Solid wheel having high thermal capacity for rail vehicles
Patent Information
- Application Number
- EP2023829019
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-12-22
- Filing Date
- 2023-12-12
- Publication Date
- 2025-08-20
AI Technical Summary
Rail vehicle wheels face significant thermal challenges due to rising braking energies, leading to excessive temperature gradients between the wheel tread and the axle, causing thermospannings and deformation issues that can result in material failure and affect the stability of the wheel's position, compromising safe operation.
A solid wheel design with a radial outer rim, inner hub, and a median line defined by specific construction points, where the rim and hub are connected by a wheel with varying thickness and curvature, allowing for improved thermal expansion and reduced radial stiffness, thereby managing temperature-induced stresses.
This design enhances the thermal performance of rail vehicle wheels, reducing thermospannings and maintaining axial stability, preventing material failure and ensuring consistent operation under increased braking loads and speeds.
Smart Images
Figure 1.1
Abstract
Description
[0001]December 11, 2023 Solid wheel with high thermal performance for rail vehicles. The invention relates to a solid wheel with high thermal performance for rail vehicles, comprising: a radially outer wheel rim, a radially inner wheel hub extending around a central axis of the solid wheel, and a wheel disc connecting the wheel rim to the wheel hub. The wheel rim has a running surface, a wheel flange, an outer side surface in a first plane, and an inner side surface in a second plane, the first plane and the second plane extending orthogonally to the central axis. The wheel rim, in the region of its running surface, has a reference plane extending orthogonally to the central axis and having a running circle diameter. The reference plane is displaced outwardly by an axial distance relative to the second plane and the inner side surface of the rim, the distance preferably being 50 mm to 80 mm.the wheel disc and the wheel hub are formed as a single piece as a solid wheel, and the wheel disc has a median line whose course is defined by several design points. The solid wheel according to the invention (also: "monoblock wheel") is a solid wheel for rail vehicles, which is particularly suitable for use on the European rail network in accordance with the Technical Specifications for Interoperability TSIWAG (freight wagons) and TSI LOC & PAS (locomotives and passenger cars), and whose product requirements are described in EN 13262 and the requirements for the approval of such wheels are described in EN 13979-1. The main field of application of the subject matter of the invention concerns wheelsets of freight wagons,where braking is predominantly achieved with brake blocks acting directly on the wheel treads. The resulting frictional power heats the wheel tread considerably, resulting in a strong thermal gradient between the wheel hub and the wheel rim. Increasing axle loads, higher speeds, and the switch from gray cast iron to composite brake blocks for acoustic reasons are leading to ever-increasing thermal stress on the wheels. For example, the K and LL brake blocks made of composite material, which have been legally required in Germany since the end of 2020, have the major advantage over gray cast iron blocks in that the wheel treads are not roughened and remain smooth, thus drastically reducing the noise emissions of a passing freight car. However, the disadvantage is the lack of heat dissipation via the brake blocks, which occurs with gray cast iron blocks.This means that the entire braking energy is now largely introduced into the wheel rim and then primarily dissipated into the surrounding air via the rim and wheel disc. The braking energies to be considered in the design of the wheels, which specifically take into account the conditions on the European rail network, are normatively defined by EN 13979-1, among others. For example, solid wheels of freight wagons with a 920 mm running circle diameter are designed for 45-minute continuous braking. The total braking energy generated in the normative design is 135 MJ. This braking energy then leads to average wheel rim temperatures of approximately 550°C, while at the end of these braking operations the wheel hubs have only warmed up to approximately 50°C. Due to the temperature, the wheel rim wants to expand, but is prevented from doing so due to the existing temperature gradients, since the less heated wheel hub hardly expands. The result is high,Thermal stresses exceeding the yield strength of the wheel materials used and resulting plastic deformation components, which then develop as residual stresses of the first type when the wheels cool down. For example, in a rail wheel in solid wheel-A, C / AC 220946WODecember 11, 2023 (i.e., monoblock design) during continuous braking, tensile stresses develop in the wheel disc due to the expanding wheel rim in the radial direction, while compressive stresses develop in the wheel rim in the circumferential direction due to the restriction of expansion by the comparatively cold wheel disc. After braking, the mechanisms of the heating process are reversed, i.e., the wheel rim now wants to contract more strongly, but is prevented from doing so by the previously plasticized and now practically enlarged wheel disc. The result is the formation of tensile residual stresses in the wheel rim in the circumferential direction, while the wheel disc is compressed by the contracting wheel rim. Depending on the design of the wheel disc, this compression process can lead to high local bending stresses and associated axial deformations on the wheel disc side.Such axial deformations of the wheel disc, which also occur in the opposite direction during braking, lead