Spur Gear Cutting Lab Experiment

Aim

To make spur gear on plane milling operation on the given specimen (mild steel)

Tools Required

1. Mild steel specimen.
2. Vernier calipers
3. Plane (face) milling cutter
4. Steel rule, scriber
5. Work holding fixtures: work piece supporting fixtures

Procedure

Calculate the gear tooth proportions

Blank diameter = ( Z + 2 ) m

Tooth depth = 2.25 m

Z = Number of teeth required

m = module Indexing calculation

Index crank movement = 40 /Z

1. The dividing head and the tail stock are bolted on the machine table.
2. Their axis must be set parallel to the machine table.
3. The gear blank is held between the dividing head and tailstock using a mandrel. The mandrel is connected with the spindle of dividing head by a carrier and catch plate.
4. The cutter is mounted on the arbor. The cutter is centered accurately with the gear blank.
5. Set the speed and feed for machining.
6. For giving depth of cut, the table is raised till the periphery of the gear blank just touches the cutter.
7. The micrometer dial of vertical feed screw is set to zero in this position.
8. Then the table is raised further to give the required depth of cut.
9. The machine is started and feed is given to the table to cut the first groove of the blank.
10. After the cut, the table is brought back to the starting position.
11. Then the gear blank is indexed for the next tooth space.
12. This is continued till all the gear teeth are cut.

Calculation:

Z = No. of teeth = 23

m = module = 2 mm

Blank Diameter = (Z + 2) m

= (23 + 2) 2 = 50 mm

Tooth Depth = 2.25 m

= 2.25 * 2 = 4.5 mm

Indexing Calculation = 40 / Z = 40 / 23 = 1 17/23

Result

The given work piece as is subjected to gear generating operation to become a finished work piece

Viva Questions

What is gear hobbing?

The process of generating a gear by means of rotating a cutter called HOB is known as HOBBING.

Mention the applications of gear shaping process?

Gear shaping used for generating both internal & external spur gears
2. Helical gears can also be generated using special attachments.

What are the limitations of gear hobbing?

Internal gears cannot be generated
2. Hobbing process cannot be applied very near to shoulders.

What are the advantages of gear planning process?

Any given model can be cut using a single cutter
2. It is a simple flexible &accurate method of generating gears

List the various gear finishing processes?

1. Gear shaving
2. Gear burnishing
3. Gear grinding
4. Gear lapping.

Mention the advantages &limitations of gear shaving process?

Advantage: The process can be used for both internal & external gears.

What are the other forming methods for manufacturing gears?

1. Gear cutting by single point form tool
2. Gear cutting by shear speed shaping process
3. Gear broaching
4. Template method
5. Gear milling using a formed end mill.

What are the other forming methods for manufacturing gears?

Gear cutting by single point form tool
Gear cutting by shear speed shaping process
Gear broaching
Template method.

Mention the applications of gear shaping process?

1. Gear shaping used for generating both internal & external spur gears
2. Helical gears can also be generated using special attachments.

List the various gear finishing processes?

Gear shaving
Gear burnishing
Gear grinding
Gear lapping

Shaping Inclined Surface –Shaping Machine

All Dimensions in mm