Next Issue
Volume 3, December
Previous Issue
Volume 3, June

Table of Contents

Lubricants, Volume 3, Issue 3 (September 2015) , Pages 493-627

  • Issues are regarded as officially published after their release is announced to the table of contents alert mailing list.
  • You may sign up for e-mail alerts to receive table of contents of newly released issues.
  • PDF is the official format for papers published in both, html and pdf forms. To view the papers in pdf format, click on the "PDF Full-text" link, and use the free Adobe Readerexternal link to open them.
Order results
Result details
Select all
Export citation of selected articles as:
Open AccessArticle
Influence of Base Oil Polarity on the Transient Shear Flow of Biodegradable Lubricating Greases
Lubricants 2015, 3(3), 611-627; https://doi.org/10.3390/lubricants3030611 - 09 Sep 2015
Cited by 2 | Viewed by 2017
Abstract
The scope of this study is to elucidate the physical mechanisms influencing the transient flow behavior of lubricating greases based on biogenic oleochemicals from a polarity point of view. This includes the mutually interacting influence of base oil polarity and thickening agents on [...] Read more.
The scope of this study is to elucidate the physical mechanisms influencing the transient flow behavior of lubricating greases based on biogenic oleochemicals from a polarity point of view. This includes the mutually interacting influence of base oil polarity and thickening agents on the rheologically-measured mechanical structural degradation in transient shear flow. Due to the high temperature dependence of Keesom forces in the background of polar-active bond mechanisms, the analysis of the transient flow response as a function of temperature allows to attribute the observed influences to differences in base oil polarity. In general, clay-thickened greases show a greater tendency to be rheologically influenced by base oil polarities than soap-thickened lubricating greases. Full article
(This article belongs to the Special Issue Lubricating Greases)
Show Figures

Figure 1

Open AccessArticle
Ultra-High Molecular Weight Polyethylene Reinforced with Multiwall Carbon Nanotubes: In Vitro Biocompatibility Study Using Macrophage-Like Cells
Lubricants 2015, 3(3), 597-610; https://doi.org/10.3390/lubricants3030597 - 31 Jul 2015
Cited by 4 | Viewed by 2337
Abstract
Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwall carbon nanotubes in biomaterials contacting with bone. This study describes the response of murine macrophage-like Raw 264.7 cells [...] Read more.
Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwall carbon nanotubes in biomaterials contacting with bone. This study describes the response of murine macrophage-like Raw 264.7 cells after two and six days of culture in contact with artificially generated particles from both, ultra-high molecular weight polyethylene polymer and the composite (multiwall carbon nanotubes and ultra-high molecular weight polyethylene). This novel composite has superior wear behavior, having thus the potential to reduce the number of revision knee arthroplasty surgeries required by wear failure of tibial articulating component and diminish particle-induced osteolysis. The results of an in vitro study of viability, and interleukin-6 and tumor necrosis factor-alpha production suggest good cytocompatibility, similar to that of conventional ultra-high molecular weight polyethylene. Full article
(This article belongs to the Special Issue Tribological Performance of Artificial Joints) Printed Edition available
Show Figures

Figure 1

Open AccessArticle
Friction Reduction and Reliability for Engines Bearings
Lubricants 2015, 3(3), 569-596; https://doi.org/10.3390/lubricants3030569 - 23 Jul 2015
Cited by 10 | Viewed by 2698
Abstract
Friction reduction is necessary in order to decrease engine emissions, so bearing friction needs to be reduced but with the constraint that low friction solutions should not affect bearing reliability. To meet this target of low friction and high reliability bearings, several technical [...] Read more.
Friction reduction is necessary in order to decrease engine emissions, so bearing friction needs to be reduced but with the constraint that low friction solutions should not affect bearing reliability. To meet this target of low friction and high reliability bearings, several technical solutions are reviewed. Particular attention is paid to evaluating friction reduction performance for each solution. Damage risks relating to customer uses are also presented in order to check that these risks are negligible with low friction solutions. Full article
(This article belongs to the Special Issue Friction and Lubrication of Bearings)
Show Figures

