Helical gear pump with progressive interference between rotor an

Hydraulic drilling motor with rotary internally and externally t

Hydraulic motor with variable speed

Internally profiled stator tube

Method and apparatus for limiting eccentric deviations of a rota

Method for making a moineau stator and resulting stator

Method of producing elastomeric stators for eccentric spiral pum

Moineau motor with conduits through the stator

Moineau pump with helicoidal coupling sleeve

Moineau pump with rotating closed end outer member and nonrotati

Moineau pump with rotating outer member

Moineau pump with rotating outer member

Moineau pumping device having a ball coupling

Moineau type gear mechanism with resilient sleeve

Motor/pump transmission construction for a Moineau type apparatu

Non-contact seal for positive displacement capture device

Non-elastomeric stator and downhole drilling motors...

Optimized fiber reinforced liner material for positive...

Optimized liner thickness for positive displacement drilling...

Overspeed protective gear box for a well pump