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Копилка знаний, сбор технических статей и материалов, брошюр по пластичным смазочным материалам


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Чтобы не разбрасывать по уже и так обьемным разделам/темам интересные статьи и материалы, а также облегчить ориентирование в них. Lube Magazine, LubesNGreases, NLGI Spokesman и прочее что имеет познавательную ценность.

 

 

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Интересная статья от Lubrizol, рассказывает про преимущества и недостатки ПАО масел и синтетических эстеров в смазках, а также про полностью синтетичные кальций-сульфонатные смазки.

 

Technologies to ENHANCE Synthetic Lubricating Greases by The Lubrizol Corporation

 

''The majority of greases (up to 80%) made with synthetic oils use polyalphaolefins (PAO) as the main component of their base oil. In terms of oxidative and thermal stability they have outstanding properties but they have some significant negatives for grease. One challenge to the grease formulator as the thickener content need to make an NLGI #2 grease is typically 50% higher than for a naphthenic mineral oil of similar viscosity (2). Despite the higher soap content, PAO greases are seemingly less shear stable and bleed oil more readily than the mineral oil equivalents. If being used in sealed bearing applications, seal swell agents need to be added to the PAO grease.''

 

Technologies to ENHANCE Synthetic Lubricating Greases.pdf

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A STUDY ON A HYBRID GREASE OF A LITHIUM GREASE AND A DIUREA GREASE Applied for Wide Temperature Range

 

''It is well known that lithium grease shows good low noise property, but is poor in grease life at higher temperature than 150 ºC. On the contrary, urea grease shows longer grease life at high temperature. But urea grease is poor in low noise property.''

''We developed the well-balanced grease (Hybrid grease) by blending lithium grease and diurea grease (blend ratio, A/ B=75/25). This grease showed longer grease life by two to three times than lithium grease at 150 ºC and also showed good low noise property as the same as Lithium grease.''

 

A STUDY ON A HYBRID GREASE OF A LITHIUM GREASE AND A DIUREA GREASE.pdf

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Очередной научный труд на тему - ''С чем бы еще смешать полимочевину'' в виде US Patent от 1992 года, от Amoco Corporation (сейчас это уже BP).

 

Polyurea and calcium soap lubricating grease thickener system

 

''Вышеупомянутые улучшенные свойства гибридного загустителя полимочевина / кальциевое мыло являются удивительными и неожиданными, поскольку они значительно превосходят то, что логически можно было бы ожидать, исходя из индивидуальных свойств, качеств и характеристик компонентов загустителя полимочевины и кальциевого мыла. Это указывает на то, что гибридный загуститель полимочевина / кальциевое мыло нельзя рассматривать как просто смесь полимочевины и кальциевого мыла. Вместо этого,  системы загустителей, по-видимому, взаимодействуют таким образом, что обеспечивают удивительные и неожиданные улучшенные свойства. Желательно, чтобы эти улучшенные свойства также могли быть достигнуты при одновременном снижении стоимости обработки компонента полимочевины и / или кальциевого мыла за счет снижения максимальной температуры термообработки во время производства.''

 

Polyurea and calcium soap lubricating grease thickener system.pdf

 

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Познавательный патент от University of Connecticut, 2000 год, об методах производства и композиций силиконовых компаундов/вязких смазок.

 

Silicone greases and methods for their production

 

Many silicone greases physically separate allowing the organopolysiloxane "oil" to bleed away from the site of lubrication over time. This is because many silicone greases contain a relatively mobile organopolysiloxane material which is physically thickened with a finely divided mineral filler to give the product a grease-like consistency. However, the organopolysiloxane retains some mobility to a degree which is dependent upon its viscosity and often will eventually bleed away from the site of lubrication.

 

The present invention was developed as a result of extensive investigation into the failure mechanisms of various silicone greases for the purpose of solving the oil bleed problem associated with prior art grease compositions. For example, prior art grease compositions contain organopolysiloxanes in the viscosity range of 800 centistokes (cS) to 3500 cS at 25° C. which is too low to be adequately physically stable for many applications. Greases prepared from such oils require very high mineral thickener levels, such as up to 60% w/w to form a grease-like material. As oil bleed occurs, a high level of abrasive mineral thickener is left behind at the previously lubricated interface.

 

SILICONE GREASES AND METHODS FOR THER PRODUCTION .pdf

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Патент от Fuchs Petrolube AG 2009 год на тему Кальций-Литиевых комплексных смазок и их применении в ШРУС, методах производства.

