paddle wheel for a retarder with axially curved paddle surfaces and sheet metal retarder

Abstract

Impeller (1) for a retarder (2) of a motor vehicle, such as a commercial vehicle, comprising an annular shell body (4) in which blades (3) made of sheet metal are mounted, wherein the blades (3) extend, on the one hand, from a radial inner side (5) to a radial outer side (6) of the shell body (4) substantially in the radial direction (14) and, on the other hand, from a shell body base (8) to a flow edge (7) substantially in the axial direction (15), wherein at least one surface formed by the respective blade (3) on the fluid-facing side (10) of the blade (3) and / or the fluid-away side (11) of the respective blade (3) has at least one curved section deviating from a flat surface when viewed from the shell body base (8) to the flow edge (7), wherein the blade (3) follows, in addition to the curvature (12), a curve (13) from the radial inner side (5) to the radial outer side (6),where the curve (13) has a concave part (16) and a convex part (17), the convex part (17) being equal in size to the concave part (16).

Description

[0001] The invention relates to a blade wheel for a retarder of a motor vehicle, such as a commercial vehicle, for example a truck, with an annular shell body / an annular shell / a torus half, in which blades made of sheet metal are fastened / attached / present, wherein the blades extend on the one hand from a radial inner side to a radial outer side of the shell body substantially in the radial direction / extend adjusted to the radial direction and on the other hand extend from a shell body base to a flow edge substantially in the axial direction / adjusted in the axial direction.

[0002] Retarders are hydrodynamic, particularly fluid-operated, continuous brakes used in trucks and buses, for example. Hydrodynamic retarders typically operate with oil, but sometimes also with water, which is fed into a converter housing when needed. The converter housing usually consists of two rotationally symmetrical and opposing paddle wheels, a rotor that can be connected to the vehicle's drive train, and a stationary stator. The rotor accelerates the supplied fluid, and centrifugal force pushes it outwards. The shape of the rotor blades directs the fluid into the stator and back again, thereby braking the rotor and subsequently also a drive shaft. Friction converts the kinetic energy into heat, which can then be dissipated through a heat exchanger, for example with the help of the engine's / combustion engine's cooling water circuit.The retarder is often controlled pneumatically via a compressed air control system. To activate, the retarder housing is filled with the working fluid from a reservoir, which is automatically pumped back when the pressure is reduced by the paddle wheels. The present invention can be used with both inline and offline retarders.

[0003] It should be noted that a retarder does not use a guide wheel. Furthermore, it essentially operates at a single operating point, which is different from conventional torque converters. This also dictates the characteristics of the retarder, as the goal here is to generate the greatest possible losses or braking torque. The flow in the retarder must therefore be optimized differently than in a conventional torque converter.

[0004] Current retarders or flow brakes are generally made of cast iron, making them massive, heavy, and expensive. To address these significant disadvantages, the applicant has already filed an older patent application, which emphasizes the idea of ​​constructing the rotor and / or stator from sheet metal. In particular, the blades of the retarder are to be made of sheet metal, particularly sheet steel. This older patent application deals with the fact that the blade wheel for hydrodynamic torque transmission and / or braking devices, with an annular shell body and a plurality of blades arranged in the shell body, is particularly improved by constructing both the shell body and the double-walled blades from sheet metal.

[0005] For example, reference is made to DE 10 2011 117 920 A1 and DE 24 56 221 A1, which show paddle wheels for hydrodynamic machines.

[0006] This is where the new invention comes in and aims to enable cheaper manufacturing and better performance for a generic paddle wheel.

[0007] This object is achieved in such a blade wheel according to the invention by the features of patent claim 1. In particular, the object is achieved in that at least one surface formed by the respective blade on the side of the blade facing the fluid / liquid / oil (in particular when the rotor rotates relative to the stator) and / or the side of the respective blade facing away from the fluid / liquid / oil has at least one curved section deviating from a flat surface when viewed from the shell body base to the flow edge.

