Cushman, Darby & Cushman
Electromagnetic clutch
 An overhang type electromagnetic clutch used for selectively connecting the rotation of an internal combustion engine to a compressor for an air conditioning system for an automobile. The clutch is provided with a rotor having a sliding surface axially spaced from an outer end of a pulley arranged around the rotor. A bit, which initially is in contact with the sliding surface at a location spaced from the axis of the rotation of the rotor, is radially moved while the rotor is rotated, so that radially spaced apart tool marks eccentric to the axis of the rotation of rotor and having a gradually increased radius are formed on the entire region of the sliding surface. An increased engagement of the sliding surface with an armature is obtained due to the provision of engagements in the circumferential direction. A bit, which initially is in contact with the sliding surface at a location corresponding to the axis of the rotation of the rotor may be first moved radially outward while the rotor is rotated, so that radially spaced apart first tool marks concentric to the axis of the rotation of rotor and having a gradually increased radius are formed on the entire region of the sliding surface. The bit is then moved radially inward so that radially spaced apart second tool marks concentric to the axis of the rotation of rotor and having a gradually decreased radius are formed on the entire region of the sliding surface. As a result, the first and second tool mark cross and provide an engagement in the circumferential direction. 
Nippondenso Co., Ltd.
F F F
F16D F16D F16D
additional inventional inventional
Junichi Shizuo
Nakagawa Watanabe