Mechanical arm and robot

The utility model is suitable for the robot field, and discloses a mechanical arm and a robot, the mechanical arm comprises a mechanical arm body and a driving device installed at the tail end of the mechanical arm body and used for driving an executing mechanism to rotate, the driving device comprises a power assembly, a first transmission part, a second transmission part, an adjusting part and a first abutting part, one of the first transmission piece and the second transmission piece is connected with the power assembly, and the other transmission piece is used for being connected with an executing mechanism. According to the mechanical arm, the probability of relative rotation between the first transmission part and the second transmission part can be reduced, the connection stability between the first transmission part and the second transmission part is improved, and the pressure between the first abutting part and the second transmission part can be adjusted through the adjusting part; therefore, the t