Chuck mechanism, robot arm, and robot

The utility model provides a chuck mechanism. The chuck mechanism comprises a mounting base, a motor, a chuck assembly and a crank component. Wherein the chuck assembly is connected with the mounting seat, and the chuck assembly comprises a gear which is hinged with the mounting seat. The rack is meshed with the gear, the rack can move forwards or backwards, and the rack comprises a first wall face close to the front and a second wall face which is spaced from the first wall face and close to the rear. The crank component is connected with the motor, and the eccentric end of the crank component is arranged between the first wall face and the second wall face. According to the utility model, the moving precision of the chuck mechanism can be improved, and the controllability is improved. 本实用新型提供一种夹头机构，包括：安装座、电机、夹头组件和曲柄构件。其中，所述夹头组件与所述安装座连接，所述夹头组件包括与所述安装座铰接的齿轮。所述齿条与所述齿轮啮合，所述齿条可往前或往后移动，所述齿条包括靠前的第一壁面和与所述第一壁面间隔并靠后的第二壁面。所述曲柄构件与所述电机连接，所述曲柄构件的偏心端置于所述第一壁面和所述第二壁面之间。本实用新型可以提高夹头机构的活动精度并且提升操控性。