to a change in the axial position of the wheel rim relative to the wheel hub. These deformations are severely restricted by standards, as they lead to changes in the wheel back and track dimensions of the wheelsets, and thus, if the limit dimensions are exceeded, the safe tracking of the wheelset on the track is directly affected. The challenges mentioned above for the designers of block-brakable solid wheels have led to a wide variety of wheel disc shapes, ranging from straight and disc-spring-like shapes to a wide variety of corrugated shapes with and without camber (camber is understood as the offset of the wheel disc between the inlet to the wheel rim and the wheel hub).In Europe, a standard freight car wheelset was introduced in 1968 with the introduction of the Y25 bogie by the International Union of Railways (UIC) through its Research and Testing Office (ORE). This standard freight car wheelset featured a corrugated wheel disc without camber and was originally intended for a 25-t axle load. Due to the camber-free wheel disc, the wheel behaves largely gauge-stable during block braking. However, the wheel disc, arranged in the measuring circle plane, exhibits comparatively high radial stiffness despite the corrugation and thus leads to a. C / AC 220946WODecember 11, 2023: In addition to high local stresses in the wheel disc with partial plasticization, block braking leads to a severe restriction of the wheel rim's expansion. The result is high residual tensile stresses in the wheel rim after cooling. Particularly when tread defects such as thermal cracks and the like occur, these residual tensile stresses are highly undesirable, as they can lead to crack propagation and ultimately to wheel failure. Possible improvements to this wheel design have led to various solutions, briefly outlined below. Document DE 2362434 A1 discloses a wheelset for rail vehicles since the 1970s that features a roughly straight wheel disc. The gauge stability of the wheel described therein is further reduced compared to the UIC standard freight car wheel due to balanced stress on the wheel disc due to the lack of corrugation. Accordingly, local stresses or residual tensile stresses are also considered.Strains in the wheel disc are at a significantly lower level due to the lack of bending components. However, above a certain temperature, the wheel disc plasticizes across its entire thickness, which, in addition to influencing the load-bearing capacity under wheel / rail forces, also results in increased residual tensile stresses in the wheel rim. A solid wheel for rail vehicles with a bell-shaped design has been known since the 1980s from document DE 3117572 C2. This wheel also features a camber-free wheel disc with a corrugation following a mathematical function, with the thickness of the wheel disc remaining small and almost constant. Therefore, the radial stiffness of this wheel is significantly reduced compared to the aforementioned wheel designs.However, due to the verification of mechanical stresses according to the regulations that have been further developed in the meantime, the thin wheel discs originally intended are no longer feasible, which is reflected in higher radialA. C / AC 220946WODecember 11, 2023. stiffness of the wheel disc and less favorable stress and strain behavior during block braking. From document EP 0798136 A1, a wheel disc has been known since the 1990s. The shape of the wheel disc corresponds approximately to half a corrugation of the wheel according to DE 3117572C2, with the corrugation depth evenly distributed on both sides of the reference plane or measuring circle plane. Thus, the wheel disc has a camber corresponding to the depth of the corrugation, and the wheel disc is oriented toward the wheel flange at the transition to the wheel rim and toward the outer hub face at the transition to the wheel hub. Due to the camber of the wheel disc, the radial elasticity of this design is increased compared to the design according to DE 3117572C2, which results in further reduced residual stresses in the wheel rim, particularly compared to the UIC / ORE wheel.However, the shape of the wheel disc leads to increased axial deflections, particularly after the wheels have cooled down, as well as to increased cyclic stresses in the wheel / rail interactions that occur during operation. Kräften.Document EP 1225065 A1 relates to a wheel disc with a corrugation similar to DE 3117 572 A1, wherein the maximum of the corrugation has been shifted so that it approximately coincides with the plane formed by the outer wheel rim face, and the transition from the wheel rim to the wheel disc or from the wheel disc to the wheel hub has been shifted from the reference plane toward the outer wheel surface, i.e., further below the tread. Document EP 1440817 A1 describes two wheel modifications that are also fundamentally based on the corrugation according to DE 3117572 A1, whereby the area of the maximum of the corrugation is not formed by a curve but by a (in cross-section) straight or flat section. The wheel disc can be designed either without camber or with a certain camber, with the inlet of the wheel disc into the wheel rim and hub oriented toward the reference plane or measuring circle plane. Distinguishing feature between theA C / AC 220946WODecember 11, 2023 Both wheel designs described consist of an angled entry of the wheel disc into the wheel rim and hub, and alternatively, a vertical entry, i.e., parallel to the reference plane. Document EP 2046585 B1 describes a freight car wheel whose corrugated wheel disc moves on both sides of the reference plane, with the corrugation crest oriented toward the outside of the wheel and the entry of the wheel disc into the hub and wheel rim toward the inside of the wheel. The corrugation crest located between the inner diameter of the wheel rim and the outer