Dual propeller shock resistant submersible propulsor unit

A submersible propulsor unit, comprising:

• a cylindrical shroud having a water inlet and a water outlet;
• a shaft assembly disposed along the axis of rotation of said shroud between said water inlet and outlet;
• a plurality of vane members for mounting said shaft assembly within said shroud;
• first and second propellers, each of which includes a separate hub rotatably mounted on said shaft assembly, wherein said second propeller is located downstream of said first propeller, and
• first and second electric motors for separately rotating said first and second propellers, each motor including a rotor mounted around the outer periphery of said propellers, and a stator mounted on said shroud around said rotor, and
• first and second bearing assemblies each of which includes a thrust bearing disposed between the hubs of said first and second propellers and said shaft assembly, wherein the thrust bearings associated with said first and second bearing assemblies are located on opposite ends of the shaft assembly.

A submersible propulsor unit, comprising:

• a cylindrical shroud having a water inlet and a water outlet;
• a shaft assembly disposed along the axis of rotation of said shroud between said water inlet and outlet;
• a plurality of vane members for mounting said shaft assembly within said shroud;
• first and second propellers, each of which includes a separate hub rotatably mounted on said shaft assembly, wherein said second propeller is located downstream of said first propeller, and wherein said first propeller acts to supercharge the second propeller during the operation of said unit;
• first and second electric motors for separately rotating said first and second propellers, each motor including a rotor mounted around the outer periphery of said propellers, and a stator mounted on said shroud around said rotor, and
• first and second bearing assemblies, each of which includes a thrust bearing disposed between the hubs of said first and second propellers and said shaft assembly, wherein the thrust bearings associated with said first and second bearing assemblies are both located on opposite ends of the shaft assembly, and wherein each bearing assembly includes means for circulating ambient water around its bearing surfaces for both lubricating and cooling said surfaces.

A submersible propulsor unit, comprising:

• a shroud having a water inlet and a water outlet;
• a shaft assembly disposed along the axis of rotation of said shroud between said water inlet and outlet;
• first and second propellers, each of which includes a separate hub rotatably mounted on said shaft assembly, wherein said second propellers is located downstream of said first propeller;
• first and second electric motors for separately rotating said first and second propellers, wherein each motor includes a rotor mounted around the outer periphery of one of said propellers, and a stator mounted on said shroud around said rotor, and
• first and second bearing assemblies, each of which includes a thrust bearing disposed between the hubs of said first and second propellers and said shaft assembly, wherein the thrust bearings associated with said first and second bearing assemblies are located on opposite ends of the shaft assembly, and wherein each of said bearing assemblies includes means for circulating ambient water around its bearing surfaces for both lubricating and cooling said assembly.

A submersible propulsor unit, comprising:

• a shroud having a water inlet and a water outlet;
• a shaft assembly disposed along the axis of rotation of said shroud between said water inlet and outlet;
• first and second propellers, each of which includes a separate hub rotatably mounted on said shaft assembly, wherein said second propeller is located downstream of said first propeller;
• first and second electric motors for separately rotating said first and second propellers, wherein each motor includes a rotor mounted around the outer periphery of one of said propellers, and a stator mounted on said shroud around said rotor, and
• first and second bearing assemblies, each of which includes a radial bearing, a thrust bearing disposed between the hubs of said first and second propellers and said shaft assembly, and a housing surrounding said radial bearing and thrust bearing and having a removable portion for affording separate access to the bearings it contains,
• wherein the thrust bearings and housings associated with said first and second bearing assemblies are located on opposite ends of the shaft assembly.