study, a loader drive axle digital model was built using 3D commercial software. On the basis of this model, the transmission efficiency of the main reducing gear, the differential planetary mechanism, and the wheel planetary reducing gear of...
The present study aims to analyze the influence of the geometric profile of the compression ring on the tribological properties of the lubricant. Additionally, the influence of the rotation speed and the engine load on the state of the lubricant is e...
The deep-sea environment has the characteristics of high pressure and low temperature. In addition to the extremely high requirements on the structural reliability, the ultra-high ambient pressure also has a great impact on the working characteristic...
This study presents a systematic investigation on the thermal power characteristics of linear conjugate internal gear pumps. Through analyzing the heat sources of each friction pair in the internal gear pump, mathematical heat generation models for k...
The minimization of friction losses in internal combustion engines is a goal of primary importance for the automotive industry, both to improve performance and to comply with increasingly stringent legislative requirements. It is therefore necessary...
This paper aims to study and demonstrate the possibilities of using reinforcement learning for the synthesis of multi-objective controllers for radial actively lubricated hybrid fluid film bearings (ALHBs), which are considered to be complex multi-ph...
The involute profile is used almost exclusively in the manufacturing of spur gears. Nevertheless, in machinery design, the evaluation of environmental factors, such as energy efficiency, has become increasingly important when choosing between feasibl...
Currently, mechanical gears with cycloid engagement are increasingly used in mechanisms along with involute ones. In modern drive mechanisms, using pin gears and gears with intermediate rolling elements (IRE) is widespread, which simultaneously use c...
This paper presents the design and experimental investigation of a multifunctional friction test bench, aiming to characterize the frictional and transmission efficiency of rope–drum systems in high-altitude wind power generation. The study add...
Loss of lubrication in aeronautic drivetrains can lead to catastrophic gearbox failure, and drivetrains must be tested to prove their resistance to loss of lubrication. Research led to a better understanding of the modes of action, interdependencies,...
In the presented work, a parametric multibody simulation model is presented that is capable of predicting the friction torque and kinematics of tapered roller bearings. For a highly accurate prediction of bearing friction, consideration of solid and...
This study presents a theoretical and experimental analysis to quantify the power losses generated by an oil jet lubricated angular contact ball bearing. The analysis is conducted for a moderate speed range (N∙dm product less than
Due to the extended geometry of internally rifled tubes with helical ribs, the rate of convective heat transfer within them is much higher compared to smooth tubes. Simultaneously, a rise in the contact surface area between the fluid and the solid bo...
Tribotronic machine elements achieve active control by incorporating sensing, control and actuation into engineering components that are otherwise conventionally passive. There has been a trend towards the development and use of active tribological (...
Skidding, which frequently occurs in high-speed rolling bearings, has a significant effect on the thermal distribution and service reliability of the bearings. An improved theoretical model of friction power loss distribution in high-speed and light-...
Low-loss gears are an interesting design approach for increasing the efficiency and thermal load limits of gearboxes. The loss-optimized gear geometry concentrates sliding around the pitch point, which results in low load-dependent gear power losses....
Friction and wear reduction in internal combustion engines are crucial for improving efficiency and durability. This study investigates the effect of microtextured surfaces on friction power loss in an engine’s piston ring-cylinder system. A nu...
In the present study, a novel approach to estimating the efficiency of roller chain power transmission systems is proposed based on sliding friction losses and damping force. The dynamics model is taken into account between chain links with lateral o...
The existing research problem is that the hypergraph-based method does not comprehensively consider the power loss factors of the mechanical transmission system, especially the existing windage power loss. In the power flow diagram, it is difficult t...
As energy efficiency becomes a significant performance indicator in mobile machines, power losses are recognized as an important criterion in the design and optimization of these systems. This paper analyses the loads and power loss due to friction i...
Finite-time thermodynamic models for an Otto cycle, an Atkinson cycle, an over-expansion Miller cycle (M1), an LIVC Miller cycle through late intake valve closure (M2) and an LIVC Miller cycle with constant compression ratio (M3) have been establishe...
Reducing friction losses is one of the most common ways to improve fluid film bearings, whose adjustable design provides additional opportunities to improve their dynamic and tribological properties. Previous studies have shown the possibility of red...
The operating conditions of the drum shearer are very complex, and its ranging arm gear system often suffers from gear scuffing and wear. Gear scuffing is caused by the adhesive wear, which is due to the instantaneous friction and flash temperature o...
The development of a sustainable powertrain requires improved thermal efficiency. Reducing frictional power losses through the use of ultra-low viscosity oil is one of the most effective and economical ways. To assess the potential for efficiency enh...
Aerostatic conical bearings with micro-orifices (ACBMOs) can simultaneously withstand both radial and axial external loads and have high power density. Nevertheless, due to the larger surface-to-volume ratio and length-to-diameter ratio of micro-orif...