diameter of the hub is offset toward the wheel rim, and the defined radii of the individual areas of the median line of the wheel disc determine its curvature.In the solution known from document EP 2801483 A1, the course of the wheel disc is based in principle on EP 0798136, whereby the radius of the center line of the wheel disc between the turning point and the transition to the wheel hub is smaller than the radius at the transition to the wheel rim. Furthermore, the distance between the corrugation at the transition to the wheel rim and the center plane of the corrugations is greater than the corrugation at the transition to the wheel hub. Document EP 3932690 A1 also describes two wheel variants that are based in principle on EP 0798136 and differ primarily in the design of the inlet of the wheel disc into the wheel rim. In the first version, the course of the wheel disc also describes a half corrugation, whereby the wheel disc on the inside of the wheel can even protrude slightly beyond the inner wheel rim face.The wheel disc's entry into the wheel rim is then designed so that it is at an angle toward the wheel's reference plane, while the wheel disc's entry into the wheel hub should run parallel to the reference plane. Alternatively, a reinforcement is provided below the wheel rim on the tread side, into which the wheel disc enters at the aforementioned angle. C / AC 220946WODecember 11, 2023 In summary, it must be stated that the previously described designs already demonstrate improvements in thermal behavior compared to the original so-called UIC / ORE wheel. However, depending on the respective design and the level of braking energy introduced, excessive axial deflections as well as high thermal stresses and resulting residual stresses still occur. The present invention overcomes these issues, providing a wheel that is also ideally suited for future increases in axle loads and travel speeds while retaining the block brake. Against this background, the invention is based on the object of further increasing the thermal performance of monoblock wheels beyond the previously achieved level without impairing the mechanical properties of the wheel.This task is solved for a solid wheel described above in that the following conditions apply to the median line and the design points, which must be met cumulatively: a) first design point: The first design point is the intersection point of a third plane running orthogonal to the center axis, which determines the axial position, and a first straight line, which determines the radial position. The third plane is shifted inwards by an axial distance relative to the reference plane and runs through the area of the wheel flange. The first straight line runs through a base point at the radially inner and axially outer corner of the wheel rim and is inclined by an angle α of between 0° and 14° with respect to a second straight line, which runs parallel to the center axis. The median line of the wheel disc runs parallel to the reference plane in the area of the first design point. A. C / AC 220946WODecember 11, 2023 b) Second construction point: ^The second construction point is the vertex of the median line, i.e., the axially outermost point of the median line.^The second construction point is the intersection point of a fifth plane orthogonal to the central axis, which determines the axial position, and a diameter that determines the radial position.^The fifth plane is shifted outwards relative to the reference plane by an axial distance. c) Third construction point:^The third construction point is the intersection point of a fourth plane orthogonal to the central axis, which determines the axial position, and a diameter that determines the radial position.^The fourth plane lies between the third plane and the fifth plane and is shifted parallel to these two planes.d) fourth construction point:^The fourth construction point is an inflection point at which the direction of curvature of the median line changes or a point on a straight line adjacent to both ends of which the direction of curvature of the median line changes.The invention relates to a solid wheel with high thermal performance for rail vehicles, comprising: a radially outer wheel rim, a radially inner wheel hub which runs around a central axis of the solid wheel, and a wheel disc which connects the wheel rim to the wheel hub, wherein the wheel rim has a running surface, a wheel flange, an outer side surface in a first plane and an inner side surface in a second plane, wherein the first plane and the second plane run orthogonal to the central axis, wherein the wheel rim in the region of its running surface has a reference plane which runs orthogonal to the central axis (also called measuring circle plane) and has a running circle diameter, wherein the reference plane is shifted outwards by an axial distance parallel to the second plane and the inner side surface of the rim, wherein theA. C / AC 220946WODecember 11, 2023 distance is preferably 50 mm to 80 mm, wherein the wheel rim, the wheel disc, and the wheel hub are formed integrally as a solid wheel, and wherein the wheel disc has a median line whose course is defined by several design points. According to the invention, it has been recognized that the object set forth in the invention can be advantageously achieved with such a solid wheel if the conditions stated in the characterizing part of patent claim 1 are cumulatively met for the median line and for the design points. The advantages of the described solid wheel are evident in the following evaluation for block braking with a continuous braking power of 50 kW over 45 minutes with composite brake blocks.While the rim of the UIC / ORE wheel with a 920 mm diameter can expand by 2.0 mm in the radial direction, based on the running circle diameter, the radial expansion of the new solid