Double-arc harmonic wave robot joint

The invention discloses a double-arc harmonic wave robot joint, and relates to the technical field of manufacturing of robots, in particular to the technical field of designing of robot joints. The inside of a joint shell is connected with a rigid double-arc gear; a flexible double-arc cup-shaped gear is engaged in the rigid double-arc gear; the inside of the flexible double-arc cup-shaped gear is connected with a wave generator through a flexible bearing and a double-arc harmonic wave speed reducer; a control end of the wave generator of the double-arc harmonic wave speed reducer is connected with a rotor of a synchronous alternating current servo motor; the center of the flexible double-arc cup-shaped gear is connected with an output bar; and the output bar is inserted into a through hole of the joint shell in a clearance mode. By the double-arc harmonic wave robot joint, the stress condition and the transmission engagement quality of a double-arc cup-shaped gear tooth root can be improved, and the bearing capacity and the torsion rigidity of the robot joint can be improved. The double-arc harmonic wave robot joint has the characteristics of stably and accurately moving, along with low noise and low heat radiation in the movement process.