Hydroelectric gear pump with varying helix angles of gear teeth

A gear pump unit for hydroelectric power generation, comprising:

• a gear pump comprising:
• a case comprising a fluid inlet and an outlet;
• a first rotor in the case, the first rotor comprising:
• a rear portion;
• an axis;
• a first position located along the axis;
• a second position located along the axis at a location between the first position and the rear portion;
• a first plurality of radially spaced teeth, wherein the first plurality of radially spaced teeth wrap around the first rotor helically in a clockwise direction, and wherein at the first position the first plurality of radially spaced teeth have a helix angle different than the helix angle of the first plurality of radially spaced teeth at the second position;
• a second rotor in the case, the second rotor comprising:
• a rear portion;
• an axis;
• a first position located along the axis;
• a second position located along the axis at a location between the first position and the rear portion;
• a second plurality of radially spaced teeth, wherein the second plurality of radially spaced teeth wrap around the second rotor helically in a counter-clockwise direction, and wherein at the first position the second plurality of radially spaced teeth have a helix angle different than the helix angle of the second plurality of radially spaced teeth at the second position, and wherein the first plurality of teeth mesh with the second plurality of teeth;
• and
• a shaft operatively connected to the first rotor and to the second rotor;
• a generator operatively connected to the shaft;
• and
• a control module operatively connected to the gear pump and configured to selectively rotate the first rotor in a first direction and to selectively rotate the second rotor in a second direction, the control module further configured to selectively reverse the rotation direction of the first rotor and to selectively reverse the rotation direction of the second rotor.