wheel is 3.1 mm, already moving towards a rim connected to the wheel disc by a split connection that does not impede the radial expansion of the rim under the influence of temperature. With this fictitious solution, the rim would be able to expand radially by 3.9 mm. This means that, compared to the UIC-ORE wheel, the residual tensile stresses in the rim after braking do not exceed values of approximately 50 N / mm², even when the rim is worn, while maintaining extremely stable track dimensions.At this stress, the associated stress intensity of a possible, reliably detectable crack in the area of the wheel rim is well below the threshold value, so that crack growth is prevented if such material damage occurs. As already explained above, the second design point is the vertex of the median line, i.e., the axially outermost point of the median line. The axial position of this A. C / AC 220946WODecember 11, 2023 To more precisely define the vertex and, in particular, to prevent the wheel disc from protruding axially outward beyond the outer side surface of the wheel rim, the following relationships were determined: The axial distance B of the vertex of the median line from the reference plane C should be as follows: B = (RB - LC) * 0.3 to 0.9. In other words: The reference plane has an axial distance LC from the inner side surface of the wheel rim; the axial distance between the reference plane and the outer side surface of the wheel rim is therefore "RB - LC." However, the vertex of the median line should be shifted axially outward by a lesser distance, namely only by 30% to 90% of this distance (0.3 times (RB - LC) to 0.9 times (RB - LC)). In this way it is ensured that not only the apex of the median line, but (at least with usual thicknesses of the wheel disc) no point of the wheel disc protrudes axially outwards beyond the outer side surface of the wheel rim.This has the advantage that the wheel disc does not protrude from the "shadow" of the wheel rim, thus preventing collisions with axle box bearing housings, chassis frames, and the like. According to one design of the solid wheel, the running circle diameter is in the range between 600 mm and 1250 mm, in particular between 840 mm and 920 mm. Running circle diameters in the range of 920 mm are particularly preferred. Solid wheels with such running circle diameters are particularly suitable for freight transport, where the challenge of improving thermal performance is particularly important due to the use of composite brake blocks. A further design of the solid wheel provides that the thickness of the wheel disc adjacent to the wheel hub is greater than the thickness of the wheel disc adjacent to the wheel rim (1), whereby the following preferably applies: 1.05 * S1 ≤ S2 ≤ 1.95 * S1. The wheel disc should therefore move from the inner wheel hub towards the outerA.C / AC 220946WODecember 11, 2023 Tapering the wheel rim. In contrast to a wheel disc with a constant thickness, a wheel disc with variable thickness has the advantage of being able to adapt the thickness to the local mechanical requirements. The tapered shape is chosen because the mechanical stresses on the wheel result primarily from the lateral force acting on the wheel flange, and thus the bending stress effective in the wheel disc reaches its maximum at the transition from the wheel disc to the wheel hub. Furthermore, this allows the stiffness of the wheel disc to be reduced toward the wheel rim, which accommodates the thermal expansion capacity of the wheel rim, and the wheel weight is also reduced in the interests of lightweight construction.The radially outer part of the wheel disc can be further configured in that the wheel disc has a first section between the first design point and the fourth design point, which is curved and preferably has a constant curvature throughout. The first section can thus be partially or completely curved, in particular circular. Alternatively or additionally, it can be provided that the wheel disc has a second section between the fourth design point and the second design point, which is curved and preferably has a constant curvature throughout. The second section can also be partially or completely curved, in particular circular. If the first and second sections are curved, it can be provided that the first section and the second section have opposite directions of curvature.The opposing curves can merge into one another at a (turning) point; however, it can also be provided that a straight line is provided between the opposing curves, running through the fourth design point, parallel to the center axis or at an angle to it. A straight line may be necessary for wheels with a particularly large running circle diameter. Opposing curvature directions result in an S-shaped curve with a change from a "left turn" to a "right turn" (or vice versa). Such a... C / AC 220946WODecember 11, 2023 This design allows the radial stiffness and thermal expansion behavior of the wheel disc to be adjusted particularly advantageously. Furthermore, with this design, bending stresses occur preferentially in the wheel disc, in contrast to the dominant normal stress components in straight wheel disc shapes. This prevents otherwise possible full plasticization of entire wheel disc areas, and only partial plasticization occurs. The radially inner part of the wheel disc can be further designed by having a third section, adjacent to the second design point, and a fourth section, adjacent to the third design point, between the second design point and the third design point, which have opposite curvature directions. Here, too, the previously mentioned advantages and properties of opposite curvature directions were recognized and utilized.For this purpose, it is further proposed that the third section be curved and preferably have a constant curvature throughout. The third