[0008] This allows for the cost-effective production of a retarder design that is significantly lighter than conventional solutions. Furthermore, the oil flow into the center of the torus is improved. Complex hollow blades, which require casting, are thus eliminated. The new design eliminates the need for expensive and inflexible manufacturing processes.

[0009] Advantageous embodiments are claimed in the subclaims and are explained in more detail below.

[0010] It is particularly advantageous if the blades are made of sheet metal with a predominantly / exactly constant thickness. This simplifies production and makes the end products reproducible even in large-scale production.

[0011] It is also advantageous if the blades are inserted into the shell body / torus or pushed through. In both cases, the blades can then be easily attached to the annular shell body / shell via a positive and / or friction fit. The inserted version guarantees oil tightness, whereas the pushed-through version is particularly easy to manufacture.

[0012] The blades can be soldered or welded to the torus, alternatively or additionally, allowing the use of material-to-material connections as an alternative or in addition to force-fitting and / or form-fitting solutions. In either case, durability is significantly improved.

[0013] The blades may also be curved in such a way that they deviate at least in one region from the connecting line between the two ends of the flow edge either in the direction of rotation or, preferably, against the direction of rotation.

[0014] The blades / selected blades, or preferably all blades, are curved along their axial direction. The blades can be curved in such a way that they are curved in at least a partial axial direction (between the flow edge and the torus base / shell body base). This can promote their use, particularly in electric truck axles.

[0015] It is useful if the curvature is convex or concave.

[0016] It is advantageous if the curvature extends completely from the base of the shell body to the flow edge, but it is also conceivable in one or more sections.

[0017] An advantageous embodiment is also characterized in that the curvature is convex / spherical on one side and concave on the other side.

[0018] The flow is beneficial if the blade follows a curve from the radial inside to the radial outside in addition to the curvature. This cleverly avoids turbulence, for example.

[0019] If the curve has a concave and a convex portion, the flow can be modulated particularly advantageously. It is also advantageous if the inflection point between the convex and concave portions lies on an imaginary connection from the radial inside of the blade to the radial outside of the blade.

[0020] It is advantageous if the concave portion is the same size, smaller, or larger than the convex portion. The invention aims to achieve an equal portion. This is based on the surfaces viewed in the axial direction. Furthermore, it is advantageous if the concave portion is arranged radially further outward than the convex portion on the side facing away from the fluid or the side facing away from the liquid when the shell body rotates.

[0021] An advantageous embodiment is also characterized in that an extension of an imaginary connection between the radial outer side of a blade extends through the radial inner side and beyond, extending off-center from the shell body. The blades are thus angled in the radial direction.

[0022] For manufacturing on the one hand and fluid flow on the other hand, it is advantageous if all blades are designed in the same way and are evenly distributed over the circumference.

[0023] The invention also relates to a retarder for a motor vehicle, such as a commercial vehicle, for example a truck, in particular in the electric axle sector, with a paddle wheel designed as a rotor according to the invention, ergo in particular without a guide wheel, but with a stator.

[0024] It is also advantageous if the blades of the stator are adapted to the blades of the rotor and, particularly preferably, are designed in the same way.

[0025] The invention is explained in more detail below with the aid of a drawing. It shows: Fig. 1 to 6 Sections of plan views of a paddle wheel seen in axial direction on paddle wheels with straight ( Fig. 1), employed but recently trained ( Fig. 2), curved against the direction of rotation of the paddle wheel ( Fig. 3), and multiply - especially double-curved - designed blade wheels, whose imaginary extensions from a radial outer side of the blades to a radial inner side of the blades do not run through the center of rotation of the blade wheel, i.e. run off-center ( Fig. 4 to 6), Fig. 7 to 12 special variants and designs, based on the Fig. 1 to 6, with a curvature / curved sections seen in the axial direction, in particular the embodiments of the Fig. 10 and Fig. 12 are particularly preferred, and Fig. 13 a retarder according to the invention with a paddle wheel designed according to the invention, wherein the paddles are only indicated and in particular according to the type of design according to Fig. 10 to 12 are designed.

