This presentation was made by me to supplement classroom lecture on Gear Cutting technology as part of the Machine Shop technology module for IV Semester of DME and DAE students of K Scheme. Useful for Polytechnic College Students of India.

3. Involute tooth

4. Involute

5. Involute

6. Steering Gear

7. Use of Rack and Pinion

8. Rack Railway

10. Escapement in a clock

11. Balance Stop

12. Mechanical Clock

16. Forming Gears

19. Plain or Simple dividing Head

22. 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 .

23. 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.

24. Dividing Head

46. Simple change gears

47. Compound change gears

48. Compound change gears

49. Selection of gears

61. Involute curve

66. Centering the cutter

70. Gear tooth vernier caliper

71. 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

72. Helix Angle

73. Helix Angle

74. Helical gear milling procedure

77. Helix Angle

79. Gearing arrangement for Helical gear milling

82. Circumference and Lead of Helix

83. Table setting for Helical gear milling

85. Equivalent spur gear teeth

86. Equivalent spur gear teeth

87. Equivalent spur gear teeth (virtual)

93. Milling of Straight bevel gears

95. Bevel gears in mesh

96. Bevel gear terms

97. Meshing bevel gears

99. 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

100. 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

102. Special cutters

105. Gear cutting with single point cutter

106. Gear cutting with single point cutter

107. Shear Speed Shaping

108. Formed End mill cutter

109. Gear Broaching

110. Gear Broaching

111. Template Method

112. 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.

114. Gear shaping

115. Gear shaping

116. Gear shaping

117. Gear shaping

118. Gear shaping

119. Gear Planing

120. Gear Planing Rack

121. Gear Planing with a rack cutter

122. Gear Planing with a rack cutter

125. Hobs

126. Gear Hobbing

127. Gear Hobbing

128. Gear Hobbing

129. Gear Generating comparison

130. Gear Hobbing

131. Gear Hobbing

132. Gear Hobbing

133. Gear Hobbing

134. Gear Hobbing

135. Gear Hobbing

136. Gear Hobbing

137. Vertical Hobbing Machine

138. Vertical Hobbing Machine

139. Various Gear Cutters

140. Gear Shaving

141. Gear Shaving Cutter

142. Gear Grinding

143. Gear Grinding

145. Thank you!