section can therefore also be partially or completely circular. With regard to the fourth section, however, it is proposed that the fourth section be curved at least in sections and / or at least in sections straight. The fourth section does not have to be completely curved and in particular does not have to have a constant curvature; instead, it can even be straight in sections, particularly in the area adjacent to the wheel hub, i.e., in the "inlet" into the wheel hub. This allows the transition between the wheel disc and the wheel hub to be designed in the desired manner. In the area of the wheel hub, the highest possible radial stiffness is desired in order to achieve a sufficiently "firm" adhesive bond between the wheel and the shaft. In this respect, for example,Wheel disc runs running more inclined into the wheel hub are counterproductive.According to a further embodiment of the solid wheel, the wheel rim has an inner surface between the base point and the transition into the first section of the wheel disc, which runs partially or completely along the firstA. C / AC 220946WODecember 11, 2023. A largely straight inner surface is particularly easy to manufacture and offers particularly high thermal and mechanical load capacity, which is advantageous, for example, for use in heavy freight transport due to the high axle loads that occur there. According to an alternative design of the solid wheel, the wheel rim, between the base point and the transition into the first section of the wheel disc, has an inner surface with an undercut, preferably with a radial depth of at least 3 mm. A circular, circumferential undercut that is curved radially outward (toward the tread) can reduce weight, thus creating a lightweight version of the solid wheel.This has advantages in passenger train traffic, where axle loads tend to be low, but special requirements for lightweight construction and soundproofing exist, especially for high-speed trains. The potential weight savings of such an undercut depends on the wheel dimensions and the specified wheelset loads. For example, for a monoblock wheel with a 920 mm running circle diameter and a 20 t axle load, the wheel weight in new condition can be reduced by up to approximately 15 kg, or approximately 4%. For this design of the solid wheel, it is further proposed that the undercut have several sections, in particular a first radius, a second radius, and a third straight line arranged between them. The radii allow for uniform transitions at both ends of the undercut, which leads to an optimized stress distribution (reduced notch effect).According to a further embodiment of the solid gear, the inner circumferential surface is provided with a shoulder with an axial width, preferably where: RB1 = (0.15 to 0.5) * (RB – LC). By providing, in addition to the undercut – especially next to the undercut – a stiffening A. C / AC 220946WODecember 11, 2023 A shoulder with a material thickness greater than the undercut is provided, ensuring sufficiently good mechanical properties. The shoulder, in particular, increases the section modulus of the wheel rim, which has a stress-reducing effect, especially in the case of wheel forces in the outer tread area and / or lateral forces acting in the direction of the wheel back (e.g., when driving over switches). Furthermore, the shoulder, especially if it is cylindrical, can facilitate the installation of sound-damping devices or absorbers. Due to the greater material thickness of the shoulder compared to the undercut, sound-damping devices or absorbers mounted there can even be particularly wide and extend beyond the undercut beyond the width of the shoulder. This allows the use of particularly high-performance sound-damping devices or absorbers.The invention is explained in more detail below with reference to a drawing which merely represents a preferred embodiment. In the drawing: Fig. 1: a first embodiment of a solid wheel according to the invention in a sectional view; and Fig. 2 a second embodiment of a solid wheel according to the invention in a sectional view. Fig. 1 shows a first embodiment of a solid wheel V according to the invention in a sectional view. The solid wheel V initially has a radially outer wheel rim 1. The radial direction is identified in Fig. 1 by the coordinate y (shown as an arrow), with the positive y-direction being directed radially outwards, while the negative y-direction is directed radially inwards (i.e. in the direction of a wheel center axis MA). The coordinate x (also shown as an arrow), on the other hand, indicates the axial direction, with the positive x-direction being directed axially inwards (i.e. towards the center of the wheelset or in the direction of theA. C / AC 220946WODecember 11, 2023 opposite solid wheel), while the negative x-direction is directed axially outward. The solid wheel V also has a radially inner wheel hub 2 and a wheel disc 3 that connects the wheel rim 1 to the wheel hub 2. The wheel rim 1 has a running surface 4 and a wheel flange 5. The running surface 4 runs on the rail and can also serve as a braking surface for a friction brake. The wheel flange 5, on the other hand, serves to transmit axial wheel guiding forces. The wheel rim 1, the wheel disc 3, and the wheel hub 2 are formed as a single piece, which is why such wheels - in contrast to multi-part wheels - are also referred to as "solid wheels" or "monoblock wheels." The wheel disc 3 has a median line ML, the course of which is defined by several design points K1, K2, K2, K4. The wheel rim 1 has an axially outer side surface in a first plane X1 and an axially inner side surface in a second plane X2.Between the outer side surface (or the first plane X1) and the inner side surface (or the second plane X2) of the wheel rim 1 is a reference plane C of the solid wheel V, defined as the measuring circle plane. A running