Study on Reverse Metod of Solid Molding for the Inner Helicoids in Helical Stator

The new type stator which has an equal thickness rubber bushing increases the performance of the PDM and screw pump substantially.Acording to the complexity of the helical surface and the uncertainty of the expression for the cross-section profile,this article concluded the equations of the the metal stator whose cross section curve is an equidistance of curtate hypocycloid.Then the mathematical expression for the cross-section of the stator and the inner helicoids which based on MURBS were studied.The article proposes reverse methods based on the discrete points data in resolving the helical surface of the stator and implementes three-dimensional solid molding of the stator automatically using computer-aided program.The conclusion will provide technical support for the design and manufacturing of the helical stator and for the calculation of the contour of cutting tools.