Nozzle device

A nozzle device comprising:

• a stationary housing with a pressurized water connector having an upstream end and a downstream end;
• a nozzle support having a front end and a rear end mounted rotatable about a rotation axis in the vicinity of said stationary housing;
• a plurality of spray orifices in said nozzle support, said nozzle support being drivable by reaction force from pressurized water issuing from said spray orifices;
• a brake device for the rotational motion of said nozzle support;
• a stationary sleeve having an upstream end and a downstream end extending centrally from said pressurized water connector;
• a hollow shaft having an upstream end and a downstream end with a central duct and a connected central passage attached to said nozzle support rotatable in said housing, said sleeve extending into said central passage of said hollow shaft, said central passage being widened in diameter relative to said central duct, pressurized water being fed from said said sleeve in said central passage into said central duct of said hollow shaft;
• and
• a labyrinth-like sealing gap between said sleeve and a bounding surface of said central passage with a plurality of grooves located in said sleeve, said gap being widened on one side by said grooves.