Electrical drive for a bicycle

摘要

An electrical drive includes a housing (12) mounted around a crank axle (40) of a bicycle. A drive shaft (30) is rotatably mounted around the crank axle (40) and a chain wheel is fixedly mounted around a first end portion (302) of the drive shaft. A single direction bearing (21) is fitted around the drive shaft (30) and a beveled gear (20) is mounted around the single direction bearing (21). A sensing race (33) is mounted on a second end portion (304) of the drive shaft (30) for rotating the drive shaft (30) along single direction only. A sensing interface (332) is mounted along an outer wall of the sensing race (33). A linking member (32) is fixedly mounted between the crank axle (40) and the sensing race (33). A speed sensing unit (38) is located adjacent to the sensing interface for sensing a rotational speed of the crank axle. <IMAGE>