Three-constant velocity output shaft four-drive speed variator

The utility model discloses a third isodromic output shaft four-drive transmission. An output shaft driving gear (7) is constantly meshed with a transition intermediate shaft drive gear (8) which is arranged on a transition intermediate shaft (9), a transition intermediate shaft driving gear (10) is arranged on the transition intermediate shaft (9) and is constantly meshed with a rear output shaft drive gear (12) which is arranged on a rear output shaft (11), and flanges (13) are arranged at both ends of the rear output shaft (11). The three joint ports of the third isodromic output shaft four-drive transmission are fully isodromic, and the third isodromic output shaft four-drive transmission can be used for automobiles driven by sole rear axles and four-drive vehicle or dune buggies simultaneously driven by front axles and rear axles, and the like; and another output interface of the third isodromic output shaft four-drive transmission is used as a force taken port. The third isodromic output shaft four-drive transmission reserves four forward speed gears and one reverse gear.