Friction ring for a wheel brake disc of a rail vehicle

Abstract

The invention relates to a friction ring (1) for a wheel brake disc of a rail vehicle, comprising a friction surface (2) and a rear face (3) which faces away from the friction surface and from which a plurality of cooling webs (6, 7, 10, 11) extend in a direction perpendicular to the friction surface (2), wherein at least some of the cooling webs (6, 7, 10, 11) are designed as first cooling webs (6) with a cross-section (Q) which tapers away from the rear face (3) on an observed plane that is parallel to the rear face (3) and which transitions into a circular shape.

Description

[0001] DESCRIPTION

[0002] Friction ring for a wheel brake disc of a rail vehicle

[0003] The present invention relates to a friction ring for a wheel brake disc of a rail vehicle according to the preamble of claim 1.

[0004] The invention further relates to a wheel brake disc of a rail vehicle.

[0005] Friction rings and wheel brake discs of this type for rail vehicles are known, for example, from DE 10 2019 118 216 A1 or DE 10 2020 112 874 A1. Such friction rings are typically bolted to a wheel web of a wheel body of a rail wheel.

[0006] The key to such friction rings is the highest possible cooling performance. This cooling performance is achieved primarily by the cooling fins arranged radially on the back of such a friction ring, which, thanks to a fan effect, ensure high air flow and thus effective cooling.

[0007] The object of the present invention is to further optimize a friction ring for a wheel brake disc of a rail vehicle with regard to its cooling performance.

[0008] This object is achieved by a friction ring for a wheel brake disc of a rail vehicle having the features of claim 1.

[0009] The stated object is further achieved by a wheel brake disc for a rail wheel of a rail vehicle having the features of claim 8.

[0010] The friction ring according to the invention for a wheel brake disc of a rail vehicle has a friction surface and a rear side facing away from the friction surface, from which a plurality of cooling ribs extend in a direction perpendicular to the friction surface. At least some of the cooling ribs are designed as first cooling ribs, with a cross-section tapering away from the rear side, viewed in a plane parallel to the rear side, and transitioning into a circular shape.

[0011] Cooling bars designed in this way have an optimal circular cross-section, at least in their cylindrical section, which offers a large surface area while at the same time providing sufficient free space for air flow.

[0012] In addition, cooling bars designed in this way are so stable due to the larger cross-section at the transition to the rear side of the friction ring compared to the free ends that they can withstand machining, which is particularly necessary after the casting of the friction ring in order to obtain a flat end face of the first cooling bars that support the friction ring on the rail wheel of the rail vehicle.

[0013] Advantageous embodiments of the invention are the subject of the subclaims.

[0014] According to an advantageous embodiment of the invention, the first cooling webs have a foot rising from the rear side and a neck extending from the foot, wherein a foot cross-section in the circumferential direction of the friction ring is larger than radially to an imaginary axis of rotation of the friction ring, wherein the head is formed with the circular cross-section.

[0015] An alignment of the foot in such a way that its longitudinal extension in the circumferential direction of the friction ring is maximum enables a particularly robust design of the first cooling bars.

[0016] The surface of the first cooling bars preferably transitions seamlessly from the base to the neck.

[0017] According to an advantageous embodiment, the first cooling webs are arranged one behind the other in the circumferential direction and thus form an approximately circular support of the friction ring on the rail wheel of the rail vehicle.

[0018] The first cooling fins are preferably arranged one behind the other in the circumferential direction near an inner edge and / or near an outer edge of the friction ring. In particular, the arrangement of the first cooling fins near both the inner edge and the outer edge of the friction ring enables both stable support of the friction ring on the wheel brake of the rail vehicle and optimized cooling geometry.

[0019] Regarding the design of the first cooling bars themselves, in a preferred embodiment, a ratio between a maximum length at the base of the first cooling bars and a diameter at the neck of the first cooling bars, viewed in a plane parallel to the rear side, is between 1.2 and 2.5.

