Rotary type electrostatic spray painting device

A rotary type electrostatic spray painting device comprising:

• a metallic housing;
• a metallic rotary shaft rotatably arranged in said housing and having a front end and a rear end;
• a cup shaped metallic spray head fixed onto the front end of said rotary shaft and having a cup shaped inner wall;
• feeding means for feeding a paint onto said cup shaped inner wall;
• drive means cooperating with said rotary shaft for rotating said rotary shaft;
• non-contact type radial bearing means arranged in said housing and cooperating with said rotary shaft for radially supporting said rotary shaft under a non-contacting state;
• air supply means producing air under pressure;
• a stationary annular plate fixed onto said housing and having opposed side walls, said annular plate having a plurality of air outflow bores which are formed on the opposite side walls of said annular plate and are connected to said air supply means;
• a pair of runners fixed onto said rotary shaft and arranged on each side of said annular plate, each of the side walls of said annular plate being slightly spaced from said corresponding runner and having a peripheral wall portion and a central wall portion which faces said corresponding runner and has said air outflow bores formed thereon, said annular plate having at least one pressure balancing bore which passes through said annular plate and is arranged in said peripheral wall portion located radially outwardly from said runners;
• a generator generating a negative high voltage and having an output connected to said housing, and;
• electrode means arranged in said housing and electrically connecting said output to said spray head.