Rim driven thruster having propeller drive modules

Abstract

A rim driven thruster comprises an annular housing, a propulsor assembly, a magnetic rotor assembly and a stator assembly. The annular housing defines a flow path extending along an axis. The propulsor assembly is supported within the housing and comprises propeller blades extending radially from the axis of the flow path. The propeller blades are configured to rotate about the axis. The magnetic rotor assembly is mounted to radially outer ends of the propeller blades. The stator assembly comprises spaced propeller drive modules mounted to an inner circumferential surface of the annular housing. The propeller drive modules are configured to provide electromagnetic torque to the magnetic rotor assembly.

1 . A rim driven thruster comprising:
 an annular housing defining a flow path extending along an axis;   a propulsor assembly supported within the annular housing, the propulsor assembly comprising propeller blades extending radially from the axis of the flow path and configured to rotate about the axis;   a magnetic rotor assembly mounted to radially outer ends of the propeller blades; and   a stator assembly comprising spaced propeller drive modules mounted to an inner circumferential surface of the annular housing and configured to provide electromagnetic torque to the magnetic rotor assembly.   
     
     
         2 . The rim driven thruster of  claim 1  wherein:
 the magnetic rotor assembly and the annular housing define a flow space within the rim driven thruster; and 
 the spaced propeller drive modules form a plurality of channels within the flow space. 
 
     
     
         3 . The rim driven thruster of  claim 2  wherein the spaced propeller drive modules occupy less than half of the flow space. 
     
     
         4 . The rim driven thruster of  claim 1  wherein the spaced propeller drive modules are spaced equally around the inner circumference of the annular housing. 
     
     
         5 . The rim driven thruster of  claim 1  wherein the spaced propeller drive modules are spaced non-uniformly around the inner circumference of the annular housing. 
     
     
         6 . The rim driven thruster of  claim 1  wherein the spaced propeller drive modules comprise:
 a plurality of electro-magnets spaced about a circumference of the stator assembly. 
 
     
     
         7 . The rim driven thruster of  claim 2  wherein each of the electro-magnets comprises:
 a ferromagnetic core stud projecting from the annular housing; and 
 a coil winding wrapped around the ferromagnetic core stud so as to extend in both axial and tangential directions. 
 
     
     
         8 . The rim driven thruster of  claim 1  wherein the spaced propeller drive modules comprise:
 a plurality of arc shaped linear actuators spaced about a circumference of the stator assembly. 
 
     
     
         9 . The rim driven thruster of  claim 8  wherein each of the plurality of arc shaped linear actuators comprises:
 a ferromagnetic core block comprising:
 an arcuate surface facing the rotor assembly; and 
 a plurality of axially extending slots disposed in the arcuate surface; and 
 
 a plurality of axially extending coils disposed in the plurality of axially extending slots. 
 
     
     
         10 . The rim driven thruster of  claim 1  wherein the propulsor assembly further comprises:
 a hub from which the propeller blades extend; 
 a shaft extending through the hub; 
 support brackets extending from the annular housing toward the shaft to support the propulsor assembly; and 
 bearings positioned between the shaft and the support brackets. 
 
     
     
         11 . The rim driven thruster of  claim 1  wherein the propulsor assembly further comprises:
 a hub from which the propeller blades extend; 
 a support rim surrounding the propulsor blades within the annular housing; and 
 bearings supporting the propulsor assembly between the support rim and the annular housing. 
 
     
     
         12 . A rim driven thruster comprising:
 an annular housing defining an axial flow path;   a propulsor assembly comprising:
 a hub mounted co-axially within the annular housing; and 
 a plurality of propeller blades extending radially out from the hub; 
   a rotor assembly comprising:
 an annular rotor core connected to the plurality of propeller blades, wherein the annular rotor core and the annular housing define a flow path; and 
 a plurality of permanent magnets disposed about the annular rotor core within the flow path; and 
   a stator assembly comprising:
 a first propeller drive module connected to the annular housing in the flow path; and 
 a second propeller drive module connected to the annular housing in the flow path to define a channel between the first and second propeller drive modules. 
   
     
     
         13 . The rim driven thruster of  claim 12  wherein the spaced propeller drive modules comprise:
 a plurality of electro-magnets spaced about a circumference of the stator assembly. 
 
     
     
         14 . The rim driven thruster of  claim 13  wherein each of the electro-magnets comprises:
 a ferromagnetic core stud projecting from the annular housing; and 
 a coil winding wrapped around the ferromagnetic core stud so as to extend in both axial and tangential directions. 
 
     
     
         15 . The rim driven thruster of  claim 12  wherein the spaced propeller drive modules comprise:
 a plurality of arc shaped linear motor spaced about a circumference of the stator assembly. 
 
     
     
         16 . The rim driven thruster of  claim 15  wherein each of the plurality of arc shaped linear motor comprises:
 a ferromagnetic core block comprising:
 an arcuate surface facing the rotor assembly; and 
 a plurality of axially extending slots disposed in the arcuate surface; and 
 
 a plurality of axially extending coils disposed in the plurality of axially extending slots. 
 
     
     
         17 . The rim driven thruster of  claim 12  wherein the spaced propeller drive modules are spaced equally within the flow path. 
     
     
         18 . The rim driven thruster of  claim 12  wherein the spaced propeller drive modules are spaced non-uniformly within the flow path. 
     
     
         19 . The rim driven thruster of  claim 12  wherein the propulsor assembly further comprises:
 a shaft extending through the hub; 
 support brackets extending from the annular housing toward the shaft to support the propulsor assembly; and 
 bearings positioned between the shaft and the support brackets. 
 
     
     
         20 . The rim driven thruster of  claim 12  wherein the propulsor assembly further comprises:
 a support rim surrounding the propulsor blades within the annular housing; and 
 bearings supporting the propulsor assembly between the support rim and the annular housing.