The invention relates to a bearing of a lever, which is provided with a pivot arm, in relation to a pressure piece in accordance with the preamble of patent claim 1.
A bearing having these features is known from DE 10 2005 034 739 A1, DE 10 2007 024 787 A1 or DE 10 2010 006 262 A1. It comprises an inner and an outer bearing shell, the races of which, which are curved in a circular shaped arc, lie radially opposite one another with rolling elements in between. The rolling element space arranged between the races, in which the bearing cage with the rolling elements grouped together therein can move, is delimited in each of the two circumferential directions by a stop. One of the stops is formed as a projection on the outer bearing shell, and the other stop is formed as a projection on the inner bearing shell. Both stops or projections project into the rolling element space, and this has proven disadvantageous in the context of the mounting of the bearing between a lever, which is provided with a pivot arm, and a pressure piece.
It is the underlying object of the invention to refine the assembly aspects of the bearing of the type of lever in question, which is provided with a pivot arm, in relation to a pressure piece.
To achieve this object, a bearing having the features of patent claim 1 is proposed. In this bearing, only the mobility of the bearing cage in one circumferential direction is limited by a projection projecting into the rolling element space. In contrast, the mobility of the bearing cage in the other, second, circumferential direction is limited without a projection extending into the rolling element space.
Instead, the proposal is for a pocket or opening, which is arranged in the other race or extends partially into said race, said pocket or opening extending only over a part of the race width and, at the transition to the curvature plane in which the other race extends, forming a stop edge. This stop edge, which is, as it were, arranged in a recessed manner, serves as a second stop for the bearing cage, this being a particularly advantageous solution in the context of mounting the bearing between a lever, which is provided with a pivot arm, and a pressure piece.
In one embodiment of the bearing, it is proposed that the other race is provided with the pocket or opening on a section of the circumference remote from the pivot arm.
The pocket or opening is preferably arranged in the center of the race width and, furthermore, the width of the pocket or opening should amount to no more than one third of the race width.
In one embodiment, it is proposed that, opposite the stop edge in the circumferential direction, the bearing cage is provided with a projection which projects into the pocket or opening. The projection is preferably formed integrally on the bearing cage, especially if the bearing cage is composed of plastic.
As viewed in the circumferential direction, the length of the projection is preferably less than the length of the pocket or opening. The width of the projection is preferably less than the width of the pocket or opening.
It is furthermore proposed that the race on the pressure-piece side is formed on a bearing shell, on which the radial projection is formed.
To secure it on the pressure piece, the bearing shell can be provided with an outward-projecting anchoring pin, said pin being anchored in the pressure piece.
To achieve low manufacturing costs in the production of the lever, it is advantageous if the pocket or opening is situated in the race on the lever side. In terms of production, it is likewise advantageous if the lever, including the pivot arm, is a forged component, and also if the pocket is the result of the forging process. In this way, the number of processing steps required in the production of the lever can be reduced and hence manufacturing costs saved.
The invention is described below with reference to the drawings, in which:
a-c show a section through the arrangement assembled ready for operation, wherein the respective states as brake application progresses are shown from left to right;
To compensate for the brake wear which arises in the course of time, the disk brake is provided with an adjusting device. This is situated in an adjusting element provided with an external thread. The external thread of the adjusting element engages in an internal thread 6. The internal thread 6 is situated in a pressure piece 7, which is configured in the manner of a crossmember and is guided in the brake application direction in the brake caliper.
The frictional force between the brake disk and the brake pads and hence the deceleration of the vehicle is dependent on the brake application force produced by a brake cylinder secured on the brake caliper, preferably an air-actuated brake cylinder. The brake cylinder, which is here symbolized only by means of its actuating force F (
Moreover, the lever 1, which can also be referred to as a brake application lever, is of fork-shaped configuration since, although there is only one pivot arm 1A, the brake application shaft of the lever consists of two sections 8A, 8B spaced apart axially. Between these two sections 8A, 8B and arranged on the same center line as the pivot arm 1A is a free space 9. The free space 9 is an extension of the internal thread 6 formed in the pressure piece 7, in which the adjusting element of the adjusting system engages.
The rear side of the two-section brake application shaft of the lever 1 is supported against the brake caliper by means of a pivot bearing (not shown). When the brake cylinder is actuated, the lever 1 pivots about this pivot bearing in the direction of the brake disk. Since, according to
The support of the lever 1 on the pressure piece 7 is divided between the two sections 8A, 8B of the brake application shaft. On each side of the free space 9 formed centrally in the lever 1 there is therefore in each case one pivot bearing 2, designed as a rolling bearing, for the pivotable support of the lever 1 in relation to the pressure piece 7. For this purpose, the lever 1 is provided with a convexly curved pressure surface 11 on each of the two sections 8A, 8B, facing the pressure piece 7. Each pressure surface 11 is partially cylindrical or partially circular with respect to the axis of rotation M.
