Abstract: A motorised pool-cleaning device (1) includes: a suction element (30); a rotary element (4) for moving the device, which define first (2) and second (3) bearing axles; a support (18) consisting of (i) a first central part (24) and (ii) first (25) and second (26) side covers which are connected to either side of the first central part, such as to form the chassis of the motorised device, and which support the rotary movement element (4); and a drive element (16, 17) for rotating the rotary movement element (4), which are disposed on the first and second side covers in a cantilevered manner.