The motion track of the swing head refers to the projection track of any point on the axis of the swing head on the workpiece surface in the swing rolling process. It reflects the motion relationship between the die and the workpiece, and has an important impact on the deformation of the workpiece. For bevel gear rotary forging, the choice of swing head trajectory will affect the forming performance of bevel gear.
Let the polar coordinates of any point on the motion track of the pendulum head be（ ρ,θ), Then the polar coordinate equation of rotary forging track is:
For the generally adopted eccentric sleeve type rotary rolling machine, β Represents the ratio of the rotational speed of the inner eccentric sleeve to the rotational speed of the outer eccentric sleeve β When different values are taken, five different motion trajectories will be obtained, as shown in the figure:
(1) When β> 0 and β When ≠ 1, it is a helix;
(2) When β= When 1, it is a circle;
(3) When β= 0, double circle;
(4) When β< 0 and β ≠ – 1, rose line;
(5) When β=- When 1, it is a straight line.