Abstract
An internally ventilated rotor, including at least two disc elements which are interconnected by at least one cooling element, the at least one cooling element having a textile fabric which extends from one disc element contact region of the cooling element, by which the cooling element is in contact with one disc element, as far as into another disc element contact region of the cooling element, by which the cooling element is in contact with another disc element.
Claims
1-15. (canceled)
16. An internally ventilated rotor, comprising at least two disc elements that are connected to one another by at least one cooling element, wherein the at least one cooling element comprises a textile fabric, which extends from a disc element contact region of the cooling element, by which the cooling element is in contact with a disc element, as far as into a different disc element contact region of the cooling element, by which the cooling element is in contact with another disc element.
17. The internally ventilated rotor according to claim 16, wherein the textile fabric comprises fibres extending in parallel and at least one of the fibres extending in parallel extends from one disc element contact region of the cooling element as far as into the other disc element contact region of the cooling element.
18. The internally ventilated rotor according to claim 17, wherein the textile fabric is a laid scrim or a woven fabric and a plurality of fibres extending in parallel therein extend from one disc element contact region of the cooling element as far as into the other disc element contact region of the cooling element.
19. The internally ventilated rotor according to claim 16, wherein the textile fabric and/or the fibres extending in parallel comprise carbon fibres, silicon carbide fibres, boron nitride fibres or mixtures thereof.
20. The internally ventilated rotor according to claim 16, wherein the at least one cooling element is a cooling plate.
21. The internally ventilated rotor according to claim 16, wherein the relation of the cooling surface area A of the cooling element, for example the cooling plate, which faces the interior of the brake disc to the volume V of the portion of the cooling element, for example the cooling plate, which faces the interior of the brake disc is at least 0.4 mm.sup.−1.
22. The internally ventilated rotor according to claim 16, comprising at least two cooling elements, for example cooling plates, which are oppositely inclined or two cooling element regions of a cooling element that are oppositely inclined one another.
23. The internally ventilated rotor according to claim 16, comprising at least one pair of adjacent cooling elements, for example cooling plates, wherein orthogonal projections of the four disc element contact regions into the respective internal surface of the disc element that is in contact with the particular disc element contact region define four projection faces (A.sub.31-1 A.sub.32-1, A.sub.31-2, A.sub.32-2) and four points (P.sub.31-1, P.sub.32-1, P.sub.31-2, P.sub.32-2) that lie inside the projection faces define the corners of a trapezium.
24. The internally ventilated rotor according to claim 16, wherein the at least one cooling element comprises at least three disc element contact regions, at least two disc element contact regions are in contact with one disc element and a disc element contact region that is arranged between these disc element contact regions along the cooling element is in contact with the other disc element and the textile fabric extends through the disc element contact region (32) that is arranged between the other disc element contact regions along the cooling element.
25. The internally ventilated rotor according to claim 24, wherein orthogonal projections of the three disc element contact regions into the respective internal surface of the disc element that is in contact with the particular disc element contact region define three projection faces (A.sub.31, A.sub.32, A.sub.33) and each point (P.sub.31, P.sub.33) that lies inside the projection faces (A.sub.31, A.sub.33) defines, together with two points (P.sub.32a, P.sub.32b) that lie inside the projection face (A.sub.32), the corners of a trapezium.
26. The internally ventilated rotor according to claim 23, wherein two of the four angles enclosed by the trapezium are the same size and/or the shorter of the two sides of the trapezium extending in parallel take up no more than 10% of the overall length of all four edges of the trapezium.
27. The internally ventilated rotor according to claim 16, wherein the disc element contact regions extend into recesses in the two disc elements.
28. The internally ventilated rotor according to claim 16, wherein at least one disc element comprises a ceramic fibre composite.
29. The internally ventilated rotor according to claim 16, wherein an integral bond and/or interlocking connection between disc element contact regions and disc elements is formed by a matrix containing silicon carbide, in which the fabric is embedded and which extends as far as into the two disc elements.
