Vehicle step apparatus and motor assembly thereof

A vehicle step apparatus, comprising:

• an extending and retracting device comprising a mounting bracket, a step bracket, and an arm assembly that is connected between the mounting bracket and the step bracket and drives the step bracket to move between an extending position and a retracting position;
• a step mounted on the step bracket;
• a motor that has a motor shaft configured as a worm;
• a gear box defining a cavity therein, at least a portion of the motor shaft being inserted into the cavity;
• a worm wheel rotatably disposed in the cavity, and comprising a worm wheel body meshing with the motor shaft and an output shaft mounted to the worm wheel body;
• a sun gear fitted over the output shaft;
• a planet carrier rotatably disposed in the cavity and connected with the arm assembly to drive the arm assembly;
• a planet gear rotatably mounted to the planet carrier and meshing with the sun gear;
• and
• an adjusting member mounted in the gear box, movable in an axial direction of the motor shaft and abutting against a free end of the motor shaft.