Stator assembly including stiffener and method of assembly thereof

Abstract

A stator assembly includes an annular body extending about a central axis and a first stator tooth extending radially from the annular body. The first stator tooth includes a first tip spaced radially from the annular body. The stator assembly also includes a second stator tooth extending radially from the annular body and spaced circumferentially from the first stator tooth. The second stator tooth includes a second tip spaced radially from the annular body. The stator assembly further includes a stiffener positioned between the first stator tooth and the second stator tooth. The stiffener is configured to resist deformation of the stator assembly.

What is claimed is: 
     
         1 . A stator assembly for an electric motor assembly, said stator assembly comprising:
 an annular body extending about a central axis;   a first stator tooth extending radially from said annular body, said first stator tooth including a first tip spaced radially from said annular body;   a second stator tooth extending radially from said annular body and spaced circumferentially from said first stator tooth, said second stator tooth including a second tip spaced radially from said annular body; and   a stiffener positioned between said first stator tooth and said second stator tooth, wherein said stiffener is configured to resist deformation of said stator assembly.   
     
     
         2 . The stator assembly in accordance with  claim 1 , wherein said stiffener is integrally formed with at least one of said first stator tooth and said second stator tooth. 
     
     
         3 . The stator assembly in accordance with  claim 1 , wherein said stiffener includes a joint formed between at least one of said first stator tooth and said second stator tooth. 
     
     
         4 . The stator assembly in accordance with  claim 1 , wherein said stiffener is coupled to at least one of said first tip and said second tip. 
     
     
         5 . The stator assembly in accordance with  claim 1  further comprising an annular member extending about the central axis and sized to be positioned in a gap between said stator assembly and a rotor assembly, wherein said stiffener extends radially from said annular member. 
     
     
         6 . The stator assembly in accordance with  claim 1 , wherein at least a portion of said first stator tooth is magnetic and is positionable between a first position and a second position, and wherein the first position facilitates positioning a conduction coil about said first stator tooth and the second position enables said first stator tooth to engage said stiffener. 
     
     
         7 . The stator assembly in accordance with  claim 1 , wherein said stiffener includes a resilient member configured to engage said first tip and said second tip. 
     
     
         8 . The stator assembly in accordance with  claim 1 , wherein said annular body includes an inner surface and an outer surface, said annular body having a first thickness defined between said inner surface and said outer surface, said first stator tooth having a second thickness, wherein a ratio of said first thickness to an outer diameter of said annular body is in at least about 0.065. 
     
     
         9 . The stator assembly in accordance with  claim 8 , wherein a curve extends between a first surface of said first stator tooth and said inner surface, said curve having a radius of at least about 3 mm, wherein a ratio the radius to a width defined between said first stator tooth and said second stator tooth is in a range of about 0.1 to about 0.5. 
     
     
         10 . The stator assembly in accordance with  claim 1 , wherein said stiffener includes a fill material configured to resist deformation of said stator assembly, wherein said fill material is located within a slot defined between said first stator tooth and said second stator tooth. 
     
     
         11 . The stator assembly in accordance with  claim 10 , wherein said fill material includes an adhesive. 
     
     
         12 . The stator assembly in accordance with  claim 10 , wherein said fill material is located between conduction coils wound about said first stator tooth and said second stator tooth. 
     
     
         13 . The stator assembly in accordance with  claim 1 , wherein said annular body includes a plurality of laminations, and wherein at least one lamination of said plurality of laminations includes said stiffener extending between tips of said first stator tooth and said second stator tooth. 
     
     
         14 . The stator assembly in accordance with  claim 1 , wherein said stator assembly has a first configuration in which said annular body is flat and a second configuration in which said annular body is cylindrical, wherein said stiffener is coupled between said first stator tooth and said second stator tooth when said stator assembly is in the second configuration. 
     
     
         15 . A method of assembling an electric motor assembly, said method comprising:
 coupling a rotor assembly to a bearing such that the rotor assembly is configured to rotate about a central axis;   positioning a stator assembly along the central axis, the stator assembly including a first stator tooth, a second stator tooth, and an annular body extending about the central axis, the first stator tooth and the second stator tooth extending radially from the annular body and spaced circumferentially apart; and   providing at least one stiffener extending between the first stator tooth and the second stator tooth, wherein the stiffener is configured to resist deformation of the stator assembly.   
     
     
         16 . The method in accordance with  claim 15 , wherein providing at least one stiffener extending between the first stator tooth and the second stator tooth comprises providing at least one stiffener integrally formed with at least one of the first stator tooth and the second stator tooth. 
     
     
         17 . The method in accordance with  claim 15 , wherein providing at least one stiffener extending between the first stator tooth and the second stator tooth comprises forming a joint between the first stator tooth and the second stator tooth. 
     
     
         18 . The method in accordance with  claim 15  further comprising positioning a fill material in a slot defined between the first stator tooth and the second stator tooth. 
     
     
         19 . The method in accordance with  claim 15 , wherein providing at least one stiffener extending between the first stator tooth and the second stator tooth comprises providing at least one stiffener positioned between a first tip of the first stator tooth and a second tip of the second stator tooth. 
     
     
         20 . The method in accordance with  claim 19  further comprising coupling the stiffener to at least one of the first tip and the second tip. 
     
     
         21 . The method in accordance with  claim 19  further comprising positioning a first conduction coil about the first stator tooth and coupling the first stator tooth to the annular body after positioning the first conduction coil about the first stator tooth. 
     
     
         22 . The method in accordance with  claim 19 , wherein the at least one stiffener is movably coupled to the first tip, the method further comprising positioning the at least one stiffener between a first position and a second position, wherein the first position facilitates positioning a conduction coil about the first stator tooth.