Patent ID: 8328646

Claim:
A torsional vibration damper ( 2 ), comprising: first and second disc parts ( 10 , 13 ) oppositely disposed to one another, against the effect of at least one energy accumulator ( 14 ) in a contra-rotatably limited manner; and a friction device ( 15 ) interposed between the latter, which is effective during relative rotation of said first and second disc parts ( 10 , 13 ), wherein: said friction device ( 15 ) is formed by first and second friction surfaces ( 17 , 18 ) on said first and second disc parts ( 10 , 13 ) respectively; the first friction surface is part of a first piece of material from which the first disc part is made; the second friction surface is part of a second piece of material from which the second disc part is made; the first friction surface is in direct contact with the second friction surface; at least said friction surfaces ( 17 , 18 ) are pressurized axially against one another by means of at least a spring element ( 30 ); and an outer circumference of said spring element ( 30 ) in the circumferential direction spans an angular range smaller than 360° .