In corresponding fashion, the oppositely situated pressure piece 7 has two concavely curved pressure surfaces 12 in the form of shells. The pressure surfaces 12 too are partially cylindrical or partially circular with respect to the axis of rotation M.
Between each of the paired pressure surfaces 11, 12 on the lever 1 and on the pressure piece 7 there is in each case one shell-shaped rolling bearing. The axis of rotation M thereof is offset relative to the axis of rotation M1 of the pivot bearing by means of which the lever 1 is supported on the rear side against the brake caliper to absorb the reaction forces. The eccentricity between the two pivoting axes or axes of rotation M, M1 leads to the pressure surfaces 11 of the lever 1 shifting forward in the direction of the pressure piece 7 as the lever 1 pivots and hence leads to the desired advance and application movement of the pressure piece 7 in the direction of the brake disk.
Each of the two pivot bearings, which are of identical configuration, includes a race 35 on the pressure-piece side, a race 45 on the lever side and, in between, a bearing space curved in the form of a partial circle, in which an individual bearing cage 36 with rolling elements 37 mounted rotatably therein is accommodated. The rolling elements 37 are elongate cylindrical rollers which roll simultaneously on the race 35 on the pressure-piece side and on the race 45 on the lever side and extend over the majority of the width of the bearing cage 36. The bearing cage 36 is preferably composed of plastic.
The race 35 on the pressure-piece side is formed on the concavely configured inner side of a curved bearing shell 32. With its convexly configured outer side 39, the curved bearing shell 32 is supported against the pressure surface 12 on the pressure piece 7. The bearing shell 32 is preferably composed of metal sheet.
A radial projection 34 is formed integrally on the outer bearing shell 32 on the end thereof adjacent to the pivot arm 1A. This projection 34 forms a stop that limits the mobility of the bearing cage 36 in one circumferential direction. The bearing cage 36 together with the rolling elements 37 can therefore move in one circumferential direction only until it strikes against this stop 34. There is therefore no risk that the bearing cage 36 will move so far in this circumferential direction, namely toward the pivot arm 1A, that it and the outer bearing shell 32 fall apart.
The mobility of the bearing cage 36 is also limited by a stop in the other circumferential direction, namely in the direction away from the pivot arm 1A. For this purpose, an opening in the form of a pocket 50 is situated in the race 45 on the lever side, which is convexly shaped and which is produced by grinding sections 8A and 8B of the lever 1. The pocket 50 is a recess in the material of the pressure surface 11 which forms the race 45 on the lever side.
The opening in the form of the pocket 50 is situated in race 45 but extends only over part of the total length of the curved race 45. It also extends only over part of the width of race 45, with the result that areas of the race remain free on both sides of the pocket 50 to allow rolling elements 37 to roll along.
The pocket 50 forms a stop edge 52 where its wall meets the partially cylindrical curvature plane E of race 45. The stop edge 52 forms a stop by limiting the mobility of the bearing cage 36 in the circumferential direction away from the pivot arm 1A.
The counterstop to the stop edge 52 is situated on the bearing cage 36. For this purpose, a projection 53 is formed on one end of the bearing cage 36, opposite the stop edge 52 in the circumferential direction. The projection 53 extends radially inward beyond the partially cylindrical plane E in which race 45 is situated, with the result that the projection 53 extends into the pocket 50.
If the bearing cage 36 is composed of plastic, the projection 53 is formed integrally on the end of the bearing cage.
It can be seen from
The effect of the two stops limiting the mobility of the bearing cage 36 is shown by
The basic positioning of the bearing cage 36 is accomplished in the normal position of the lever according to
The pocket 50 is situated on the section of the circumference of race 45 which is furthest away from the pivot arm 1A, preferably on the last quarter of the partially cylindrical race 45. This is because, in the situation of maximum brake application force shown in
Since the purpose of the pocket 50 is to provide the further stop edge 52 for the bearing cage 36, a narrow width of the pocket 50 is sufficient. The narrower this width, the more width is available as a contact and rolling surface for the rolling elements 37, all of which extend over the full width of race 45. The width of the pocket 50 is preferably no more than one third of the contact width of the rolling elements 37 on race 45.
In the embodiment described here, the pocket 50 is arranged within the area of race 45, i.e. pocket 50 is surrounded on all sides by race 45. Depending on the lever geometry, however, it is also possible, using a pocket 50 which extends only partially into the area of race 45 in the circumferential direction, to obtain the second stop 52 which limits the mobility of the bearing cage 36 in the second circumferential direction. In this case too, the stop edge 52 is situated where the wall of the pocket 50 meets the curvature plane E in which race 45 is situated.
