Segment type friction material

摘要

A segment-type friction material comprises segment pieces each having a supply passage formed thereon to supply lubricating oil to a surface of each of the segment pieces. The segment-type friction material further comprises oil grooves each having an outer peripheral opening portion extended in a curved shape or a linear shape. Thereby, lubricating oil is sufficiently supplied to the surface of each of the segment pieces from an outer peripheral side thereof or an inner peripheral side thereof and a clearance between the segment-type friction material and its associated separator plate is assured. Moreover, a space for the lubricating oil to flow through an outer periphery is sufficiently assured and a drag torque is reduced.

主权项

1. A segment-type friction material, comprising:
a ring-shaped metal core; and a plurality of segment pieces made by cutting a friction material substrate, the segment pieces being joined on both surfaces along an entire circumference or on one surface along an entire circumference of the metal core with an adhesive so that a plurality of oil grooves is formed to extend in a radial direction by a clearance between adjacent ones of the segment pieces, wherein the segment pieces comprise a plurality of groups, while each of the plurality of groups comprising a plurality of the segment pieces arranged in succession, each of the segment pieces in each of the plurality of groups has a single supply passage provided on a top surfaces thereof for supplying lubricant oil to the top surfaces thereof such that all the segment pieces in each of the plurality of groups have the single supply passages extending in a same direction to be parallel to each other and such that the single supply passages in one of the plurality of groups extend in a direction different from a direction in which the single supply passages in another of the plurality of groups extend, wherein the supply passage is formed as a recess provided on the top surface of the segment piece such as to reach from an inner peripheral end portion to an outer peripheral end portion of the segment piece and such as to supply the lubricant oil from the supply passage to an entire area of the top surface of the segment piece, and wherein the recess of the supply passage has a cross-sectional area crossing at right angles to a longitudinal direction of the supply passage set to be within a range from 30% to 50% of a cross-sectional area crossing at right angles to a longitudinal direction of the oil groove such as to make the lubricant oil supplied to the supply passage overflow and spread via the supply passage further from an inner peripheral side to an outer peripheral side of the top surface of the segment piece or further from the outer peripheral side to the inner peripheral side of the top surface of the segment piece so as to supply the lubricant oil to an entire area of the top surface of the segment piece.