Middle automatic five-speed motor

The invention discloses a middle automatic five-speed motor, and relates to the field of power-assisted bicycles. According to the technical scheme, the power assisting device is characterized by comprising a middle shaft mechanism, a power assisting driving mechanism and a speed change mechanism, the fixing shaft is sleeved with a first planetary gear assembly, a first integrated centrifugal clutch assembly, a second planetary gear assembly, a third planetary gear assembly, a second integrated centrifugal clutch assembly and a fourth planetary gear assembly which are sequentially arranged in the axial direction. Automatic switching of five gears can be achieved through the output speed, the riding experience can be optimized, the structure is compact, and the number of parts, the assembling procedure and the overall size can be optimized. 本发明公开了一种中置自动五速电机，其涉及助力自行车领域。其技术方案要点包括中轴机构、助力驱动机构以及变速机构，所述变速机构包括固定轴和输出套壳，所述固定轴上套设有沿轴向依次布置的第一行星齿轮组件、第一集成化离心离合组件、第二行星齿轮组件、第三行星齿轮组件、第二集成化离心离合组件以及第四行星齿轮组件。本发明可以利用输出速度来实现五个挡位的自动变