Clutch, middle motor and electric power-assisted bicycle

The clutch comprises an outer ring piece, a middle disc and an inner ring piece which are sequentially arranged in a sleeving mode from outside to inside. The outer ring piece is used for driving the middle disc to rotate together in a first direction when being driven to rotate in the first direction, and the transmission connection between the middle disc and the inner ring piece is disconnected; the inner ring piece is used for driving the middle disc to rotate together in the first direction when driven to rotate in the first direction, and the transmission connection between the middle disc and the outer ring piece is disconnected. The clutch is made of the outer ring piece, the middle disc and the inner ring piece, compared with an existing clutch, a one-way bearing is omitted, and therefore the clutch is simpler in structure and lower in cost. 本发明涉及一种离合器、中置电机和电动助力自行车，其中，离合器包括自外向内依次套设的外圈件、中盘和内圈件；所述外圈件用于受驱动沿第一方向转动时带动所述中盘一起沿所述第一方向转动，且使所述中盘断开与所述内圈件之间的传动连接；所述内圈件用于受驱动沿所述第一方向转动时带动所述中盘一起沿第一方向转动，且使所述中盘断开与所述外圈件之