Novel three-level center driving speed reducer

The utility model discloses a three-stage central transmission deceleration machine, wherein a first gear shaft (2) and an output shaft (11) are coaxially provided on a casing (1) via a bearing, two third small gear shafts (8) are symmetrically provided at two sides of the first gear shaft (2) and the output shaft (11), a second small gear shaft (5) is provided between the first gear shaft (2) and the third small gear shafts (8), a first small gear (3) on the first gear shaft (2) is meshed with the first large gear (4) on a second small gear shaft (5), a second small gear (6) on the second small gear shaft (5) is meshed with a second large gear (7) on the third small gear shafts (8), a third small gear (9) on the third small gear shafts (8) is meshed with a third large gear (10) on the output shaft (11). The utility model can confirm low production cost, simple installment and maintenance, large power cover range and high efficiency.