Rotary atomizer

A rotary atomizer for applying a spray jet of a coating agent to a component, comprising:

• a) a shaping air ring to discharge shaping air to form the spray jet of the coating agent,
• b) a bell cup shaft rotating during operation, the bell cup shaft being hollow,
• c) a paint tube arranged substantially coaxially in the bell cup shaft, wherein the bell cup shaft and the paint tube enclose an annular gap with a certain gap width in a radial direction,
• d) a paint nozzle which is arranged substantially coaxially in the paint tube and discharges the coating agent to be applied substantially in an axial direction through an outlet opening, and
• e) a bell cup mounted on the bell cup shaft and rotating during operation with
• e1) a gap between a front side of the shaping air ring and a rear side of the bell cup with a certain gap width in the axial direction,
• e2) a central bore for axial feed-through of the paint nozzle with an annular gap between the bell cup and the paint nozzle with a certain gap width in the radial direction,
• e3) an annular spray edge for spraying the coating agent,
• e4) an outer circumferential surface,
• e5) an exterior rinsing chamber on the rear side of the bell cup for rinsing the outer circumferential surface with a rinsing agent, the exterior rinsing chamber forming an annular gap on an outside of the bell cup shaft with a specific gap width in the radial direction,
• e6) several exterior rinsing channels in the bell cup between the paint nozzle and the exterior rinsing chamber for feeding rinsing agent from the paint nozzle onto the outer circumferential surface of the bell cup for exterior rinsing of the bell cup
• e7) a nozzle chamber on the rear side of the bell cup for receiving the paint nozzle with an annular gap between the paint nozzle and an inner wall of the nozzle chamber with a certain gap width in the radial direction,
• e8) an overflow surface at a front face of the bell cup, wherein the coating agent to be applied, coming from the outlet opening of the paint nozzle, flows in operation outwards over the overflow surface to the spray edge of the bell cup,
• e9) a distributor disc for distributing the coating agent emerging from the outlet opening of the paint nozzle, wherein the distributor disc
• is arranged in the bell cup at a front side of the bell cup,
• directs the coating agent coming from the paint nozzle partly radially outwards onto the overflow surface of the bell cup and partly axially through a central bore in the distributor disc onto an end face of the distributor disc,
• wherein the distributor disc encloses with the overflow surface of the bell cup a gap with a certain gap width,
• e10) a distributor disc holder which is arranged in the bell cup and has a central bore with a specific diameter, the distributor disc being mounted on the distributor disc holder, and,
• f) wherein rotary atomizer is designed in such a way that an air pressure at the outlet opening of the paint nozzle during operation is lower than an air pressure in the nozzle chamber of the bell cup and in the exterior rinsing channels, in order to prevent a backflow of the coating agent from the outlet opening of the paint nozzle backwards in a direction of the nozzle chamber as a result of a pressure difference.