Figure 1

Open AccessReview
In Vitro Analyses of the Toxicity, Immunological, and Gene Expression Effects of Cobalt-Chromium Alloy Wear Debris and Co Ions Derived from Metal-on-Metal Hip Implants
Lubricants 2015, 3(3), 539-568; https://doi.org/10.3390/lubricants3030539 - 14 Jul 2015
Cited by 13 | Viewed by 2458
Abstract
Joint replacement has proven to be an extremely successful and cost-effective means of relieving arthritic pain and improving quality of life for recipients. Wear debris-induced osteolysis is, however, a major limitation and causes orthopaedic implant aseptic loosening, and various cell types including macrophages, [...] Read more.
Joint replacement has proven to be an extremely successful and cost-effective means of relieving arthritic pain and improving quality of life for recipients. Wear debris-induced osteolysis is, however, a major limitation and causes orthopaedic implant aseptic loosening, and various cell types including macrophages, monocytes, osteoblasts, and osteoclasts, are involved. During the last few years, there has been increasing concern about metal-on-metal (MoM) hip replacements regarding adverse reactions to metal debris associated with the MoM articulation. Even though MoM-bearing technology was initially aimed to extend the durability of hip replacements and to reduce the requirement for revision, they have been reported to release at least three times more cobalt and chromium ions than metal-on-polyethylene (MoP) hip replacements. As a result, the toxicity of metal particles and ions produced by bearing surfaces, both locally in the periprosthetic space and systemically, became a concern. Several investigations have been carried out to understand the mechanisms responsible for the adverse response to metal wear debris. This review aims at summarising in vitro analyses of the toxicity, immunological, and gene expression effects of cobalt ions and wear debris derived from MoM hip implants. Full article
(This article belongs to the Special Issue Tribological Performance of Artificial Joints) Printed Edition available
Show Figures

Figure 1

Open AccessArticle
A Generic Friction Model for Radial Slider Bearing Simulation Considering Elastic and Plastic Deformation
Lubricants 2015, 3(3), 522-538; https://doi.org/10.3390/lubricants3030522 - 30 Jun 2015
Cited by 11 | Viewed by 2478
Abstract
The investigation of component dynamics is one of the main tasks of internal combustion engine (ICE) simulation. This prediction is important in order to understand complex loading conditions, which happen in a running ICE. Due to the need for fuel saving, mechanical friction, [...] Read more.
The investigation of component dynamics is one of the main tasks of internal combustion engine (ICE) simulation. This prediction is important in order to understand complex loading conditions, which happen in a running ICE. Due to the need for fuel saving, mechanical friction, in particular in radial slider bearings, is one important investigation target. A generic friction modeling approach for radial slider bearings, which can be applied to lubricated contact regimes, will be presented in this paper. Besides viscous friction, the approach considers in particular boundary friction. The parameterization of the friction model is done using surface material and surface roughness measurement data. Furthermore, fluid properties depending on the applied oil additives are being considered. The application of the model will be demonstrated for a typical engineering task of a connecting rod big end study to outline the effects of contact surface texture. AlSn-based and polymer coated bearing shells will be analyzed and compared with respect to friction reduction effects, running-in behavior and thermal load capabilities. Full article
(This article belongs to the Special Issue Numerical Simulation of Static and Dynamic Friction)
Show Figures

Figure 1

Open AccessArticle
Probability of Face Contact for a High-Speed Pressurised Liquid Film Bearing Including a Slip Boundary Condition
Lubricants 2015, 3(3), 493-521; https://doi.org/10.3390/lubricants3030493 - 24 Jun 2015
Cited by 3 | Viewed by 1920
Abstract
An initial deterministic mathematical model for the dynamic motion of a simple pressurised liquid film bearing is derived and utilised to evaluate the possibility of bearing contact for thin film operation. For a very thin film bearing the flow incorporates a Navier slip [...] Read more.
An initial deterministic mathematical model for the dynamic motion of a simple pressurised liquid film bearing is derived and utilised to evaluate the possibility of bearing contact for thin film operation. For a very thin film bearing the flow incorporates a Navier slip boundary condition as parametrised by a slip length that in general is subject to significant variability and is difficult to determine with precision. This work considers the formulation of a modified Reynolds equation for the pressurised liquid flow in a highly rotating coned bearing. Coupling of the axial motion of the stator is induced by prescribed axial oscillations of the rotor through the liquid film. The bearing gap is obtained from solving a nonlinear second-order non-autonomous ordinary differential equation, via a mapping solver. Variability in the value of the slip length parameter is addressed by considering it as a random variable with prescribed mean and standard deviation. The method of derived distributions is used to exactly quantify the impact of variability in the slip length with a parametric study investigating the effect of both the deterministic and distribution parameters on the probability of contact. Additionally, as the axial rotor oscillations also have a random aspect due to possible varying excitations of the system, the probability of contact is investigated for both random amplitude of the periodic rotor oscillations and random slip length, resulting in a two parameter random input problem. The probability of contact is examined to obtain exact solutions and evaluate a range of bearing configurations. Full article
(This article belongs to the Special Issue Friction and Lubrication of Bearings)
Show Figures

Figure 1

Previous Issue
Next Issue
Back to TopTop