摘要:

AbstractBecause of the interaction of the large number of parameters influencing stick‐slip, it is very difficult to perform repeatable and reproducible tests that define the anti‐stick‐slip properties of lubricants. In order better to understand the difficulties encountered in stick‐slip testing, an overview of the influencing parameters, with a discussion of each parameter, is given in this paper.Some modifications of the reciprocating stick‐slip tester that was used in the ASTM test procedure before the latter was withdrawn, in order to improve the repeatability of its test results, are discussed. The significance of the results is checked by comparison with a rotary stick‐slip tester.Finally, recommendations for correct stick‐slip testing and interpretation of stick‐slip result

ISSN:1354-4063    

DOI:10.1002/tt.3020030402

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

摘要:

AbstractDiesel exhaust particulates contain an organic fraction than can be attributed to the engine lubricant. This lubricant fraction varies from a mass fraction of 15% to over 50%, depending on the engine and the operating conditions. This paper addresses the issue of developing novel lubricants that have a lower contribution to diesel particulate. In this work, an analytical technique (TGA/DTA) was developed to measure rapidly the lubricant contribution to diesel particulate. Two apparatus were constructed to simulate the interactions between carbonaceous soot and lubricant products under a variety of test conditions. The combination of simulation apparatus and analytical technique guided the development of lubricants with reduced contribution to particulate. Several formulated lubricants were developed, based on concepts of lower volatility and better oxidative and thermal stability. Initial testing of these lubricants in the simulation apparatus indicated several candidates with reduced interaction with diesel particulate soot.

ISSN:1354-4063    

DOI:10.1002/tt.3020030403

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

摘要:

AbstractReliable laboratory screening tests are an important stage in the development of automotive oils, because these oils are required to pass expensive engine tests to establish their performance credentials. The oxidation stability of crankcase lubricants is a vital parameter which defines the longevity of these oils in service. ASTM Sequence IIID and IIIE tests are used in the industry to evaluate this parameter. The present paper describes the development of a simple, bubbling oxygen, glassware, catalyst inhibited, type oxidation test. The test conditions have been optimised to get better discretion in the results, and the test results, when statistically correlated with the corresponding ASTM Sequence IIID and IIIE data, indicate that a 50–375% viscosity rise in HOOT will ensure a comfortable IIID pass with 98% confidence. However, in the case of IIIE, a viscosity rise of HOOT below 50% may indicate a IIID+ or IIIE performance with only 50% confidence. Improvement of the correlation between HOOT and IIIE can only be achieved by increasing the severity of the test condition

ISSN:1354-4063    

DOI:10.1002/tt.3020030404

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

摘要:

AbstractAccurate diesel lubricating oil testing, formerly relegated only to oil laboratories, can now be performed routinely aboard ship using a series of first‐generation, new‐concept, oil analysis meters. The modern design equipment yields reliable oil test data whose quality approaches that derived from traditional, but often difficult to perform, oil laboratory testing. This equipment contains operating concepts that were jointly codeveloped for fleet use by contractors with direct technical input from NSWCCD‐SSES engineering personnel. The oil testers available are compact, affordable, streamlined, microprocessor‐based devices, containing simplified hardware and menu‐driven software. Further, these devices were designed with extensive onboard oil‐test data storage capabilities. Engine test data obtained is stored so that it can be offloaded to a printer or a computer for operational trending, characteristics that are useful for long‐term tracking of engine conditions, commensurate with condition‐based machinery maintenance concepts. Design ideas employed in the equipment were aimed at making it essentially equivalent to laboratory testing, yet operator‐friendly and easy to use.Evaluation of the testers was completed in about three years from initial conception until commercial products were realised. Included in the evaluaton studies were statistical data comparisons with established testing procedures, along with long‐term fleet testing. The equipment includes kinematic viscosity, fuel dilution (FD), and total base number (TBN) meters.Additional work is continuing on the development of similar equipment for assessing moisture, solids contamination, wear/particle analysis, and total acid number (TAN) evaluations in other oils, so that the US fleet may increase real‐time analysis and dia

ISSN:1354-4063    

DOI:10.1002/tt.3020030405

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

摘要:

AbstractThe development of materials for tribological applications requires characterisation of their friction and wear behaviour. This characterisation is often based on tribological model testing, working with simple shaped specimens, running under well‐defined conditions. Discrepancies in test results may arise from the fact that non‐standard tests with different sets of operational parameters are used.An essential starting point for the development of tribological standards is knowledge of the main parameters that influence the tribological properties. One aspect that is not often adequately taken into account is the surface finish of the test specimens. Results are presented of friction and wear tests with self‐mated SSiC couples (ball on disc), running in water in an oscillating sliding mode. The surfaces of the disc were ground, lapped, or polished, respectively, running against a polished ball.For certain test conditions, the influence of the surface finish on wear is found to be negligible, while for other conditions, the wear rate can differ by one order of magnitude or even more.The consequences for the standardisation of wear tests of ceramic materials are disc

ISSN:1354-4063    

DOI:10.1002/tt.3020030406

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

摘要:

AbstractThe total demand for lubricants in India is in the region of 855,000 tonnes a year. This constitutes 1.5% of total petroleum products consumption. Presently, there are three lubricant refineries in the country with a total installed capacity of 535,000 tonnes. The shortfall, of about 370,000 tonnes (approximately 45% of demand), is met through imports. In addition, there are generated 60,000–65,000 tonnes a year of base oil through rerefining of used oils. The three refineries are being expanded in order to raise base oil production to 810,000 tonnes per annum. Some other refinery projects are also under consideration and approval by the government. The current expansion programmes, together with the projected new refineries, are expected to make India self‐sufficient in terms of base stock production lubricant.Overall, lubricant production in India is entirely dependent on imported lubricant‐bearing crudes, and not on the indigenous crudes, which are non‐lube bearing. With recent advances in engine design, together with improved lubricant quality through high‐performance lubricants, the consumption, or demand rate, has been in decline or unchanging in most countries. In India, a gap still exists between production and demand of lubricants, necessitating import. Since they are a high‐value, non‐energy product, lubricant conservation measures are therefore essential.Interest in rerefining of used oil is increasing, with more and more emphasis on making the processes environmentally friendly. The conventional acid‐clay rerefining process is environmentally unfriendly, and hence needs modification. An attempt is made in this paper to highlight various rerefining processes available. The relative merits and demerits of each process are discussed, and among the various processes, that based on molecular/high vacuum distillation is co

ISSN:1354-4063    

DOI:10.1002/tt.3020030407

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020030408

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020030409

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020030410

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY

ISSN:1354-4063    

DOI:10.1002/tt.3020030401

出版商:John Wiley&Sons, Ltd    

年代:1997

数据来源: WILEY