Disc Brake for a Commercial Vehicle

Abstract

A disc brake has a brake caliper in which two brake pads are arranged so that they can be pressed against a brake disc in operation, one of which on the clamping side is actuatable via at least one axially adjustable adjusting spindle carrying a pressure piece by way of a clamping device and the adjusting spindle being guided through an opening of a closure cover closing a receiving chamber of the brake caliper, thereby forming an annular gap. A sealing arrangement is provided for sealing the receiving chamber in the region of the opening, which sealing arrangement bears, on the one hand, against the pressure piece and, on the other hand, is held at the inner side of a collar that circumferentially delimits the opening and extends axially, the sealing arrangement has a bellows and a concentrically arranged secondary seal, and the secondary seal and the bellows are formed integrally, in such a manner that the secondary seal, which has a central opening and is more dimensionally stable than the bellows, has a circumferential wall which is fastened by frictional engagement or by a material bond to the inside of the collar, the bottom angled relative to the wall of the secondary seal bearing with its edge delimiting the central opening, formed as a bead, against the adjusting spindle, and the bellows being connected, with its end formed as a thickened portion opposite the circumferential wall of the secondary seal, to the pressure piece by positive engagement, material bonding, or frictional engagement.

Claims

1. A disc brake, comprising: a brake caliper in which two brake pads are arrangeable so as to be pressable against a brake disc in operation, one of the two brake pads on a clamping side is actuatable via at least one axially adjustable adjusting spindle carrying a pressure piece, the adjusting spindle being guided through an opening of a closure cover closing a receiving chamber of the brake caliper, thereby forming an annular gap; a sealing arrangement configured to seal the receiving chamber in a region of the opening, which sealing arrangement bears, on the one hand, against the pressure piece and, on the other hand, is held at an inner side of a collar that circumferentially delimits the opening and extends axially, wherein the sealing arrangement comprises a bellows and a concentrically arranged secondary seal, the secondary seal and the bellows being formed integrally, wherein the secondary seal, which has a central opening and is more dimensionally stable than the bellows, has a circumferential wall which is fastened by frictional engagement or by a material bond to the inner side of the collar, a bottom angled relative to the circumferential wall of the secondary seal bearing with an edge delimiting the central opening, formed as a bead, against the adjusting spindle, and wherein the bellows is connected, with an end formed as a thickened portion opposite the circumferential wall of the secondary seal, to the pressure piece by positive engagement, material bonding, or frictional engagement.

2. The disc brake as claimed in claim 1, wherein the secondary seal is pot-shaped.

3. The disc brake as claimed in claim 1, wherein the thickened portion of the bellows bearing against the pressure piece comprises a support ring with which the thickened portion is pressable against the pressure piece, and/or the end region of the secondary seal bearing frictionally against the collar comprises a dimensionally stable reinforcement ring.

4. The disc brake as claimed in claim 1, wherein the thickened portion of the bellows bearing against the pressure piece is formed as an O-ring.

5. The disc brake as claimed in claim 1, wherein a support ring is fastened at the pressure piece, against which the thickened portion bears for axial securing of the bellows.

6. The disc brake as claimed in claim 1, wherein the adjusting spindle has, at an end region facing the pressure piece, a circumferential collar against which the thickened portion bears.

7. The disc brake as claimed in claim 1, wherein a spring or wire ring is embedded in the end region of the bellows bearing against the pressure piece for frictional retention of the bellows at the pressure piece.

8. The disc brake as claimed in claim 1, wherein the thickened portion of the bellows bearing against the pressure piece is formed as a polygonal portion in cross-section, which is bonded to the pressure piece.

9. The disc brake as claimed in claim 1, wherein the bellows is connected to the pressure piece by a tongue-and-groove connection.

10. The disc brake as claimed in claim 1, wherein the pressure piece has a circumferential groove in which a bead-shaped thickening of the bellows is seated.

11. The disc brake as claimed in claim 1, wherein the sealing arrangement is a two-component injection molded sealing arrangement.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0027] FIG. 1 shows a disc brake according to the prior art as a sectional plan view; and

[0028] FIGS. 2 to 7 each show an exemplary embodiment of the invention as part of the disc brake in an enlarged detail view.

DETAILED DESCRIPTION OF THE DRAWINGS

[0029] In FIG. 1, a disc brake according to the prior art is shown schematically, with a brake caliper 1 designed as a sliding caliper and straddling a brake disc (not shown), in which two brake pads (likewise not shown) are arranged in a brake carrier 2 and, in operation, i.e. during braking, can be pressed against the brake disc.

[0030] In this case, the brake pad on the clamping side is first pressed against the brake disc by means of a clamping device 3, and subsequently, due to the reaction forces resulting from displacement of the brake caliper 1, the brake pad on the reaction side is likewise pressed against the brake disc.