[0026] The figures are merely schematic and serve only to facilitate understanding of the invention. The same elements are provided with the same reference numerals. Features of the individual embodiments may be interchanged.

[0027] In the Fig. 1 is a first embodiment of a paddle wheel 1 according to the invention for a retarder 2, as shown in Fig. 13. The impeller 1 has a plurality of blades 3. The blades 3, as well as a shell body 4 that accommodates them, are made of sheet metal. The blades 3 extend from a radial inner side 5 to a radial outer side 6.

[0028] In the embodiment according to Fig. 1, the blades 3 are aligned so straight that a flow edge 7 extends axially spaced from a shell body base 8.

[0029] How then particularly well in the Fig. 10, Fig. 11 and Fig. 12, the impellers 1 according to the invention have such blades 3 which, during operation of the liquid / oil, have a direction of rotation 9 (see Fig. 1 to 6) have a facing side 10 and a facing side 11. The surfaces on the facing side 10 and the facing side 11 are curved (ie follow a curvature 12) in such a way that they deviate from an (otherwise) flat surface / imaginary flat surface.

[0030] In the Fig. 10 to 12, the curvature is indicated by the reference number 12. Deviating from this, a curve 13, which the blades 3 and thus also the flow edge 7 follow, is shown in the Fig. 3 to 6 are referenced by the reference numeral 13. Viewed in the radial direction, a blade configuration according to the invention can thus be straight, in particular inclined, but also curved.

[0031] In the Fig.4, in one embodiment, a concave portion 16 of the blade 2 is present radially further inward than a convex portion 17 of the blade 2. List of reference symbols 1 paddle wheel 2 retarders 3 shovels 4 shell bodies 5 radial inside 6 radial outer side 7 Flow edge 8 Shell body base 9 Direction of rotation 10 facing side 11 opposite side 12 Curvature 13 Curve 14 Radial direction 15 Axial direction 16 concave portion 17 convex part

Claims

[1] Impeller (1) for a retarder (2) of a motor vehicle, such as a commercial vehicle, with an annular shell body (4) in which blades (3) made of sheet metal are fastened, wherein the blades (3) extend on the one hand from a radial inner side (5) to a radial outer side (6) of the shell body (4) essentially in the radial direction (14) and on the other hand extend from a shell body base (8) to a flow edge (7) essentially in the axial direction (15), wherein at least one surface formed by the respective blade (3) on the side (10) of the blade (3) facing the fluid and / or the side (11) of the respective blade (3) facing away from the fluid has at least one curved section deviating from a flat surface when viewed from the shell body base (8) to the flow edge (7), wherein the blade (3) in addition to the curvature (12) of a curve (13) from the radial inner side (5) to the radial Outside (6) follows,wherein the curve (13) has a concave portion (16) and a convex portion (17), the convex portion (17) being equal to the concave portion (16). [2] Impeller (1) according to claim 1, characterized by that the curvature (12) is convex or concave. [3] Impeller (1) according to claim 1 or 2, characterized by that the curvature (12) extends completely from the shell body base (8) to the flow edge (7). [4] Impeller (1) according to one of claims 1 to 3, characterized by that the curvature (12) is convex on one side and concave on the other side. [5] Impeller (1) according to one of claims 1 to 4, characterized by that an extension of an imaginary connection of the radial outer side (6) of a blade (3) runs through the radial inner side (5) and beyond it off-center of the shell body (4). [6] Impeller (1) according to one of claims 1 to 5, characterized bythat all blades (3) are designed in the same way. [7] Retarder (2) for a motor vehicle, such as a commercial vehicle, for example a truck, with a paddle wheel (1) designed as a rotor according to one of the preceding claims.

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