US Patent 9021645 Pool cleaning robot

A pool cleaning robot for cleaning a surface of a swimming pool, said robot comprising: a main housing; main wheels being configured for propelling the robot; an auxiliary brushwheel disposed between said main wheels and configured for being rotated by the robot about an axis of rotation; and at least one inlet being formed in a bottom panel of the housing between said main wheels and being configured for intake of water and debris, wherein said main wheels are configured for being rotated by the robot at a first angular velocity, and said auxiliary brushwheel is configured for being rotated by the robot at a second angular velocity which is greater than the first angular velocity.