Reasonable solution to the inverse problem of direct drive screw

Screw reversal may cause tripping poles, light pole bending rejection, ground drives damaged parts, Pellet mill  jeopardize the safety of the operator, so reasonable solution to the inverse problem of direct drive screw is particularly important.Screw driving force in the loss or downtime inversion problem exists, causing screw reversal generally two reasons: one is in the screw pump work, drive motor torque rod to pass through nearly 1000 meters to the pump , sucker inevitably produce elastic deformation and a twist angle, thus storing elastic energy when the drive motor is not  oil refinery , the rod will drive the opposite direction to reverse the mechanical system; another drive system is shut down, the oil casing level difference exists, nearly 1000 meters of oil by gravity from the tubing down, the pressure level generated by the rotor screw pump will reverse.