Wednesday, February 27, 2008

Form Milling of Helical Gear

The procedure is similar to form-milling of spur gear. In this case a universal milling machine is used. The module of cutter chosen is equal to the normal module of helical gear to be cut. With the cutter mounted on the arbor of horizontal milling machine, the table is set to the helix angle of the gear. To carry out the helical milling, the dividing head is connected to the lead screw of the table. The gears are chosen so as to give the necessary lead on the gear. Lead of helical gear is given by:

L = d. cot
where L = Lead of the gear,
d = reference diameter of the gear, and
 = helix angle of the gear.

The gear is then cut similar to cutting a spur gear. If the helix angle of the gear is large, it may not be possible to set the table of the universal milling machine to the required helix angle. In this case a vertical milling attachment is used and is set in the horizontal position, setting the cutter at 90o from the normal position. The table is then set to the lead angle of the helical gear.

3 comments:

willam said...

Gear cutting tool design and production requires much specialized knowledge, which has been acquired and refined over generations.
scalping cutters

shivabizconn said...

Thanks for sharing with us
Malkar Industries Spur Gears, Worm Gears, Lead Screws,Serration Cutters, Helical Gears.

Hamza Shaheer said...

Can you please define the process of Gear Train design to transmit lead to the helical gear while cutting on the milling machine.