Abstract: A rotary positive displacement pump of the internally-meshing screw type having a stator, a rotor and an inlet or outlet chamber at one end of the rotor has a drive comprising a connecting member rigidly secured to the rotor and extending through the chamber, which connecting member, beyond the end of the chamber remote from the rotor, is joined by a connecting rod with two universal joints to a drive shaft, connecting member in the chamber being supported by a bearing flexibly carried on a resilient support member which is sealed to the outer race of the bearing and also to the chamber wall.