Download or read book An Analytical and Numerical Study of Profiled Hydrostatic Thrust Bearings written by Jianpeng Feng and published by . This book was released on 2004 with total page 168 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the lubrication problem associated with profiled hydrostatic thrust bearings is studied using analytical, numerical, and experimental techniques. The coupled fluid-solid problem is solved using a sequentially coupled iterative method where the classical Reynolds equation is used to obtain the lubrication pressure and ABAQUS/STANDARD is used to obtain the bearing surface deformation. A novel feature of the work is that it considers several new designs obtained by varying the geometry of the socket, which in turn alters the contact between the piston ball and the slipper bearing. The performance of the new designs are analyzed and compared with the standard design performance. The surface profile of the bearings is measured experimentally and its effect on the bearing performance is studied numerically. The load carrying capacity results are compared with experimentally measured values. Further, for the standard design bearing, the effect of pocket width is also studied. A numerical technique based on variational formulation is developed to study the bearing problem with translation. The results show that the translation speed effect is more significant in shallow pocket thrust bearings and generates a bigger tilt moment than in deep pocket thrust bearings. At high translation speeds, the pressure profile shows a sharp spike (Rayleigh step effect) at the trailing land step interface. A finite difference scheme is developed to capture the spike. Comparisons with three-dimensional CFD simulations indicate that the method works well in predicting the pressure spike as well as the tilting moment.

Download or read book Experimental and Numerical Analysis of Flow and Pressure Fields Inside a Variable Depth Single Pocket Hydrostatic Bearing written by Frank Eugene Horvat and published by . This book was released on 2008 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper studies the experimental and numerical development of flow patterns and pressure profiles inside a variable depth pocket of a hydrostatic journal bearing. The parameters used in this study consist of the pockets aspect ratio, restrictor inlet conditions and shaft velocity. The investigation will be conducted at both low and high shaft rotational speeds. The flow visualization method uses a full flow field tracking Lagrangian method to track microsphere particles injected in the main stream of pocket's feedline and thus reconstruct the flow pattern in the pocket. A high intensity pulsed laser is used to create a thin sheet of light that locates and illuminate the particles in a plane, while a long distance microscope (LDM) video camera is used to record digitally the flow images. The experimental endeavor is supplemented by a numerical simulation which uses CFD-ACE+ (of ESI Corporation, Huntsville, AL) as the computational engine. This package utilizes the full three-dimensional Navier-Stokes equations applied for a steady-state incompressible Newtonian fluid with constant properties flowing in a hydrostatic pocket. The results offered herein present both numerical velocity vector and pressure fields and experimental qualitative flow patterns for the shallow and deep pockets.

Download or read book A Numerical Study of Roughness Effects on the Performance of Hydrostatic Thrust Bearings written by Kirat Shah and published by . This book was released on 2005 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this work, the effects of surface roughness on the performance of hydrostatic thrust bearings are investigated using numerical techniques. Both shallow pocket and deep pocket bearings are analyzed for lubrication conditions where the roughness is of the same order of magnitude as the minimum film thickness. The classical Reynold's equation is taken as the governing equation for the lubrication problem and the effects of surface roughness are analyzed using numerically generated rough surfaces. Rough surfaces are generated by Patir's linear transformation method and Wu's Fast Fourier Transform method. Generated surfaces using these methods exhibit the Gaussian distribution of roughness heights. In order to analyze the effects of Non-Gaussian distribution of roughness heights, the Johnson system of translation is used. The Johnson system of translation converts given Gaussian distribution to the non-Gaussian distribution as per user input. Non-Gaussian distribution of roughness heights are characterized using different values of skewness and kurtosis. Using the numerically generated rough surfaces as the bearing surfaces, a finite difference method is developed to solve the lubrication equation. It is found that in the case of deep pocket bearings, negatively skewed surfaces decrease the load carrying capacity, and positively skewed surfaces increase the load carrying capacity. On the other hand, in the case of shallow pocket bearings, both types of roughness increase the load carrying capacity. However, increase in the load carrying capacity due to negatively skewed surfaces is lower than that in positively skewed surfaces. Furthermore, the change in the load carrying capacity of shallow pocket bearings due to the roughness is higher than the change in load carrying capacity of deep pocket bearings.

Download or read book Hydrodynamic and Hydrostatic Lubricated Bearings with Particular Reference to Air Bearings written by M. A. Koenders and published by . This book was released on 1958 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1975 with total page 1000 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Dissertation Abstracts International written by and published by . This book was released on 2007 with total page 960 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Hydrostatic Lubrication written by R. Bassani and published by Elsevier. This book was released on 1992-08-20 with total page 559 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrostatic lubrication is characterized by the complete separation of the conjugated surfaces of a kinematic pair, by means of a film of fluid, which is pressurized by an external piece of equipment. Its distinguishing features are lack of wear, low friction, high load capacity, a high degree of stiffness and the ability to damp vibrations.This book reviews the study of externally pressurized lubrication, both from the theoretical and the technical point of view, thereby serving the needs of both researchers as well as students and technical designers. In this connection, design suggestions for the most common types of hydrostatic bearings have been included, as well as a number of examples. A comprehensive bibliography is included with each chapter providing up to date references for more in depth coverage.

