Patent ID: 8132618

Claim:
A system for retarding the backspin of a rod string, comprising: a progressive cavity pump including a helical rotor disposed within a mating stator; a rod string having a longitudinal axis, a first end, and a second end coupled to the rotor; a rotation retarding device coupled to the first end of the rod string, wherein the rotation retarding device is configured to retard the rotation of the rod string relative to the stator, the rotation retarding device comprising; a housing having an upper end, a lower end, and a brake cavity; a shaft at least partially disposed in the brake cavity, wherein the shaft is rotatably coupled to the housing; and a hydrodynamic brake disposed in the brake cavity, wherein the hydrodynamic brake is configured to retard the rotation of the shaft relative to the housing; and a lifting device coupled to the rotation retarding device, wherein the lifting device is configured to apply an axial lifting force to the rotation retarding device and the rotor.