The following topics are explained in this application -GEARS INTRODUCTION -ADVANTAGES AND DISADVANTAGES OF GEAR DRIVES -CLASSIFICATION OF GEARS -FORMS OF TEETH -ADVANTAGES OF CYCLOIDAL AND INVOLUTE GEARS -SYSTEMS OF GEAR TEETH -GEAR MATERIALS -MINIMUM NUMBER OF TEETH ON THE PINION IN ORDER TO AVOID INTERFERENCE -DESIGN CONSIDERATION FOR A GEAR DRIVE -CAUSES OF GEAR TOOTH FAILURE -SPUR GEAR -HELICAL GEAR -TERMS USED IN HELICAL GEARS -CROWN GEAR -HERRINGBONE GEAR -BEVEL GEAR -CLASSIFICATION OF BEVEL GEAR -HYPOID GEAR -RACK AND PINION -SPIRAL BEVEL GEAR -SUN AND PLANET GEAR -WORM GEAR -GEAR TERMINOLOGY -GEAR TRAIN INTRODUCTION -TYPES OF GEAR TRAINS