Brake Unit

Abstract

The invention relates to a brake unit and a method for maintaining a brake unit, wherein the brake unit comprises a carrier unit and a jaw unit, wherein the carrier unit can be secured to the fixed portion of a utility vehicle chassis and has a first guiding member and a second guiding member, wherein the first guiding member and the first guiding member are spaced apart from each other, wherein the jaw unit is secured by the guiding members against displacement in a guiding direction, wherein the jaw unit is secured by means of a securing element which can be secured to one of the guiding members against displacement along an axial line, wherein the jaw unit can be displaced in an actuation direction.

Claims

1.-15. (canceled)

16. A brake unit for use in a drum brake, comprising: a carrier unit configured to be secured to a fixed portion of a utility vehicle chassis and having a first guiding member and a second guiding member, wherein the first guiding member and the second guiding member are spaced apart from each other; and a jaw unit secured by the guiding members against displacement in a guiding direction, wherein the jaw unit is secured by a securing element configured to be secured to one of the guiding members against displacement along an axial line; wherein the jaw unit is configured to be displaced in an actuation direction relative to the carrier unit; and wherein the guiding members comprise two portions integral with the carrier unit which extend inside a brake drum.

17. The brake unit as claimed in claim 16, wherein at least one of a first securing element is releasably secured to the first guiding member and a second securing element is releasably secured to the second guiding member.

18. The brake unit as claimed in claim 16, wherein the securing element is configured to be introduced parallel with the guiding direction into a recess of the guiding member and configured to be brought into at least one of non-positive-locking and positive-locking engagement with an engagement geometry.

19. The brake unit as claimed in claim 18, wherein the recess has a stop to which the securing element is configured to be secured in a non-positive-locking manner and is secured against rotation about a parallel line with respect to the guiding direction.

20. The brake unit as claimed in claim 16, wherein the securing element has a securing portion configured to be brought into engagement with a groove of the jaw unit such that an undercut which acts parallel with the axial line is formed between the securing element and the groove.

21. The brake unit as claimed in claim 18, wherein the securing element comprises a threaded pin configured to be screwed into the recess of the guiding member and which has a cylindrical securing portion.

22. The brake unit as claimed in claim 16, wherein the securing element forms an undercut which secures the jaw unit only in a removal direction along the axial line against displacement relative to the carrier unit, and wherein the guiding member includes an adhesion member which extends substantially in the guiding direction and which forms with the jaw unit an undercut which acts counter to the removal direction.

23. The brake unit as claimed in claim 22, wherein the guiding member forms with the retention member and the securing element a substantially U-shaped geometry.

24. The brake unit as claimed in claim 16, wherein the carrier unit at least partially forms the housing of an actuation unit.

25. The brake unit as claimed in claim 16, wherein the securing element engages with an overlapping length on the jaw unit, wherein in an assembled state of the brake unit the jaw unit is spaced apart from the guiding member with a maximum play, and wherein the ratio between the maximum play and the overlapping length is from 0.01 to 0.6.

26. The brake unit as claimed in claim 25, wherein the ratio between the maximum play and the overlapping length is from 0.05 to 0.4.

27. The brake unit as claimed in claim 26, wherein the ratio between the maximum play and the overlapping length is from 0.05 to 0.2.

28. The brake unit as claimed in claim 16, wherein the carrier unit has four guiding members, two of which in each case secure a jaw unit against displacement parallel with the guiding direction, wherein a first pair of guiding members of the four guiding members is formed in a plane-symmetrical manner with respect to a second pair of guiding members of the four guiding members with respect to a plane defined by the guiding direction and the axial line.

29. The brake unit as claimed in claim 16, wherein the jaw unit is pretensioned by a restoring element against an actuation unit.

30. The brake unit as claimed in claim 16, wherein a plurality of securing elements are provided on a guiding member and secure the jaw unit against displacement along the axial line.

31. A method for maintaining a brake unit, comprising: providing, in a first state, a jaw unit is displaceably retained inside a brake drum on a carrier unit and a securing element in an actuation direction; wherein the carrier unit has two guiding members which are in the form of cast or forged portions, between which the jaw unit is retained and which extend inside a brake drum; moving the securing element out of engagement with the jaw unit; displacing the jaw unit along an axial line; and removing the jaw unit from the inner side of the brake drum, wherein the carrier unit remains inside the brake drum.

32. The method as claimed in claim 31, further comprising: inserting the jaw unit with new brake linings along the axial line into the inner side of the brake drum and arranging the jaw unit between two guiding members of the carrier unit subsequent to removing the jaw unit from the inner side of the brake drum; and bringing the securing element into engagement with the jaw unit in order to secure it against displacement along the axial line subsequent to inserting the jaw unit.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0020] FIG. 1a is a first view of a first preferred embodiment of the brake unit according to the invention;

[0021] FIG. 1b is a second view of the preferred embodiment shown in FIG. 1a;

[0022] FIG. 2 is a partially sectioned view of another preferred embodiment of the brake unit according to the invention;

