Self-propelled cleaning apparatus for large diameter pipes

A cleaning apparatus for cleaning an inside surface of a large diameter pipe, the apparatus comprising:

• rotating feeding tubes with spray nozzles adapted to supply pressurized cleaning liquid to the inside surface of the large diameter pipe;
• a hollow shaft rotatable about a centerline of the apparatus and feeding the rotating tubes with pressurized liquid;
• a coupling between an external supply hose and the hollow shaft, which takes the thrust from the external supply hose and which transfers the pressurized liquid to the hollow shaft;
• a pneumatic supply hose for actuating an air motor, wherein the air motor rotates the hollow shaft;
• a supporting structure, which supports the air motor, worm gears, driving wheels and pressure wheels;
• worm gears reducing the speed of allocated driving wheels;
• and
• means to transfer rotational speed from the air motor to the hollow shaft and to the driving wheels,
• characterized in that the supporting structure is made of modular pieces, which can be bolted together for a basic structure, forming a forward center angle and a rear center angle, connected by a supporting structure element;
• that at a bottom portion of the center angles are two driving wheels, which extend radially from the center line of the hollow shaft by an angle α and transfer the forward movement;
• that at a rear side of the rear center angle α frame connects a main worm gear, which supports with its housing a single air motor, and which is part of the hollow shaft with a hollow shaft piece of a driven gear and thus acting as a bearing for the hollow shaft;
• that the hollow shaft comprises a rotor shaft and a concentric drive shaft with bearings, which are slidable along the hollow shaft for assembly, and which are fixed to the forward center angle and the rear center angle;
• that for each driving wheel a worm gear is attached with its housing to a wheel frame, whereby a shaft extension of the driven gear takes an output sprocket to act by a roller chain on a driving wheel input sprocket;
• that the driving shaft has sprockets, which act by roller chain on input sprockets situated on an input driven shaft of the worm gear;
• that each driving wheel of the driving wheels is situated in a wheel frame, which is attached to the housing of a corresponding worm gear, and which has an extending shaft end with the input sprocket;
• that on the top of the apparatus, between the forward center angle and the rear center angle α pressure wheel is located, which is guided by a swing arm with hinge connections, and which is pressed radially upwards by two pneumatic cylinders to prevent slipping of the driving wheels due to missing friction;
• and
• that the hollow shaft comprises an inside tube for the transport of the pressurized liquid and of an outer drive shaft taking assembled shaft pieces with bearings and driving sprockets.