Gear Cutting Presentation for Polytechnic College Students of India

Machine Shop Technology ,[object Object],[object Object],[object Object],[object Object]

Unit - IV ,[object Object],[object Object]

Gear Manufacturing Processes ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Methods of Machining (cutting) Gears ,[object Object],[object Object],[object Object]

Forming Gears ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Forming gears in a milling machine ,[object Object],[object Object],[object Object],[object Object],[object Object]

Dividing Head ,[object Object],[object Object],[object Object],[object Object]

Simple Dividing Head ,[object Object],[object Object],[object Object],[object Object],[object Object]

Universal Dividing Head ,[object Object],[object Object],[object Object],[object Object],[object Object]

Universal Dividing Head 1-shaft; 2-index crank; 3-index-crank pin; 4-index plate; 5-housing; 6-swivel block of housing; 7-lock; 8-driving dog; 9-spindle; - 10-plate for direct indexing; 11-tailstock .

The construction of the index head 1-index plate; 2-index crank; 3-spindle; 4-worm wheel (z=40); 5-necks to receive pick-off gears; 6-worm (k=1); 7-sector arm.

Methods of Indexing ,[object Object],[object Object],[object Object],[object Object]

Direct Indexing ,[object Object],[object Object],[object Object],[object Object]

Direct Indexing in Universal Dividing Head ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Direct Indexing ,[object Object],[object Object]

Plain Indexing (or) Simple Indexing ,[object Object],[object Object],[object Object],[object Object],[object Object]

Simple Indexing ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Differential Indexing ,[object Object],[object Object],[object Object],[object Object],[object Object]

Differential Indexing ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Rule for Differential Indexing ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Rule for Differential Indexing (contd..) ,[object Object],[object Object],[object Object],[object Object],A-N Simple gear train Compound gear train Positive One idler No idler Negative Two idlers One idler

Rule for Differential Indexing (contd..) ,[object Object],[object Object],[object Object]

Angular Indexing ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Linear Indexing ,[object Object],[object Object],[object Object]

Terms used in spur gear ,[object Object],[object Object],[object Object],[object Object],[object Object]

Terms used in spur gear (contd..) ,[object Object],[object Object],[object Object],[object Object]

Line of Action ,[object Object],[object Object],[object Object]

Spur gear proportions as per BIS ,[object Object],S.No Name of tooth element Gear tooth proportions 1. Pitch diameter Zm 2. Addendum m 3. Dedendum 1.25m 4. Working depth 2m 5. Tooth depth 2.25m 6. Outside diameter (Z+2)m 7. Tooth thickness 1.5708m 8. Clearance 0.25m 9. Circular pitch π m 10. Radius of fillet 0.4m to 0.45m

Spur gear milling procedure ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Spur gear milling procedure ,[object Object],[object Object],[object Object],[object Object],[object Object]

Spur gear milling procedure (contd..) ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Spur gear milling procedure (contd..) ,[object Object],[object Object],[object Object],[object Object],[object Object]

Spur gear milling procedure (contd..) ,[object Object],[object Object],[object Object],[object Object]

Helical gear tooth proportions Where Normal Module “Mn” = m cos α m = Module α = Helix angle S.No Name of tooth element Tooth proportions in terms of normal module with 20° pressure angle 1. Pitch diameter Zm 2. Addendum Mn 3. Dedendum 1.25 Mn 4. Tooth depth 2.25 Mn 5. Outside diameter Zm + 2 Mn 6. Normal tooth thickness 1.5708 Mn

Helical gear milling procedure

Helical gear milling procedure ,[object Object],[object Object]

Gearing arrangement for Helical gear milling

Change gears for helical milling ,[object Object],[object Object],[object Object]

Change gears for helical milling ,[object Object],[object Object]

Circumference and Lead of Helix

Table setting for Helical gear milling

Equivalent spur gear teeth ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Equivalent spur gear teeth (virtual)

“ Lead of the machine” ,[object Object],[object Object]

“ Lead of the machine” ,[object Object],[object Object],[object Object],[object Object]

Helical gear milling procedure ,[object Object],= = Where p = pitch of the lead screw; D = pitch circle diameter; α = Helix angle Driver teeth/Driven teeth = A/B X C/D (A and C are driving gears. B and D are driven gears) Lead of the machine Lead of the work Driver teeth Driven teeth 40p πD/tan α

Milling of Straight bevel gears

Steps for milling a straight bevel gear ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Bevel gear tooth proportions S.No Name of tooth element Tooth proportions for 20° pressure angle Symbol 1. Pitch diameter Zm d 2. Addendum (large end) 1 m ha 3. Dedendum (large end) 1.25 m hd 4. Tooth depth (large end) 2.25 m h 5. Tooth thickness (large end) 1.5708 m s 6. Circular pitch π m p

Bevel gear elements and angles S.No Name of tooth element Symbol Formula 1. Face width b b = 0.5 to 0.33 R 2. Cone distance R R = 0.5 / sin β 3. Addendum angle θa tan θa = ha / R 4. Dedendum angle θ d tan θ d = hd / R 5. Pitch cone angle β Sin β = 0.5 d / R

Milling straight bevel gears ,[object Object],[object Object],[object Object],[object Object],[object Object]

Gear cutting with single point cutter

Gear Generating Process Gear generation is based on the fact that “any two involute gears of the same module will mesh together” Gear teeth are generated in the gear blank because of the relative rolling motion of the cutter and the blank. One of the mating gears in a cutter which reciprocates and also rotates as a mating gear. Accurate tooth profile is generated in this process.

[object Object],[object Object],[object Object],Gear generating methods

Gear Planing with a rack cutter

Gear Hobbing ,[object Object],[object Object],[object Object],[object Object],[object Object]

Gear Hobbing ,[object Object],[object Object],[object Object],[object Object],[object Object],[object Object]

Gear Cutting Presentation for Polytechnic College Students of India

Gear Cutting Presentation for Polytechnic College Students of India

Recomendados

Más contenido relacionado

Was ist angesagt?

Was ist angesagt?(20)

Destacado

Destacado(20)

Similar a Gear Cutting Presentation for Polytechnic College Students of India

Similar a Gear Cutting Presentation for Polytechnic College Students of India(20)

Más de kichu

Más de kichu(11)

Último

Último(20)

Gear Cutting Presentation for Polytechnic College Students of India