Tribology and Mechanical Components Branch Overview

Wear, 1985

Tribology Letters, 2003

Many moving mechanical assemblies (MMAs) for space applications rely on a small, initial charge of lubricant for the entire mission lifetime, often in excess of five years. In many cases, the premature failure of a lubricated component can result in mission failure. If lubricant could be re-supplied to the contact in-situ, the life of the MMA could be extended. A

Tribology Transactions, 2003

Database, the largest collection of aeronautical and space science STI in the world. The Program Office is also NASA's institutional mechanism for disseminating the results of its research and development activities. These results are published by NASA in the NASA STI Report Series, which includes the following report types:

2012

The problem of overweight containers becomes a majo r concern of the maritime community. Huge number of containers are damaged and /or lost overboard every year as a result of stow collapse due to overweigh t containers. Apart from that, this problem affects in a dangerou s way the safety of ships by affecting the ships in tact stability. The maritime industry efforts continue to find a possib le solving problem solution in order to prevent acc idents but the problem still remained open. This paper presents th e risks involved in overweight containers and the i mpact of this problem on the maritime safety and safety of ships.

AIP PUBLISHING, 2021

There are continuous efforts on efficient and compact power transmitting aids and one of them is planetary gearbox find a major role in automotive and industrial applications. Planetary gearboxes are widely used where high power density with reduced dynamic vibrations and quiet operations is expected. Planetary gear transmissions have proved multi-fold advantages in comparison to conventional transmissions. The power gets divided over several planets resulting in a compact arrangement. In this paper, a review on the design, analysis, and optimization of a multistage planetary gearbox for a higher gear reduction ratio used for power transmissions is presented.

(CVD), physical vapor deposition (PVD), and ion implantation (11).A common feature of these techniques The use of surface-modification treatments is a widely is their ability to produce dense and adherent modified accepted practice to reduce the wear and modify the surfaces without need for subsequent friction behavior of surface regions while maintaining grinding/polishing treatments. Another feature of these desirable bulk properties (e.g. strength, hardness, techniques is their ability to introduce a wide range of thermal conductivity, etc.) of the underlying substrate, elements into near-surface regions. These treatments range from conventional diffusion processes, such as carburizing steels for case-hardening gears, to advanced non-equilibrium processes such as ETl PROGRAMACTIVITIES ion implantation or ion plating. The objective of research efforts in the Engineered Tribological Interfaces (ETl) Research efforts funded through the ETl task area of the task area of the DOE OTM/Tribology Programis to Tribology program are performed at a number of research develop and investigate new or emerging institutions. Table I lists these institutions and briefly surface-modification processes that show a potential for describes the subject of their efforts. The activities at improving and controlling the tribological behavior of Argonne National Laboratory (ANL) have focused surfaces and thus permit engineers to design primarily on evaluating the tribological properties under components for advanced heat engines based on dry and lubricated conditions of ceramics coatedwith desired bulk properties and near-surface tribological lubricious coatings using beam-assisted PVD processes. properties. Other efforts at ANL focus on: development and tribological evaluation of microwave-assistedCVD The research is oriented toward processes that are processes for deposition of smooth polycrystalline applicable in advanced transportation technologies and diamond filmson ceramics, deposition and evaluation of focuses on components. Especially germane in this diamond-like-carbon(DLC) films formed using ion-beamrespect is the case of advanced reciprocating engines deposition (IBD) processes, deposition of thick, dense, where upper-cylinder areas may operate at temperatures metallic coatings on porous ceramics, and deposition of that exceed the range of normal liquid lubricants. This is wear-resistant coatings using beam-assistedand plasmaconsidered by most experts to be the most critical issue sputtering PVD processes. The effort at the Naval facing the development of advanced heat engines. Research Laboratory (NRL) focused on characterizing Analogous needs exist for low-friction surfaces in the effects of process parameters on the microstructural bearings and seals for the regenerator cores for and mechanical (e.g. hardness and adhesion) properties automotive-gas turbine engines, of beam-assisted PVD TiN and Cr203 coatings deposited on steels. The effort at Universal Energy This paper reviews a number of programs funded Systems (UES) investigated the tribological and throughthe Engineered TribologicalInterfaces(ETl) microstructural propertiesof ceramicsthat were ion-Task area of the Tribology Program that utilize energetic implanted with lubricious elements (e.g. Mo and S) or beamsof atoms to enhance the mechanical and that were first PVD-coated and then ion-beam-mixedwith microstructural properties of near-surface regions to high-energy (MeV range) ions. The effort at the Basic improve the tribological performance of critical Industry Research Laboratory (BIRL) involves the components. The processes used in these programs development and tribological evaluation of high-rateinclude techniques based on chemical vapor deposition reactive-sputtered coatings (e.g. nitrides

Friction, 2020

The reach of tribology has expanded in diverse fields and tribology related research activities have seen immense growth during the last decade. This review takes stock of the recent advances in research pertaining to different aspects of tribology within the last 2 to 3 years. Different aspects of tribology that have been reviewed including lubrication, wear and surface engineering, biotribology, high temperature tribology, and computational tribology. This review attempts to highlight recent research and also presents future outlook pertaining to these aspects. It may however be noted that there are limitations of this review. One of the most important of these is that tribology being a highly multidisciplinary field, the research results are widely spread across various disciplines and there can be omissions because of this. Secondly, the topics dealt with in the field of tribology include only some of the salient topics (such as lubrication, wear, surface engineering, biotribolo...

Tribology International, 2004

The spark-ignited reciprocating internal combustion engine has been the powerplant of choice for automotive and light truck applications for over 100 years. Whether this engine type will remain dominant in the future will depend on automakers' ability to find economically viable solutions to many constraints. Legislative demands continue to mount for better fuel economy, reduced exhaust emissions, increased recycleability and freedom from hazardous substances. Simultaneously, consumers are reluctant to accept any decrease in performance, features, range, quality and reliability. The tribological implications of changes in current engine materials are discussed. While these challenges are formidable, it is considered likely that, through evolution, the reciprocating engine will remain ahead of its more revolutionary competitors (e.g. fuel cells) for many years to come.

2015

Harmonic Drive® gears are used in several space flight mechanisms such as SADM’s or pointing mechanisms. Main reasons for choosing the gears are advantages like zero backlash, high gear stiffness and high transmission accuracy. Nowadays typically grease lubrication is used, whereas this is linked to the risk of outgassing and limits the operational temperature. In order to increase the temperature range, trials to apply solid lubricants to Harmonic Drive® gears, were performed. Based on these trials it was found that the gears can be operated even at -269°C. Anyhow, although being used in various cryogenic applications, the reachable lifetime is comparably short. So as to improve the achievable endurance an essential development was necessary. Hence the EU – funded project HarmLES was executed in order to significantly increase the accessible lifetime. Following an integrated approach covering gear design, materials and coating, the prototype of a new Harmonic Drive® gear type was d...

1992

The experimental evaluation of advanced mechanical properties that characterize the behavior of emerging materials for aerospace structures under a broad range of conditions representative of those encountered in service was emphasized in this investigation. The information ...