Pin tooth cycloid reducer and industrial robot

A pin tooth cycloid reducer, comprising:

• a first cycloid structure system and a second cycloid structure system, disposed in an axial direction, wherein the first cycloid structure system is sleeved on an eccentric shaft, and each cycloid structure system comprises at least one cycloid structure in the axial direction;
• wherein the cycloid structure comprises:
• a cycloid disk, a plurality of pin teeth distributed circumferentially and a pin tooth housing, successively disposed from inside to outside in a radial direction;
• wherein the plurality of pin teeth are rotatably fixed to the pin tooth housing, and the cycloid disk engages with the plurality of pin teeth;
• wherein all pin tooth housings in the pin tooth cycloid reducer are coaxially disposed;
• wherein at least one cycloid disk in the second cycloid structure system and at least one cycloid disk in the first cycloid structure system are circumferentially fixed, and circumferentially fixed cycloid disks are coaxially disposed;
• wherein when the eccentric shaft rotates, the cycloid disk in the first cycloid structure system rotates at a first angle α relative to the corresponding pin tooth housing, and the cycloid disk in the second cycloid structure system rotates at a second angle β relative to the corresponding pin tooth housing, where the first angle α does not equal to the second angle β.