Stator assembly and motor

The invention discloses a stator assembly and a motor, the stator assembly comprises an annular stator core and an M-phase stator winding, the stator core is provided with N slots, and the stator winding is wound into L layers in the slots by U-shaped hairpin coils; each sub-winding is provided with a plurality of U-shaped hairpin coils, and the U-shaped hairpin coils comprise a first hairpin coil, a second hairpin coil and a third hairpin coil; the first card issuing coil is located on the first layer, the second card issuing coil is located between the first layer and the Lth layer, two straight line segments of the second card issuing coil are arranged on adjacent layers, L is an even number, the third card issuing coil is located on the Lth layer, L is an odd number, and two straight line segments of the third card issuing coil are correspondingly arranged on the L layer and the L-1 layer; l is an even number, the pitch of the first hairpin coil is smaller than N/2p, L is an odd number, the pitch of the f