Chih Lin

Bio: Chih Lin is an academic researcher from Baker Hughes. The author has contributed to research in topics: Lubrication & Bearing (mechanical). The author has an hindex of 9, co-authored 15 publications receiving 343 citations.

Surface Texturing of Tribological Interfaces Using the Vibromechanical Texturing Method

Abstract: Modifying the surface topography of tribological interfaces has the potential to improve the friction performance of certain mechanical components that experience sliding contact. Vibromechanical texturing (VMT), an improved texturing method based on the convenient turning process, is introduced. This process is performed on a standard computer numeric controlled (CNC) lathe, which is retrofitted with a piezoelectric-actuated tool positioning stage. Controlled vibratory motion of the tool is used to cut microsized dimples into the surface of the workpiece. Two types of workpiece materials are used: aluminum and hardened steel, with three forms of workpiece geometries: outer cylinder, inner cylinder, and flat/end face. The accuracy of the texturing method is compared with a basic surface topography model, which predicts texture dimensions within an 11% error for aluminum and up to 90% error for hardened steel, using the current open-loop control system. Further analysis of the textured samples shows no significant signs of process-induced damage. It is demonstrated that this VMT method is a versatile, accurate technique that has potential to be a cost-effective means for surface texturing of tribological components.

Development of a Set of Stribeck Curves for Conformal Contacts of Rough Surfaces

Abstract: The Stribeck curve is an overall view of friction variation in the entire range of lubrication, including the hydrodynamic, mixed, and boundary lubrication This paper presents the results of research on the friction of a journal-bearing conformal contact system in the form of Stribeck curves through numerical simulation The surface roughness of the journal and the bearing and material elasticity and thermoelasticity are included in the modeling, and their influences on the results of Stribeck curves are discussed A three-dimensional Stribeck surface is constructed to illustrate the load effect on friction for the modeled journal-bearing structure Review led by Gary Barber

Rolling contact fatigue performance of vibro-mechanical textured surfaces

Abstract: The rolling contact fatigue (RCF) performance of vibro-mechanical textured surfaces in a point elastohydrodynamic lubrication (EHL) condition is investigated. Two dimple designs, small (100 μ m × 100 μ m) and large (240 μ m × 100 μ m), are compared with a nontextured sample. Experimental RCF tests show that the textured surfaces exhibit a significantly reduced number of cycles to failure compared with the nontextured sample for the high load, pure rolling conditions evaluated. In order to understand these results, numerical models are used to calculate the lubrication and contact pressure conditions and the subsurface stress distribution. The fatigue failure trends observed experimentally are compared with the simulation results with good agreement. It is determined that RCF performance is related to the presence and size of the generated dimple.

Mixed Lubrication of Coupled Journal-Thrust-Bearing Systems Including Mass Conserving Cavitation

Abstract: A mixed lubrication model is developed to investigate the lubrication of coupled journal-thrust-bearing systems The governing equations are mapped into a computational domain with a conformal mapping technique developed in a previous study by Wang et al (2002) In order to study the influence of the boundary conditions on the performance of the bearing system, either the Reynolds boundary conditions or the JFO's mass conserving conditions are applied to the governing Reynolds equations The performance of a typical coupled journal-thrust bearing system is numerically investigated and the effects of viscosity, misalignment angle and feeding scheme are discussed

A review of physics-based models in prognostics: Application to gears and bearings of rotating machinery:

Abstract: Health condition monitoring for rotating machinery has been developed for many years due to its potential to reduce the cost of the maintenance operations and increase availability. Covering aspects include sensors, signal processing, health assessment and decision-making. This article focuses on prognostics based on physics-based models. While the majority of the research in health condition monitoring focuses on data-driven techniques, physics-based techniques are particularly important if accuracy is a critical factor and testing is restricted. Moreover, the benefits of both approaches can be combined when data-driven and physics-based techniques are integrated. This article reviews the concept of physics-based models for prognostics. An overview of common failure modes of rotating machinery is provided along with the most relevant degradation mechanisms. The models available to represent these degradation mechanisms and their application for prognostics are discussed. Models that have not been applied...