FLOOR CLEANING APPARATUS

1 . A floor cleaning apparatus ( 1 ) comprising:

a cleaning assembly ( 500 );

a suction unit ( 10 ) provided with a motor ( 11 ) and an impeller ( 12 ) coupled with the motor ( 11 );

an inlet channeling unit ( 20 ), operative at an inlet side of the suction unit ( 10 ), wherein the inlet channeling unit ( 20 ) is in fluid communication with at least one portion of the cleaning assembly ( 500 );

an outlet channeling unit ( 30 ), connecting an outlet side of the suction unit ( 10 ) to at least one exhaust aperture ( 40 ) of the floor cleaning apparatus ( 1 );

wherein the outlet channeling unit ( 30 ) comprises:

a first expansion chamber ( 31 ) facing the outlet side of the impeller ( 12 ) and having an outlet port ( 31 a ) in fluid communication with the exhaust aperture ( 40 ),

at least one intercepting wall ( 100 ) comprising a plurality of through holes ( 101 ), the intercepting wall ( 100 ) operating inside the first expansion chamber ( 31 ) and being positioned to intercept air flow moving from the impeller outlet side to the outlet port ( 31 a ) of the first expansion chamber ( 31 ).

2 . The floor cleaning apparatus ( 1 ) according to claim 1 , wherein the first expansion chamber ( 31 ) extends about a periphery of the impeller ( 12 ) defining an annular flow volume entirely surrounding the impeller ( 12 ) and wherein the intercepting wall ( 100 ) has an annular shape and is inserted in the annular flow volume of the first expansion chamber ( 31 ).

3 . The floor cleaning apparatus ( 1 ) according to claim 1 , wherein the first expansion chamber ( 31 ) radially extends between the outlet side of the impeller ( 12 ) and an outer peripheral wall ( 31 c ) surrounding the impeller ( 12 ) and is positioned at a radial distance from the outlet side of the impeller ( 12 ), wherein the at least one intercepting wall ( 100 ) is positioned radially between the outlet side of the impeller ( 12 ) and the outer peripheral wall ( 31 c ) of the first expansion chamber ( 31 );

wherein the first expansion chamber ( 31 ) and/or the intercepting wall ( 100 ) are concentrically positioned relative to the impeller ( 12 ) and extend all around the impeller periphery;

and wherein the annular flow volume of the first expansion chamber ( 31 ) has a constant radial width.

4 . The floor cleaning apparatus ( 1 ) according to claim 1 , wherein the through holes ( 101 ) on the intercepting wall ( 100 ) have axial symmetry, optionally cylindrical conformation;

wherein each one of the plurality of through holes ( 101 ) has an area of fluid passage, measured perpendicular to the respective axis of symmetry ( 101 a ), of between 3 mm2 and 180 mm2;

wherein the through holes ( 101 ) have respective axes of symmetry ( 101 a ) parallel to each other or converging towards a common axis, optionally converging towards an impeller axis of symmetry ( 12 a ).

5 . The floor cleaning apparatus ( 1 ) according to claim 1 , wherein each one of the through holes ( 101 ) has a cross section, taken perpendicular to the respective axes of symmetry ( 101 a ), which is circular and which has a diameter of between 2 mm and 15 mm.

6 . The floor cleaning apparatus ( 1 ) according to claim 1 , wherein the through holes are distributed, optionally homogeneously distributed, on the intercepting wall and positioned all around the impeller periphery; optionally wherein one or more series of through holes are present on the intercepting wall, with each series of through holes comprising through holes at a same angular distance from one another and positioned all around the impeller periphery.

7 . The floor cleaning apparatus ( 1 ) according to claim 2 , wherein the annular flow volume of the first expansion chamber ( 31 ) has a transversal air flow cross sectional area, measured perpendicular to the axis of rotation ( 12 a ) of the impeller ( 12 ), having a prefixed maximum area and having an annulus shape;

wherein a first compression channel ( 33 ) connects the first expansion chamber ( 31 ) to a second expansion chamber ( 32 ) and wherein the first compression channel ( 33 ) has a transversal air flow cross sectional area, measured perpendicular to the axis of rotation ( 12 a ) of the impeller ( 12 ), having a prefixed minimum area which is smaller than said maximum transversal air flow cross sectional area of the annular flow volume of the first expansion chamber ( 31 ).

8 . The floor cleaning apparatus ( 1 ) according to claim 7 , wherein the first compression channel ( 33 ) is directed upwards, optionally extends at least in part parallel to axis of rotation ( 12 a ) of the impeller ( 12 ), and wherein the second expansion chamber ( 32 ) is positioned above, substantially in overlapping, the first expansion chamber ( 31 ); and wherein the second expansion chamber ( 32 ) extends around the motor ( 11 ).

9 . The floor cleaning apparatus ( 1 ) according to claim 7 , wherein the outlet channeling unit ( 30 ) comprises:

a third expansion chamber ( 34 ) positioned downstream the second expansion chamber ( 32 ), and

a second compression channel ( 35 ) placing in fluid communication the second expansion chamber ( 32 ) with the third expansion chamber ( 34 );

a transition channel ( 38 ) extending between the third expansion chamber ( 34 ) and a fourth expansion chamber ( 39 ) terminating into the exhaust aperture ( 40 ) of the floor cleaning apparatus ( 1 ),

wherein the transition channel ( 38 ) defines a compression of air and has an air flow path with zig-zag conformation for air flowing from the third expansion chamber ( 34 ) to the fourth expansion chamber ( 39 ), wherein the air flow path changes direction at least twice before reaching the exhaust aperture ( 40 ).

10 . The floor cleaning apparatus ( 1 ) according to claim 1 , comprising at least one spent liquid receptacle ( 75 ) and at least one suction pipe ( 41 ), wherein the inlet channeling unit ( 20 ) is in fluid communication with said at least one portion of the cleaning assembly ( 500 ) via the suction pipe ( 41 );

and wherein the inlet channeling unit ( 20 ) is positioned above the spent liquid receptacle ( 75 ) and is in fluid communication with the suction pipe ( 41 ) and the suction pipe ( 41 ) connects said at least one portion of the cleaning assembly ( 500 ) with the at least one spent liquid receptacle ( 75 ).

11 . The floor cleaning apparatus ( 1 ) according to claim 1 , wherein no alveolar material is applied to walls delimiting the first expansion chamber or to walls delimiting the second expansion chamber or to walls delimiting the third expansion chamber; optionally wherein the entire outlet channeling unit ( 30 ) comprises no alveolar material applied contacting an air flow crossing the outlet channeling unit and/or the entire inlet channeling unit ( 20 ) comprises no alveolar material contacting an air flow crossing the inlet channeling unit.