Concentrated winding stator coil for an electric rotary machine
A first layer coil is wound around the surface of a tooth in a direction advancing from a proximal end portion to a distal end portion of this tooth. A second layer coil is wound on the first layer coil in a direction advancing from the distal end portion to the proximal end portion of the tooth coil. Lead wires extend outward in the radial direction from a winding start end of the first layer coil and a winding terminal end of the second layer coil. Respective tooth coils of the same phase are serially connected to arrange three phase windings. A crossover bus bar group is accommodated in a space having a square cross section defined by a core back and a coil end of the tooth coil.
1. A concentrated winding stator coil for an electric rotary machine, comprising:
tooth coils provided for respective teeth, each tooth coil comprising a first layer coil wound on the surface of a tooth of a stator core in a direction advancing from a proximal end portion to a distal end portion of said tooth, a second layer coil disposed on said first layer coil and wound in a direction advancing from said distal end portion to said proximal end portion of said tooth, a winding start end and a winding terminal end disposed adjacently to said proximal end portion of said tooth, and a pair of lead wires extending outward in a radial direction from said winding start end and said winding terminal end;
a predetermined number of crossover bus bars disposed in a circumferential direction to successively connect said lead wires of the tooth coils having the same phase, so as to arrange a phase winding consisting of all of the tooth coils having said same phase and serially connected; and
neutral bus bars mutually connecting terminal ends of final tooth coils of respective phases to form a neutral point,
wherein
said crossover bus bars and said neutral bus bars are provided adjacently to a radial outer side of a coil end protruding in an axial direction of said tooth coil and also adjacently to one end face of a core back of said stator core; and
said neutral bus bars are disposed at positions identical in both axial and radial directions with those of the bus bars of predetermined phase.
2. The concentrated winding stator coil for an electric rotary machine in accordance with claim 1 , wherein said crossover bus bars are accommodated in a bus bar accommodation space which is shorter than the height of said coil end in an axial direction and shorter than a diameter of said core back.
3. The concentrated winding stator coil for an electric rotary machine in accordance with claim 2 , wherein the lead wires of said tooth coils are connected to said crossover bus bars and said neutral bus bars in said bus bar accommodation space.
4. The concentrated winding stator coil for an electric rotary machine in accordance with claim 1 , wherein said crossover bus bars are offset in the axial direction in a predetermined phase order, and the crossover bus bars of the same phase are disposed at same positions in both axial and radial directions.
5. The concentrated winding stator coil for an electric rotary machine in accordance with claim 1 , wherein said crossover bus bars are offset in the radial direction in a predetermined phase order, and the crossover bus bars of the same phase are disposed at same positions in both axial and radial directions.
6. The concentrated winding stator coil for an electric rotary machine in accordance with claim 5 , wherein said lead wires are extended substantially in the radial direction toward the crossover bus bars and the neutral bus bars, and connected to said crossover bus bars and said neutral bus bars at same positions in the axial direction.