GANDHINAGAR INSTITUTE OF

TECHNOLOGY

ACTIVE LEARNING ASSIGNMENTON

“Gear Manufacturing Processes”PRODUCTION TECHNOLOGY [2161909]

MECHANICAL 6 (D3)

PREPARED BY:- UPADHYAY AYUSH

(150123119053)

GUIDED BY:- Prof. CHINTAN BARELWALA

Content Extrusion Process

Stamping Process Sintering Process Injection Molding Process Cold Drawing Process Forging Process

It is a manufacturing process where material is drawn through a die, giving the material a new cross-sectional shape that is usually constant throughout the lengths of the material. Dies with multiple openings can extrude several strands simultaneously, as well as create hollow cross-sections by using a pin (mandrel) in the die.

Extrusion

Extrusion process is used to form teeth on long rods, which are then cut into usable lengths and machined for bores and keyways etc. Nonferrous materials such as aluminum and copper alloys are commonly extruded rather than steels. Results in good surface finish with clean edges and pore free dense structure with higher strength

Small sized gear can also be made by extrusion process. There is saving in material & machining time.

This method can produce any shape of tooth & it is suitable for high volume production. Gears produced by extrusion find application in watches, clocks, type writers etc.

Sheet metal can be stamped with tooth shapes to form low precision gears at low cost in high quantities. Surface finish and accuracy are poor.

Stamping

Precision Stamping The dies are made of higher precision with close

tolerances. The stamped gears will not have burrs.

Application Toy gears, hand operated machine gears, slow speed

mechanism gears

Clock gears, watch gears etc.

Application

After stamping, the gears are shaved; they give best finish & accuracy.

The materials which can be stamped are: low, medium & high carbon steels, stainless steel.

This method is suitable for large volume production.

Stamped Gear

The metal powder is pressed in dies to convert into tooth shape, after which the product is sintered. After sintering, the gear may be coined to increase density & surface finish. This method is usually used only for small gears.

Sintering Process

Blended Powder Compacted Rigid Tooling ( Powder compacted rigidly)

Pre-sinter

Repress or Coining Re-sinter Gear

Sintering Process

High quality gears can be made by powder metallurgy method.

Gears made by powder metallurgy method find application in toys, instruments, small motor drives etc.

Advantages Accuracy similar to die cast gears Material properties can be tailor made Typically suited for small size gears Economical for large lot size only Secondary machining is not required

Applications

Injection Molding Injection molding is used to make nonmetallic gears in

various thermoplastics such as nylon. These are low precision gears in small sizes but have the advantages of low cost and the ability to be run without lubricant at light loads.

Applications Injection molded gears are used in cameras,

projectors, wind shield wipers, speedometer, lawn sprinklers, washing machine

The materials for injection molding components are Nylon, cellulose acetate, polystyrene, polyimide, phenolics.

Materials

Cold drawing forms teeth on steel rods by drawing them through hardened dies. The cold working increases strength and reduces ductility. The rods are then cut into usable lengths and machined for bores and keyways, etc.

Cold Drawing

The steps in forging process are represented in fig and the forged gears are shown in fig.

Forging

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