circle diameter LD is measured in the reference plane C. Furthermore, the reference plane C serves as a starting point for different wheel profiles, which apply depending on the applicable norm or standard. The transverse dimensions of the wheelset relevant for safe track guidance in the rail network are derived from these norms or standards. For example, a distance LC arises between the inner side surface (or the second plane X2) of the wheel rim 1 and the reference plane C, which can be, for example, 70 mm (Technical Specification for Interoperability for the Railway System in the European Union for the Subsystems Rolling Stock – Freight Wagons, Locomotives and Passenger Carriages – uniform for the track gauges 1435, 1524, 1600, and 1668 mm).For railways outside this operating group, the applicable standards apply. The wheel rim 1 has a radial thickness RD, which is composed of a wear component VA and the residual wheel rim thickness RRD, which must not be undercut during operation for strength reasons (RD = VA + A). C / AC 220946WO 11 December 2023RDD). The wheel rim 1 also has an axial width RB, which is preferably in the range between 120 mm and 150 mm and in particular 135 mm kann.Wheel hub 2 provides a secure connection between the solid wheel V and the wheelset shaft (not shown in Fig. 1). It is typically cold-pressed or hot-shrinked onto a shaft seat with an oversize. Wheel hub 2 has a bore diameter D1N, which is determined by the fatigue strength verification for the shaft seat, which results from the applicable standards, in Europe according to EN 13103-1. The oversize between wheel hub 2 and shaft seat depends on the loads occurring on the wheelset, such as braking torques, short-circuit torques, the lateral forces between wheel and rail, the process parameters during assembly, and the temperature gradients within the wheel and between the wheel and shaft, and is preferably between 0.75 ‰ and 2.5 ‰. Wheel hub 2 has an axially outer hub diameter D2a and an axially inner hub diameter D2i. The following applies to these: 1.14 * D1N ≤ D2a or D2i ≤ 1.55 * D1N.The entry of the median line ML of the wheel disc 3 into the wheel rim 1 runs parallel to the reference plane C in an imaginary third plane X3 at an axial distance A. This third plane X3 is to be determined such that the entire thickness S1 of the wheel disc 3 is located in the area of the entry into the wheel rim 1 within the area of the wheel flange 5 (this should apply in any case to a wheel with a wheel flange in new condition). The intersection point of this third plane X3 with the wheel rim inner diameter D4 results in the first design point K1 of the wheel disc 3. The wheel rim inner diameter D4 results from a base point Y1 of the wheel rim 1 and a first straight line G1, which is at an angle α between 0° and 14° (inwards) to an axial (i.e. parallel to the wheel center axis A). C / AC 220946WODecember 11, 2023MA). The wheel rim 1 has an inner surface Mi, which in the first design of the solid wheel V (Fig. 1) runs almost entirely along the first straight line G1. The wheel disc 3, which runs from the first design point K1 in the direction of the wheel hub 2, describes with its median line ML a "wave crest" that is directed outwards in the axial direction. This wave crest begins - starting at the wheel rim 1 - with a curved (e.g. circular) rising first section A1 up to the fourth construction point K4 (which mathematically represents a "turning point" at which the direction of curvature changes; alternatively, the fourth construction point can be part of a straight line whose two ends border on opposite curvatures) followed by a curved (e.g. circular) flattening second section A2 with the second construction point K2 as the vertex of the wave crest.This is followed – further towards the wheel hub 2 – by a curved (e.g. circular) descending third section A3 and a partially curved, flattening fourth section A4 with a tangential transition into a fourth plane X4 running parallel to the reference plane C with the third design point K3 as the end point of the wheel disc 3, through which the inlet into the wheel hub 2 is defined. The third design point K3 is an intersection point with a hub diameter D3, which is formed according to the relationship: D3 = maximum value (D2a, D2i) + minimum value (L2a, L2i) * 0.15 to 0.6. L2a corresponds to the axial distance between an (axially outer) hub outer end face in a seventh plane X7 and the fourth plane X4, and L2i corresponds to the axial distance between an (axially inner) hub inner end face in a sixth plane X6 and the fourth plane X4.The distance of the fourth plane X4 in the x-direction is preferably between the third plane X3 (first construction point K1) and the fifth plane X5 (second construction point K2).A. C / AC 220946WO December 11, 2023The second design point K2 of the wheel disc 3 is formed from the intersection point between the second design point K2 of the median line ML and the fifth plane X5 running parallel to the reference plane C, where:DK2 = 0.35 to 0.6 * (D4 – D3) + D3The axial distance B of this fifth plane X5 from the reference plane C is given by folgt:B = (RB – LC) * 0.3 to 0.9The thickness of the wheel disc 3 is determined on the basis of numerical calculations and, in addition to the thermal stresses, must also take into account the cyclic stresses due to the wheel / rail forces. This circumstance is taken into account in that the course of the wheel disc 3 is tapered according to the median line ML between the design points K3 and K4 in the direction of the wheel rim 1, whereby the ratio of the thickness S1 (adjacent to the wheel rim 1) and the thickness S2 (adjacent to the wheel hub 2) is: 1.05 * S1 ≤ S2 ≤ 1.95 * S1 The transition from the wheel disc 3 to the wheel hub 2 and from the wheel disc 3 to the wheel rim 1 occurs through radii or elliptical transitions