DE10154333B4 - wheel brake - Google Patents

Abstract

Wheel brake, comprising
- One with the wheel (3) co-rotating brake body, in particular a brake disc (1),
- At least one not with the wheel (3) co-rotating, pressable against the brake body, brake pad (2) with a pad lining (22),
- Wherein the contact surface (9) of the brake body, in particular the brake disc (1) to the brake pad (2) out of ceramic material, wherein
- The brake body, in particular the brake disc (1), a base body (1 a) made of metal and on the base body (1 a) at least one disc covering (21) as a contact surface (9) made of ceramic material,
characterized in that
- The disc covering (21) of a plurality of segments (6a, b, x, y) of a ring, in particular a disc-shaped ring, consists, and
- The segments (6x, y) viewed in the radial direction with oblique, from the mounting surface (8) to the contact surface (9) to the center of the segment (6x, y) inclined towards side surfaces (13) are equipped, and the base body (1a ) equipped with dovetail-shaped undercut (14) accordingly ...

Description

I. Field of application

The The invention relates to wheel brakes, especially disc brakes for road and rail vehicles as well as the landing gear of aircraft.

II. Technical background

to Simplification is referred to below exclusively by disc brakes, without limiting the invention to this, since all put forward here solutions Also applicable to drum brakes and other forms of wheel brakes. The invention is directed to such wheel brakes, in which as at least a part of the friction pair of the brake so-called ceramic Material is used.

When Ceramic material in the present application is a material which defines carbides and / or nitrides, in particular silicon carbide or silicon nitride and / or where fillers, in particular carbides, in a matrix of carbon, in particular in the form of carbon fibers.

conventional Disc brakes previously consisted of a brake disc made of metal, especially gray iron, Aluminum or steel, against which a brake pad with a brake pad pressed has been. Such a brake pad, a so-called "organic brake pad", consists of a Mixture containing organic components (e.g., resins, rubber), in particular in the form of organic fibers (eg aramid fibers), inorganic constituents, in particular metals and metal compounds, in particular in the form of fibers (eg mineral fibers, steel fibers, glass fibers, Ceramic fibers), fillers, Friction adjuvants (eg, graphite or barium sulfate) and / or Binders, in particular resins, in particular Fenol resin contains. Examples for organic fillers are styrene butadiene rubber, acrylonitrile butadiene rubber, Urethane rubber, ethylene-propylene rubber, Isoprene rubber, silicone rubber or other unvulcanized Rubber.

There in these friction pairings at a z. B. passenger cars no Life was achievable, where at least the harder part the friction pair, in this case, the brake disc made of metal, the Lifespan of the motor vehicle reached, and the brake pad still much more often had to be changed, other friction pairings were developed.

So Wheel brakes are already known in which the brake disc as a whole made of ceramic material, and the pad lining of the brake pad either also had ceramic material as a friction lining or the usual, only slightly modified in their composition, previously mentioned organic Brake pads like with metal brake discs.

there was in place of the above-described ceramic material initially only Carbon, in particular reinforced with a proportion of carbon fibers, eg. As carbon cloth, used with a binder, usually a phenolic or epoxy resin, offset and compressed and cured has been. Thereafter, the carbonization and graphitization of the compact, usually several times in succession to achieve a corresponding density, followed by the mechanical processing of the material.

This Carbon fiber reinforced Carbon (CFC) is still used today in racing cars of the formula 1 and the wheel brakes on aircraft both for the brake disc and used as a brake pad lining. The advantages of low weight and the high braking performance but with the disadvantages a short service life due to high abrasion, poor wet braking behavior and an oxidative combustion in air at temperatures from about 480 ° C.

By Storing a carbide or nitride, in particular a silicon carbide (SiC) powder, although this temperature limit was raised to about 1100 ° C, due to the chemical incompatibility Of carbon and SiC, however, had the carbon, in particular the carbon fibers, by coating or soaking z. Example by means of phenolic resins or CVD infiltration of methane against direct contact with the SiC be protected, so that a total of a variety of manufacturing steps to manufacture Such a brake disc of so-called. CSiC material was required.

Farther also such CSiC discs had the principal disadvantage - in addition to the high production costs - one high brittleness and very heavy mechanical workability, for example for Balancing purposes.

