Encoder mounting structure and motor

The utility model provides an encoder mounting structure and a motor, and relates to the technical field of motors. The encoder installation structure comprises a protective cover, the protective cover comprises a cover body part and a flange installation part, one end of the cover body part is provided with a through hole, the other end of the cover body part is provided with the flange installation part, and the flange installation part is used for being detachably connected with the peripheral edge of a motor tail end bearing outer cover; the cover plate is detachably connected to the outer side face of the cover body part and used for covering the penetrating hole. According to the utility model, the hollow shaft rotary encoder can be installed in the cavity and connected with the non-driving end of the output shaft of the motor inserted into the cavity, the sealing performance of the cavity can be ensured, dust and moisture are prevented from entering the cavity, the solid shaft rotary encoder can be ins