A progressive cavity pump for inflating downhole inflatable packers. The pump includes a case defining an inlet port and an outlet passageway therein in which the outlet passageway is in communication with the inflatable packer at a location below the pump in the well bore. An elastomeric stator is disposed in the case between the inlet port and the outlet passageway, and the stator has a convoluted inner surface. A rotor is disposed in the stator and rotatable with respect thereto. The rotor defines a convoluted outer surface thereon engaged with the inner surface of the stator such that a plurality of progressive pumping cavities are defined therebetween. As the rotor is rotated within the stator, fluid is moved from one cavity to the next, thereby pumping fluid from the inlet to the outlet. The rotor has a central opening therethrough which provides communication between the packer and an upper testing string portion. The rotor is supported on bearings and/or bushings. An oil reservoir provides lubrication to the bearings. A debris collection chamber collects debris in the pump. The rotor and stator are sized such that the differential pressure across the pump is limited to a predetermined level so that the packers cannot be over-inflated.