The DE 43 22 113 A1 describes a brake disc for disc brakes, wherein a support body is provided with two annular, symmetrical layers as a brake pad, column 2, lines 21 to 25, 1 , The layer consists of metal, metal sintered or a metal-ceramic sintered material, column 9, lines 58 to 67. The support body 1 is, as in 11 . 12 shown, with ring lands 10, 11 verse hen, which surround the layer 6 laterally.

The DE 197 27 587 A1 describes a brake unit of brake disc and brake pad. According to claim 1, the brake disc is combined with a brake pad with organically bound matrix.

The DE 197 27 587 A1 describes a brake unit of brake disc and brake pad. According to claim 1, the brake disc is combined with a brake pad with organically bound matrix.

III. Presentation of the invention

a) Technical task

It is therefore the object according to the present Invention, a wheel brake and a method for their preparation to create, which despite cost-effective manufacturability a less susceptibility against damage by blows and allows better mechanical workability of the brake disc.

b) Solution of the task

These The object is solved by the features of claims 1 and 15. advantageous embodiments emerge from the dependent claims.

The production of a brake disc made of a metal base body and ceramic disc material applied thereon has so far been precluded by a series of technical prejudices:
Since the ceramic materials are produced by sintering, that is, as molded compacts, it was believed that it was the most cost-effective way to make the entire brake disc directly as such a compact.

One Another disadvantage was that the very different thermal expansion of the metal base body - about 3 sometimes higher - than the of ceramic material, in particular CSiC material, due to rapid and severe temperature fluctuations during operation of the brake disc to a destruction the connection would lead.

• – Eine solche Bremsscheibe ist sehr viel kostengünstiger herzustellen trotz des zusätzlichen Montageaufwandes des Scheibenbelages am Basiskörper, da der Preis primär durch die Kosten der keramischen Anteile bestimmt wird, und diese sehr viel günstiger als eine komplette keramische Bremsscheibe herzustellen sind.
• – Sofern nur der Reibbelag der Bremsscheibe aus keramischem Material besteht, ist dessen geometrische Form sehr viel einfacher als bei der Herstellung der gesamten Bremsscheibe, so dass auch das beim Sintern auftretende Schwund verhalten leichter exakt vorherbestimmt werden kann und dadurch die geometrische Maßhaltigkeit der gesinterten Teile verbessert werden kann.
• – Zusätzlich ist eine exakte Formgebung vor allem auf der Kontaktseite des Scheibenbelages zu dem späteren Bremsklotz hin durch entsprechende Ebenheit leichter einzuhalten, während auf den Befestigungsflächen zum Basiskörper hin ein Ausgleich durch Einbringen einer Distanzmasse, beispielsweise eines Klebers, ausgeglichen werden kann.
• – Die Gefahr einer Zerstörung der Bremsscheibe, z. B. durch einen Steinschlag, kann zum einen dadurch verringert werden, dass am radialen Außenumfang ein verbreiterter Wulst des Basiskörpers aus Metall die Außenfläche des keramischen Scheibenbelages teilweise abdeckt und dadurch schützt. Die Gefahr eines quer zur Hauptebene der Scheibenbremse auftretenden Steinschlages bei einem schnellfahrenden Kraftfahrzeug ist dagegen geringer.
• – Zusätzlich kann – vor allem bei flächiger Befestigung des Scheibenbelages auf dem Basiskörper – selbst bei Auftreten eines Steinschlages und Brechen des Scheibenbelages das Abfallen der Bruchstücke des Scheibenbelages vom Basiskörper verhindert werden und dadurch die Bremse wenigstens teilweise noch funktionsfähig bleiben. Selbst bei völligem Abfallen des Belages ist das darunter liegende Basismaterial, meist Grauguß, noch als Not-Reibbelag nutzbar.
• – Da die fertige Bremsscheibe hinsichtlich ihres Gewichts mehrheitlich aus dem Gewicht des Basiskörpers bestehen wird, kann ein Auswuchten der fertig hergestellten Bremsscheibe durch Auswuchten an dem metallenen Basiskörper erfolgen, wofür die üblichen Methoden wie Materialabnahme durch Fräsen, Drehen, Bohren benutzt werden können.

