External cover-cooled rotary electric machine and casing used therein

An external cover-cooled rotary electric machine comprising:

• a casing comprising:
• a first bracket;
• a second bracket;
• and
• a center frame that is held and fastened between end surfaces of said first bracket and said second bracket from two axial ends;
• a stator comprising:
• an annular stator core that is held so as to be fitted into said center frame;
• and
• a stator winding that is mounted into said stator core;
• and
• a rotor that is rotatably supported by said first bracket and said second bracket, and that is rotatably disposed inside said stator,
• said external cover-cooled rotary electric machine performing cooling by making a refrigerant flow through said center frame, wherein:
• said center frame is formed into a tubular body that has a cylindrical inner circumferential surface;
• a first mated recess portion and a second mated recess portion are formed annularly on each of two axial end surfaces of said center frame by a cutting process such that a first inner wall surface that is selected from an inner circumferential inner wall surface and an outer circumferential inner wall surface is formed into a mated surface;
• a refrigerant passage through which said refrigerant is made to flow is formed inside said center frame so as to have an opening on at least one of said first mated recess portion and said second mated recess portion;
• a first mated protrusion and a second mated protrusion are disposed so as to project annularly from respective end surfaces of said first bracket and said second bracket by a cutting process such that a first wall surface that is selected from an inner circumferential wall surface and an outer circumferential wall surface that fits together with said first inner wall surface so as to be mated is formed into a mated surface;
• said center frame is fastened to said first bracket and said second bracket by said first mated protrusion and said second mated protrusion being fitted together with said first mated recess portion and said second mated recess portion so as to be mated;
• and
• an elastic sealing member is disposed annularly on an opposite side of whichever mated recess portion of said first mated recess portion and said second mated recess portion said refrigerant passage has said opening from said first inner wall surface so as to be held between an end surface of said center frame and an end surface of whichever bracket of said first bracket and said second bracket faces said mated recess portion.