Capping head for the application of caps on containers or bottles

A capping head (10) for the application of caps on containers or bottles, comprising a hollow housing (11) internally defining at least a first chamber (19) in which a shaft (13) rotating about a longitudinal axis (A) is housed, the rotating shaft (13) being coupled with the hollow housing (11) through the interposition of a magnetic or electromagnetic decoupling assembly (20) configured to generate thermal dissipation power and comprising at least a rotor (21) and a stator (22), the magnetic or electromagnetic decoupling assembly (20) being suitable to allow a relative rotation between the hollow housing (11) and the rotating shaft (13) when the rotating shaft (13) is subjected to a braking torque exceeding a threshold torque, wherein inside the hollow housing (11) there are means for enhancing the thermal dissipation power, said means comprising elements (28a, 29a, 26, 17a, 17b) which are different from the rotor (21) and the stator (22) and on which eddy currents flow, wherein said elements (28a, 29a, 26, 17a, 17b) which are different from the rotor (21) and the stator (22) and on which eddy currents flow comprise at least one out of:

• at least one coating layer (29a) of an outer surface portion (29) of the stator (22) radially facing the rotor (21);
• and/or
• at least one coating layer (28a) of an outer surface portion (28) of the rotor (21) radially facing the stator (22);
• and/or
• at least one axial extension element (26) of the stator (22) of the magnetic or electromagnetic decoupling assembly (20);
• and/or
• at least one annular element (17a, 17b) placed at the rotor (21) of the magnetic or electromagnetic decoupling assembly (20) in such a way as to define an axial extension of the same rotor (21) and located around the rotating shaft (13), said at least one annular element (17a, 17b) having such radial size that it does not prevent stator (22) from sliding between a position of maximum overlap and a position of minimum overlap with rotor (21).