Download or read book Analysis and Computer Program for Evaluation of Rotating Incompressibly Lubricated Pressurized Thrust Bearings written by David P. Fleming and published by . This book was released on 1971 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Stability Analysis of Hydrostatic Air Thrust Bearings written by Gary Joseph Kimmet and published by . This book was released on 1969 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book On the Analytical and Experimental Investigation of a Hydrostatic Axisymmetric Compliant surface Thrust Bearing written by V. Castelli and published by . This book was released on 1966 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: The paper presents experimental and theoretical data on the axisymmetric hydrostatic thrust bearing with one bonded compliant surface. The theoretical results are exact and are based on linear elasticity theory. The effects of compliance on the behavior of the thrust bearing are discussed and illustrated. (Author).

Download or read book Principles of Tribology written by Shizhu Wen and published by John Wiley & Sons. This book was released on 2012-02-21 with total page 477 pages. Available in PDF, EPUB and Kindle. Book excerpt: Professors Wen and Huang present current developments in tribology research along with tribology fundamentals and applications, including lubrication theory, lubrication design, friction mechanism, wear mechanism, friction control, and their applications. In addition to classical tribology, Wen and Huang cover the research areas of the modern tribology, as well as the regularities and characteristics of tribological phenomena in practice. Furthermore, the authors present the basic theory, numerical analysis methods, and experimental measuring techniques of tribology as well as their applications in engineering. Provides a systematic presentation of tribology fundamentals and their applications Discusses the current states and development trends in tribology research Applies the applications to modern day engineering Computer programs available for download from the book’s companion site Principles of Tribology is aimed at postgraduates and senior-level undergraduates studying tribology, and can be used for courses covering theory and applications. Tribology professionals and students specializing in allied areas of mechanical engineering and materials science will also find the book to be a helpful reference or introduction to the topic. Companion website for the book: www.wiley.com/go/wen/tribology

Download or read book Fundamentals of Machine Elements Third Edition written by Steven R. Schmid and published by CRC Press. This book was released on 2014-07-18 with total page 633 pages. Available in PDF, EPUB and Kindle. Book excerpt: New and Improved SI Edition—Uses SI Units Exclusively in the Text Adapting to the changing nature of the engineering profession, this third edition of Fundamentals of Machine Elements aggressively delves into the fundamentals and design of machine elements with an SI version. This latest edition includes a plethora of pedagogy, providing a greater understanding of theory and design. Significantly Enhanced and Fully Illustrated The material has been organized to aid students of all levels in design synthesis and analysis approaches, to provide guidance through design procedures for synthesis issues, and to expose readers to a wide variety of machine elements. Each chapter contains a quote and photograph related to the chapter as well as case studies, examples, design procedures, an abstract, list of symbols and subscripts, recommended readings, a summary of equations, and end-of-chapter problems. What’s New in the Third Edition: Covers life cycle engineering Provides a description of the hardness and common hardness tests Offers an inclusion of flat groove stress concentration factors Adds the staircase method for determining endurance limits and includes Haigh diagrams to show the effects of mean stress Discusses typical surface finishes in machine elements and manufacturing processes used to produce them Presents a new treatment of spline, pin, and retaining ring design, and a new section on the design of shaft couplings Reflects the latest International Standards Organization standards Simplifies the geometry factors for bevel gears Includes a design synthesis approach for worm gears Expands the discussion of fasteners and welds Discusses the importance of the heat affected zone for weld quality Describes the classes of welds and their analysis methods Considers gas springs and wave springs Contains the latest standards and manufacturer’s recommendations on belt design, chains, and wire ropes The text also expands the appendices to include a wide variety of material properties, geometry factors for fracture analysis, and new summaries of beam deflection.

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 836 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bulk Flow Analysis of Hybrid Thrust Bearings for Advanced Cryogenic Turbopumps written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: A bulk-flow analysis and computer program for prediction of the static load performance and dynamic force coefficients of angled injection, orifice-compensated hydrostatic/hydrodynamic thrust bearings have been completed. The product of the research is an efficient computational tool for the design of high-speed thrust bearings for cryogenic fluid turbopumps. The study addresses the needs of a growing technology that requires of reliable fluid film bearings to provide the maximum operating life with optimum controllable rotordynamic characteristics at the lowest cost. The motion of a cryogenic fluid on the thin film lands of a thrust bearing is governed by a set of bulk-flow mass and momentum conservation and energy transport equations. Mass flow conservation and a simple model for momentum transport within the hydrostatic bearing recesses are also accounted for. The bulk-flow model includes flow turbulence with fluid inertia advection, Coriolis and centrifugal acceleration effects on the bearing recesses and film lands. The cryogenic fluid properties are obtained from realistic thermophysical equations of state. Turbulent bulk-flow shear parameters are based on Hirs' model with Moody's friction factor equations allowing a simple simulation for machined bearing surface roughness. A perturbation analysis leads to zeroth-order nonlinear equations governing the fluid flow for the thrust bearing operating at a static equilibrium position, and first-order linear equations describing the perturbed fluid flow for small amplitude shaft motions in the axial direction. Numerical solution to the zeroth-order flow field equations renders the bearing flow rate, thrust load, drag torque and power dissipation. Solution to the first-order equations determines the axial stiffness, damping and inertia force coefficients. The computational method uses well established algorithms and generic subprograms available from prior developments. The Fortran9O computer program hydrothrust runs ...

Download or read book Numerical Analysis of Elastohydrodynamic Lubrication for Thrust Bearing Design written by and published by . This book was released on 2002 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transactions of the American Society of Mechanical Engineers written by American Society of Mechanical Engineers and published by . This book was released on 1963 with total page 1326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vols. 2, 4-11, 62-68 include the Society's Membership list; v. 55-80 include the Journal of applied mechanics (also issued separately) as contributions from the Society's Applied Mechanics Division.

Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1970 with total page 1798 pages. Available in PDF, EPUB and Kindle. Book excerpt: