ISSN:0954-0075    

DOI:10.1002/ls.3010100202

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractOxidation stability is the single most important characteristic of lubricants that affects their service life and high‐temperature applicability. The chemical composition of base oils determines to a large extent the oxidation stability of the lubricants. For steam turbine oils, oxidation stability is more important still, as the oil is expected to remain in the system for 10–20 years. Selection of appropriate base oils, therefore, is crucial for the formulation of turbine oils. The oxidation stability of turbine oils is estimated by three bench tests, ASTM D‐943, ASTM D‐2272, and IP 280, which vary in severity, and are all time‐consuming. In this context, the prediction of oxidation test performance (oxidation stability) of base oils from their chemical composition appears to be very a

ISSN:0954-0075    

DOI:10.1002/ls.3010100203

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractUseful expressions are developed for the damping coefficient of two types of viscous dampers that contain electrorheological (ER) fluids. The damping action in the first type occurs in flow between stationary parallel plates; the second type has annular flow between two stationary concentric cylinders. For ER fluid control, an electric field is applied across the gap in which the fluid flow occurs. The solution for the concentric cylinder damper is based on a thin gap approximation. These solutions may facilitate solving mechanical systems problems, using ER fluids, and demonstrate the controllability of ER dampers.

ISSN:0954-0075    

DOI:10.1002/ls.3010100204

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractThe extreme‐pressure (EP) and antiwear (AW) performance of three soluble molybdenum compounds (commercial molybdenum dialkyldithiophosphate, commercial molybdenum dialkyl dithiocarbamate, and synthesised molybdenum dialkyl dithiocarbamate), and two sulphur‐containing EP compounds (sulphurised jojoba oil and sulphurised O‐stearyl‐S‐oleyl xanthate) have been studied alone and in combination, using a four‐ball tester. The behaviour of the additives in combination has been found to be selective, and dependent on the chemistry and ratio of the additive components. In general, the addition of Mo‐type friction modifiers (FM) to sulphurised EP compounds has shown a synergism, of varying order, in their EP and

ISSN:0954-0075    

DOI:10.1002/ls.3010100205

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractThe antifriction properties of calcium phenate‐type detergents of different lubricity were investigated by laboratory methods. Simulation of the operating environment in super‐long‐stroke marine diesel engines was achieved using concentrated sulphuric acid. The influence of the tested additives on engine oil antifriction properties was determined after their being mixed with acid. The tribological performance of oil samples with 50 and 70 TBN values was characterised by testing on a friction machine, and by thickness determination of friction surface layers using Auger spectroscopy. It was found that the effectiveness of antifriction action of the detergents tested depends on the thermal stability of the lubricating layers, the temperature at which the destruction of the boundary lubricating layers occurred, and the thickness of secondary structure layers in the metal surface of the friction

ISSN:0954-0075    

DOI:10.1002/ls.3010100206

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

摘要:

AbstractThiophosphates of zinc and molybdenum have been used in lubricant formulations to impart extreme pressure and anti‐wear properties for some time. Zinc dialkyldithiophosphate has found favour in greases as a multifunctional ‐ antioxidant, extreme pressure and antiwear ‐ add

ISSN:0954-0075    

DOI:10.1002/ls.3010100207

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY

ISSN:0954-0075    

DOI:10.1002/ls.3010100201

出版商:John Wiley&Sons, Ltd    

年代:1998

数据来源: WILEY