Small tooth difference planetary reducer and elevator traction machine using same

The invention provides a small tooth difference planetary reducer, and belongs to a motor driving device. The small tooth difference planetary reducer comprises a machine base group (12) arranged on the periphery of the reducer and a bottom plate (15), an input eccentric shaft (5) which is fixed through a first bearing (6) and the machine base group (12), a planetary wheel (9) fixed on the input eccentric shaft (5) and an inner gear (7) positioned on the periphery of the planetary wheel (9), wherein the input eccentric shaft (5) is provided with two eccentric shaft sections which are arranged in a 180-degree manner; the two eccentric shaft sections are respectively provided with the planetary wheel (9) through a second bearing (11), more than six pin holes (9-1) are uniformly distributed on the planetary wheel (9), and the pin holes (9-1) are provided with pin shafts (10) which axially pass through the planetary wheel (9); and the pin shafts (10) are of a simple support beam structure, and the two ends of the