Reduction unit for mixing machines of the crown wheel type

The invention relates to a reduction unit for mixing machines of the "crown wheel" type, said mixing machine being of the type that comprises a tank (1), at least one horizontal arm (2) rotateable about a central vertical axis (3) having at least one extremity projecting from said tank (1) and, at at least one extremity of said horizontal arm (2), an assembly of vanes (4) rotateable about a second vertical axis (5), the reduction unit comprising at least one motor (9), first motion transmission-reduction means (11, 12, 13, 14, 15) between said extremity of the central vertical axis (2) projecting from the tank and the axis (10) of the motor (9), such that a reduction of about 1:50 - 1:80 (preferably 1:70) is obtained, second transmission-reduction means (18, 19, 20, 21, 22, 23) arranged between the upper extremity of said central vertical axis (2) and the second vertical axis (5) of rotation of the assembly of vanes (4); a post (8) being provided about said central vertical axis (2), fixed on the lower side on the floor of the tank (1) and bearing, on the upper side, at least one element (18) of the second transmission-reduction means.