30. The internally ventilated rotor according to claim 16, wherein the number of disc elements is two and both disc elements are friction disc elements.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0043] The invention will be illustrated by the following drawings and embodiments, without being limited thereto, in which
[0044] FIG. 1 shows a rotor according to the invention,
[0045] FIG. 2 shows an enlarged cut-out of the rotor shown in FIG. 1,
[0046] FIG. 3 shows a cooling element of the rotor from FIGS. 1 and 2, in which the textile fabric is a laid scrim,
[0047] FIGS. 4A and 4B show the same section through the rotor from FIGS. 1 and 2, each comprising different information,
[0048] FIG. 5 shows another rotor according to the invention,
[0049] FIG. 5A shows a cut-out of a cooling element of the rotor from FIG. 5,
[0050] FIG. 6A shows a section through the rotor from FIG. 5.
[0051] FIG. 6B shows a section through the rotor from FIG. 5.
[0052] FIG. 7A illustrates the production of another rotor according to the invention by means of sections,
[0053] FIG. 7B illustrates the production of another rotor according to the invention by means of sections,
[0054] FIG. 8 shows another rotor according to the invention,
[0055] FIG. 9 shows cut-outs of cooling elements of the rotor from FIG. 8, and
[0056] FIG. 10 shows a cut-out of FIG. 8 from above.
DETAILED DESCRIPTION
[0057] The internally ventilated rotors 1 shown in the drawings comprise two disc elements 2 that are connected to one another by means of at least one cooling element 3 (FIGS. 1 and 5). The at least one cooling element 3 comprises a textile fabric 4, as shown in FIG. 3 for the rotor from FIG. 1 and in FIG. 5A for the rotor from FIG. 5. According to the invention, the textile fabric 4 extends from a disc element contact region 31 of the cooling element 3, by means of which the cooling element 3 is in contact with a disc element 2, as far as into another disc element contact region 32, by means of which the cooling element 3 is in contact with another disc element 2. This can be seen from FIGS. 2 and 3 for the rotor from FIG. 1 and from FIGS. 5A and 6A for the rotor from FIG. 5. The textile fabric 4 is only shown in FIGS. 3 and 5A. For reasons of clarity, the depiction of the textile fabric 4 has been dispensed with in the other drawings.
[0058] In all the embodiments of the rotor according to the invention shown in the drawings, all the textile fabrics 4 comprise fibres 5 extending in parallel. These are carbon fibres in each case. However, other fibres would also be conceivable, for example silicon carbide fibres and boron nitride fibres. This can be seen from FIGS. 3 and 5A. In the examples shown in these drawings, not only at least one of the fibres 5 extending in parallel extends from one disc element contact region 31 of the cooling element 3 as far as into the other disc element contact region 32 of the cooling element in each case, but rather all the fibres 5 extending in parallel. Therefore, in FIG. 3, the textile fabric 4 is a laid scrim 41 and a plurality of fibres 5 extending in parallel therein extend from one disc element contact region 31 of the cooling element 3 as far as into the other disc element contact region 32 of the cooling element 3.
[0059] In the rotor of FIGS. 1 to 4B, the cooling elements 3 are cooling plates (30-1 and 30-2 in the section of FIG. 4A). In the rotor of FIGS. 5 to 6B, cord-shaped cooling elements 3 extend up and down in a circular fashion and thereby each come into contact with the two disc elements 2 in an alternating fashion. This can be implemented by means of a towpreg, for example, which is passed through two material plies, for example nonwoven fabric plies that are spaced apart, from the top down and then again from the bottom up in an alternating fashion in order to connect the material plies to one another at the desired distance. The material plies stitched in this way by means of a towpreg may be transferred, for example, into a rotor according to the invention in that solidifiable disc element compound (for example a polymer resin mixed with carbon fibre bundle portions) is applied to the two external surfaces of the material plies, this compound solidifies, for example hardens, and the green body obtained is then carbonised and subsequently infiltrated with silicon. A towpreg is understood to mean a cord-shaped impregnated bundle of fibres. It can be impregnated with a resin, for example. The bundle of fibres can, for example, be a bundle of carbon fibres. Instead of the towpreg, however, a non-impregnated cord-shaped bundle of fibres could also be used, for example a cord-shaped bundle of carbon fibres.
