Electrical machines for integration into a propulsion engine

Abstract

An electrical machine includes a stator assembly coupled to an engine stator component of a propulsion engine. The stator assembly includes a stator support assembly fixedly attached to the engine stator component and a stator disposed on the stator support structure. An electrical machine shaft is coupled to an end of a shaft of the propulsion engine via an intermediate shaft member extending axially between the end of the shaft and the electrical machine shaft. A bearing support frame extends from the propulsion engine, the bearing support frame defining a bearing cavity in conjunction with the electrical machine shaft. Electrical machine bearings radially extend from the bearing support frame to rotatably contact the electrical machine shaft. A rotor attached to a rotor support structure attached to the electrical machine shaft. The rotor rotates in conjunction with the electrical machine shaft to exchange energy with the shaft of the propulsion engine.

What is claimed is: 
     
         1 . A stator assembly coupled to an engine stator component of a propulsion engine, the stator assembly comprising:
 a stator support assembly fixedly attached to the engine stator component;   a stator disposed on a supporting surface of a stator support structure; and   a rotor assembly comprising a rotor support structure connected to a shaft of the propulsion engine and a rotor attached to the rotor support structure such that the rotor is disposed radially inward of the stator, wherein the rotor exchanges rotational energy with the shaft to operate as either an electrical motor or an electrical generator.   
     
     
         2 . The stator assembly of  claim 1 , wherein the stator assembly circumferentially surrounds the rotor assembly such that the rotor assembly is disposed radially between the shaft and the stator assembly. 
     
     
         3 . The stator assembly of  claim 1 , wherein the stator support assembly comprises a stator support arm extending in an axial direction parallel to the shaft, the stator support arm defining the supporting surface, wherein the stator support arm is at least as long as the rotor assembly in the axial direction such that an entirety of the rotor assembly is disposed in a rotor cavity delineated by the stator support arm and the stator support arm shields the propulsion engine from the rotor assembly. 
     
     
         4 . The stator assembly of  claim 1 , further comprising:
 an electrical connection device coupled to the stator support assembly; and   an electrical line extending from the stator to the electrical connection device.   
     
     
         5 . The stator assembly of  claim 4 , further comprising an electrical machine control unit, the electrical machine control unit being electrically connected to the stator via the electrical connection device, wherein the electrical machine control unit is configured to switch operation of the electrical machine between a generator mode to generate electrical power from rotation of the shaft and a motor mode in which the stator adds rotational energy to the shaft. 
     
     
         6 . The stator assembly of  claim 1 , wherein the rotor assembly is directly connected to an end of the shaft. 
     
     
         7 . The stator assembly of  claim 1 , wherein no portion of the stator assembly extends axially aft of the rotor assembly. 
     
     
         8 . The stator assembly of  claim 1 , further comprising:
 an electrical machine shaft coupled to an end of the shaft of the propulsion engine via an intermediate shaft member extending axially between the shaft and the electrical machine shaft; and   a generator bearing assembly comprising:
 a bearing support frame extending between the electrical machine shaft and the engine stator component; and 
 generator bearings supporting the electrical machine shaft, wherein the electrical machine shaft rotates within the generator bearings in conjunction with the shaft of the propulsion engine to rotate the rotor. 
   
     
     
         9 . The stator assembly of  claim 1 , further comprising a cooling system comprising one or more cooling manifolds directing coolant from a coolant source to regions proximate to the stator and the rotor. 
     
     
         10 . An electrical machine, comprising:
 a stator assembly coupled to an engine stator component of a propulsion engine, the stator assembly comprising a stator support assembly fixedly attached to the engine stator component;   a stator disposed on a supporting surface of a stator support structure; and   a rotor assembly comprising a rotor support structure directly connected to a shaft of the propulsion engine and a rotor attached to the rotor support structure, wherein:
 the rotor is disposed radially inward of the stator such that the stator assembly circumferentially surrounds the rotor, and at least one of:
 the rotor rotates in conjunction with the shaft to generate a power signal; and 
 the electrical machine receives power from an external source to provide rotational energy to the shaft. 
 
   
     
     
         11 . The electrical machine of  claim 10 , wherein the rotor support structure is directly connected to an end of the shaft of the propulsion engine by a removable connection such that the rotor assembly is independently removable from the propulsion engine. 
     
     
         12 . The electrical machine of  claim 10 , wherein the rotor support structure is directly connected to the shaft between ends of the shaft of the propulsion engine. 
     
     
         13 . The electrical machine of  claim 10 , wherein the rotor support structure extends in a radial and an axial direction from an end of the shaft to mechanically alter a natural vibration mode of the shaft. 
     
     
         14 . The electrical machine of  claim 10 , further comprising an electrical machine control unit, the electrical machine control unit being electrically connected to the stator, wherein the electrical machine control unit is configured to actively modulate an electrical machine load to influence rotation of the electrical machine to dampen vibrations of the shaft. 
     
     
         15 . The electrical machine of  claim 10 , further comprising a cooling system comprising one or more cooling manifolds that direct coolant from a coolant source to regions proximate to the stator and the rotor. 
     
     
         16 . The electrical machine of  claim 15 , wherein an electrical line extending from the stator is at least partially routed through the one or more cooling manifolds. 
     
     
         17 . An electrical machine, comprising:
 a stator assembly coupled to an engine stator component of a propulsion engine, the stator assembly comprising:
 a stator support assembly fixedly attached to the engine stator component; 
 a stator disposed on a supporting surface of a stator support structure; 
 an electrical machine shaft coupled to an end of a shaft of the propulsion engine via an intermediate shaft member extending axially between the end of the shaft and the electrical machine shaft; 
 a bearing support frame extending from the propulsion engine, the bearing support frame including an axial portion extending in an axial direction; 
 electrical machine bearings radially extending from the axial portion of the bearing support frame to rotatably contact the electrical machine shaft; and 
 a sealing member disposed axially aft of the electrical machine bearings, the sealing member extending from the axial portion of the bearing support frame to the electrical machine shaft; and 
   a rotor assembly comprising:
 a rotor support structure connected to the electrical machine shaft; and 
 a rotor attached to the rotor support structure such that the rotor is disposed radially inward of the stator, wherein at least one of:
 the rotor rotates in conjunction with the shaft of the propulsion engine via the intermediate shaft member to generate a power signal; and 
 the electrical machine receives power from an external source to provide rotational energy to the shaft. 
 
   
     
     
         18 . The electrical machine of  claim 17 , wherein the rotor support structure is connected to the electrical machine shaft axially rearward of the electrical machine bearings to facilitate removal of the rotor from the electrical machine shaft. 
     
     
         19 . The electrical machine of  claim 17 , further comprising a decoupling device attached to the propulsion engine, the decoupling device positioned to axially overlap the intermediate shaft member to decouple the intermediate shaft member. 
     
     
         20 . The electrical machine of  claim 17 , further comprising a seal extending between the bearing support frame and the electrical machine shaft, the seal fluidly isolating the electrical machine bearings from bearings of the propulsion engine.