However, these actually existing disadvantages can be solved and, in view of the achievable advantages, take a back seat:

• - Such a brake disc is much more cost-effective to produce despite the additional installation cost of the disc covering on the base body, since the price is primarily determined by the cost of the ceramic components, and they are much cheaper to produce a complete ceramic brake disc.
• - If only the friction lining of the brake disc is made of ceramic material, its geometric shape is much simpler than in the production of the entire brake disc, so that the shrinkage occurring during sintering behave easier can be accurately predicted accurately and thereby improves the geometrical dimensional accuracy of the sintered parts can be.
• - In addition, an exact shape especially on the contact side of the disc covering to the later brake pad out by appropriate flatness easier to comply, while on the mounting surfaces to the base body towards a balance by introducing a distance mass, such as an adhesive can be compensated.
• - The risk of destruction of the brake disc, z. B. by a stone chipping, can be reduced by the fact that at the radial outer periphery of a widened bead of the base body made of metal partially covers the outer surface of the ceramic disc covering and thereby protects. The risk of a rock impact occurring transversely to the main plane of the disc brake in a fast moving motor vehicle, however, is lower.
• - In addition, especially in the case of surface attachment of the disc covering on the base body - even if a stone chip and breaking the disc covering the falling of the fragments of the disc covering are prevented from the base body and thereby the brake at least partially still remain functional. Even if the lining completely falls off, the underlying base material, usually cast iron, can still be used as an emergency friction lining.
• - Since the finished brake disc in terms of their weight will consist mainly of the weight of the base body, a balancing of the finished brake disc can be done by balancing on the metal base body, for which the usual methods such as material removal by milling, turning, drilling can be used.

As a base body, the previously existing production methods and manufacturing equipment can be maintained, since the base body as before preferably made of cast metal, so-called gray cast iron exists. It must only be provided on the frontal outer surfaces corresponding configurations for receiving the ceramic disc covering, in particular an annular, outwardly frontally open, recess provided during casting with or subsequently by z. B. Turning can be made.

There the disc coverings have to have only a low intrinsic stability of ceramic material, and the stability the brake disc for the most part Part due to stability of the base body is achieved the ceramic disc coverings very thin, in particular with a thickness of less than 1 cm, measured in the axial direction, be used.

The problem of different thermal expansion between the ceramic disc covering and the metal base body can be solved in different ways depending on the method of attachment between the two parts:
Basically, it should be noted that between the ceramic lining and disk body in a brake disk attachment must be selected, which only prevents a greater relative movement between the two parts in the direction of rotation. A relative movement in the radial direction is tolerable up to a few millimeters.

Conversely, with drum brakes:
Again, a relative rotation between the two components must primarily be avoided, while a shift z. B. in the axial direction within limits.

Back again to the disc brake is a possibility in the surface bonding the attachment surfaces of disc covering and base body up to today. The problem of different thermal expansion the lower the two parts will be the lower Expansion of the individual parts, in particular of the individual parts of the disc covering, is.

there If a disc covering is not used in one piece, ie in the form of a disc-shaped ring, but this from several over the scope is complementary Segments assembled, which glued side by side on the base body are and between them have expansion joints, which is an elongation allow the individual segments when heated. These strain amounts are sufficiently small to absorb them by a resilient adhesive to be able to.

In addition, the problem of greater thermal expansion of the base body of cast iron is relativized by the fact that the heat conduction from the disc covering to the base body is already relatively low, that the thermal conductivity of the ceramic disc covering itself is low and in addition the heat transfer can be minimized at their attachment surfaces:
This is possible by using an adhesive with low thermal conductivity, or by non-planar but only partial-area bonding, and thus insulating voids between disc covering and base body.

According to the invention, positive fastening methods are proposed:
When screwing, riveting or fastening by means of locking pins, these preferably have to extend in the axial direction and open into the contact surface of the disc covering, where care must be taken to sufficiently deep sunk these fasteners against the contact surface.

In all cases is the introduction of too strong punctual loads on the To avoid attachment points in the disc surface.

This is when riveting by default of the tensile force in use a blind rivet possible and at latching pins, which have latching projections at their front end and get caught on the base body, by determining their length and / or the indentation force for the Locking pins. In particular, you can such fasteners through openings in the base body extending, which in the central, radially outward opening vents the common used ventilated inside Open brake discs. In particular, the locking lugs of locking pins can be supported in the inner surfaces.

The thermal expansion is thereby enabled that in the radial direction sufficient play between these fasteners, So screws, rivets or locking pins, and the corresponding Through openings in the disc covering or in the base body exists, in particular these openings as longholes are formed extending in the radial direction.

