Bidirectionally rotatable mechanism, bidirectional sander, and bidirectional cleaner

A bidirectionally rotatable mechanism, comprising an actuator, an inner shaft, and an outer shaft, the inner shaft and the outer shaft being actuated to rotate by the actuator, the outer shaft being sleeved outside the inner shaft, wherein a speed reducer is arranged between an output shaft of the actuator and the inner shaft;

• the speed reducer comprises an inner ring gear in which a reduction gear assembly is embedded, the reduction gear assembly comprising a planetary reduction gear meshing with the inner ring gear and a transmission shaft, the planetary reduction gear being in transmission connection with the output shaft, the transmission shaft being in transmission connection with the inner shaft;
• a first gear is arranged on an outer peripheral surface of the inner shaft;
• an outer transmission assembly in transmission connection with the outer shaft is arranged outside the inner shaft, the outer transmission assembly comprising a support element, an upper planetary carrier, a planetary gear meshing with the first gear, and a lower planetary carrier connected to the outer shaft;
• a support wheel is provided at a lower end of the support element, the upper planetary carrier being sleeved on an outer periphery of the support wheel;
• the planetary gear comprises a first gear portion and a second gear portion, the first gear portion meshing with the support wheel, the second gear portion meshing with the first gear;
• and the planetary gear is arranged between the upper planetary carrier and the lower planetary carrier.