If the lever 1, including the pivot arm 1A thereof, is a component manufactured by forging, the pocket 50 is also the result of the forging process. It is not necessary to subject the pocket 50 and, in particular, the stop edge 52 formed thereon at the transition to the curvature plane E of race 45 to dedicated machining steps if race 45 is machined with high precision, e.g. by grinding the forging in the region of the races 45.
To secure the respective bearing shell 32 on the pressure piece 7, each bearing shell 32 is anchored in the pressure piece 7 by means of an outward-projecting anchoring pin 60. The anchoring pin 60 is of rectangular cross section with two longer sides and two shorter sides and is seated in a substantially likewise rectangular opening in an anchor 61 which, for its part, is seated in a bore 62 (
The bearing shell 32, which is supported against the pressure piece 7, is provided with radially inward-directed side walls 71, 72 on both longitudinal edges. Situated between the side walls 71, 72 is the bearing cage 36, which is therefore guided laterally by the side walls 71, 72. Projections 74 of a width such that the projections 74 extend over longitudinal edges 73 of the bearing cage 36 are formed on both side walls 71, 72, as a result of which the projections 74 lock the bearing cage 36 in the radial direction in the bearing shell 32. The bearing cage 36 therefore cannot come out of the bearing shell 32 radially. The projections 74 are, for example, local deformations of the material of the edges of the side walls 71, 72.
For the compactness of the pivot bearing shown in
In particular, the side walls 71, 72 are so short that they extend less far radially than the cylindrical circumferential surfaces 37A (
To enable the bearing shell and bearing cage to be arranged in a manner which prevents separation in the circumferential direction, this being highly advantageous during the transportation and assembly of the shell bearing, the bearing cage 36 in the embodiment according to
At the locking projections 77, the bearing cage 36 is wider than over the rest of its length. If the bearing cage 36 is pushed into the bearing shell 32 in the circumferential direction, the locking projections 77 can yield elastically inward through contact with the insertion bevels and then slide along the inner sides of the side walls 71, 72. Because of their arrangement on the resilient sections 76, the locking projections 77 can spring back behind the ends of the side walls 71, 72. They project laterally outward and, since the overall width of the catch noses is greater than the internal clearance between the two side walls 71, 72, said catch noses can engage behind the ends of the side walls 71, 72 to effect retention.
The bearing cage 36 can then no longer move backward. It is locked in the assembly position shown in
The remaining freedom of movement of the bearing cage 36 is limited by the stop 34 and the stop edges 78 on the ends of the side walls 91, 92. The freedom of movement is made somewhat greater than the maximum rolling movement during a braking operation. Thus, the retention elements 75 have no function in the installed state of the unit consisting of the bearing cage 36 and the bearing shell 32.
Two noses 79 formed on the bearing cage 36 are spaced apart with a spacing corresponding to the width of the stop 34, thus allowing the bearing cage 36 to be pre-positioned during assembly in an initial position relative to the bearing shell 32 by means of frictional engagement between the insides of the noses 79 and the outer surfaces of the stop 34. Here, the frictional engagement is so low that it does not represent a disadvantageous obstacle during operation but is sufficient for fixing up to the point of mounting in the disk brake.
A second embodiment of the pivot bearing 2, which forms a module, is shown in
In the second embodiment, the bearing shell 32 is provided with a slotted hole 80 in race 35. As an alternative, a recess in the form of a slotted hole, e.g. a correspondingly designed depression, can be formed in race 35. Extending into the slotted hole 80 or recess in the form of a slotted hole is a projection 83, which is formed integrally on the end of the bearing cage 36. The projection 83 is of a radial length such that it extends beyond race 35 into the slotted hole 80 and into a recess in the form of a slotted hole arranged there.
A stop 81 is formed on the projection 83, facing the pivot arm 1A of the lever 1. With this stop 81, the projection 83 strikes against a stop 82 formed on the bearing shell 32 during a movement of the bearing cage 36 in the direction of the pivot arm 1A. The end of the slotted hole 80 closer to the pivot arm 1A serves as a stop 82.
The projection 83 does not extend radially beyond the convexly curved outer side 39 of the bearing shell 32 in order to ensure that contact between this outer side 39 and the pressure surface 12 of the pressure piece 7 is not impaired.
In principle, it is possible that there is a further stop 86 (
However, the same measures as those in the pivot bearing according to the first embodiment are preferred for limiting the mobility of the bearing cage 36 in this other circumferential direction. In the race 45 on the lever side there is therefore the pocket 50 already described with the stop edge 52. The projection 53 is formed on the bearing cage 36, opposite the stop edge 52 in the circumferential direction (
If the bearing cage 36 of the second embodiment is composed of plastic, both the radially outward-directed projection 83 and the radially inward-directed projection 53 are formed integrally on the bearing cage. For this purpose, the bearing cage 36 is composed in the circumferential direction of a main section, in which the rolling elements 37 are arranged, and, toward the ends, of end sections. Projection 83 and projection 53 are each formed integrally on one of these end sections, ensuring that the rolling elements 37 are not obstructed.
