Gear Making Workshop Technology Mansoor Ghazi, Department of Mechanical Engineering College of E&ME, NUST Pakistan

Contents Functions of Gears Gear Types Gear Nomenclature Conventional Manufacturing Processes

Gear Fundamentals

What Is A Gear ? A rotating machine part/element with teeth cut into it which is used to: Transmit torque or Alter velocity or Change direction of motion or Perform any combination of above functions A gear meshes with another gear(s) to form a transmission system. Relative motion between gears take place due to meshing of gear teeth.

Gear Types - Illustrated

Gear Nomenclature CHECK WHAT IS GEAR MODULE !

Gear manufacturing Overview

Conventional Manufacturing Processes Gear Cutting Hobbing Shaping Planning Milling Gear Forming Casting Forging Gear Finishing Grinding Shaving

Overview of Gear Manufacturing Gear cutting processes involve cutting the teeth onto a blank gear with help of shaped cutters. Gear forming processes are employed to produce gears without material removal. Used for mass production of low criticality gears. Gear finishing processes are employed after gear forming or cutting. These processes are used to impart required finishing before gear assembly. Majority of gears are made of carbon and low-alloy steels.

Gear cutting

Gear Hobbing Relatively inexpensive yet fairly accurate, hobbing employs helical cutters to cut teeth into a blank gear. The helical cutter called ‘hob’ rotates on an axis perpendicular to the axis of blank gear. The hob moves radially to the depth of teeth and is then fed axially along the width of the gear teeth. The hob and blank gear rotate in constant timed relation with each other that determines the number of teeth being cut into the gear.

Gear Hobbing - Illustrated

Gear Shaping A gear of desired teeth profile is used to cut similar shaped teeth into the blank gear. The cutting gear rotates along with the blank gear while simultaneously reciprocating parallel to the cut teeth. Unlike hobbing, shaping is capable of producing internal gears. Worm gears cannot be produced with shaping.

Gear Shaping - Illustrated Pinon Type Cutter Rack Type Cutter

Gear Milling - Illustrated

Gear forming & Finishing

Fundamentals Gear forming processes include: Casting Forging Roll Forming Stamping Powder Metallurgy Extrusion Gear forming processes are employed to mass produce relatively smaller size gears with appreciable accuracy and mechanical properties. Gear finishing processes are used to impart surface finishing to generated and formed gears.

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