[0060] Alternatively, the application of the solidifiable disc element compound can be dispensed with and only the towpreg and optionally resin components contained in the material plies connected therewith may be hardened, then carbonised and subsequently infiltrated with silicon. In order to avoid any unevenness on the surfaces oriented towards the outside caused by the towpreg or cooling element precursor, protruding towpreg portions can be milled off. FIGS. 7A and 7B show that cooling elements 3 can firstly be brought into contact with the disc elements or disc element precursors such that they protrude beyond the external surfaces of the disc elements or the disc element precursors present prior to a silicon infiltration process (FIG. 7A). The towpreg can be passed through two material plies, for example nonwoven fabric layers that are spaced apart, from the top down and then again from the bottom up in an alternating fashion, as described above. The arrow leading from FIG. 7A to the top illustration in FIG. 7B shows that the portions of the cooling elements 3 protruding beyond the external surfaces of the disc elements can be milled off. Milling-off can, for example, be done before infiltration with silicon, since the SiC-free cooling element precursor that is present at this point can be processed more easily than after infiltration with silicon (which is associated with the formation of very hard SiC).
[0061] In all the examples shown, the relation of the cooling surface area A of the cooling element 3 facing the interior of the brake disc to the volume V of the portion of the cooling element facing the interior of the brake disc is far greater than 0.4 mm.sup.−1.
[0062] It is clearly visible that, in all the embodiments shown, the cooling elements 3, 3-1, 3-2 extend at an angle of less than 89° with respect to these two disc elements at the point that is arranged between two adjacent disc elements 2 and is equidistant from these two disc elements 2. Sections 4A, 6A and 7B each show this the clearest, even without the point that is equidistant from each of the two adjacent disc elements being shown in one of the drawings. From these sections it is also immediately clear that they each comprise at least two cooling elements (3-1 and 3-2 in FIG. 7B) that are oppositely inclined, such as cooling plates (30-1, 30-2 in FIG. 4A) that are oppositely inclined, or two cooling element regions of a cooling element (310, 320 in FIG. 6A) that are oppositely inclined.
[0063] FIGS. 4B, 6B and 7B show dotted trapeziums, by means of which rotors that are particular preferred according to the invention can be described in more detail. The four corners of the trapezium each lie in projection faces that are defined by orthogonal projections, i.e. projections that are orthogonal to the internal surfaces of the disc elements. The outlines of the projection faces are shown by dashed lines extending in the projection direction in each of the sections in FIGS. 4A, 4B, 6A, 6B and 7B.
[0064] The rotor according to the invention of FIGS. 1 to 4B comprises pairs of adjacent cooling plates (30-1, 30-2 in FIG. 4A). Orthogonal projections (see dashed lines in FIGS. 4A and 4B) of the four disc element contact regions 31-1, 32-1, 31-2, 32-2 into the respective internal surface 21, 22 of the disc element that is in contact with the particular disc element contact region define four projection faces A.sub.31-1, A.sub.32-1, A.sub.31-2, A.sub.32-2. Four points P.sub.31-1, P.sub.32-1, P.sub.31-2, P.sub.32-2 lying inside the projection faces in turn define the corners of said trapezium.
