Robotic dust collector and self-propelled device

A robotic dust collector includes a body, a wheel, a wheel motor, and a suspension device. The body accommodates a storage unit to store therein dust and dirt sucked in from a suction inlet. The wheel supports the body. The wheel motor generates motive power to rotate the wheel. The suspension device includes a support member, a motive-force generating mechanism, and an adjustment mechanism. The wheel is supported rotatably about a center axis by the support member. The motive-force generating mechanism gives a motive force to the support member to generate a biasing force to cause the wheel to protrude from a bottom face of the body. The adjustment mechanism adjusts the biasing force based on a protrusion amount of the wheel from the bottom face. The suspension device gives the biasing force adjusted by the adjustment mechanism to the wheel.