NVH Reduction Lubricants for Transmission Systems

A housing base arrangement for reducing structure-borne sound radiation in drive trains, comprising a support plate with slots that absorb weight forces from the housing and a base plate connected to the support plate for fastening and supporting the base. The slots are designed to dampen audible structure-borne sound in the frequency range of 20 Hz to 20 kHz, while allowing mechanical oscillations to be transmitted to the base. The arrangement enables a cost-effective and low-noise drive train, particularly suitable for industrial wind turbines.

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A grease composition for reducing noise and vibration in sliding members, comprising a copolymer of an aromatic vinyl compound and a conjugated diene compound, a soap-based thickener, and a lubricating oil. The copolymer contains a polymer block derived from an aromatic vinyl compound, such as styrene, and a polymer block derived from a conjugated diene compound, such as butadiene. The copolymer exhibits improved vibration damping properties and thermal stability.

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Purpose The purpose of this study is to investigate the effects of nanoadditive lubricants on the vibration and noise characteristics of helical gears compared with conventional lubricants. The experiment aims to analyze whether nanoadditive lubricants can effectively reduce gear vibration and noise under different speeds and loads. It also analyzes the sensitivity of the vibration reduction to load and speed changes. In addition, it compares the axial and radial vibration reduction effects. The goal is to explore the application of nanolubricants for vibration damping and noise reduction in gear transmissions. The results provide a basis for further research on nanolubricant effects under high-speed conditions. Design/methodology/approach Helical gears of 20CrMnTi were lubricated with conventional oil and nanoadditive oils. An open helical gearbox with spray lubrication was tested under different speeds (200500 rpm) and loads (20100 Nm). Gear noise was measured by a sound level meter. Axial and radial vibrations were detected using an M+P VibRunner system and fast Fourier transfo... Read More

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Electric vehicles (EVs) have gained increased attention in recent years owing to their excellent performance and emission of less hazardous products to the surroundings. The varied design of EVs compared to the internal combustion engine vehicles has created new requirements in lubricants and fluids for their operation. The increasing electrification of vehicle drivetrains has led to lubricants being in contact with more electrical components, such as motors, sensors, battery modules, and power electronics. This has led to different operating conditions, such as being subjected to an electric field, higher rpm, and higher thermal stress, affecting the electrical properties of lubricants, especially for electrified transmission fluid. The electrical properties of lubricants play a vital role in preventing corona discharge and arc absorbance, which can cause premature failure and electromagnetic interference problems in motors, leading to bearing instability, excessive vibrations, and noise. Understanding the interactions of lubricants with the electric field is crucial for optimizing ... Read More

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Transmission mechanism with a lubricating member that contains lubricant and comes into contact with a rotating member while applying a preload based on an elastic force, thereby efficiently lubricating the rotating member with a small amount of lubricant. The lubricating member can be an elastic material or an absorbent member impregnated with lubricant, and can be designed to circulate lubricant, absorb heat, and capture dust particles. The mechanism can be used in applications such as cam mechanisms, gearboxes, and other rotating systems.

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Abstract Vibro-impacts are common in various automotive power transmission applications. They lead to noise issues known as rattling. Input or output toque fluctuations cause gear teeth to separate and commit to complex sequences of drive and coast-side impacts spanning the entire backlash zone. Several recent experimental and theoretical studies characterized the underlying nonlinear structure of the rattling behavior of gear systems, ignoring any influences of lubrication conditions. Those rattle models with no lubricant provisions were shown to compare well with the dry contact measurements. This experimental study aims at complementing these earlier studies providing acoustics and torsional vibration measurements from a single gear pair excited by input torque fluctuations as it operates dry, jet-lubricated and dip-lubricated conditions. A rattle test machine equipped with a lubrication system is presented. Corresponding vibro-impact and sound pressure measurements are provided for a wide range of operating and lubrication conditions. Noise and torsional vibration data under diff... Read More

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The wheel reducer has a compact structure and high transmission power, and is widely used in new energy vehicles. However, it has a narrow space which limits lubrication. This also causes insufficient gear lubrication and poor heat dissipation, which influences the performance and service life of the wheel reducer. Therefore, it is important to find a way for the gear lubrication effectively. In this study, using computer simulation, the influencing factors of gear lubrication of an automobile wheel reducer were explored. The effect of gear speed and the degree of oil immersion on gear lubrication were also analyzed to lubricate the gear efficiently and improve the performance of the wheel reducer.

