摘要:

AbstractTwenty‐two samples of zinc carboxylates were prepared from saturated, non‐cyclic carboxylic acids with systematically altered hydrocarbon chain structures under well‐defined conditions. Essential temperature‐ and solvent‐induced changes concerning the coordination of the carboxylate group are shown using selected prepared samples, and general rules for systems containing zinc carboxylates in nonpolar media are presented.It is shown that there are three possible structural forms for zinc carboxylates: polymeric sheet, polymeric chain, and closed tetranuclear oxo complex molecules. These forms are closely related through their physical and chemical transitions.The results show that the spatial structure of the hydrocarbon chain is a crucial factor, besides physical and chemical conditions, limiting the possible forms of zinc carboxylates present in the system. The principles presented enable us to predict and design the behaviour of a system containing zinc carboxylate

ISSN:0954-0075    

DOI:10.1002/ls.3010110202

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY

摘要:

AbstractTo reduce energy consumption, it is important to increase the efficiency of gears used for power transmission. In the present work, the efficiencies of gear drives with standard and profile shifted involute gears are measured by changing the type of lubricating oil. A new equation for calculating efficiency is derived by taking into account the additional friction torque that depends on the shape of the teeth. The efficiencies calculated with the new equation agree well with those obtained by experiments conducted using two planetary gear drives with different tooth shapes and with different reduction ratios (u = 4. 89 and 151). The new equation is applicable to the design of gear drives with higher efficiency.

ISSN:0954-0075    

DOI:10.1002/ls.3010110203

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY

摘要:

AbstractThis paper reports on the synthesis and tribological performance of N‐ZDDP, a type of additive containing nitrogen, that is O,O‐diaryl‐N‐methylene‐O,O‐zinc dialkyldithiophosphate, synthesised by Mannich and other reactions, and useful for improving antioxidation and anticorrosion behaviour in hydraulic, gear, and engine oils. Compared with conventional zinc dialkyldithiophosphate (ZDDP), N‐ZDDP widens the thermal decomposition temperature range, and its antioxidant behaviour is improved by 40%, and its anticorrosion properties by 50%. The load‐carrying capacity of N‐ZDDP is superior to that of ZDDP; its wear resistance, however, is simila

ISSN:0954-0075    

DOI:10.1002/ls.3010110204

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY

摘要:

AbstractThis paper describes the synthesis of highly reactive polyisobutene (PIB), a special type of PIB used as a component in the production of lubricant and fuel additives. The reactivity and the chemical structure are described in detail, in relation to the nature of the product and its uses as an additive component.

ISSN:0954-0075    

DOI:10.1002/ls.3010110205

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY

摘要:

AbstractThere is a basic interest in the activity of antifriction additives, which are important to fuel economy and the wear of engine components. This paper investigates the influence of some antifriction compounds, including molybdenum dithiophosphine and dithiocarbamine, on the layers formed on rubbing parts. It was found that there were differences in the antifriction performance of the oils containing the candidate additives, and the paper offers an explanation of the mechanism of action at work.

ISSN:0954-0075    

DOI:10.1002/ls.3010110206

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY

摘要:

AbstractIron rhenate was compounded by a chemical method, which can be reproduced during the wear process of Fe‐Re alloys at elevated temperatures. The friction coefficient of iron rhenate was determined using five types of ball material (Si3N4, Al2O3, glass, 440 C, and Hast C) matching seven types of disc material (Al2O3, 761 iron base superalloy, glass, stainless steel, bronze, copper, and Al‐Li), using a ball‐on‐disc device. The results show that the iron rhenate plays a role in lubrication from room temperature to 600°C. The lubrication behaviour is related to the nature of the matching pairs: the hardness of the materials, the compatibility of iron rhenate with the materials of the matching pairs, and the surface roughness of the disc most affect the lubrication behaviour of iron rhenate. The principle of tribologically matching pairs is

ISSN:0954-0075    

DOI:10.1002/ls.3010110207

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY

摘要:

AbstractAshless antiwear, antioxidant, and extreme‐pressure additives based on hydrocarbon‐soluble metallic complexes of thio‐bis‐phenols, their method of preparation, and their use as additives in oils and industrial greases, have been studied. This paper presents a description of their derivation and perf

ISSN:0954-0075    

DOI:10.1002/ls.3010110208

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY

ISSN:0954-0075    

DOI:10.1002/ls.3010110201

出版商:John Wiley&Sons, Ltd    

年代:1999

数据来源: WILEY