Manufacturing Processes : Manufacturing Processes By:-
Akash Goyel
Vinit Garg
Gears : Gears Applications
1.Automobiles
2.Gear Boxes
3.Machine Tools
4.Indutrial and agricultural machinery
: Requirements
1.Robust construction
2.Reliable performance
3. High efficiency
4.Economy
5. Long life
Factors for selection of Materials : Factors for selection of Materials 1.Type of service
2.Peripheral speed
3.Deegre of accuracy
4.Manufacturing process
5.Dimensions and weight
6.Allowable stress
7.Shock resistance
8.Wear resistance
: Manufacturing Processes of Gears
: Roll forming
Gear blank mounted on shaft
Pressed against hardened steel
Accurate and does not require finishing
Stronger in tension and fatigue
Used for spur and helical gears
: Stamping
Made in punch press from sheet
Shaved for finish and accuracy
Suitable for large production
Used in toys, watches and clocks.
: Powder Metallurgy
Metal powder is pressed into dies
Sintering is done
The product is coined to increase density and surface finish
Used in toys, instruments and motor drivers.
:
Features of Hobbing : Features of Hobbing Process of generating teeth by means of hob
Continuous indexing process
Hob and gear moves at relative speed
Arial – spur and helical gears
Radial and Tangential – Worm and worm wheel
Gear Shaping : Gear Shaping Rack type cutter
Pinion type cutter
: Rack type
Cutter has form of basic rack for which gear is to be generated
Cutter reciprocates and removes metal during cutting stroke
When cutter and blank have completed distance equal to one pitch of blank, motion of blank is arrested, the cutter is withdrawn to give relief to cutting edges and cutter is returned to starting position
Pinion type : Pinion type Pinion is used to generate a tooth profile
Cutter is fed radically into blank equal to depth of tooth required
Cutter may be reciprocated in horizontal or vertical axis.
Features of Gear Shaping : Features of Gear Shaping Very high accuracy
Both internal and external gears can be cut
Low production rate as compared to hobbing
Return stroke is wasted
Worm & worm wheels can not be produced
Milling : Milling Disc type cutter
End mill cutter
Disc type : Disc type Gear blank is mounted on arbor
Cutter is aligned vertically with indexing head spindle
Table of machine is moved upwards by an amount equal to full depth of gear tooth
Longitudinal feed of table is engaged
Blank is then indexed to next position
Gear Planning : Gear Planning The Sunderland Process
The Maag Process
: The work is mounted with axis horizontal (Sunderland) or vertical (Maag) & the cutter is carried on a saddle position that moves vertically downwards as cutting proceeds
Gear Finishing : Gear Finishing Shaving
Lapping
Grinding
Shot Blasting
Phosphate coating
: Thank You
Slide 22: Forging
Steel bar is forged into cups, cones, wear rings, and automotive rings in hot forging. Steel bar is fed through an induction heater system until it reaches a temperature near melting. This temperature offers maximum formability for hot forging. The heated bar is sheared into slugs once it reaches the forging press. Then the slug is upset, partially formed, and pierced. The main forging press produces about 8 parts per minute. Smaller forgings are rolled into larger rings in open die ring rolling where the part is worked between a king wheel and mandrel. Ring rolling imparts directionality to the grain structure that goes with the shape of the part. This increases the application strength and fatigue life of the part. After ring rolling, the part is further sized on diameter to bring it closer to near net shape. The forging then is placed on the draw line which offers several options for cooling: air, controlled temperature, etc.