Axial magnetic characteristics

which include axial magnetic flux density and phase shift time

of cup-type axial magnetic field contacts with irons and that without irons are studied by 3D finite element method.The results show that: ①Axial magnetic flux density of cup-shaped AMF contacts with irons in the middle plane of contacts gap is changed to be a concave-shaped distribution at peak current.It weakens near the center

while it strengthens observably at the irons area.The values of the two contacts are almost the same at the no irons area while the current is zero

but the axial magnetic flux density of cup-shaped AMF contacts with irons strengthens observably at the irons area.With the increasing of contacts gap

axial magnetic flux density of cup-shaped AMF contacts with irons changes little at the no irons area

while it weakens obviously at the irons area.Axial magnetic flux density of cup-shaped AMF contacts without irons weakens uniformity all over the range.②Phase shift time of cup-shaped AMF contacts with irons increases all over the region.With the increasing of contacts gap

the phase shift time of the two contacts both decrease.③Axial magnetic flux density and its distribution are changed observably after the introducing of irons

but the eddy effect is also remarkable.Both of the positive and negative effects should be considered in designing the contact.