[0020] According to a further preferred embodiment, a portion of the cooling webs are designed as second cooling webs, with a circular cross-section in a plane viewed parallel to the rear side, wherein a vertical extension of the second cooling webs perpendicular to the plane of the rear side is smaller than a vertical extension of the first cooling webs.

[0021] These second cooling bars serve exclusively to cool the friction ring.

[0022] According to a further preferred embodiment, fifth cooling webs designed as cooling ribs are formed between the two rows of first cooling webs in the circumferential direction and extend over almost the entire radial width of the friction ring

[0023] In a preferred development, cylindrically shaped third cooling webs and cams are arranged distributed between the two rows of first cooling webs viewed in the radial direction.

[0024] According to a further embodiment, sixth cooling webs serving to receive the screws are formed between the two rows of first cooling webs, viewed in the radial direction. In addition to a screw-receiving area, these sixth cooling webs have a web adjoining the screw-receiving area and extending radially inward, said web having a contact surface. The contact surfaces of the sixth cooling webs lie in an imaginary circular line with the contact surfaces of the first cooling webs and the contact surfaces of the fifth cooling webs. A wheel brake disc according to the invention for a rail wheel of a rail vehicle has two friction rings fastened on opposite sides of the rail wheel and is characterized in that the friction rings are designed as described above.

[0025] Preferred embodiments are explained in more detail below with reference to the accompanying drawings.

[0026] They show:

[0027] Fig. 1 is an isometric view of a friction ring provided with cooling fins designed as cooling fins according to the prior art,

[0028] Fig. 2 is a corresponding isometric view of the rear side of a friction ring according to the invention with first cooling webs arranged near an inner edge and near an outer edge of the friction ring,

[0029] Fig. 3 is an enlarged detail of the friction ring shown in Fig. 2 to illustrate the structure of a first cooling web,

[0030] Fig. 4 is an isometric view of an alternative embodiment of a friction ring according to the invention with first cooling webs arranged near an inner edge of the friction ring,

[0031] Fig. 5 is a further isometric view of an alternative embodiment of a friction ring according to the invention with first cooling webs arranged near an inner edge and near an outer edge of the friction ring, and

[0032] Fig.6 is a plan view of a section of the friction ring shown in Fig. 5.

[0033] In the following description of the figures, terms such as top, bottom, left, right, front, rear, etc., refer exclusively to the exemplary representation and position of the friction ring, friction surface, rear side, cooling fins, and the like chosen in the respective figures. These terms are not to be understood as limiting; i.e., these references may change due to different operating positions or the mirror-symmetrical design, etc.

[0034] Figure 1 shows a rear side of a friction ring known from the prior art with a plurality of cooling webs 140 shaped as cooling fins as well as screw receptacles 180 formed on cooling fins and cams 190 also connected to cooling fins, by means of which a good cooling effect of such a friction ring is already achieved.

[0035] Figure 2 shows a corresponding representation of a friction ring 1 according to the invention, with a rear side 3 which faces away from a friction surface of the friction ring 1 indicated by the reference number 2.

[0036] A wheel brake disc preferably consists of a pair of such friction rings 1, wherein one friction ring 1 is fastened on opposite sides of a rail wheel.

[0037] From the rear side 3 of the friction ring 1 extend a plurality of cooling webs 6, 7, 10, 11 as well as a screw receptacle 8 with a cylindrical outer surface, through which respective screws can be screwed from the side of the friction surface 2 into the rail wheel of a rail vehicle in order to fasten the friction ring 1 to the rail wheel of the rail vehicle.

[0038] Furthermore, 3 cams 9 are formed on the rear side, with grooves 92 extending radially to an imaginary axis of rotation of the rail wheel or of the friction ring 1 attached to it, which serve to receive sliding blocks (not shown here) which are arranged on the rail wheel of the rail vehicle and which serve to support the friction ring 1 on the rail wheel of the rail vehicle.