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<div>Lubrication has been a major area of interest in engineering. Especially in vehicle transmissions, lubrication plays a very crucial role because gears and bearings are constantly subjected to heavy loads. Proper lubrication is essential for maintaining system performance and ensuring endurance life. Insufficient lubrication can lead to excessive wear, increased friction, and eventually, failures in the transmission components. However, excess lubrication can result in power losses due to the resistance offered by the excessive lubricant. Therefore, achieving effective lubrication using optimized lubrication system design is vital for ensuring the longevity and efficiency of the transmission system.</div> <div>Majorly, two types of lubrication methods are used in transmissions: splash lubrication and forced lubrication. This article focuses on forced lubrication, where the lubrication system actively delivers the required flow of lubricant to specific locations within the transmission. Pump outflow, orifice diameters, and channel dimensions are a few of the crit... Read More

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This reprint features 12 research articles that contribute to the research on lubricated bearings. The articles focus on the latest steps in understanding bearing operating behavior, its interaction with lubricants, and its role as a component in the drive train. In addition to the description of novel modeling approaches, a variety of experimental data are presented to provide interesting identification results as well as validation data for the research and engineering community.

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A lubricating oil composition for transmissions, particularly those with wet clutches, that balances fuel efficiency, bearing life, and shift shock prevention. The composition comprises a lubricant base oil blend of mineral and synthetic oils, a calcium sulfonate detergent, a polyalkyl methacrylate polymer, and an amine friction modifier. The base oil blend is formulated to maintain optimal viscosity and film thickness while the additives enhance bearing life, shift performance, and wear protection.

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In recent years, the demand for friction reduction in oil lubrication systems has become increasingly important due to the need to improve fuel economy and achieve carbon neutrality. Ester-based lubricants are known to show low friction and environmentally friendly, and they have high viscosity indexes. In the present paper, first, in situ reflectance spectroscopy was used to clarify the behavior of the oil-film thickness increase during sliding. The results showed that as the number of ester bonds increased from 1 to 4, the ester oil film thickened and the friction coefficient decreased from 0.10 to 0.06. In addition, oleic-acid-type lubricants were found to have superior ability to form a thicker oil film than the isostearic acid type.

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The paper carries out a detailed summary of water-lubricated bearings from five typical aspects: the lubrication regime, the fluid-solid interaction(FSI), the thermal effect, the tribological behaviors and vibration-noise performances. For the lubrication regime, the influencing factors of lubrication regime transition, the judgement criteria and the lubrication mechanism are extracted and acquired. The methodology and the parameters that influencing the temperature rise are summarized. The generation mechanism of tribological behaviors and vibration & noise are obtained. The method of friction reduction, wear decrease, vibration alleviation and noise suppression, the judgement criteria of tribological behaviors and vibration & noise are gained. The paper systematically combs and summarizes the theories and methods of water-lubricated bearings, and points out the existing problems and technologies that need to be solved urgently. The findings can provide a distinct theoretical and methodological reference for further investigation on water-lubricated bearings.

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A lubricating oil composition for reducing noise and vibration in rotating machinery, comprising high phenyl silicone oil, PTFE micropowder, and a polyether-modified silicone oil defoamer. The composition provides improved shock absorption and noise reduction while maintaining low viscosity and convenient refill characteristics.

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Lubricant for ball screw devices and electric power steering systems that exhibits high dynamic viscoelasticity at operating conditions, characterized by a loss tangent (tan δ) of greater than 0.11 at 25°C, 10 rad/s, and 0.01% strain. The lubricant enables improved performance and reliability in ball screw devices and electric power steering systems by maintaining optimal friction and wear characteristics under dynamic loading conditions.

