Abstract: During EMC testing of electric motors, a rotation transmission device that penetrates a wall in an electromagnetic anechoic chamber has been unable to achieve high rotation and high torque, because of the skipping rope phenomenon. In order to achieve rotation transmission at high rotation and high torque, a fiber-reinforced plastic shaft is supported by a bearing inside a conductive housing; and a conductive brush that obstructs a space between the housing and the shaft surface is provided so as to provide electrical conduction between the housing and the shaft and prevent radio wave leakage. A plurality of bearings could be used, excluding at both ends, in order to achieve rotation transmission at high rotation and high torque.

Abstract: An in-wheel motor, comprising: a rotor (14) of a surface permanent magnet type, wherein a plurality of permanent magnets (15) are fixed along an inner circumferential surface of the rotor; wedge-shaped protrusions (42) for fixing the permanent magnets (15) on the rotor (14); and a stator (30) disposed inside the rotor (14), wherein teeth (35) and slots (36) are alternately formed on an outer circumferential portion of the stator; wherein the number of the permanent magnets (15) is 32, and the number of the slots 36 is 24; wherein each of the permanent magnets (15) has chamfers (43) on each of the ends so that a magnetic flux cannot concentrate, and is convex toward the stator (30), in a cross-section perpendicular to a rotary axis of the rotor (14).