In order to study the forced state and deformation regularity of an inner contour line of a double helix single screw pump stator lining, then analysing the internal pressure, pressure difference, material nonlinearity and Poisson's ratio of the rubber by FEM analysis software, the effects of the factors on stress and srain of a stator lining and deformation regularity of the inner contour line were analysed, and a displacement equation under uniformity internal pressure and maximum displacement formula under heterogeneous internal pressure of the inner contour line of a stator lining were fitted. The results show that the stress and strain of the stator lining vary periodically and the displacement is by sinusoidally varying of the stator lining inner contour line under uniform internal pressure, and displacement varying is linear relation as internal pressure varying. Under pressure difference, the maximum of stress and strain transfer to the location of pressure difference, and the deformation regularity is changed, moreover, the values and varying ranges of displacement increase together. A tiny change of Poisson's ratio of the rubber can cause great effect on the deformation of the stator lining. Therefore, the rubberizing and varying of Poisson's ratio must be payed close attention during production, so as to enhancing the mechanical property of rubber. The work herein establishes a theoretical foundation for the choice of interference fit and linetype optimization design, and it has significant purport in engineering for improving work efficiency and useful life of the double helix single screw pump.
