Patent ID: 8418662

Claim:
An apparatus for visually inspecting and removing a foreign substance from a gap of a heat tube bundle in an upper part of a tube sheet of a second side of a steam generator, comprising: a robot comprising a transfer unit that moves on a wall surface within a ring of the steam generator, a lift that is provided in the transfer unit to vertically move upward and downward, a visual inspector that is rotatably provided in the lift, and that moves upward and downward by driving the lift, and that monitors sludge or a foreign substance injected into a gap of the heat tube, and a foreign substance remover that is provided at one side of the visual inspector and that removes the sludge or the foreign substance existing in the gap of the heat tube; a controller that is provided at one side of the steam generator for controlling the robot on the spot; a remote controller that is provided at the outside, and that is connected to the controller for controlling the robot; and an encoder mounting fixture that is fixed to one side of a handhole of the steam generator, and that is connected to the controller through a first cable, and that receives and supplies a second cable connected to the robot, wherein the transfer unit comprises: a main body that has a pair of first motors therein; a front wheel arm that is rotatably provided in both sides of one side of the main body, and that has a first thread at one end surface thereof, and that has a first magnetic wheel in one surface of the other side thereof; a first gear group that is provided within the front wheel arm and that drives the first magnetic wheel provided in the front wheel arm by transferring power of the first motor; a rear wheel arm that is symmetrical to the front wheel arm and rotatably provided in both surfaces of the other side of the main body, and that has a second thread in one end surface thereof, and that has a second magnetic wheel in one surface of the other side thereof; a second gear group that is provided within the rear wheel arm and that drives the second magnetic wheel provided in the rear wheel arm by transferring power of the first motor; a power transmission means that transfers power of the first motor to the second gear group; an equalizer that is provided in the main body to engage with the first thread of the front wheel arm and the second thread of the rear wheel arm and that is slidably provided when the first wheel arm and the rear wheel arm are rotated by the first and second magnetic wheels attached to the inner wall surface of the steam generator when an operator pulls the main body; a fixing and release means that is provided in the main body and that fixes and releases the moved equalizer; and a first spring that is provided between the main body and the equalizer and that returns the rotated front wheel arm and rear wheel arm to their original positions by pushing the equalizer in which fixing is released by the fixing and release means.