Patent ID: 8763200

Claim:
A robot cleaner comprising a main body and drive devices installed respectively at left and right peripheral positions on the basis of the center of the main body to drive the main body, wherein each of the drive devices includes: a main wheel to drive the main body; a drive motor to generate rotation power required to rotate the main wheel; a gear assembly to transmit rotation power of the drive motor to the main wheel; a drive shaft to interconnect the gear assembly and the main wheel so as to assist the main wheel in rotating by rotation power transmitted from the gear assembly, the drive shaft extending from the main wheel toward the center of the main body; and an auxiliary wheel to drive the main body, the auxiliary wheel being connected to a distal end of the drive shaft extending toward the center of the main body so as to be located closer to the center of the main body than the main wheel, and wherein, if the main wheel is lifted from a floor as the main body is caught at the center thereof by an obstacle when passing over the obstacle during traveling, the auxiliary wheel protrudes downward of the main body to reach the floor, assisting the main body in traveling to escape from the obstacle.