DESIGN AND CONSTRUCTION OF MICHELL TILTING PAD APPARATUS

Project Abstract

This research project focuses on the design and construction of a Michell tilting pad apparatus. The Michell tilting pad bearing is a type of fluid film bearing that offers superior stability and load-bearing capabilities compared to traditional bearings. The research aims to design and construct a test apparatus that can accurately measure the performance characteristics of Michell tilting pad bearings under different operating conditions. The design process involves creating a test rig that can simulate the conditions experienced by Michell tilting pad bearings in practical applications. This includes the incorporation of adjustable load mechanisms, temperature control systems, and data acquisition tools to monitor various parameters such as temperature, pressure, and pad tilt angles. The construction phase will involve fabricating the components of the test rig according to the design specifications and assembling them into a functional apparatus. The experimental phase of the project will involve testing the Michell tilting pad apparatus under different operating conditions to evaluate its performance characteristics. This includes measuring parameters such as load capacity, stiffness, and stability under varying speeds and loads. The data collected during the experiments will be analyzed to assess the effectiveness of the Michell tilting pad bearing design and its suitability for different industrial applications. The significance of this research lies in the potential benefits of using Michell tilting pad bearings in various engineering applications. These bearings offer improved stability and load-bearing capabilities, making them suitable for high-speed rotating machinery such as turbines, compressors, and pumps. By designing and constructing a test apparatus to evaluate the performance of Michell tilting pad bearings, this research aims to provide valuable insights into their operational characteristics and potential advantages over traditional bearing designs. Overall, this research project aims to contribute to the advancement of bearing technology by exploring the performance characteristics of Michell tilting pad bearings. The design and construction of a dedicated test apparatus will enable researchers and engineers to study the behavior of these bearings in detail and assess their suitability for different industrial applications. The findings of this research could lead to the widespread adoption of Michell tilting pad bearings in various engineering fields, thereby improving the efficiency and reliability of rotating machinery.

Project Overview

<p> </p><p><strong>INTRODUCTION</strong></p><p>The Michell tilting pad apparatus is a hydrodynamic measuring instrument developed in the early 1880’s in the laboratory of Beauchamp Tower in England. Tower was employed to study the friction in railway journal bearings and come up with the best method of lubricating them. The Michell tilting pad apparatus is used broadly in two different experiments namely;<br>1) Determination of the load carrying capacity of the slider bearing.<br>2) Confirming the theory of the hydrodynamic lubrication.<br>Tilting pad journal bearings are a source of both static support and dynamic stiffness and damping. Tilting pad journal bearings have a number of pads, typically four or five. Each pad in the bearing is free to rotate about a pivot and cannot support a moment. As a result, the destabilizing forces are greatly reduced or eliminated, and the bearings are no longer a potential source of rotordynamic instability. This feature has made tilting pad journal bearings the standard fluid-film bearing for most high-speed applications. High-speed rotordynamic applications often have rotors that pass through one or two bending critical speeds as the machines are accelerated to the operating speed. The damping from the fluid film bearings is required to safely pass through these bending critical speeds as the rotating element is accelerated. The damping also helps suppress potentially destabilizing forces from sources such as radial seals, balance pistons, impeller eye seals, internal friction fits, and unbalanced electromagnetic forces.</p><p><strong>1.1 AIMS AND OBJECTIVES OF THE PROJECT</strong></p><p>The project designing, constructing and testing on the Michell tilting pad apparatus is aimed at achieving the following objectives:<br>1) To verify the hydrodynamic theory of lubrication as it was propounded by Beauchamp Tower in 1880 AD.<br>2) To determine the load carrying capacity of the tilting pad slider bearing<br>3) To provide the fluid mechanics laboratory of the Mechanical Engineering Department with a hydrodynamic fluid analyzing apparatus.<br>4) To activate and motivate the students potentials into practically solving problems facing mankind.<br>5) To run tests with the apparatus and compare the results obtained with the established or ideal standards.</p><p><strong>1.2 PROJECT JUSTIFICATION</strong></p><p>Engineering is known to be to be practice-oriented discipline. In Other Words, no useful Engineering endeavor can exist in theory only, it must be applied to touch and transform life through meaningful practice. Therefore, this project task given to us is to ensure the knowledge we students gained throughout our five year degree programme and channeled towards the construction of Mechanical Engineering equipments.</p><div></div><p><strong>1.3 APPLICATIONS AND USES</strong></p><p>The Michell tilting pad apparatus is applicable in experiments which does not require;<br>3<br>1) Hydrostatic lubrication<br>2) Boundary lubrication<br>3) Solid lubrication<br>4) Elastohydrodynamic form of lubrication.<br>It only finds its application useful in full film or fluid lubrications in motion, in which there is a situation that the load carrying surfaces of the bearing are separated by an adequate supply at all times of a relatively thick film of lubricant, so as to prevent metal to metal contact and that the stability thus obtained can be explained by the laws of fluid mechanics. The Mitchell tilting pad is a Mechanical Engineering apparatus with the above aims and objectives.</p><p>1.4 LIMITATIONS</p><p>The Michell tilting pad apparatus is limited to use with the specified oil viscosity (SAE20W/50) or White oil which is typical automobile engine oil. The Michell tilting pad apparatus is also limited to operation when there is power failure or insufficient supply of power that drives the electric motor, other limitations are stipulated below;<br>1) The use of lubricants that do not obey Newton’s law of viscous flow.<br>2) The use of compressible lubricants<br>3) Fluid pressure varying in the axial direction.<br>From the limitations stated above, it is necessary to identify the Newton’s viscous effect, which states that the shear stress in the fluid is proportional to the rate of change of velocity with respect to ‘y’.</p> <br><p></p>