The two working surfaces of the first envelope worm are ruled surfaces
by this characteristic
a new method of establishing accurate 3D geometry model of the worm gearing is presented.A precise geometry model of the first envelope worm gearing is created
which is then imported into ABAQUS.By the contact finite element method
the contact loads among teeth are gained.It is found that the contact load decreases from the mesh-in tooth to mesh-out tooth.At last
the influence of the β on load sharing among teeth is researched by finite element method.It is found that if the non-contact zone doesn’t exist on the gear surface of the worm