that tangentially connect the wheel hub outer surfaces or wheel rim inner surfaces with the wheel disc. Fig. 2 shows a second embodiment of a solid wheel V' according to the invention in a sectional view. The already described in connection with Fig.The reference numerals used in Fig. 1 are used correspondingly in Fig. 2. The essentialA. C / AC 220946WODecember 11, 2023 The difference between the second embodiment of the solid wheel V' (shown in Fig. 2) and the first embodiment of the solid wheel V' (shown in Fig. 1) lies in the design of the radially inner side of the wheel rim 1, in particular in the profile of the inner circumferential surface Mi. The inner circumferential surface Mi extends from the base point Y1 to the transition into the first section A1 of the wheel disc 3. In contrast to the first embodiment of the solid wheel V (Fig. 1), in which the inner circumferential surface Mi runs almost entirely along the first straight line G1, the inner circumferential surface Mi in the second embodiment of the solid wheel V' (Fig. 2) has a shoulder AN and an undercut H. The shoulder AN extends from the base point Y1 in the axial direction to an outer second base point Y2 and has an axial width RB1. The approach AN can (as shown in Fig. 2) run along the straight line G2, i.e. parallel to the wheel center axis MA.This results in a cylindrical shape of the extension AN, which can simplify the attachment of soundproofing systems or absorbers, for example. Alternatively (and unlike what is shown in Fig. 2), the extension AN can also be inclined, for example along the first straight line G1, which runs at an angle α between 0° and 14° (inward) to the second straight line G2, which runs axially (i.e., parallel to the wheel center axis MA). The undercut H extends from the outer second base point Y2 to an inner third base point Y3. Starting from the straight line G1, the undercut H has a radial depth T (measured orthogonally to the straight line G1).The undercut H can comprise several different sections, for example a first radius R1 (adjacent to the third base point Y3, which is formed by the intersection of the first radius R1 with the first straight line G1), a second radius R2 (adjacent to the second base point Y2), and a third straight line G3 arranged therebetween. Alternatively (and differently than shown in Fig. 2), an ellipse or a basket arch can also be arranged between the first radius R1 and the second radius R2. The third straight line G3 can be arranged under an A. C / AC 220946WODecember 11, 2023 Angle α1 between 0° and 14° (inward) to the second straight line G2 running axially (i.e., parallel to the wheel center axis MA). The radially outwardly curved shape of the undercut H (toward the tread 4) achieves a weight reduction, resulting in a reduced residual wheel rim thickness RRD1, which is preferably at least 12 mm. Sufficient rigidity is ensured in particular by the projection AN. The solid wheel V' shown in Fig. 2 is therefore a lightweight variant of the solid wheel VA shown in Fig. 1. C / AC 220946WODecember 11, 2023 List of reference symbols: 1: Wheel rim 2: Wheel hub 3: Wheel disc 4: Tread 5: Wheel flange A: Axial distance (between reference plane C and third plane X3) A1: First section (of the median line ML / of the wheel disc 3) A2: Second section (of the median line ML / of the wheel disc 3) A3: Third section (of the median line ML / of the wheel disc 3) A4: Fourth section (of the median line ML / of the wheel disc 3) AN: Extension C: Reference plane (of the solid wheel V, V') D1N: Bore diameter (of the wheel hub 2) D2a: Outer hub diameter D2i: Inner hub diameter D3: Hub diameter (of the design point K3) D4: Wheel rim inner diameter G1: First straight line G2: Second straight line G3: Third straight line H: Undercut K1: First design point K2: Second Design point K3: third design point K4: fourth design point L2a: distance (fourth plane X4 – seventh plane X7) L2i: distance (fourth plane X4 – sixth plane X6) LC: axial distance (between reference plane C and inner side surface X2) AC / AC 220946WODecember 11, 2023 LD: Running circle diameter MA: Centerline (of the solid wheel V, V') Mi: Inner surface (of the wheel rim 1) ML: Median line (of the wheel disc 3) R1: First radius (of the undercut H) R2: Second radius (of the undercut H) RB: Wheel rim width (axial) RB1: Axial width (of the shoulder AN) RD: Wheel rim thickness (radial) RRD: Remaining wheel rim thickness (radial) RRD1: Reduced remaining wheel rim thickness (radial) S1: Thickness of wheel disc 3 (adjacent to the wheel rim 1) S2: Thickness of wheel disc 3 (adjacent to the wheel hub 2) T: Depth (of the undercut H) V,V': Solid wheel VA: Wear percentage x: axial direction X1: first plane (axial outer side surface of the wheel rim 1) X2: second plane (axial inner side surface of the wheel rim 1) X3: third plane (entry plane median line ML in the wheel rim 1) X4: fourth plane (entry plane median line ML in the wheel hub 2) X5: fifth plane (apex plane) X6: sixth plane (hub inner face) X7: seventh plane (hub outer face) y: radial direction Y1: base point (of the wheel rim 1) Y2: second base point (of the wheel rim 1) Y3: third base point (of the wheel rim 1) α: angle (of the straight line G1) A, C / AC 220946WO December 11, 2023 α1: Angle (of the line G3) A C / AC 220946WO December 11, 2023
Claims
