Electric joint structure

The invention discloses an electric joint structure, which belongs to the technical field of robots, and comprises a shell, and a driver assembly, an encoder assembly, a motor assembly and a speed reducer assembly which are arranged in an inner cavity of the shell, a motor rear cover is arranged in an inner cavity of the shell; the encoder assembly is installed on one side of the motor rear cover. One end of the driver assembly is connected with one end of the encoder assembly; the motor assembly comprises a motor shaft which is installed on the motor rear cover and is provided with an installation cavity; at least part of the speed reducer assembly is located in the portion, on the other side of the motor rear cover, of the installation cavity, and one end of the speed reducer assembly is connected with the shell. At least part of the speed reducer assembly is arranged in the mounting cavity in the motor shaft, the axial size of the electric joint is greatly reduced, the length of a connecting piece is reduc