Even though here also in one piece used annular disc coverings can be Nevertheless, the composition of the annular brake pad is composed of several Segments over To spread the circumference preferable because the joints between each Additional segments can improve the braking effect and additionally if damaged by rockfall etc. only one segment is destroyed, and because of the remaining undamaged segments - their Size in the circumferential direction should preferably be less than the extension of the coating of the brake pad in the circumferential direction - the brake remains functional.

The composition of the annular disc covering of individual segments is also advantageous with regard to the attachment to the base body by positive reception, for example insertion of a radially from inside to outside ßen extending dovetail, whose width tapers radially outwards conically:
By the centrifugal forces during rotation of the disc brake, the individual segments are thereby pressed into the dovetail guides, which are formed on the base body, so that a loss of the individual segments is impossible. In addition, a surface bonding between the segment and the base body can take place, which then additionally in a preloaded state, ie during z. B. the rotation as under operating conditions, take place, so that a fast-curing adhesive should apply.

Also a fastening by means of screws, rivets or locking pins like described above is possible but preferably at the radially outer end of Segmentes, allowing a thermal expansion radially inwardly is not hindered. In the opposite direction would that the narrower the dovetail guide to project radially outward.

Under circumstances can attach to an additional except through the dovetail guide Completely be omitted and it only has to falling out of the segments radially inward by attaching an inner boundary ring on the base body, for example by Screw, be provided on the radial inner circumference of the segments.

c) embodiments

A embodiment according to the invention in the following with reference to the figures described in more detail by way of example. Show it:

1 : a disc brake in a sectional view,

2 a ring-shaped one-piece disc covering,

3a a segmented disc covering in the top view,

3b the disc of 3a in section, and

3c a similar slice in section, and

3d a radial section through 3a ,

1 is a common disc brake in section along the axial direction 10 shown, wherein in the brake disc shown there 1 on the frontal outer surfaces as a disc covering 21 a respective one-piece annular disc covering 21 according to 2 or also a segmented disc covering according to 3 Can be used.

1 shows the substantially rotationally symmetrical brake disc 1 with a base body 1a made of metal, in particular gray cast iron, in which from a central hub portion radially outward as an annular disk of the functional part of the base body 1 protrudes. The hub part is frontally with the hub 4 bolted to the vehicle while on the opposite end side of the hub part of the base body 1a the rim of the wheel 3 is seated with its central middle part.

In the annular disk-shaped functional part of the base body 1a are open to the end faces, annular receiving spaces for arranging the annular disc-shaped disc coverings 21 provided thereby characterized on its radially outer side of the existing there widened in the axial direction bead 19 of the base body 1a Partially engaged behind in the axial direction and thereby held in a form-fitting manner radially outward.

In addition, the corresponding axially projecting disc pads 21 , which are preferably formed identically in practice, in the space provided for receiving the base body 1a , the central and radially outward open in the middle of the known ventilation holes 12 may have distributed over the circumference, either by surface bonding by means of an adhesive 20 additionally attached or form-fitting z. B. by screwing by means of screws 24 or - as shown in the lower half - by latching by means of locking pins 17 their locking projections near the front end preferably with the inner surfaces of the ventilation openings 12 can get caught.

screw 24 , Locking pins 17 and others in the axial direction 10 extending fasteners must be so far compared to the outer contact surface 9 of the disc covering 21 be set back that even with wear of the disc covering 21 still no contact of these elements by the in the axial direction from the outside on the disc surface 21 pressing block coverings 22 the brake pads 2 which is done by a metal back plate 23 are worn and are usually attached thereto by gluing.

The openings 18 in the base body 1 for passing the locking pins 17 or screwing in screws 24 or inserting rivets 16 , in particular of blind rivets 16 , serve, are preferably as extending in the radial direction slots 18 ' educated. Despite the attachment by means of these fasteners can before preferably between the attachment surface 8th of the disc covering and the base body 1a a balancing mass 26 be introduced, the manufacturing inaccuracies with respect to the shape of the mutually fixed parts compensated and a two-dimensional force introduction, especially in the disc covering 21 promotes and at the same time as thermal insulation between disc surface 21 and base body 1a can act.

In 2a is in the top view, so viewed in the axial direction 10 , a one-piece, disc-ring-shaped disc covering over the entire circumference 21 shown. openings 28 for passing through fastening elements in the axial direction are preferably arranged on two radially spaced circular rings.