[0023] FIG. 3 is a partially sectioned view of another preferred embodiment; and

[0024] FIG. 4 is a view of another preferred embodiment of the brake unit according to the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] In the view shown in FIG. 1A of a preferred embodiment of the brake unit 1 according to the invention, this brake unit is arranged inside a brake drum 10. The brake unit 1 has a carrier unit 2 and preferably two jaw units 4. The carrier unit 2 has at least a first guiding member 21 and a second guiding member 22, wherein they are spaced apart from each other and are preferably constructed integrally with the additional regions of the carrier unit. The jaw unit 4 is arranged between the guiding members 21, 22 and secured against displacement longitudinally or parallel with a guiding direction F. That is to say, the jaw unit 4 is supported either on the first guiding member 21 or on the second guiding member 22 and is thereby secured against displacement in the guiding direction F by the guiding members 21, 22. Furthermore, the jaw unit 4 has at the side facing a guiding member 21, 22 in each case a groove 41 in which a securing element 51, 52 engages and secures the jaw unit 4 against displacement longitudinally or parallel with an axial line A. The axial line A is in this instance preferably the viewing direction of the embodiment shown and in a particularly preferred manner the rotation axis of the brake drum 10 about the brake unit 1. The securing element 51, 52 is preferably constructed as a threaded pin and screwed into a corresponding recess in the guiding member 21, 22. In this preferred embodiment, the carrier unit 2 is preferably constructed in a mirror-symmetrical manner with respect to a plane defined by the axial line A and the guiding direction F. That is to say, the carrier unit 2 has in the lower region thereof two guiding members 23, 24 which are constructed in a substantially identical manner to the guiding members 21, 22 which are arranged in the upper region and on which a securing element 51, 52 is also provided and a jaw unit 4 is secured against displacement in the guiding direction F and the axial line A. The carrier unit 2 is preferably constructed centrally between the four guiding members 21, 22, 23, 24 as a housing of an actuation unit 6, wherein the actuation unit 6 acts on the jaw units 4 which are supported in each case on the carrier unit 2 with a force in order to press them against the inner side of the brake drum 10. In this instance, the jaw units 4 are preferably pretensioned by two restoring elements 12 against the actuation unit 6. The jaw units 4 shown in this preferred embodiment can consequently preferably be displaced only in one actuation direction B relative to the carrier unit 2.

[0026] FIG. 1b shows the sectioned view identified in FIG. 1a of the preferred embodiment of the brake unit 1 as shown in FIG. 1a. In this instance, in particular the engagement region between the securing element 51 and the corresponding guiding member 21 is disclosed. It can further be seen that the securing element 51 in each case has a securing portion 55 which is brought into positive-locking engagement with the groove 41 of the jaw unit 4. Furthermore, there is shown the overlapping length U which is preferably a multiple of the play S between the jaw unit 4 and the guiding member 21.

[0027] FIG. 2 is a sectioned view of another preferred embodiment of the brake unit 1 according to the invention, wherein the recess 25 is provided in the guiding member 21 with an engagement element 26 which is constructed as an inner thread. It can further be seen that there is provided at the side of the recess 25 facing the jaw unit 4 a stop 27, against which a securing element 51 which is illustrated with broken lines can be moved into abutment and as a result of the screwing with respect to the engagement means 26 can be tensioned against the stop so that undesirable unscrewing during operation of the brake unit 1 can be prevented. Furthermore, the securing element 51 has a securing portion 55 which protrudes through the reduced recess at the right-hand side of the stop 27 and which can be brought into positive-locking engagement with the groove 41 in the jaw unit 4 with an overlapping length U. It is further illustrated that there is provided between the jaw unit 4 and the guiding member 21 a gap which has a width of a play S. In the context of the present invention, it is particularly preferable for the play S to be significantly smaller than the overlapping length U.

[0028] FIG. 3 is a sectioned view of another preferred embodiment of the brake unit 1 according to the invention, wherein the securing element 51 is not constructed as a screw but is instead a sheet-like element which is screwed along the axial line A preferably by means of a screw element against a side of the guiding member 21. In this instance, the securing element 51 secures the jaw unit 4 only against displacement relative to the carrier unit 2 in a removal direction E. In this case, the removal direction E preferably extends parallel with the axial line A. At the end thereof opposite the securing element 51, the guiding member 21 preferably has a retention portion 28 which secures the jaw unit 4 against displacement counter to the removal direction E relative to the carrier unit 2.

[0029] FIG. 4 shows another preferred embodiment of the brake unit according to the invention in which only one securing element 52 is required in order to secure the jaw unit 4 against displacement along the axial line A. In this instance, the jaw unit 4, as illustrated with broken lines, is introduced in a slightly oblique position into the intermediate space between the first guiding member 21 and the second guiding member 22 and engages at the side thereof shown at the top left in a groove in the first guiding member 21. Furthermore, the guiding members 21, 22 each have a retention portion 28 which prevents a displacement of the jaw unit 4 along the axial line A in at least one direction. After the jaw unit 4 has been inserted into the carrier unit 2, the securing element 52 is screwed to the second guiding member and in this manner secures the jaw unit 4 in the installation position thereof, in particular with respect to the guiding direction F and the axial line A.

LIST OF REFERENCE NUMERALS

[0030] 2Carrier unit

[0031] 21First guiding member

[0032] 22Second guiding member

[0033] 23Third guiding member

[0034] 24Fourth guiding member

[0035] 25Recess

[0036] 26Engagement means

[0037] 28Retention member

[0038] 4Jaw unit

[0039] 51First securing element

[0040] 52Second securing element

[0041] 55Securing portion

[0042] 10Brake drum

[0043] 12Restoring element

[0044] AAxial line

[0045] BActuation direction

[0046] FGuiding direction

[0047] ERemoval direction

[0048] SMaximum play

[0049] UOverlapping length