Aluminum alloy motor enclosure with super-high rotating differential rate has been produced by low pressure casting.Horizontal four opening mould structure and main core vertical upper-opening mould structure were adopted in the mould.In addition

an opening gating system was designed

in which the ingate was set at the position of 45°with side-prating surface.The liquid aluminum alloy was poured at 680～720 ℃ and the lower-mould and side-mould were preheated at 300～350 ℃ and 250～300 ℃

respectively.Constant-pressure automatic control system was employed for liquid surface pressure-applying device

meanwhile

quenching and artificial aging were used.The mechanical properties of the enclosure are obviously superior to those required in the nation standard through above mentioned ways.