[0039] As can also be seen in Figure 2, the cooling webs 6, 7 are not designed as cooling fins, but as essentially cylindrical cooling webs. The first cooling webs 6 are designed with a cross-section that tapers away from the rear side 3 in a plane parallel to the rear side 3 and transitions into a circular shape. The second cooling webs 7 are designed as cooling webs with a consistently cylindrical shape. All of the cooling webs 6, 7, 10 and also the cooling webs 11, as shown in Figure 4, are preferably formed directly onto the friction ring 1 using a casting process.

[0040] The first cooling webs 6, which, in addition to the cams 9 and the end faces of the screw receptacles 8, serve to attach the friction ring 1 to the wheel brake of the rail vehicle, usually have to be reworked after the casting process in order to obtain an exactly flat contact surface 63 at the free end of the first cooling webs 6.

[0041] The first cooling webs 6 are, as can be clearly seen in Figure 3, formed with a foot 61 rising from the rear side and a neck 62 extending from the foot 61 away from the rear side 3.

[0042] The foot 61 is approximately oval in cross-section viewed in a plane parallel to the rear side 3. The maximum extent of the foot cross-section QF, ie, its maximum length L, extends in the circumferential direction of the friction ring 1 in the preferred embodiment shown here, which is greater than the maximum cross-sectional width in a radial direction, viewed radially to an imaginary axis of rotation of the friction ring 1.

[0043] Starting from the rear side 3, the neck preferably extends continuously from the foot 61 until the foot 61 merges into a cylindrical neck 62, the front end of which forms the contact surface 63 for contact with the rail wheel of the rail vehicle.

[0044] It is also conceivable to align the foot cross-section so that it is larger in the radial direction than in the circumferential direction.

[0045] As further shown in Figure 2, the first cooling webs 6 are arranged one behind the other in the circumferential direction.

[0046] Preferably, such a row of first cooling webs 6 extends circumferentially one behind the other near an inner edge 4 and preferably near an outer edge 5 of the friction ring 1, as shown in Figure 2. In the alternative embodiment shown in Figure 4, such first cooling webs 6 are arranged exclusively near an inner edge 4 of the friction ring 1.

[0047] Between the two rows of first cooling bars 6, a plurality of second cooling bars 7 are formed in Figure 2, which are of cylindrical shape.

[0048] These second cooling webs 7 have a height extension Hz which, viewed perpendicular to the plane of the rear side 3, is smaller than the height extension He of the first cooling webs 6.

[0049] Particularly preferably, a ratio between the maximum length L at the base 61 of the first cooling bars 6 and a diameter di at the neck 62 of the first cooling bars 6 is between 1.2 and 2.5. This ratio enables optimal cooling performance while simultaneously ensuring high stability of the first cooling bars 6.

[0050] In the alternative embodiment shown in Figure 4, T-shaped cooling webs 11 are formed on the rear side 3 of the friction ring 1 near the outer edge 5, which enable a particularly stable support of the friction ring 1 on the rail wheel of the rail vehicle.

[0051] In the further alternative embodiment shown in Figures 5 and 6, first cooling webs 6 are again arranged both near the inner edge 4 and near the outer edge 5 of the friction ring 1.

[0052] Between the two rows of first cooling webs 6, fifth cooling webs 12 are formed as cooling ribs, viewed in the circumferential direction, which extend over almost the entire radial width of the friction ring 1.

[0053] These fifth cooling bars 12, viewed in the radial direction, also have contact surfaces 121 at their ends for contact with the rail wheel of the rail vehicle. A lowered region 122 extending between the contact surfaces 121 is flatter in its vertical extent than the region of the contact surfaces 121, so that air can flow between the lowered region 122 and the rail wheel.

[0054] Furthermore, in this embodiment, analogous to the embodiments shown in Figures 2 and 4, cylindrically shaped third webs 10 and cams 9 are distributed. Instead of the screw receptacles 8, sixth cooling webs 13 are also formed here, which serve to receive the screws. In addition to a screw-receiving area 132, these sixth cooling webs have a radially inwardly extending web adjoining the screw-receiving area and having a further contact surface 131. The contact surfaces 131 lie in an imaginary circular line with the contact surfaces 63 of the first cooling webs 6 and the contact surfaces 121 of the fifth cooling webs.