In this study, a method for estimating the efficiency of electric bicycle power train systems consisting of typical components, such as an electric motor, gears, sprockets, and chains is presented. In order to calculate the efficiency of a power trai...
This work focuses on the friction and temperature behavior of thermo-elastohydrodynamically lubricated (TEHL) contacts under rolling-sliding conditions. For this purpose, a twin-disk test rig is used with a hybrid setup of plain and fiber-reinforced...
In the present investigation, a study is carried out using numerical simulation on the effects of cylinder deactivation on tribological parameters and emissions in an internal combustion engine. For the development of the research, a tribological mod...
Friction loss in an internal combustion engine largely depends on elastohydrodynamic lubrication. The piston compression ring is a contributor to such parasitic losses in the piston subsystem. The complex elastodynamics of the ring are responsible fo...
This paper presents a transient mixed-lubrication hydrodynamic and gas flow simulation model for a piston ring pack for a four-stroke internal combustion engine. The analyses carried out compare two fuel types, hydrogen and gasoline, at a 2000 rpm lo...
Oil-immersed cooling provides an effective cooling scheme for high-power hub motors with compact structure and serious heating problems. However, with this cooling method, some oil friction loss will be generated, making the output torque and efficie...
The electro-hydrostatic actuator (EHA) is one of the most prevalent types of power-by-wire (PBW) actuation systems. With the increase in EHA power density, using the pump’s leakage oil to cool the motor has been gradually adopted to solve the p...
The objective of the present investigation is to analyze the tribological performance between the union of the cylinder liner and the compression ring under the influence of surface texturing and different lubrication boundary conditions. The analysi...
Mechanical seals ensure the internal sealing of centrifugal pumps from the surrounding environment. They are one of the most critical components in a centrifugal pump. For this reason, the condition of mechanical seals should be monitored during oper...
In the current energy landscape, efficiency is a critical topic. Therefore, even in the case of geared transmissions, it is essential to predict and calculate power losses as accurately as possible from the design phase. There are mainly three catego...
To reduce the friction loss and the piston-knocking noise from the perspective of the design of the cylinder bore profile, the piston-ring cylinder bore (PRCB) dynamic model of an L6 diesel engine was developed using AVL-Excite-Piston & Rings. Ba...
The overturning and eccentric abrasion of the slipper worsens the lubrication characteristics and increases the friction power loss and kinetic energy consumption of the slipper/swashplate interface to reduce the axial piston pump efficiency. A coupl...
Optimizing the design of the top compression ring holds immense importance in reducing friction across both traditional Internal Combustion (IC) engines and hybrid power systems. This study investigates the impact of alternative fuels, specifically h...
Due to the poor thermal characteristics of the air, the absorber roughness of solar air collectors is commonly artificially increased in order to enhance the heat transfer to the air stream. However, this is also accompanied by an undesirable increas...
In tilting-pad journal bearings (TPJB), power loss corresponds to the internal friction in the shearing of the oil. Besides the lubrication gap, intermediate spaces between the pads account for a notable amount of frictional losses. Against the backg...
The growing market of large-power photovoltaic irrigation systems (PVISs)—made of systems with different and several motor pumps working in parallel—needs simulation tools capable to estimate their energy and water productivity. The objec...
Modulated pressure waves propagating in the drilling fluids inside the drill string are a reliable real-time communication technology that transmit data from downhole to the surface during oil and gas drilling. In the analysis of pressure waves&rsquo...
Both the dynamic characteristics and structural nonlinearities of an actuator will affect the flutter boundary of a fin–actuator system. The actuator models used in past research are not universal, the accuracy is difficult to guarantee, and the cons...
An open type of microchannel with diamond pin fins (OM-DPFs) is introduced for the cooling of high-performance electronic chips. For a Reynolds number (Re) of 247~1173, a three-dimensional model is established to explore the hydrothermal properties o...
Piston top rings in the combustion engine play a crucial role in the overall hydrodynamic performance of engines, such as power loss, minimum film thickness and friction forces, by ensuring sealing and minimizing the leakage of burnt gases. This pres...
The potential benefit of cylinder deactivation (CDA) on power and emission performances has been numerically investigated on a locomotive 16-cylinder diesel engine. A 1D model combined with a predictive friction model and a 3D combustion model based...
In order to enhance the surface friction performance of the aluminum-silicon (Al-Si) alloy cylinder liner, chemical etching and laser finishing techniques are applied to improve the friction performance. The cylinder liner samples are worn against a...
In this work, friction loss investigations and comparisons of three different four-cylinder engines for passenger car applications are presented, using a recently developed combined approach. By merging extensive experimental with reliable and predic...
Decreasing production and rising prices of cars, especially those with electric drive, lead to longer use of cars with internal combustion engines. It can be assumed that in the future, more and more cars powered by such engines with high mileage and...
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