Stator assembly and motor

The utility model discloses a stator assembly and a motor, the stator assembly comprises a stator iron core and a stator winding, the stator iron core is provided with a plurality of stator slots, and the plurality of stator slots are formed on the radial inner surface of the stator iron core and are spaced at a predetermined slot pitch along the circumferential direction of the stator iron core; the stator winding comprises a plurality of phase windings mounted on the stator core, M layers are formed on each stator slot, and M is an odd number greater than or equal to 3; each phase winding comprises a plurality of coil units which are connected in series, and each coil unit comprises a first U-shaped hairpin winding, an I-shaped hairpin winding and a second U-shaped hairpin winding; the first U-shaped hairpin winding is located on the innermost layer of the stator groove, the I-shaped hairpin winding is located on the middle layer of the stator groove, the second U-shaped hairpin winding is located on the ou