Like projection 53, projection 83 and hence also slotted hole 80 are of relatively narrow width. The width of projection 83 is at most one third of the width of the bearing cage 36.
It is advantageous if the width of the slotted hole 80 changes somewhat over its length, wherein the narrowest width is equal to or somewhat less than the width of the projection 83 projecting into the slotted hole 80. This is because it is possible in this way to pre-position the bearing cage 36 by wedging or by frictional engagement relative to the bearing shell 32, e.g. in the position shown in
Admittedly, the slotted hole 80 leads to a reduction in the area remaining for the outer race 35. However, it should be borne in mind that the slotted hole 80 is situated in that section of the circumference of race 35 which is closest to the pivot arm 1A, preferably in the last quarter of race 35. This is because, in the situation of maximum brake application force shown in
The insertion of the bearing cage 36 provided with the rolling elements 37 into the surrounding bearing shell 32 can be simplified by the formation of insertion bevels or insertion ramps on projection 83 and/or on the inner side of the bearing shell 32, wherein the bearing cage is retained in the bearing shell 32 once these bevels or ramps have been traversed, with the result that there is then no longer any risk that the parts 36, 32 will fall apart. A brief bending, associated therewith, of the bearing cage and/or of the bearing shell 32 is expected here but is not disadvantageous.
Another embodiment of the lever 1 is shown in
The bearing shells 90 have the same partially cylindrical shape as that achieved by machine grinding of the lever 1 to give the pressure surfaces 11 and races 45 in the embodiments already described. Here, therefore, the partially cylindrical outer side of each bearing shell 90 forms the curvature plane E and the race 45 on the lever side.
The bearing shell 90 consists of deformed and punched metal sheet. At the location where the pocket formed behind it in the lever 1 is situated, it is provided with an opening 50, which is arranged in race 45 or extends partially into the race. The opening 50 extends only over part of the race width and, at the transition to the curvature plane E on the outside, forms the stop edge 52 which limits the mobility of the bearing cage 36 in the circumferential direction. The pocket formed below the opening 50 in the lever 1 is of at least the same width and length as the width and length of the opening 50.
At the edges arranged transversely to the circumferential direction, the bearing shell 90 is provided with bent portions 91. Here, the bent portions are in the form of four fastening tabs 91, which engage behind the lever, thus ensuring that each bearing shell 90 is secured non-rotatably on the brake application section 8A, 8B.
The two bearing shells 90 are of identical configuration. It is therefore impossible for them to be mounted incorrectly by being mixed up.
Each of the two bearing shells 90 is produced from a flat metal sheet and has only inward-bent portions in the form of the fastening tabs 91. To increase the stability of the bearing shell 90, the sides thereof may be bent over, but only inward. Radially toward the outside, on the other hand, each bearing shell 90 is without any elements projecting beyond the partially cylindrical curvature plane E. Apart from its curvature, the outer side of the bearing shell 90, which faces away from the lever 1, is therefore completely level and without projecting or protruding parts.
In an alternative embodiment, the opening 50 is admittedly present in the bearing shells 90 but there is no pocket behind it. Nevertheless, the intended second limiting stop is achieved by means of the opening 50 if the thickness of the material of the metal sheet of which the bearing shell 90 is composed is such that the projection 53 formed on the bearing cage 36 extends only into this opening 50 and not into the material of the lever 1. In this case, the stop edge 52 is formed by the transition between the edge of the opening 50 and the curvature plane E of the race defined by the outer side of the bearing shell 90.
Number | Date | Country | Kind |
---|---|---|---|
10 2014 112 241 | Aug 2014 | DE | national |
Filing Document | Filing Date | Country | Kind |
---|---|---|---|
PCT/DE2015/100350 | 8/24/2015 | WO | 00 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2016/029903 | 3/3/2016 | WO | A |
Number | Name | Date | Kind |
---|---|---|---|
5433298 | Antony | Jul 1995 | A |
5819884 | Giering | Oct 1998 | A |
7419036 | Birkeneder | Sep 2008 | B2 |
8313246 | Oishi | Nov 2012 | B2 |
8403114 | Falter | Mar 2013 | B2 |
8632256 | Katayama | Jan 2014 | B2 |
Number | Date | Country |
---|---|---|
42 15 200 | Nov 1993 | DE |
10 2007 024787 | Nov 2008 | DE |
10 2010 006262 | Aug 2011 | DE |
0 589 206 | Mar 1994 | EP |
Entry |
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ISR for PCT/DE2015/100350 dated Feb. 29, 2016. |
Number | Date | Country | |
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20170204903 A1 | Jul 2017 | US |