# Kinematic analysis of spiral gear shaping

According to the analysis, in order to cut a complete spiral gear, the gear shaping and workpiece blank must have the movement as shown in the following figure:

(1) Cutting movement

During gear shaping, the gear shaping cutter moves up and down rapidly along the axis direction of the gear blank, which is the main movement of the gear shaping cutter, also known as cutting movement. The cutting speed is expressed by the number of reciprocating strokes per minute.

(2) Circular feed motion

During gear shaping, the cutter shaft rotates slowly around its own axis. The speed of gear shaping cutter rotation affects the speed of gear cutting. The size of the circular feed is calculated by the arc length of each reciprocating stroke of the gear shaping cutter turning on the circumference of its sub circle, and sometimes expressed by the total number of reciprocating strokes within one cycle of the gear shaping cutter turning.

After the gear shaping starts to contact the gear blank, at the same time of circular feed, the gear shaping makes radial feed to the gear blank (or the gear blank makes radial feed to the gear shaping), until the full depth of the tooth (refers to one-time cutting). The size of the radial feed is expressed by the radial movement of each reciprocating stroke of the gear shaping cutter.

(4) Fancheng movement (or fancomponent tooth movement)

In order to cut all the teeth on the gear blank, it is necessary to make the worktable drive the gear blank to rotate, and maintain a pair of gear meshing relationship with the gear shaping cutter.

(5) Let the knife move

The up and down reciprocating movement of the gear shaping cutter, down is the working stroke, up is the return stroke. In order to ensure that the gear shaping does not contact the tooth surface when returning, so as to avoid scratching the machined tooth surface and reducing the wear of the tool, the gear blank should be a distance away from the gear shaping. The common large and small gear shaping are gear shaping cutters, and the medium-sized machine tools are worktable cutters. This movement is controlled by the cam, which can make the parts of the gear shaping return to their original position at the moment before the gear shaping cutter cuts downward.

(6) Rapid rotary movement of gear shaping cutter shaft and table

In order to align the blank quickly and clamp the blank conveniently, the cutter shaft or table of gear shaping can rotate quickly.