Optical encoder and motor

The utility model provides an optical encoder and a motor. The optical encoder comprises an encoder support, a circuit board and a grating assembly, wherein the encoder support and the circuit board sequentially penetrate through a rear shaft of the motor, and the grating assembly is connected with the rear shaft penetrating out of the circuit board. Wherein the encoder support is fixed on a rearend cover of the motor, the circuit board is fixed on the encoder support, the grating assembly is fixed on a rear shaft of the motor and rotates along with the rear shaft of the motor, and a gap exists between the grating assembly and the circuit board; a code channel is arranged on one face, opposite to the circuit board, of the grating assembly, and a photoelectric element is arranged on one face, opposite to the grating assembly, of the circuit board. The optical encoder is simple and compact in structure, stable and accurate encoder signals can be provided, and the coaxiality is easy to fix when the circuit board