Known serial torsional vibration dampers include a spring retainer plate, an intermediate plate, and an output flange. A first set of springs is retained by and engaged with the spring retainer plate and engaged with the cover plate. A second set of springs is engaged with the intermediate plate and the output plate. The second set of springs can be engaged with the spring retainer plate as well. Typically, the spring retainer plate and the intermediate plate are non-rotatably connected, for example by rivets, in particular sheet metal rivets. Ideally the rivets are placed near openings in the spring retainer plate for the first set of springs without interfering with operation of the first set of springs. However, the portion of the spring retainer plate best suited for receiving the rivets is curved to form the outermost portion of the spring retainer plate, which retains the first set of springs in axial and radial directions. In other words, without this increment on the holes diameter placement, the contact wouldn't be uniform between these components surfaces (sheet metal rivets and flange tabs). Also, in order to get more clearance between the flange stop radius and the sheet metal rivet flat surfaces, the diameter of the sheet metal rivet holes are increased to avoid radial stack-up issues between components. The rivet heads contact the curved surface of the spring retainer, which degrades the strength and durability of the rivet connection.
USPTO Backgrounds
USPTO Backgrounds