[0065] The rotor according to the invention, which is shown in the section in FIG. 7B, comprises an arrangement of cooling elements that have been separated or severed, similar to the cooling plates in FIGS. 1 to 4B. By means of the milling-off process, the original continuous cooling element precursor has been completely severed in the protruding regions such that it comprises pairs of adjacent cooling elements (3-1, 3-2 at the top of FIG. 7B). Orthogonal projections (see dashed lines at the top and bottom of FIG. 7B) of the four disc element contact regions 31-1, 32-1, 31-2, 32-2 into the respective internal surfaces 21, 22 of the disc element that is in contact with the particular disc element contact region define four projection faces A.sub.31-1, A.sub.32-1, A.sub.31-2, A.sub.32-2, just like in the sections in FIGS. 4A and 4B. Here, too, four points P.sub.31-1, P.sub.32-1, P.sub.31-2, P.sub.32-2 lying inside the projection faces define the corners of said trapezium.
[0066] In contrast to the rotors in FIGS. 1 to 5A and 7B, the cord-shaped cooling element 3 in FIGS. 5 to 6B comprises not only two, but a plurality of, disc element contact regions 31, 32, 33 . . . , only three of which are shown in FIGS. 6A and 6B. The trapezium can still be defined in the same way as the rotors in FIGS. 1 to 5A and 7B. However, two of the four corners of the trapezium P.sub.32a, P.sub.32b then lie in a single projection face A.sub.32, as shown in FIG. 6B. In the rotor in FIGS. 5 to 6B, the cooling element 3 comprises a plurality of disc element contact regions 31, 32, 33. At least two disc element contact regions 31, 33 are in contact with one of the disc elements. A disc element contact region 32 arranged between these disc element contact regions 31, 33 along the cooling element is in contact with the other disc element. The textile fabric 4 extends through the disc element contact region 32 that lies between the other disc element contact regions 31, 33 along the cooling element. In such embodiments of the invention, the textile fabric generally extends from one end of the cord-shaped cooling element as far as the other end of the cord-shaped cooling element and through all the disc element contact regions arranged between the ends. Orthogonal projections of the three disc element contact regions 31, 32, 33 into the respective internal surface 21, 22 of the disc element that is in contact with the respective disc element contact region therefore define three projection faces A.sub.31, A.sub.32 A.sub.33 in this case. Each point P.sub.31, P.sub.33 lying inside the projection faces A.sub.31, A.sub.33 defines, together with two points P.sub.32a, P.sub.32b lying inside the projection face A.sub.32, the corners of the trapezium.
[0067] In FIGS. 4B, 6B and 7B, in each case, two of the four angles formed by the trapezium are the same size.
[0068] In order to allow for especially rigid anchoring in the disc elements, the textile fabric extends as far as the disc element in all the embodiments of the invention shown in the drawings. Independently of the embodiments specifically shown here, this is always particularly preferable according to the invention. The disc element contact regions 31, 32, 33, 31-1, 31-2, 32-1, 32-2 therefore extend in recesses in the two disc elements 2.
[0069] In all the drawings, rotors are shown in which both disc elements are silicon carbide/carbon fibre composite friction discs and in which an integral bond and interlocking connection between disc element contact regions 31, 32, 33, 31-1, 32-1, 31-2, 32-2 and disc elements 2 is formed by a matrix containing silicon carbide, in which the textile fabric 4 or the carbon fibres included extending in parallel in said fabric are embedded. The matrix extends as far as into the two disc elements.
[0070] Similarly to the rotor according to the invention of FIGS. 1 to 4B, the rotor according to the invention of FIGS. 8 to 10 also comprises cooling elements 3 as pairs of adjacent cooling plates (30-1, 30-2). The cooling plates are not only oppositely inclined, but are also arranged such that the two edges closer to the axis of rotation of the rotor extend more closely to one another than the two edges of the cooling plates further away from the axis of rotation of the rotor; or such that the two edges closer to the axis of rotation of the rotor are further away from one another than the two edges of the cooling plates that are further away from the axis of rotation of the rotor. Cooling channels may be defined by means of such an arrangement of cooling plates 30-1, 30-2, which channels taper or widen in the radial direction.
