Grooved friction material, method of making same, and wet friction member using grooved friction material

Abstract

Grooved friction materials (12 or 14) each include a single-layer pyrolytic-carbon fabric material formed of woven or nonwoven yarn strands (20 and 22). The pyrolytic-carbon fabric material (12 or 14) has a top surface (16) and a bottom surface (18), the top surface (16) having molded grooves (28) therein. The yarn strands (20 and 22) at the grooves (28) exhibit superior integrity because they are generally whole, undamaged yarn strands. Wet friction members for friction engaging mechanisms include a support member (54, 56, or 58) and at least one piece (48, 50, or 52) of grooved friction material (14) adhered to a surface of the support member. The bulk grooved friction material (14), from which the individual pieces (48, 50, or 52) are cut, is a single-layer pyrolytic-carbon fabric material formed of yarn strands (20 and 22) and has a top surface (16) with grooves (28) therein. The yarn strands (20 and 22) at the grooves (28) are generally whole and undamaged. A method for making a grooved friction material (12 or 14) includes the steps of molding a carbon-fiber fabric (10) coated with a carbon-containing polymeric material, carbonizing the molded carbon-fiber fabric, and densifying the carbonized carbon-fiber fabric with pyrolytic carbon. The molding step is performed in a die adapted to form grooves (28) in the top surface (16) of the carbon-fiber fabric (10).

Dependencies are inferred from the claim text.