Rotary electric machine

A rotary electric machine comprising:

• a stator including a stator winding which is inserted to be positioned within a plurality of slots formed at a stator core;
• and
• a rotor supported at the stator to be movable relative to the stator in a first direction and arranged to face the stator in a second direction, the rotor including a plurality of pairs of rotor poles at a rotor core, each pair of the plurality of pairs of rotor poles including different polarities from each other, wherein
• the stator includes a fractional slot configuration where the number of slots per pole per phase is a non-integer,
• the stator winding is wound by a fractional slot winding,
• one of the stator core and the rotor core includes a base portion and either a single position portion or a plurality of position portions which is connected to the base portion in a third direction and which is displaced relative to the base portion in the first direction, the third direction being orthogonal to the first direction and the second direction,
• either the single position portion or the plurality of position portions obtains a first average skew amount Sav1 serving as an average skew amount relative to the base portion for reducing at least one of a noise and a vibration that occurs at a driving of the rotary electric machine,
• the first average skew amount Sav1 in a case where a lamination thickness of the base portion in the third direction and a lamination thickness of either the single position portion or the plurality of position portions in the third direction are the same as one another is expressed by a formula 1:
• Sav1=(c−1)/(2×d) (Formula 1)
• where c is a denominator part of an irreducible fraction representing a proper fraction part of a mixed fraction by which the number of slots per pole per phase is expressed, the mixed fraction including an integer part a and the irreducible fraction including a numerator part b,
• where d is a skew amount specifying portion serving as an integer equal to or greater than the denominator part c, a reciprocal of the skew amount specifying portion d indicating a skew amount in a stator pole pitch,
• the first average skew amount Sav1 is calculated in a state where a skew amount of the base portion is specified to be zero and the value zero of the skew amount of the base portion is included for the calculation, the first average skew amount Sav1 serving as an average skew amount in the stator pole pitch, and
• the integer part a, the numerator part b and the denominator part c are positive integers, the denominator part c being equal to or greater than two and inhibited from being a multiple of three.