Abstract: An electric motor has a polygon stator core. The polygon stator core includes yoke portions and teeth extending inwardly from the yoke portions. A winding slot is formed between adjacent teeth. Adjacent yoke portions are interconnected by a connecting portion. The winding slots include first winding slots and second winding slots of different shapes. The ratio of the area of a first winding slot to the area of a second winding slot is greater than or equal to 0.9 but less than or equal to 1.1. By changing the shape of the stator core, the size of the winding slots may be increased without increasing the radial dimension of the motor.

Abstract: An electric motor has a polygon stator core. The polygon stator core includes yoke portions and teeth extending inwardly from the yoke portions. A winding slot is formed between adjacent teeth. Adjacent yoke portions are interconnected by a connecting portion. The winding slots include first winding slots and second winding slots of different shapes. The ratio of the area of a first winding slot to the area of a second winding slot is greater than or equal to 0.9 but less than or equal to 1.1. By changing the shape of the stator core, the size of the winding slots may be increased without increasing the radial dimension of the motor.

Abstract: A torque transmission assembly has a first shaft, a second shaft and a coupling. The coupling has a first connecting member and a second connecting member. The first connecting member is coaxially fixed to the first shaft. The second connecting member is fixed to the second shaft. The first connecting member has a base with a metallic engaging member embedded inside. The engaging member directly connects to the first shaft. A plurality of projecting members is formed on the base. The projecting members extend in the axial direction and are circumferentially spaced. The second connecting member has a main body and a plurality of drive arms radially extending from the main body. The drive arms are sandwiched between corresponding projecting members of the first connecting member so that the first connecting member and the second connecting member rotate together.

Abstract: A torque transmission assembly has a first shaft, a second shaft and a coupling. The coupling has a first connecting member and a second connecting member. The first connecting member is coaxially fixed to the first shaft. The second connecting member is fixed to the second shaft. The first connecting member has a base with a metallic engaging member embedded inside. The engaging member directly connects to the first shaft. A plurality of projecting members is formed on the base. The projecting members extend in the axial direction and are circumferentially spaced. The second connecting member has a main body and a plurality of drive arms radially extending from the main body. The drive arms are sandwiched between corresponding projecting members of the first connecting member so that the first connecting member and the second connecting member rotate together.