 

Calcium/Lithium Complex Greases and Encapsulated Constant Velocity Joint Containing the Grease and Method for their Production.

 

It has been found that unlike conventional lithium or calcium greases, the calcium/lithium complex soaps according to the invention (Ca/Li complex soaps) having a high fraction of calcium exhibit unexpectedly good properties when used as lubricating grease for constant velocity joints. Such products differ significantly from conventional Li/Ca greases.

 

CalciumLithium Complex Greases - FUCHS patent .pdf

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Две статьи на тему применения органического молибдена в смазочных материалах, в том числе SP Free.

 

Comparing tribological behaviors of sulfur- and phosphorus-free organomolybdenum additive with ZDDP and MoDTC

 

Tribological behaviors of organomolybdenum additive.pdf

 

Molybdenum to the Rescue

 

Molybdenum to the Rescue.pdf

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Патент на смазку для шариковых ШРУС типа Rzeppa/Fixed Ball & Double Offset Joint (DOJ) от Kyodo Yushi / NTN, крайне подробный и просто написанный, что особенно интересно в составе есть синтетичные эстеры, органический молибден, а также MoS2 и PTFE.

 

This invention relates to a grease composition for a Constant Velocity joint which can reduce variation in rotational resistance, at a low temperature, of the Constant Velocity joint and a Constant Velocity joint containing said grease composition. More specifically, this invention relates to a grease composition for a constant Velocity joint which is suitable to reduce variation in rotational resistance, at a low temperature, of a fixed type Constant Velocity joint or a sliding type Constant Velocity joint used for automobile driving shafts, and a constant Velocity joint containing the same.

 

Grease composition for constant velocity joint 2005.pdf

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Research on Friction Charateristics of Constant Velocity Joint Grease

Materials Technology & Analysis Team, Hyundai Motor Company

 

A GAF (generated axial force) is produced at a plunging-type CVJ (constant velocity joint). A high GAF can cause vibrations in a vehicle. Grease is used to reduce friction between the roller and the track of the outer case of a CVJ. The grease performance depends on the surface conditions and operating temperature. The surface of the outer case is extremely rough and hard. In recent times, the maximum operating temperature of CVJs has crossed 140 C, because the exhaust line is now located close to the CVJ. In this study, we examined the friction characteristics of friction additives at 25-150 C and determined an optimal formulation with a low friction coefficient. This formulation can be used to develop low-friction grease that can reduce the GAF pro- duced at a CVJ by approximately 7-26%.

 

Research on Friction Characteristics of Constant Velocity Joint Grease_ENG.pdf

 

Research on Friction Characteristics of Constant Velocity Joint Grease_KR.pdf

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Sealing compatibility of ester base oils

 

Dr. Hermann Josef Stolz, Dr. Wilhelm Huber, Dr. Martina Mennicken-Meuthen, Denise Weber,
Peter Greven GmbH & Co.KG

 

When using ester base oils, the product developers focus initially on application parameters such as viscosity, viscosity index, oxidation stability and pour point. But other parameters are not less important. This also includes the seal compatibility. In the past, sealing materials like elastomers were optimized for the contact with mineral oils. These days, synthetic esters gain importance and are more often used. As there are fundamental differences between mineral and synthetic based esters the used sealing materials are not always compatible with the new base oils. For example, elastomers – especially those with higher polarity – tend to swell more when exposed to a synthetic ester while mineral oils only lead to slight swelling or even shrinking.

 

Lube-Tech-138-Sealing-compatibility-of-ester-base-oils.pdf

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Overcoming Obstacles in Water Resistant H1 Specialty Greases Using Polymers

 

Erik Willett, PhD Functional Products Inc. Macedonia, OH USA

 

Water resistance is a critical performance aspect of grease that often becomes an obstacle in developing non-industrial greases for the H1 incidental food contact or biobased grease markets. A specialty grease formulation may perform well in many categories but fail water resistance testing by methods such as ASTM D4049 (water sprayoff) or ASTM D1264 (water washout). Improving water resistance late in the grease development process can involve extensive changes to the formulation. For example, HX1 base stocks are highly refined, which results in greases with low cohesion and little ability to resist the ingress of water as well as poor solubility for additives needed to fix the problem. This work shows how two HX1 grease polymers may be used in combination with a diverse range of HX1 base stocks to improve the water resistance of full PAO/mPAO base oil blends at significant cost reduction.

