Ventilated brake disc

Abstract

A friction ring configured to be fixed to a hub at one or more fixation points is provided. The friction ring includes a ring shaped body; an outer surface configured to be contacted by a brake mechanism; an inner surface configured to contact a portion of a hub or axle to impart a braking force thereto; at least one through-hole for receiving a fastener for fixing the friction ring to the hub or axle; and at least two protrusions extending from the inner surface of the friction ring forming a channel. A cross-sectional area of an inflow portion of the channel is smaller than a cross-sectional area of an outflow portion of the channel. A brake assembly including a hub and the fixation ring is also provided.

What is claimed is: 
     
         1 . A friction ring comprising:
 plural segments configured to be positioned around a hub or an axle to form a ring-shaped body, each of the segments including:
 a front side and a rear side each having an outer surface positioned to be contacted by a brake mechanism and an inner surface positioned to contact a portion of the hub or the axle to impart a braking force; 
 one or more through-holes extending between the outer surface of the front side and the outer surface of the rear side and positioned to receive a fastener for fixing the segment to the hub or the axle; and 
 protrusions extending from the inner surface of the front side to the inner surface of the rear side of the segment, the protrusions forming a radially open channel therebetween, 
   wherein a cross-sectional area of an inflow portion of the channel between the protrusions is smaller than a cross-sectional area of an outflow portion of the channel between the protrusions.   
     
     
         2 . The friction ring of  claim 1 , wherein, for each of the segments, the channel extends between a circumferential inner edge and a circumferential outer edge of the segment and is positioned to direct airflow across the inner surface of the front side or the inner surface of the rear side of the segment. 
     
     
         3 . The friction ring of  claim 1 , wherein, for each of the segments, the inflow portion of the channel is disposed radially inward from the outflow portion of the channel such that airflow is directed from an inner circumferential edge to an outer circumferential edge of the segment. 
     
     
         4 . The friction ring of  claim 1 , wherein, for each of the segments, at least one of the through-holes is positioned to affix the segment to the hub or the axle at a fixation point to increase an air inlet area relative to the segment being affixed to the hub or the axle at multiple fixation points. 
     
     
         5 . The friction ring of  claim 1 , wherein the protrusions comprise radially extending fins. 
     
     
         6 . The friction ring of  claim 5 , wherein the radially extending fins are tapered in the radial direction such that a radially inner portion of the radially extending fins is narrower than a radially outer portion of the radially extending fins. 
     
     
         7 . The friction ring of  claim 6 , wherein the radially extending fins are tapered in a transverse direction such that portions of the radially extending fins closer to the inner surfaces than the outer surfaces are wider than portions of the radially extending fins that are closer to centers of the radially extending fins. 
     
     
         8 . The friction ring of  claim 5 , wherein each of the radially extending fins defines a linear longitudinal axis extending from a radially inner portion of the fin to a radially outer portion of the fin, and wherein the linear longitudinal axis of each of the radially extending fins is offset from a radius of the ring-shaped body by at least 5 degrees. 
     
     
         9 . The friction ring of  claim 5 , further comprising at least one transverse rib extending between a pair of neighboring fins of the radially extending fins. 
     
     
         10 . The friction ring of  claim 9 , wherein the one or more through-holes are positioned radially inwardly from the at least one transverse rib. 
     
     
         11 . The friction ring of  claim 1 , wherein the protrusions are positioned such that a single radius of the ring-shaped body passes through both of the protrusions. 
     
     
         12 . A brake assembly comprising:
 a brake disc including segments arranged to form a front friction ring and a rear friction ring, the front friction ring and the rear friction ring configured to contact a braking mechanism;   a hub configured to be connected to an axle, the hub comprising a central rotor and a radially extending flange encircling at least a portion of the central rotor; and   a pin fixed to and extending through the flange for fixing the brake disc to the flange, wherein each of the segments of the brake disc includes:
 a front side and a rear side, each of the front side and the rear side comprising an outer surface configured to be contacted by the braking mechanism and an inner surface connected to a portion of the hub or the axle to impart a braking force to the hub or the axle; 
 one or more through-holes extending between the outer surface of the front side and the outer surface of the rear side of the segment for receiving the pin for connecting the segment to the hub or the axle; and 
 protrusions extending from the inner surface of the front side to the inner surface of the rear side of the segment, the protrusions forming a radially open channel therebetween, wherein a cross-sectional area of an inflow portion of the channel between the protrusions is smaller than a cross-sectional area of an outflow portion of the channel between the protrusions. 
   
     
     
         13 . The brake assembly of  claim 12 , wherein, for each of the segments, the channel extends between a circumferential inner edge and a circumferential outer edge of the inner surface of the sides of the segment, the channel positioned to direct airflow across the inner surface of the front and rear side of the segment. 
     
     
         14 . The brake assembly of  claim 12 , wherein each of the segments is fixed to the hub at a single fixation point. 
     
     
         15 . The brake assembly of  claim 14 , wherein, while fixed to the hub, each of the segments is rotatable about the single fixation point. 
     
     
         16 . The brake assembly of  claim 12 , wherein each of the segments is fixed to the hub at a single fixation point to increase an air inlet area relative to the segments being fixed to the hub at multiple fixation points. 
     
     
         17 . The brake assembly of  claim 12 , wherein the protrusions comprise a radially extending fin, and further comprising one or more transverse ribs extending between the radially extending fins, the transverse ribs positioned to define a curving airflow path. 
     
     
         18 . The brake assembly of  claim 12 , wherein the protrusions are positioned such that a radius of one or more of the segments passes through at least two of the protrusions. 
     
     
         19 . A brake disc comprising:
 one or more segments each including a front side and a rear side, each of the front side and the rear side comprising an outer surface configured to be contacted by a brake mechanism and an inner surface configured to contact a portion of a hub or an axle to impart a braking force to the hub or the axle;   one or more through-holes extending from the outer surface of the front side to the outer surface of the rear side, the one or more through-holes shaped to receive one or more pins for connecting to the hub or the axle; and   protrusions extending from the inner surface of the front side to the inner surface of the rear side, the protrusions forming a radially open channel therebetween,   wherein a cross-sectional area of an inflow portion of the channel between the protrusions is smaller than a cross-sectional area of an outflow portion of the channel between the protrusions.   
     
     
         20 . The brake disc of  claim 19 , wherein the channel extends between a circumferential inner edge and a circumferential outer edge and is positioned to direct airflow across the inner surface of the front side and the inner surface of the rear side.