A rotary shaft assembly includes a first supporting arm, a second supporting arm, a connecting arm connecting the first supporting arm and the second supporting arm and a driving device coupled to the second supporting arm. The driving device includes a rotor assembly and a stator assembly. The first supporting arm, the second supporting arm, and the connecting arm are integrally formed. The first supporting arm and the second supporting arm are arranged symmetrically with respect to a central point of the connecting arm. The second supporting arm comprises a connecting base arranged at an end distal from the connecting arm. The connecting base includes a receiving groove, and the rotor assembly is directly received in the receiving groove.