December 11, 2023Patent Claims1. Solid wheel (V, V') with high thermal performance for rail vehicles,m it:^ a radially outer wheel rim (1), ^ a radially inner wheel hub (2) which runs around a central axis (MA) of the solid wheel (V), and ^ a wheel disc (3) which connects the wheel rim (1) to the wheel hub (2), ^ wherein the wheel rim (1) has a running surface (4), a flange (5), an outer side surface in a first plane (X1) and an inner side surface in a second plane (X2), ^ wherein the first plane (X1) and the second plane (X2) run orthogonally to the central axis (MA), ^ wherein the wheel rim (1) has, in the region of its running surface (4), a reference plane (C) which runs orthogonally to the central axis (MA) and has a running circle diameter (LD), ^ wherein the reference plane (C) is displaced outwards by an axial distance (LC) parallel to the second plane (X2) and the inner side surface of the rim (1), wherein the distance (LC) is preferably 50 mm to 80 mm,^wherein the wheel rim (1), the wheel disc (3) and the wheel hub (2) are formed as a single piece as a solid wheel (V),and^wherein the wheel disc (3) has a median line (ML), the course of which is defined by several construction points (K1, K2, K3, K4), characterized in that the following conditions apply to the median line (ML) and to the construction points (K1, K2, K3, K4): a) first construction point (K1):, - 2 - ^The first construction point (K1) is the intersection point of a third plane (X3) orthogonal to the central axis (MA), which determines the axial position, and a first straight line (G1), which determines the radial position bestimmt.^The third plane (X3) is shifted inward relative to the reference plane (C) by an axial distance (A) and runs through the area of the wheel flange (5). ^The first straight line (G1) runs through a base point (Y1) at the radially inner and axially outer corner of the wheel rim (1) and is inclined by an angle (α) of between 0° and 14° with respect to a second straight line (G2), which runs parallel to the center axis (MA). ^The median line (ML) of the wheel disc (3) runs parallel to the reference plane (C) in the area of the first design point (K1). b) Second design point (K2): ^The second design point (K2) is the vertex of the median line (ML), i.e., the axially outermost point of the median line (ML). ^The second construction point (K2) is the intersection point of a fifth plane (X5) orthogonal to the central axis (MA), which determines the axial position, and a diameter (DK2), which determines the radial position bestimmt.^The fifth plane (X5) is displaced outwards relative to the reference plane (C) by an axial distance (B). c) Third construction point (K3):^The third construction point (K3) is the intersection point of a fourth plane (X4) orthogonal to the central axis (MA), which determines the axial position, and a diameter (D3), which determines the radial position bestimmt. ^The fourth plane (X4) lies between the third plane (X3) and the fifth plane (X5) and is parallel to these two planes. d) fourth construction point (K4): A C / AC 220946WO December 11, 2023 - 3 - ^The fourth design point (K4) is an inflection point at which the direction of curvature of the median line (ML) changes or a point on a straight line, adjacent to both ends of which the direction of curvature of the median line (ML) changes.
2. Solid wheel (V, V') according to claim 1, characterized in that the running circle diameter (LD) is in the range between 600 mm and 1250 mm, in particular between 840 mm and 920 mm.
3. Solid wheel (V, V') according to claim 1 or claim 2, characterized in that the thickness (S2) of the wheel disc (3) adjacent to the wheel hub (2) is greater than the thickness (S1) of the wheel disc (3) adjacent to the wheel rim (1), wherein preferably: 1.05 * S1 ≤ S2 ≤ 1.95 * S1.4.Solid wheel (V, V') according to one of claims 1 to 3, characterized in that the wheel disc (3) has a first section (A1) between the first construction point (K1) and the fourth construction point (K4) which is curved and preferably has a constant curvature throughout. aufweist.
5. Solid wheel (V, V') according to one of the claims 1 to 4, characterized in that the wheel disc (3) has a second section (A2) between the fourth construction point (K4) and the second construction point (K2), which is curved and preferably has a constant curvature throughout aufweist.
6. Solid wheel (V, V') according to claim 4 or 5,A C / AC 220946WO December 11, 2023 - 4 - characterized in that the first section (A1) and the second section (A2) have opposite directions of curvature.
7. Solid wheel (V, V') according to one of claims 1 to 6, characterized in that the wheel disc (3) has, between the second design point (K2) and the third design point (K3), a third section (A3) which borders on the second design point (K2), and a fourth section (A4) which borders on the third design point (K3), which have opposite directions of curvature.
8. Solid wheel (V, V') according to claim 7, characterized in that the third section (A3) is curved and preferably has a constant curvature throughout.
9. Solid wheel (V, V') according to claim 7 or 8, characterized in that the fourth section (A4) is curved at least in sections and / or is straight at least in sections.
10. Solid wheel (V) according to one of claims 1 to 9, characterized in that the wheel rim (1) has an inner circumferential surface (Mi) between the base point (Y1) and the transition into the first section (A1) of the wheel disc (3), which runs partially or completely along the first straight line (G1).
11. Solid wheel (V') according to one of claims 1 to 9, characterized in that the sA. C / AC 220946WO December 11, 2023 - 5 - the wheel rim (1) has an inner circumferential surface (Mi) between the base point (Y1) and the transition into the first section (A1) of the wheel disc (3), which has an undercut (H) that preferably has a radial depth (T) of at least 3 mm.
12. Solid wheel (V') according to claim 11, characterized in that the undercut (H) has several sections, in particular a first radius (R1), a second radius (R2), and a third straight line (G3) arranged therebetween.
13. Solid wheel (V') according to claim 11 or 12, characterized in that the inner circumferential surface (Mi) has a shoulder (AN) with an axial width (RB1), wherein preferably: RB1 = (0.15 to 0.5) * (RB - LC).A C / AC 220946WO December 11, 2023