Axial flux motor, fan assembly and associated method

Abstract

An electric motor for use with a power supply includes a housing and a stator fixedly secured to the housing. The stator has a plurality of coils secured to the stator. The motor also includes a first rotor secured to the stator and having a first number of poles and a second rotor secured to the stator and having a second number of poles. The second number being different than the first number. The plurality of coils cooperates with the first rotor to rotate the first rotor at a first rotor rotational speed and the plurality of coils cooperates with the second rotor to rotate the second rotor at a second rotor rotational speed. The second rotor rotational speed is substantially different than the first rotor rotational speed.

What is claimed is: 
     
         1 . An electric motor for use with a power supply, comprising:
 a housing;   a stator fixedly secured to the housing and having a plurality of coils secured thereto;   a first rotor rotatably secured to the stator and having a first number of poles;   a second rotor rotatably secured to the stator and having a second number of poles, the second number being different than the first number, the plurality of coils including a first set of coils receiving a first set of coils peak positive voltage from the power supply at a first time, a second set of coils receiving a second set of coils peak positive voltage from the power supply at a second time slightly later than the peak positive voltage of the first set of coils and a third set of coils receiving a third set of coils peak positive voltage from the power supply at a third time slightly later than the peak positive voltage of the second set of coils, the plurality of coils cooperating with the first rotor to rotate the first rotor at a first rotor rotational speed and the plurality of coils cooperating with the second rotor to rotate the second rotor at a second rotor rotational speed, the second rotor rotational speed being substantially different than the first rotor rotational speed.   
     
     
         2 . The electric motor in accordance with  claim 1 , further comprising a controller cooperating with the coils in the stator and the power supply to operate the motor. 
     
     
         3 . The electric motor in accordance with  claim 1 , wherein the motor is a permanent magnet motor. 
     
     
         4 . The electric motor in accordance with  claim 1 , wherein the motor is an axial flux motor. 
     
     
         5 . The electric motor in accordance with  claim 1 , wherein the first rotor rotational speed and the second rotor rotational speed are in opposite directions. 
     
     
         6 . The electric motor in accordance with  claim 1 :
 wherein the first number of poles is 10; and   wherein the second number of poles is 14.   
     
     
         7 . A fan assembly adapted for use in an outdoor unit of a heating, ventilation and air conditioning application to cool air conditioning condensing coils, said fan assembly, comprising:
 a motor having:
 a housing; 
 a stator fixedly secured to the housing and having a plurality of coils secured thereto; 
 a first rotor rotatably secured to the stator and having a first number of poles; 
 a second rotor rotatably secured to the stator and having a second number of poles, the second number being different than the first number, the plurality of coils cooperating with the first rotor to rotate the first rotor at a first rotor rotational speed and the plurality of coils cooperating with the second rotor to rotate the second rotor at a second rotor rotational speed, the second rotor rotational speed being substantially different than the first rotor rotational speed; 
   a first blade connected to the first rotor; and   a second blade connected to the second rotor.   
     
     
         8 . The fan assembly in accordance with  claim 7 : wherein the blade is spaced from the second blade a fan spacing distance; and wherein at least one of the first blade and the second blade are adjustably coupled to the motor, such that the fan spacing distance is adjustable. 
     
     
         9 . The fan assembly in accordance with  claim 7 , wherein the first rotor rotational speed and second rotor rotational speed are in opposite directions. 
     
     
         10 . The fan assembly in accordance with  claim 7 , further comprising a controller, the controller adapted to cooperate with the coils in the stator to operate the motor. 
     
     
         11 . The fan assembly in accordance with  claim 7 , wherein at least one of the first blade and the second blade has a variable pitch or flexibility to optimize at least one of air flow, efficiency, reduced noise, noise cancellation, and vibration reduction. 
     
     
         12 . The fan assembly in accordance with  claim 7 , wherein the motor is adapted to absorb energy from at least one of the first blade and the second blade. 
     
     
         13 . The fan assembly in accordance with  claim 7 , wherein said motor is a radial flux motor. 
     
     
         14 . The fan assembly in accordance with  claim 7 , wherein the first blade has a first diameter and the second blade has a second diameter, the first diameter being substantially different from the second diameter. 
     
     
         15 . The fan assembly in accordance with  claim 7 , wherein said motor is a switched reluctance motor. 
     
     
         16 . The fan assembly in accordance with  claim 7 , wherein said motor is a conical air gap motor. 
     
     
         17 . The fan assembly in accordance with  claim 7 :
 wherein the first number of poles is 10; and   wherein the second number of poles is 14.   
     
     
         18 . A method of providing an electronically computed electric motor with two different rotational speeds, comprising:
 providing a housing;   providing a stator having a plurality of coils;   fixedly securing the stator to the housing;   providing a first rotor having a first number of poles;   rotatably securing the first rotor to the stator;   providing a second rotor having a second number of poles, the second number being different than the first number;   rotatably securing the second rotor to the stator; and   energizing the plurality of coils to simultaneously rotate the first rotor at a first rotor rotational speed and the second rotor at a second rotor rotational speed, the second rotor rotational speed being substantially different than the first rotor rotational speed.   
     
     
         19 . The method of  claim 18 :
 further comprising the step of providing a controller;   wherein the step of providing a plurality of coils includes providing a first set of coils, a second set of coils and a third set of coils;   further comprising the step of connecting the controller to the coils;   further comprising the step of adapting the controller to cooperate with the coils in the stator to operate the motor;   further comprising the step of receiving from a power supply a first set of coils peak positive voltage;   further comprising the step of sending to the first set of coils a first set of coils peak positive voltage at a first time;   further comprising the step of receiving from the power supply a second set of coils peak positive voltage;   further comprising the step of sending to the second set of coils a second set of coils peak positive voltage at a second time slightly later than the first time; and   further comprising the step of sending to the third set of coils a third set of coils peak positive voltage at a third time slightly later than the second time, the plurality of coils cooperating with the first rotor to rotate the first rotor at a first rotor rotational speed and the plurality of coils cooperating with the second rotor to rotate the second rotor at a second rotor rotational speed, the second rotor rotational speed being substantially different than the first rotor rotational speed.   
     
     
         20 . The method of  claim 18 , wherein the step of energizing the plurality of coils comprises energizing the plurality of coils to simultaneously rotate the first rotor at a first rotor rotational speed in a first rotational direction and the second rotor at a second rotor rotational speed in a second rotational direction, opposite the rotational direction of the first rotor.