Rubber viscous torsional dampers and method of making same

In a method of making a tuned viscous torsional vibration damper assembly of the type having circular supporting plate means with a radially outwardly extending circular body and a radially inner hub portion adapted to be secured to a rotary member such as a crankshaft subject to vibrations to be damped by the damper, said body being received concentrically within a radially inwardly opening annular working chamber of an annular inertia mass, a viscous damping medium in said chamber between shear film spaced working surfaces of said body and said inertia mass, said inertia mass having concentric annular grooves of substantial radial extent and located at opposite sides of and facing axially toward said body contiguous to the opening from said chamber, said grooves having axially directed annular face areas on said inertia mass facing toward oppositely axially facing face areas on said body, and elastic tuning spring, spacing and sealing rings of radial extent similar to that of the radial extent of said grooves and having opposite axially directed sides attached to and coupling said face areas of said inertia mass in said grooves with said face areas on said body, the improvement comprising:

• providing separate substantially flat annular disks of substantially the same radial extent as said elastic rings, and wherein each of said disks is rigidly unyielding in its radial plane and has oppositely facing axially directed faces;
• vulcanize bonding one of said axially directed faces of one of said disks to one side of one of said elastic rings;
• vulcanize bonding one of the axially directed faces of another of said disks to one side of the other of said elastic rings;
• and permanently rigidly adhesively securing said disks in place in fluid sealing relation against the face areas respectively opposed by the remaining axially directed faces of the disks.

In a tuned viscous torsional vibration damper assembly of the type having circular supporting plate means with a radially outwardly extending circular body and a radially inner hub portion adapted to be secured to a rotary member such as a crankshaft subject to vibrations to be damped by the damper, said body being received concentrically within a radially inwardly opening annular working chamber of an annular inertia mass, a viscous damping medium in said chamber between shear film spaced working surfaces of said body and said inertia mass, and said inertia mass having concentric annular grooves at opposite sides of and facing axially toward said body contiguous to the opening from said chamber, with elastic tuning spring, spacing and sealing rings coupling opposing surface areas of said inertia mass in said grooves and opposing surface areas on said body, the improvement comprising:

• said plate means body having keying holes therethrough in said surface areas and spaced from both radial edges of said elastic rings;
• said elastic rings having faces vulcanize bonded to said surface areas on said plate means body;
• and keying lugs comprising vulcanized material of said rings and connecting said elastic rings through said holes, said keying lugs supplementing said vulcanize bonding of the elastic rings to said surface areas on said body and also facilitating molding and vulcanizing of the rings in place on the plate means body;
• flat annular disks which are rigidly unyielding in their planes vulcanize bonded to said opposite faces of the elastic rings;
• and structural adhesive fixedly securing said disks to said surface areas of said inertia mass in said grooves.

A method of making a tuned viscous torsional vibration damper assembly of the type having circular supporting plate means with a radially outwardly extending circular body and a radially inner hub portion adapted to be secured to a rotary member such as a crankshaft subject to vibrations to be damped by the damper, said body being received concentrically within a radially inwardly opening annular working chamber of an annular inertia mass, a viscous damping medium in said chamber between shear film spaced working surfaces of said body and said inertia mass, and said inertia mass having concentric annular grooves at opposite sides of and facing axially toward said body contiguous to the opening from said chamber, with elastic tuning spring, spacing and sealing rings coupling opposing surface areas of said inertia mass in said grooves and opposing surface areas on said body, the improvement comprising:

• providing in said plate means body keying holes extending through said surface areas and spaced from both radial edges of said elastic rings;
• vulcanize bonding axial faces of said elastic rings to said surface areas of said plate body means and providing keying lugs by vulcanizing the same material as said elastic rings and thereby integrally connecting said elastic rings through said holes;
• vulcanize bonding to the axially opposite face of each of said rings a flat annular disk which is rigidly unyielding in its plane;
• and adhesively fixedly securing said disks to said surface areas of said inertia mass in said annular grooves.