Helical gear pump
AssigneePCM Pompes
InventorJean-Paul Papin
Life of this patent
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Abstract
Gear pump, or Moineau pump, comprising two helical gears one inside the other, the internal helical gear, which is rotary (the rotor) having one tooth fewer than the external helical gear, which is stationary (the stator), characterized in that the rotor and the stator are made of respective materials which have respective coefficients of thermal expansion which lead to respective expansions of the rotor and of the stator which are such that an approximately constant clearance is maintained between the rotor and the stator over a range of ambient temperatures spanning between about 15.degree. C. and about 300.degree. C.
Claims7
Gear pump in the form of a Moineau pump, comprising two helical gears one inside the other, the internal helical gear defining a rotor which is rotary and has one tooth fewer than the external helical gear, which defines a stator and is stationary, the rotor and the stator being made of respective materials which have different coefficients of thermal expansion which lead to respective expansions of the rotor and of the stator which are such that an approximately constant clearance is maintained between the rotor and the stator over a range of ambient temperatures spanning between about 15.degree. C. and about 300.degree. C.
Dependencies are inferred from the claim text.