Calculation on pressure angle of ring-plate typed planetary indexing cam mechanism

A mathematical expression has been carried out by vectors on the meshing status of needle teeth,the number of needle teeth that meshing simultaneously was calculated.The pressure angle was defined according to the particularity of mechanism's transmission.In the meshing course of ring-plate typed planetary indexing cam mechanism there exists a moment of disengagement between certain needle teeth and cam.Its special transmission course makes the pressure angle of certain needle teeth an obtuse angle within certain moments of the indexing period.Whether that needle tooth is participating force bearing or not can be determined according to the moment of disengagement was within the acceleration section or the deceleration section.