Gear forming

Gear forming 

This is a process of machining gears using a form-milling cutter in a milling machine.  Gears can be cut using a form-milling cutter, which has the shape of the gear teeth.  The form-milling cutter, called dp cutters (diametral pitch cutters, used in inch systems, which is equivalent to inverse of module), has the shape of the teeth similar to the tooth space with the involute form of the equivalent size gear.  The commercial gear - milling cutters are available as a set for a given module or diametral pitch. 

Gear forming

frictional-clutches.

      These can be used on either horizontal - axis or vertical - axis milling machines, though horizontal axis is more common.  The vertical - axis cutters will be similar to end mills with tooth profile on the cutting edge.  The cutting tool, as shown in Fig.  10.  15, is fed radially into the workpiece till the full depth is reached Then the workpiece is fed past the cutter to complete machining of one tooth space.

      

Fig. Dp cutter use for milling

   The workpiece is actually mounted in the dividing head.  The machining process is repeated after indexing the gear blank by one tooth.  Sometimes it may be necessary to index by more than one tooth since the work material gets heated by the heavy material removal, which may affect the accuracy of the surface generated.  The tooth space actually depends upon the number of teeth. 

    Accordingly, a range of cutters with number 1108 are available to cover the entire range of gears to be machined as shown in Table.  This is made possible by approximating the tooth profile by considering the fact that, profile variation is relatively small between the gears with close-range teeth.  For achieving closer accuracy, additional 7 cutters to account for the intermediate range of gears are also available, as shown in the third and fourth columns of Table.