 

Overcoming Obstacles in Water Resistant H1.pdf

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Determination of low-temperature properties of lubricating greases

 

Elżbieta Trzaska, Agnieszka Skibińska Oil and Gas Institute – National Research Institute

 

The article presents the results of laboratory tests of low-temperature properties of lithium complex greases produced on base oils, characterized by a different chemical structure. Low-temperature properties of lubricating greases were determined according to the following test methods:

 

• low-temperature cone penetration – PN-ISO 13737

• flow pressure – DIN 51805-2

• apparent viscosity – PN-C-04146

 

It was found that the low-temperature properties of lubricating greases can be modified by introducing oils with a different chemical structure into the oil base. The lowest temperature of application of the tested lithium complex greases was determined.

 

Determination_of_low_temperature_properties.pdf

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Брошюра Castrol Range of Industrial Lubricants, полная версия от 2013 года

 

image.thumb.png.6709fca75072b7187cfaa1e25965d6c1.png

 

Сastrol-Range-of-Industrial-Lubricants.pdf

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Modified Fatty Acids as Alternative Soap Thickeners for Lubricating Greases

 

Devin Granger, PhD and Shadaab Maghrabi, PhD Ingevity Corporation, Charleston, SC USA

 

In 2020 and 2021, the COVID-19 pandemic has highlighted the fragility of global supply chains. Port closures in supply hubs have the potential to disrupt the 12-hydroxystearic acid (12-HSA) supply chain due to the vast majority of the supply used for grease thickeners passing through these hubs.[1] The introduction of effective alternatives to 12-HSA for use as grease thickeners can help grease manufacturers by alleviating their dependence on imports and reducing the possibility of production disruptions caused by supply chain breakdowns.

 

This paper describes initial experimental results that indicate that modified fatty acids (MFAs) not derived from castor oil can be used to form thickeners that are shear stable. The developmental MFAs can be used as obtained or blended with other fatty acids to form grease thickeners.

 

Modified Fatty Acids as Alternative Soap Thickeners.pdf

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Интересная статья от журнала сообщества Society of Tribologists and Lubrication Engineers (STLE), касательно того что согласно последним исследованиям специально сформулированные полимерные добавки могут выступать как модификатор трения в смазочных материалах, адсорбируясь на поверхностях трения и создавая поверхностную пленку, снижая коэффициент трения.

 

Characterizing the velocimetry of viscosity modifier-containing lubricants in the elastohydrodynamic regime

 

Eliane Gendreau and Janet Wong Department of Mechanical Engineering Imperial College London, South Kensington Campus, London

 

Viscosity modifiers are polymeric additives where the primary function is to increase the viscosity of lubricants. They improve the viscosity-temperature relationship while ensuring a good shear stability of the oil.  An interesting property of viscosity modifiers is that they can also play the role of friction modifiers. Polymeric additives adsorbing on the contact surfaces form a boundary film that leads to a reduction in friction.

 

Recent studies in the boundary lubrication regime have proven that functionalized copolymers have the potential to be friction modifiers in addition to their use as viscosity modifiers.

 

 

Characterizing the velocimetry of viscosity.pdf

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Polyurea Thickened Lubricating Grease—The Effect of Degree of Polymerization on Rheological and Tribological Properties

 

Max Jopen 1, Patrick Degen 2, Stephan Henzler 2, Bastian Grabe 1 , Wolf Hiller 1 and Ralf Weberskirch 1,*
1 Faculty of Chemistry and Chemical Biology, Technical University of Dortmund
2 Carl Bechem GmbH

 

Lubricating greases based on urea thickeners are frequently used in high-performance applications since their invention in 1954. One property that has so far been neglected in the further development of these systems due to their low solubility and the resulting difficulty of analysis, is to better understand how the degree of polymerization affect such polyurea lubricating systems.

 

In this work, we prepared three different oligo- or polyurea systems with different degrees of polymerization (DP) and investigated the influence of DP on rheological and tribological properties. The results
showed that the DP has an influence on the flow limit in rheology as well as on the extreme pressure (EP) and anti-wear (AW) properties as examined by tribology measurements. By optimizing the DP for a thickener system, comparable EP and AW properties can be achieved through the use of additives. The DP showed an increasing influence on the flow limit. This could reduce damage to rolling bearings due to lateral loading at rest. Therefore, modifying the DP of the polyurea systems shows similar effects as the addition of external additives. Overall, this would reduce the use of additives in industrial applications.

 

Polyurea Thickened Lubricating Grease.pdf

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