Step motor

A step motor, comprising a housing, a stator assembly fixed to an inner peripheral side of the housing, a rotor assembly supported by the housing and rotationally connected to the housing, and a reduction gearbox assembly connected to an output end of the rotor assembly for power transmission;

• wherein the stator assembly is arranged around the rotor assembly and spaced apart from the rotor assembly, the housing comprises an outer shell and a first end cover and a second end cover respectively fixed to both ends of the outer shell, the reduction gearbox assembly is fixed on a side of the second end cover away from the outer shell, the rotor assembly comprises a rotary shaft rotationally connected to the first end cover and the second end cover, respectively, as well as a permanent magnet sleeved on and fixed to the rotary shaft, and an outer peripheral side of the permanent magnet is spaced apart from the stator assembly;
• and
• wherein the step motor further comprises an elastic piece having a flat plate structure and fixed to the first end cover, the elastic piece comprises a limiting portion abutting against an end of the rotary shaft away from the reduction gearbox assembly, a ring-shaped fixing portion arranged around the limiting portion, and at least two elastic arms connecting the limiting portion with the fixing portion, and the fixing portion is fixed to the first end cover.