Method of making torsional vibration damper having a roll spun housing

A method of making a viscous torsional vibration damper of the kind operating on the shear film principle and having an annular channel shaped housing providing an annular working chamber within which is mounted an annular complementary inertia mass ring and a viscous damping fluid substantially filling shear film spaces between working surface of the inertia ring and confronting working surfaces of the housing within said chamber, comprising:

• forming said housing with an annular channel shaped working chamber shell with a central hub flange;
• roll spinning said housing shell;
• as an incident to said roll spinning work hardening and burnishing working surfaces within said working chamber;
• providing a closure for said chamber and with a portion of said closure overlapping said hub flange;
• and
• fixedly securing said cover plate to said housing by welding.

A method of making a viscous torsional vibration damper of the kind operating on the shear film principle and having an annular channel shaped housing providing an annular working chamber within which is mounted an annular complementary inertia mass ring and a viscous damping fluid substantially filling shear film spaces between working surfaces of the inertia ring and confronting working surfaces of the housing within said chamber, comprising:

• roll spinning a generally channel shaped annular shell with an axially facing base wall and spaced axially extending radially spaced walls and spinning roll burnishing said housing working surfaces;
• roll forming an axially outwardly facing shoulder seat on the distal edge of one of said spaced walls;
• in said roll forming shaping a lip flange surrounding said seat in radially offset relation to said one wall;
• and
• hermetically securing a circular closure in closing relation to said working chamber and in said securing hermetically sealing an annular edge of said closure in respect to said shoulder seat.