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According to the design requirements of load equalization and vibration reduction for the stern bearing, a water-lubricated stern bearing with self-adaptation capacity is proposed. The bearing is mainly composed of three parts: the bearing bush, the elastic element, and the damping alloy. The elastic element is used to realize static and dynamic load sharing of the stern bearing, reduce the edge effect of the stern bearing, and make the contact pressure evenly distributed in the axial direction, thereby improving the service life of the bearing and reducing the frictional excitation of the bearing. Damping alloy is used to attenuate the shaft vibration transmission from the bearing to the foundation to optimize the vibration transmission characteristics. The revised lubrication models for such bearings are put forward. By analyzing the vibration characteristics of the stern bearing, the results show that the vibration transmission characteristics of the thruster excited to the bearing node are optimized, and the vibration response at the first-order fixed frequency is significantly r... Read More

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A lubricating oil composition for transmissions with improved fatigue life and reduced viscosity, comprising a base oil and an olefin copolymer with a specific molecular weight and hydrodynamic radius range. The composition satisfies a numerical formula relating the olefin copolymer content to the base oil viscosity, and can be produced by blending the base oil and olefin copolymer within specified ranges. The composition is suitable for automatic and continuously variable transmissions, and can be used in a lubricating method that enhances fuel efficiency while maintaining transmission durability.

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A lubricating composition for automatic transmissions that provides improved fuel economy, anti-wear durability, and pump durability while maintaining friction control and anti-shudder performance. The composition comprises an oil of lubricating viscosity, a borated dispersant with sulphur or phosphorus functionality, a calcium-containing detergent, and a combination of phosphorus-containing compounds, along with a linear polymer viscosity modifier and optional additives such as friction modifiers, antioxidants, and corrosion inhibitors.

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This paper proposes a novel double-liner bearing in order to overcome the disadvantages of traditional water-lubricated single-liner bearings. It is expected to achieve a new breakthrough in the performances of high-load, low-resistance, vibration-attenuation and noise-reduction. The fluid-structure interaction dynamic model of sandwich liner bearing is established. Turbulent effect is taken into account. The influences of eccentricity ratios and liner thickness on the lubrication performance are studied. The evolution mechanisms of liner thickness on lubrication performances are revealed. The results show that there are superior lubrication behaviors in sandwich liner bearing. The present study enriches the theoretical systems of the lubrication. It provides new ideas and ways for the design and R&D of the bearing, which is of great significance.

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Lubrication is vital to improve performance, efficiency and durability in transmissions; it serves to minimize wear, noise, vibration and friction. The proper functioning of lubricated transmissions relies on interactions amongst a wide range of physical phenomena (contact dynamics, fluid-structure interaction and heat transfer) operating at different spatial and temporal scales. A lubricated transmission model is proposed in this work to obtain accurate information regarding all physical domains and the coupling thereof to quantify performance, efficiency and durability. The model consists of a thermo-elastically coupled flexible multibody model for the gear pair and a Thermo-Elasto-Hydrodynamic Lubrication (TEHL) model for the lubricant, both based on first principle modelling to ensure high fidelity.

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The article analyzes the vibrations of rolling bearings and their influence on the operation of bearings. An increase in the speed of operation and a boost in power and forces cause an increase in the intensity of vibration fields. The impact of vibrations leads to a change in the characteristics of the contacting surfaces, an increase in friction at the joints and heating of the conjugations. The article describes the factors disturbing vibrations in the joints of machine parts. Ways to reduce vibrations are formulated, including as a result of the use of various lubricants. The analysis of the operability of the rolling bearings of the machine components before and after the use of repair and recovery compounds in lubricants is carried out. The use of repair and restoration compounds based on mineral additives and its addition to the lubricant makes it possible to evaluate the effectiveness of repair and restoration compounds on the processes of friction and wear in rolling bearings. The use of liquid lubricants with mineral additives with a particle dispersion of up to 10 microns ... Read More

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