Internally-ventilated brake disks with improved cooling

1. An internally ventilated brake disk in the form of a circular ring disk with cooling channels in the interior of the disk which extend, respectively, from the inner circumference to the outer circumference of the circular ring disk, characterized in that

the cooling channels are branched from the inside to the outside such that one channel opening on the inner circumference is connected with at least two channel openings on the outer circumference, and that one channel opening on the outer circumference is connected with at most one channel opening on the inner circumference, wherein the number of the branching points is 2 or greater than 2, and

that the distances from the center of the disk to the branching points lie in two non-overlapping intervals ri+(ra−ri)*x, wherein x assumes a value of x 1 =0.1 to 0.5 for the first interval and x 2 =0.3 to 0.8 for the second interval, wherein the difference between x 2 and x 1 amounts to at least 0.05, and

the ratio of the total surface Fa of the cross section, measured perpendicular to the center line of the channels, of the openings of channels lying on the outer circumference to the total surface Fi of the cross section, measured perpendicular to the center line of the channels, of the openings of the channels lying on the inner circumference amounts to Fa/Fi=0.1 to 1.07.

2. The internally ventilated brake disk of claim 1 characterized in that the projections of the center lines of the cooling channels onto the plane of the circular ring disk are curved, and wherein the bending radius amounts to at least 53% of the outer radius of the circular ring disk.

3. The internally ventilated brake disk according to claim 2 , characterised in that the curvature radius of the projections of the center lines of the channels onto the plane of the circular ring disk increase from the inside towards the outside, wherein the curvature radius on the inner ends of the channels amount to up to 45% of the outer radius of the circular ring disk.

4. The internally ventilated brake disk of claim 1 , characterised in that the projections of the center lines of the channels onto the plane of the circular ring disk on the inner circumference of the circular ring disk stand at an angle of up to 25° to the radial direction.

5. The internally ventilated brake disk of claim 1 wherein the ratio of the number Na of the openings of the channels lying on the outer circumference to the number Ni of the openings of the channels lying on the inner circumference is Na:Ni=3:1 to 5:1.

6. The internally ventilated brake disk according to claim 1 , characterised in that the difference between x 2 and x 1 amounts to at least 0.1.