In the sectional view - as in 2 B shown - can the annular disc surface 21 just, in particular with mutually parallel end faces, be formed, or distributed over the circumference on its mounting surface 8th to Ba siskörper 1 surveys 25 , in particular radially extending elevations 25 , in particular in the form of a continuous wave profile running along the circumference with elevations 25 ' and equally spaced depressions therebetween.

These radial elevations 25 find their analogous inverse correspondence in the shape of the outer surface of the base body 1a as for a segmented lining, for example in the sectional view of a mounted brake disc in 3b , Right face, shown, and prevent positive locking a relative rotation between the disc surface 21 and base body 1a , This is the formation of surveys 25 at the attachment surface 8th the sintered ring disc of the disc covering 21 preferable, since corresponding radially extending recesses in the metal base body 1a by machining, such as milling, are easier to produce than the reverse combination.

3 shows in the supervision of the 3a a brake disc 1 in which on the base body 1a in the desired ring area no one-piece annular disc covering 21 is applied, but this is composed of distributed over the circumference of individual segments 6a . 6b . 6x ,

The individual segments 6 are in the circumferential direction spaced from each other and thus form expansion joints between them, which can be larger and smaller in thermal expansion of the individual segments. The outer periphery of the disc covering 21 and thus also the segments 6 enclosing bead 19 of the base body 1a , which provides additional protection against radial rockfall, can be seen as well as - in the upper part of the picture 3a - A precisely radial course of the expansion joints between the individual segments, resulting in a segment shape, the width of which is greater on the outer circumference than on the inner circumference.

This is true even for those in the right half of the 3a represented segments 6a . 6b However, there is the expansion joint between the segments under an always the same intermediate angle 7 inclined to the radial direction so as not to allow the expansion joint to pass over its entire radial width all at once into the region of the brake lining when the brake disk and the adjacent brake lining rotate.

3b shows an anti-rotation between the segments and the base body 1a - Regardless of the attachment between them by means of gluing and / or riveting, screwing, locking - in which the base body 1a in the region of the expansion joints axially outwardly projecting webs 15 ' that exists between the - in 3b parallel to each other axially outwardly aspiring - side surfaces 13 two adjacent segments 6a . 6b , intervene as in the left half of the picture 3b shown. The right half shows the reverse shape, ie the formation of radial elevations 25 on the segment 6 which engages in a corresponding depression in the base body, thereby unnecessarily weakens it.

In the lower half of the 3a In contrast, another form of attachment is shown, which in the sectional view of 3c you can see:
The individual segments have this 6x at the supervision of 3a considers a shape tapering from the inner circumference to the outer circumference so that the expansion joints between the segments 6x Broadening from the inside to the outside, and thus also the webs located there 15 that from the base body 1a protrude axially outward.

However, this allows these webs 15 dovetail-shaped and, accordingly, the radially extending side surfaces of the individual segments 6x analog inclined, so from the mounting surface 8th to the outer contact surface 9 towards the radial longitudinal center of the segment 6x rising, training.

The inclination of the side surfaces 13 and thus the bridges 15 and the rejuvenation of the entire segment 6x radially outward are chosen so that the individual segments 6x from the center of the brake disc radially outward between the dovetailed webs 15 can be inserted and fixed by pressure radially outward self-centering. In this Location can be a screw etc., or even surface bonding to the mounting surface 8th done or even a positive lock by arranging a retaining ring 27 radially within the inner circumference of the individual segments 6x on the base body 1a after they are all in position, as in the radial section of the 3d shown.

By slight radial displacement of this circlip 27 can be made in a simple manner, a balancing of the mounted brake disc.

There is the disadvantage that the webs 15 between the individual segments 6x Be very wide radially outward and an increasing proportion of the circumference is not occupied by friction lining.

As in the upper half of the 3a represented, the segments can 6y Conversely, so also widening radially outward conical, with over the radial extent of equal width, in particular exactly jet-shaped extending webs 15 , Accordingly, then the insertion of the segments 6y radially from outside to inside. The segments 6y must then by a radially applied to the outer circumference circlip 27 ' , which at the same time functions as the bead 19 be secured against the action of centrifugal force, the retaining ring 27 ' annular in one piece or also segmented, for example, from two to four parts exists.

