Rotating electric machine with lane-changed coils
A stator coil has a first layer wound around a tooth portion of a stator core-sequentially from the radially outer side to the radially inner side of a stator, and is wound while a winding direction is reversed for each layer. If the outermost layer is denoted by n (n is an odd number equal to or greater than 3) and the final turn in each layer is denoted by m (m is equal to or greater than 2), the m-th turn in the n-th layer is wound on the radially outer side of the stator, the stator coil on the radially inner side is lane-changed on a shorter-side tooth portion, and a part of the stator coil on the radially outer side in the outermost layer is lane-changed on a longer-side tooth portion.
1. A rotating electric machine comprising:
a housing storing an entirety thereof;
a rotor rotatably attached to the housing via a rotational shaft; and
a stator attached to the housing so as to be opposed to an outer circumference of the rotor, wherein
the stator includes: an annular stator core fixed to the housing and having tooth portions forming a plurality of slots; and a plurality of stator coils wound around the tooth portions via bobbins formed from an insulating material made of resin,
each stator coil has a first layer wound around the tooth portion sequentially from a radially outer side to a radially inner side of the stator, and is wound while a winding direction is reversed for each layer, and
if each layer is numbered 1 to n where an outermost layer is denoted by n, where n is an odd number equal to or greater than 3, each turn is numbered 1 to m where a final turn in each layer is denoted by m, where m is equal to or greater than 2, the m-th turn in the n-th layer is wound on a radially outer side of the stator, each stator coil on the radially inner side is lane-changed on a shorter-side tooth portion, and a part of each stator coil on the radially outer side is lane-changed on a longer-side tooth portion.
2. The rotating electric machine according to claim 1 , wherein
in winding from a final turn in a (n−1)-th layer to a first turn in the outermost layer of each stator coil, the stator coil is wound from one shorter side to a longer side of the tooth portion, and the winding from the other shorter side to a longer side is performed so as to provide a gap corresponding to at least two wires of the stator coil on the radially outer side.
3. The rotating electric machine according to claim 2 , wherein
in winding from a second turn in the outermost layer to the final turn in the outermost layer of each stator coil, the stator coil is sequentially wound from the radially outer side to the radially inner side of the stator, and the stator coil is lane-changed from a radially innermost side to be wound into the gap.
4. The rotating electric machine according to claim 3 , wherein
lane change on the longer-side tooth portion is performed at the gap.
5. The rotating electric machine according to claim 1 , wherein
in turns in the outermost layer of each stator coil, a cross portion due to lane change formed by turns in the same layer is located on only one shorter-side tooth portion.
6. The rotating electric machine according to claim 1 , wherein
a winding start terminal wire in a start turn and a winding end terminal wire in a final turn of each stator coil are led out from the shorter-side tooth portions at both ends in an axial direction along the rotational shaft.