1. Title of the invention: Concept of Single tooth removal from regular internal spline through use of shaping cutter with 2 no of teeth (180 degrees apart).
2. Field of invention: The present invention relates to the Spline shaping cutter design.
3. Use of invention: This invention finds application in Internal Spline tooth removal for Fool proof assembly of spline parts.
4. Background
In Aircraft industry it is necessary to Assemble and disassemble the Transmission and rotor system components as a part of periodic maintenance checks. Hence Fool proofing of the parts is done for Transmission and rotor system components to facilitate easy assembly and disassembly of the parts. In the present case study the Component has internal splines with single tooth removed for fool proof assembly and to meet the component requirements.This invention explains the concept of single tooth removal.
Description of the problem
The component as shown in figure 1 was designed to facilitate fool proof assembly of the component with the mating part. The internal spline as shown in figurel is located at 130mm from the component Tip. The Internal dia of component is 41mm from one end of the component. At the other end of the component the internal dia is narrow preventing the use of spline broach for carrying out spline cutting operation. The use of end mill is also prohibited for the single tooth removal as the end mill may damage the spline profile which is not desirable.
Hence this removal of single tooth requires Special shaping cutter with 2 teeth which are 180 degrees apart.
Introduction to Shaping
Gear shaping is one of the best choices for components in which the splines are adjacent to shoulders and parts with internal splines and blind ended parts.
In shaping cutter removes material from work piece in the form of chips in the forward stroke only. In return stroke of the cutter material is not removed and the cutter and work must be separated so that the cutting edges are not damaged or dulled by dragging them backwards
throuah the cut.

This process employs a gear-shaped cutter; a given gear-shaped cutter is conjugate to all tooth numbers of that pitch. Thus, a gear made as a cutting tool can generate the teeth of a blank when the two are rotated at proper speeds. The cutting tool can be imagined as a gear that axially traverses the blank with a reciprocating axial motion as it rotates. The teeth on the gear cutter are appropriately relieved to form cutting edges on one face.
Two outstanding features of shaping involve shouldered and internal gears. Compound gears and shaft gears frequently are designed so compactly that a hob cutter interferes with adjacent material. In such cases, shaping can be used since the stroke of the gear-shaped cutter requires very little round space on one side of the gear. For internal gears, the shaping process is the only basic method of tooth generation. The shaping process can be used for the generation of helical gears. However, each helix angle requires special tooling.
Special pinion-type cutters with tip chamfering flanks for machining major diameter fit shaft profiles with tooth tip chamfers and special pinion-type cutters with projections on their tooth tips for machining minor diameter fit. Shaft profiles with root clearance are designed for specific tooth-number groups and can only be used to generate these groups. Cutters for major diameter fit hub profiles can be used for single profiles or hub tooth number groups, depending on the centering diameter tolerances.
5. Detailed Description:
Shaping method:
The single tooth removal from component was done in the following steps
1) On the regular shaping cutter (with 16 teeth) tooth center line was marked and with respect to the tooth center line flat surface is made at two places on the cutter as shown in figure.
2) The Tooth center line was marked on the shaping cutter (with 2 teeth).
With respect to the tooth center line flat surface is made at two places on the cutter as shown in figure 2.
3) Initially regular internal spline was cut on the component with shaping cutter of 16 no of teeth by truing the flat surface on the full teeth shaping cutter.
4) In the component internal spline Circular space width center line was marked for one tooth.
5) The single tooth removal shaping cutter was aligned by truing the flat surface on the cutter.
6) The shaping operation is carried out with the single tooth removal cutter (with 2 teeth 180 degrees apart) and consequently one spline tooth was removed from the component.