Ceramic Bearings Essay

ACKNOWLEDGEMENT

CONTENTS

1. Abstract. 2. Introduction. 3. Types of ceramic bearings. 4. Features. 5. Advantages. 6. Technical charts and graphs. 7. Applications. 8. Limitations. 9. Conclusions. 10. References.

Chapter I.
ABSTRACT

Want to save a million barrels of petroleum a year, simply by changing the bearings in your machines? It sounds too good to be true, but new materials now make more-efficient ball bearings possible. All-ceramic bearings’ lower density, friction, and lubrication needs let them last longer and save energy. Bearings use ceramics like silicon nitride (Si3N4), alumina (Al2O3), or zirconia (ZrO2) . Ceramic materials resist acids, alkalis, and salt. For these reasons, bearings using ceramic balls and races don’t need oil or grease.

Chapter II.
INTRODUCTION

A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races. The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit the loads through the balls. In most applications, one race is stationary and the other is attached to the rotating assembly (e.g., a hub or shaft). As one of the bearing races rotates it causes the balls to rotate as well. Because the balls are rolling they have a much lower coefficient of friction than if two flat surfaces were sliding against each other.

Ball bearings tend to have lower load capacity for their size than other kinds of rolling-element bearings due to the smaller contact area between the balls and races. However, they can tolerate some misalignment of the inner and outer races. Ceramic bearings have the normal steel balls replaced by white ceramic balls. The ceramic