Lithium-Soap Greases | ScienceGate

This study describes the influence of flow properties of lithium soap greases on torque of small ball bearings. Three types of greases with different worked penetration were tested in this study. Their rheological properties are revealed by a cone plate type rheometer. Shear stresses under various shear rates are fitted with the Herschel-Bulkley equation. In addition, viscoelastic behaviors of the greases are measured by small amplitude oscillatory shear. The crossover stress that means the shear stress at G’=G” is obtained for the greases. Then, the bearing torque when three types of greases are used as a lubricant is measured. As the results, the grease with higher crossover stress shows the lower bearing torque regardless of that it has larger apparent viscosity. On the other hand, the grease with lower crossover stress shows the higher bearing torque regardless of that it has lower apparent viscosity. These results imply that the channeling state appears in the grease with higher crossover stress while the churning state appears in the grease with lower crossover stress.

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Effects of Soap Fiber Structure on Boundary Lubrication of Lithium Soap Greases

Tribology Online ◽

10.2474/trol.6.219 ◽

2011 ◽

Vol 6 (4) ◽

pp. 219-225 ◽

Cited By ~ 4

Author(s):

Atsushi Yokouchi ◽

Michita Hokao ◽

Joichi Sugimura

Keyword(s):

Boundary Lubrication ◽

Fiber Structure ◽

Lithium Soap

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Influence of Soap Fiber Structure on Frictional Property of Lithium Soap Grease

ASME/STLE 2007 International Joint Tribology Conference, Parts A and B ◽

10.1115/ijtc2007-44377 ◽

2007 ◽

Cited By ~ 1

Author(s):

Atsushi Yokouchi ◽

Yuji Yamamoto

Keyword(s):

Surface Area ◽

Point Contact ◽

Frictional Resistance ◽

Frictional Property ◽

Test Apparatus ◽

Fiber Structure ◽

Base Oil ◽

Lithium Soap ◽

Sliding Test ◽

Better Than

The authors have reported on results from a sliding test, which was conducted using a ball-on-disk type point-contact sliding test apparatus under gradually increased loading. Under slow sliding conditions where formation of an oil film is not expected, friction-resistant properties of grease are better than those of base oil. This result indicates that the soap fibers in grease work to protect the rubbing surface. Grease with long soap fibers shows better frictional resistance properties and offers greater protection against friction at the rubbing surface than grease with short soap fibers. In this paper, we examined factors that influence different frictional resistance properties according to soap fiber structures in the grease. Evaluation results of the friction-resistant properties of soap fibers alone, and the evaluation results of conditions of entraining grease into the rubbing surface area, show that friction-resistant properties vary according to the soap fiber structure in grease as a result of the conditions of introducing grease into the rubbing surface area.

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An experimental check on the dominant role of reorienting methyl groups on the spin-lattice relaxation behaviour in a C17 lithium soap

Journal of Magnetic Resonance (1969) ◽

10.1016/0022-2364(71)90109-0 ◽

1971 ◽

Vol 4 (2) ◽

pp. 236-240 ◽

Cited By ~ 2

Author(s):

K Van Putts ◽

G.J.N Egmond

Keyword(s):

Dominant Role ◽

Lattice Relaxation ◽

Spin Lattice Relaxation ◽

Methyl Groups ◽

Relaxation Behaviour ◽

Experimental Check ◽

Spin Lattice ◽

Lithium Soap

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Grease thixotropy: evaluation of grease microstructure change due to shear and relaxation

Industrial Lubrication and Tribology ◽

10.1108/ilt-02-2012-0014 ◽

2014 ◽

Vol 66 (2) ◽

pp. 223-237 ◽

Cited By ~ 22

Author(s):

Maciej Paszkowski ◽

Sylwia Olsztyńska-Janus

Keyword(s):

Qualitative Assessment ◽

Structural Components ◽

Lubricating Grease ◽

Content Type ◽

Base Oil ◽

Force Microscopy ◽

Atomic Force ◽

Physicochemical Interactions ◽

Lithium Soap ◽

Mineral Base

Purpose – The thixotropy of lubricating grease thickened with lithium 12-hydroxystearate with mineral base oil was investigated. The thixotropy has a significant influence on the flow resistance and pressure drop in the structural components of lubrication systems, which is of major importance as today the latter are being centralized and automated. The paper aims to discuss these issues. Design/methodology/approach – Rheometer studies on thixotropy were carried out and the grease microstructure was visualized using atomic force microscopy (AFM). Total reflection Fourier transform infrared spectroscopy (ATR-FTIR) was used to study the physicochemical interactions which indicate the disintegration and recovery of the grease microstructure. Findings – A qualitative assessment of the physicochemical interactions between lithium soap floccules was made and a theory of the self-ordering effect of lithium 12-hydroxystearate associated molecules during shearing and their aggregation and flocculation during relaxation has been proposed. Originality/value – Because of the complexity of the disintegration and recovery of the lubricating grease thickener microstructure, there is still limited physical understanding of the mechanism of this process. Therefore, the present research was undertaken to identify the phenomena involved.

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