Reduction gearbox ( 10, 10', 10", 10 III, 10 IV, 10 V) comprising a housing ( 11, 11 ', 11", 11 III, 11 IV, 11 V), at least one toothed crown element ( 13, 13', 13", 13 I II, 13 IV, 13 V), a power input, at least two power take-offs ( 17, 17', 17", 17 III, 17 IV, 17 V), at least one take-off joint ( 19, 19', 19 "); wherein: - the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) forms a gear toothing; - the power input is configured for driving the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V); - the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) is configured for driving both power take-offs (17, 17', 17", 17 III, 17 IV, 17 V) by rotating about itself around a crown rotation axis; - each power take-off ( 17, 17', 17 ") comprises a rotating interface configured for rotating about itself about a take-off rotation axis (ARP1, ARP2) and to engage and drive a shaft or other driven rotating element; - the power input is configured for engaging with the toothing of the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) coming into contact therewith in at least one crown contact point; - the at least one take-off joint ( 19, 19', 19") allows to vary the orientation in space of at least one take-off rotation axis (ARP1, ARP2) by rotating it relative to the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) around a respective take-off rotation centre (CRP1, CRP2); characterized in that: - the distance (DPC1, DPC2), according to the crown rotation axis, of each take-off rotation centre (CRP1, CRP2) from the crown contact plane (PCCor) is equal to or less than twice the external radius (RCext) of the toothing of the toothed crown element (13, 13', 13", 13 III, 13 IV, 13 V), wherein the crown contact plane (PCCor) is the ideal plane perpendicular to the crown rotation axis and passing through the at least one crown contact point; - the at least one take-off joint (19, 19', 19") or each take-off joint (19, 19', 19") is at least partially contained in the toothed crown element (13, 13', 13",13 III, 13 IV, 13 V). - the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) forms a gear toothing; - the power input is configured for driving the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V); - the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) is configured for driving both power take-offs (17, 17', 17", 17 III, 17 IV, 17 V) by rotating about itself around a crown rotation axis; - each power take-off ( 17, 17', 17 ") comprises a rotating interface configured for rotating about itself about a take-off rotation axis (ARP1, ARP2) and to engage and drive a shaft or other driven rotating element; - the power input is configured for engaging with the toothing of the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) coming into contact therewith in at least one crown contact point; - the at least one take-off joint ( 19, 19', 19") allows to vary the orientation in space of at least one take-off rotation axis (ARP1, ARP2) by rotating it relative to the toothed crown element ( 13, 13', 13", 13 III, 13 IV, 13 V) around a respective take-off rotation centre (CRP1, CRP2); characterized in that: - the distance (DPC1, DPC2), according to the crown rotation axis, of each take-off rotation centre (CRP1, CRP2) from the crown contact plane (PCCor) is equal to or less than twice the external radius (RCext) of the toothing of the toothed crown element (13, 13', 13", 13 III, 13 IV, 13 V), wherein the crown contact plane (PCCor) is the ideal plane perpendicular to the crown rotation axis and passing through the at least one crown contact point; - the at least one take-off joint (19, 19', 19") or each take-off joint (19, 19', 19") is at least partially contained in the toothed crown element (13, 13', 13",13 III, 13 IV, 13 V).