Reduced diameter devices with an electromagnetic clutch

Abstract

A device with an electromagnetic clutch includes a tubular member of steel which is secured to, and cantilevered by, a flange member secured to a housing of the device. A pulley having magnetic pole faces is rotatably mounted on the tubular member by one or more bearings. A drive shaft of the device extends out of the housing and through the tubular member, and supports a magnetic armature on the extended end. An electromagnet associating with the pulley is fixedly supported on the flange member to supply magnetic attraction force for attracting the armature plate to the pulley. In the arrangement, since the wall thickness of the tubular member is made thin, the outer diameter of the clutch can be reduced without degrading the transmission of rotational force. And a shaft seal assembly can be mounted on the drive shaft within the tubular member. Furthermore, the inner ring of the bearing is held between the flange member and a retaining ring fitted onto the tubular member, to be prevented from axial movement. In order to prevent the inner ring from rotating, the inner ring is locked to the flange member by connection of projections and mating depressions formed thereto. Thus, the assembling operation of the electromagnetic clutch is simplified.