1

brake disc

2

brake pad

3

wheel

4

hub

5

caliper

6a, b, x

segment

7

intermediate angle

8th

mounting surface

9

contact surfaces

10

axially

11

main level

12

ventilation opening

13

side surface

14

undercut

15

web

16

rivet

17

Plunger

18

opening

19

bead

20

Glue

21

disk liner

22

Klotz covering

23

backplate

24

screw

25

radial survey

26

Leveling compound

27

circlip

28

openings

Claims (14)

Wheel brake, comprising - one with the wheel ( 3 ) with rotating brake body, in particular a brake disc ( 1 ), - at least one not with the wheel ( 3 ) co-rotating, pressable against the brake body, brake pad ( 2 ) with a pad lining ( 22 ), - where the contact surface ( 9 ) of the brake body, in particular the brake disc ( 1 ), to the brake pad ( 2 ) consists of ceramic material, wherein - the brake body, in particular the brake disc ( 1 ), a base body ( 1a ) made of metal and on the base body ( 1a ) at least one disc covering ( 21 ) as a contact surface ( 9 ) of ceramic material, characterized in that - the disc covering ( 21 ) of several segments ( 6a , b, x, y) of a ring, in particular of a disk-shaped ring, and - the segments ( 6x , y) viewed in the radial direction with oblique, from the mounting surface ( 8th ) to the contact surface ( 9 ) to the middle of the segment ( 6x , y) inclined side surfaces ( 13 ), and the base body ( 1a ) according to dovetail-shaped undercut ( 14 ) equipped bridges ( 15 ) for holding the segments ( 6x , y). Wheel brake according to claim 1, characterized in that the base body ( 1a ) made of metal, in particular of a steel material, in particular gray cast iron. Wheel brake according to one of the preceding claims, characterized characterized in that contains ceramic material silicon carbide (SiC), in particular added in a matrix of carbon, in particular in the form of carbon fibers, in particular, the carbon or the carbon fibers by Phenolic resin against direct contact with the ceramic material protected is. Wheel brake according to one of the preceding claims, characterized in that the disc covering ( 21 ) on the base body ( 1a ) is positively secured, in particular by means of screws, rivets, cooperating projections and recesses. Wheel brake according to one of the preceding claims, characterized in that the disc covering ( 21 ) on the base body ( 1a ) non-positively, in particular by means of bonding, in particular by means of surface bonding, with the base body ( 1a ) connected is. Wheel brake according to one of the preceding claims, characterized in that the base body ( 1a ) on both faces with identical disc coverings ( 21a , b) is equipped. Wheel brake according to one of the preceding claims, characterized in that the block lining ( 22 ) of organic material, in particular of a mixture which organic constituents, in particular in the form of organic fibers, in addition to inorganic constituents and / or binders exists. Wheel brake according to one of the preceding claims, characterized in that the disc covering ( 21 ) has the shape of a ring, in particular an annular disc, in particular in one-piece form. Wheel brake according to one of the preceding claims, characterized in that the joints between the individual segments ( 6a , b) obliquely to the radial direction with always the same intermediate angle ( 7 ) to the radial direction. Wheel brake according to one of the preceding claims, characterized in that the segments ( 6x ...) in the axial direction ( 10 ) viewed have a radially decreasing from the inside to the outside width and in particular are formed symmetrically to its longitudinal direction extending in the radial direction. Wheel brake according to one of the preceding claims, characterized in that the segments ( 6y ...) in the axial direction ( 10 ) considered have a radially increasing from inside to outside width and in particular are formed symmetrically to their longitudinal direction extending in the radial direction. Wheel brake according to one of the preceding claims, characterized in that in the case of positive fastening of the disc covering ( 21a , b) the fastening elements, in particular rivets ( 16 ) or locking pins ( 17 ), through openings ( 18 ) parallel to the axial direction in the base body ( 1a ) are arranged, and in the inner, radial ventilation openings ( 12 ) of the base body ( 1a ), catching us especially at their boundary surfaces. Wheel brake according to one of the preceding claims, characterized in that the openings ( 18 ) in the radial direction a larger diameter than the fastening means, in particular rivets ( 16 ) or locking pins ( 17 ), and in particular as radially extending slots ( 18 ' ) are formed. Wheel brake according to one of the preceding claims, characterized in that the base body ( 1a ) radially outside of the disc lining ( 21 ) an axially the outer periphery of the disc covering ( 21a , b) or its segments ( 6 ) engaging bead ( 19 ) having.