[0055] List of reference symbols

[0056] 1 friction ring

[0057] 2 friction surface

[0058] 3 Back

[0059] 4 inner edge

[0060] 5 Outer edge

[0061] 6 first cooling bar

[0062] 61 feet

[0063] 62 neck

[0064] 63 contact surface

[0065] 7 second cooling bar

[0066] 8 screw receptacles

[0067] 9 cams

[0068] 91 Coat

[0069] 92 groove

[0070] 10 third cooling bar

[0071] 11 fourth cooling bar

[0072] 12 fifth cooling bar

[0073] 121 contact surface

[0074] 122 lowered area

[0075] 13 sixth cooling bar

[0076] 131 contact surface

[0077] 132 screw receiving area

[0078] Q cross-section

[0079] QF foot cross-section

[0080] L Maximum length of the foot

Claims

Claims Friction ring (1) for a wheel brake disc of a rail vehicle, with a friction surface (2) and a rear side (3) facing away from the friction surface, from which a plurality of cooling webs (6, 7, 10, 11, 12, 13) extend in a direction perpendicular to the friction surface (2), characterized in that at least a portion of the cooling webs (6, 7, 10, 11, 12, 13) are designed as first cooling webs (6), with a cross-section (Q) tapering away from the rear side (3) in a plane viewed parallel to the rear side (3) and merging into a circular shape. Friction ring (1) according to claim 1, characterized in that the first cooling webs (6) have a foot (61) rising from the rear side (3) and a neck (62) extending from the foot, wherein a foot cross-section (QF) in the circumferential direction of the friction ring (1) is larger than radially to an imaginary axis of rotation of the friction ring (1), wherein the neck (62) is formed with the circular cross-section (Q).Friction ring (1) according to claim 2, characterized in that a lateral surface of the first cooling webs (6) transitions seamlessly from the base (61) into the neck (62). Friction ring (1) according to one of the preceding claims, characterized in that the first cooling webs (6) are arranged one behind the other in the circumferential direction. Friction ring (1) according to claim 4, characterized in that the first cooling webs (6) are arranged one behind the other in the circumferential direction near an inner edge (4) and / or near an outer edge (5) of the friction ring (1). Friction ring (1) according to one of the preceding claims, characterized in that a ratio between a maximum length (L) at the base (61) of the first cooling webs (6) and a diameter (d1) at the neck (62) of the first cooling webs (6) is between 1.2 and 2.

5. Friction ring (1) according to one of the preceding claims, characterized in that a portion of the cooling webs (6, 7, 10, 11) are designed as second cooling webs (7) with a circular cross-section in a plane viewed parallel to the rear side (3), wherein a vertical extent of the second cooling webs (7) perpendicular to the plane of the rear side (3) is smaller than a vertical extent of the first cooling webs (6). Friction ring (1) according to one of the preceding claims, characterized in that fifth cooling webs (12) designed as cooling ribs, viewed in the circumferential direction, are formed between the two rows of first cooling webs (6), which extend over almost the entire radial width of the friction ring (1). Friction ring (1) according to claim 8, characterized in that cylindrically shaped third cooling webs (10) and cams (9) are distributed between the two rows of first cooling webs (6), viewed in the radial direction.Friction ring (1) according to claim 8 or 9, characterized in that between the two rows of first cooling webs (6), viewed in the radial direction, sixth cooling webs (13) are formed which serve to receive screws and which, in addition to a screw-receiving region (132), have a web which adjoins the screw-receiving region (132) and extends radially inward, said web having a contact surface (131), wherein the contact surfaces (131) of the sixth cooling webs (13) lie in an imaginary circular line with contact surfaces (63) of the first cooling webs (6) and the contact surfaces (121) of the fifth cooling webs (12). Wheel brake disc for a rail wheel of a rail vehicle, comprising two friction rings (1) fastened on opposite sides of the rail wheel, characterized in that the friction rings (1) are designed according to one or more of the preceding claims.

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