[0031] In the example, the clamping device 3 comprises two axially adjustable adjusting spindles 4 arranged parallel to and spaced apart from one another, which are guided through an opening 9 of a closure cover 7 that closes a receiving chamber of the brake caliper 1, thereby forming an annular gap.

[0032] For sealing the receiving chamber in the region of each opening 9, a sealing arrangement 12 is provided, which consists of a bellows 10 and a secondary seal 11, which are each formed and fastened separately from one another.

[0033] In this case, the secondary seal 11 is held, on the one hand, at the closure cover 7 and, on the other hand, bears against the adjusting spindle 4. The bellows 10 is also held at the closure cover 7, on the one hand, while on the other hand it bears against a pressure piece 5 which is fastened at the end of the adjusting spindle 4 facing the brake pad.

[0034] The adjusting spindle 4 is connected to an adjusting device 6, by means of which compensation for wear-induced clearance is possible.

[0035] The annular gap formed is closed on its side facing away from the receiving chamber by the bellows 10, which circumferentially surrounds the opening 7 and is held in a sealing manner on a collar integrally formed on the closure cover 7 and extending axially in the direction of the brake pad on the clamping side.

[0036] The secondary seal 11 protects the receiving chamber from penetrating dirt in the event that the bellows 10 is damaged and no longer guarantees its protective function.

[0037] In FIGS. 2 to 7, the sealing arrangement 12 according to embodiments of the invention can be seen in each case as an enlarged partial sectional view which, as mentioned, consists of the bellows 10 and the secondary seal 11, said secondary seal being designed in a pot shape.

[0038] With its edge region facing away from the adjusting spindle 4, the secondary seal 11 is fastened by frictional engagement or material bonding to the inner side of the collar 8 and, in any case, secured against rotation relative to the collar 8. For this purpose, a dimensionally stable reinforcement ring 13, preferably made of metal and, in the example, Z-shaped in cross section, is embedded in the edge region. By the applied contact pressure, the secondary seal 11 is held frictionally on the collar 8. The bellows 10 adjoins the secondary seal 11 in this region.

[0039] An edge angled relative to the axially extending circumferential surface of the secondary seal 11, delimiting a central opening of the secondary seal 11, is formed as a bead 15 which bears in a sealing manner against the adjusting spindle 4 in such a manner that free rotation and axial movement are possible.

[0040] The bellows 10 is connected, by its end formed as a thickened portion opposite the wall of the secondary seal 11, to the pressure piece 5 by positive engagement, material bonding, or frictional engagement.

[0041] In the exemplary embodiment shown in FIG. 2, this end is reinforced for this purpose by an embedded support ring 14, J-shaped in cross section, by which frictional engagement with the pressure piece 5 is possible, but which is also suitable for producing an adhesive connection.

[0042] In the embodiment shown in FIG. 3, the end of the bellows 10 bearing against the pressure piece 5 is formed as an O-ring 16, which bears against the pressure piece 5 and is secured in the axial direction by a support ring 17, arranged opposite the pressure piece 5 and connected to the pressure piece 5 by frictional engagement or material bonding, the O-ring 16 bearing against the support ring 17.

[0043] FIG. 4 shows a variant of the fastening of the bellows 10 to the pressure piece 5, in which a collar 18 is integrally formed on the adjusting spindle 4 for axial support of the O-ring 16, which collar likewise serves as a support for the O-ring 16, thereby providing axial securing of the O-ring 16.

[0044] In the example shown in FIG. 5, the connection of the bellows 10 to the pressure piece 5 is effected by an embedded spring or wire ring 19 to produce a frictional engagement, whereas FIG. 6 shows the connection region of the bellows 10 with the pressure piece 5, in which the end of the bellows 10 is formed as a polygonal portion 20, in this case cuboid-shaped in cross section, which is bonded to the pressure piece 5.

[0045] Finally, FIG. 7 shows a further variant, in which the connection of the bellows 10 is effected by a tongue-and-groove connection, the pressure piece 5 having a circumferential groove 22 in which the bead-like thickening 21 of the bellows 10 is seated, thereby likewise ensuring axial securing of the bellows 10.

[0046] The foregoing disclosure has been set forth merely to illustrate the invention and is not intended to be limiting. Since modifications of the disclosed embodiments incorporating the spirit and substance of the invention may occur to persons skilled in the art, the invention should be construed to include everything within the scope of the appended claims and equivalents thereof.

LIST OF REFERENCE SIGNS

[0047] 1 brake caliper [0048] 2 brake carrier [0049] 3 clamping device [0050] 4 adjusting spindle [0051] pressure piece [0052] 6 adjusting device [0053] 7 closure cover [0054] 8 collar [0055] 9 opening [0056] bellows [0057] 11 secondary seal [0058] 12 sealing arrangement [0059] 13 reinforcement ring [0060] 14 support ring [0061] 15 bead [0062] 16 O-ring [0063] 17 support ring [0064] 18 collar [0065] 19 spring or wire ring [0066] 20 polygonal portion [0067] 21 bead-like thickening [0068] 22 groove