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Author: A. O. Lebeck
Publisher:
Published: 1976
Total Pages: 0
ISBN-13:
DOWNLOAD EBOOKThe objective of this research is to further the understanding of mechanical face seal lubrication phenomena. The ultimate objective is to develop the capability of designing contacting face seals having a longer life, greater.
Author: Alan O. Lebeck
Publisher: John Wiley & Sons
Published: 1992-04-16
Total Pages: 804
ISBN-13: 9780471515333
DOWNLOAD EBOOKExamines the fundamentals and practice of both the design and operation of face seals, ranging from washing machines to rocket engine turbopumps. Topics include materials, tribology, heat transfer and solid mechanics. A variety of simple and complex models are proposed and evaluated and specific problems such as heat checking, blistering and instability are considered. Offers 64 tables and 364 references plus useful recommendations regarding the future of seal design.
Author:
Publisher:
Published: 1978
Total Pages: 782
ISBN-13:
DOWNLOAD EBOOKLists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Author:
Publisher:
Published: 1977
Total Pages: 564
ISBN-13:
DOWNLOAD EBOOKAuthor:
Publisher:
Published: 1978
Total Pages: 922
ISBN-13:
DOWNLOAD EBOOKSections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Author: A. O. Lebeck
Publisher:
Published: 1977
Total Pages: 157
ISBN-13:
DOWNLOAD EBOOKIn this report lubrication effects caused by waviness in contacting mechanical face seals are investigated. A lubrication model is developed which includes the effects of hydrodynamic lubrication in conjunction with asperity contact, asperity contact pressure A lubrication model is developed which includes the effects of hydrodynamic lubrication in conjunction with asperity contact, asperity contact pressure, elastic deformation of the seal rings, and wear of the surfaces. Several sources of initial waviness are considered. Based on a one dimensional model, it is shown that some amount of hydrodynamic load support can be expected to occur in a water seal even though there is a considerable fraction of rubbing contact. As the fraction of load supported by hydrodynamic pressure becomes greater, the average wear rate will become smaller. Thus any parameter changes which cause greater hydrodynamic support are desireable. It is shown that there exists an optimum initial waviness and face width to maximize hydrodynamic load support. It is also shown that lower values of surface roughness lead to higher load support. Time dependent effects are obtained by including wear in the model. It is shown ethat most initial waviness will wear away under steady state operating conditions, and thus hydrodynamic load support will decrease with time. Neither thermal effects nor friction effects alter this behavior. However, a variable sealed pressure may lead to a stable or increasing fraction of hydrodynamic load support.
Author: A. O. Lebeck
Publisher:
Published: 1978
Total Pages: 190
ISBN-13:
DOWNLOAD EBOOKIn this report a model is developed which describes lubrication effects caused by circumferential waviness in face seals. This two dimensional model accounts for the effects of hydrodynamic and hydrostatic pressure, fluid film cavitation, surface roughness, asperity contact and load support, and elastic deflection. The fraction of load supported by fluid pressure, relative wear rate, pressure distribution, friction, and leakage are predicted given the waviness, pressure, speed, material, geometry, viscosity, and surface roughness. The model is applicable to heavily loaded, low viscosity seals where partial contact is expected. The results from the model have been compared to available experimental results. The model shows that the magnitude of surface roughness is the most important parameter determining the extent of hydrodynamic lubrication. Seal faces with low roughness are more likely to display hydrodynamic effects than seal faces having larger roughness.
Author: Ping Huang
Publisher: John Wiley & Sons
Published: 2015-05-05
Total Pages: 368
ISBN-13: 1118920996
DOWNLOAD EBOOKThe book not only offers scientists and engineers a clear inter-disciplinary introduction and orientation to all major EHL problems and their solutions but, most importantly, it also provides numerical programs on specific application in engineering. • A one-stop reference providing equations and their solutions to all major elastohydrodynamic lubrication (EHL) problems, plus numerical programs on specific applications in engineering • offers engineers and scientists a clear inter-disciplinary introduction and a concise program for practical engineering applications to most important EHL problems and their solutions • brings together a number of case studies in one text, each being solved using solution methods which share common features and methods
Author: S. M. Sidik
Publisher:
Published: 1978
Total Pages: 52
ISBN-13:
DOWNLOAD EBOOKRelations for the asperity contact time fraction during elastohydrodynamic (EHD) lubrication of a typical ball bearing are presented. The analysis is based on a two-dimensional random surface model, and actual profile traces of the bearing surfaces were used as statistical sample records. The results of the analysis show that transition from 90 percent contact to 1 percent contact occurs within a dimensionless film thickness range of approximately 4 to 5. This thickness ratio is several times larger than reported in the literature where one-dimensional random surface models were used.
Author: Frederick D. Ju
Publisher:
Published: 1983
Total Pages: 122
ISBN-13:
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