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DE-102019110860-B4 - Measure to extend the service life of a sliding roller in an electromechanical brake

DE102019110860B4DE 102019110860 B4DE102019110860 B4DE 102019110860B4DE-102019110860-B4

Abstract

The invention relates to a brake, in particular an electromechanical disc brake for a commercial vehicle, comprising: a brake caliper with a caliper support, a pressure piece movably mounted in the brake caliper, a lever pivotably mounted in the brake caliper about an axis of rotation and configured to transmit a braking force from a brake cylinder to the pressure piece, a rolling element that guides the lever along the axis of rotation and pivotably supports it, and a support element for supporting the rolling element against the caliper support. The invention solves the underlying problem in a brake of the aforementioned type by providing the support element with a central section and two end sections adjacent to the central section, with the support element and/or the caliper support being shaped such that a clearance is formed between the end sections and the caliper support, at least in an unloaded state of the brake. The invention solves the underlying problem in a second aspect by providing a brake caliper and in a third aspect by providing a support element for such a brake.

Inventors

  • Colin Hackspacher
  • Paul Henning

Assignees

  • ZF CV SYSTEMS EUROPE BV

Dates

Publication Date
20260513
Application Date
20190426

Claims (14)

  1. Brake (1, 1', 1'', 1'''', 1''''), comprising: - a brake caliper (10, 10', 10'', 10'''') with a caliper support (12, 12 ', 12''), - a pressure piece (20) movably mounted in the brake caliper (10, 10', 10'', 10''''), - a lever (40) pivotably mounted about an axis of rotation (42) in the brake caliper (10, 10', 10'', 10''''), which is configured to transmit a braking force from a brake cylinder to the pressure piece (20), - a rolling element (50, 50') which guides the lever (40) along the axis of rotation (42) and pivotably supports it, and - a support element (60, 60', 60'', 60''', 60'''') for supporting the rolling element (50, 50') against the caliper support (12, 12', 12'') of the brake caliper (10, 10', 10'', 10''''), characterized in that the support element (60, 60', 60'', 60''', 60'''') has a central section (62, 62''') has two end sections (64a,b, 64a',b', 64a''b'', 64a'''',b''') adjacent to the middle section (62), wherein the support element (60, 60', 60'', 60'''', 60'''') and/or the saddle support (12, 12', 12'') are shaped such that between the end sections (64a,b, 64a',b', 64a'',b'', 64a''',b'''') and the saddle support (12, 12 ', 12'') there is at least in an unloaded state of the brake (1, 1', 1'', 1'''', 1'''') a clearance (70a,b, 70a',b', 70a'',b'', 70a''',b''') is trained.
  2. Brake (1, 1'', 1''', 1'''') after Claim 1 , wherein the end sections (64a,b, 64a,b'', 64a''',b''') of the support element (60, 60', 60'', 60'''', 60'''') each have a recess to form part of the free space (70a,b, 70a'',b'', 70a''',b''') with the saddle support (12, 12'') or the entire free space (70a,b, 70a,b', 70a,b'', 70a,b''') which is bounded by the saddle support (12, 12'').
  3. Brake (1, 1', 1'', 1''', 1'''') after Claim 1 or 2 , wherein the saddle support (12', 12'') in the respective area opposite the end sections (64a',b', 64a'',b'') of the support element (60, 60', 60'', 60'''', 60'''') has a recess to form part of the free space (70a,b'70a,b'') with the end sections (64a,b', 64a,'') of the support element (60, 60', 60'', 60', 60'''') or a recess to form the free space (70a,b'70a,b') with the end sections (64a,b', 64a,b'') of the support element (60, 60', 60'', 60'''', 60''''), wherein the free space (70a,b'70a,b'') is only provided on the support element (60, 60', 60'', 60'''', 60'''').
  4. Brake (1, 1', 1'', 1'''', 1'''') according to one of the preceding claims, wherein the clearance (70a,b, 70a',b', 70a'',b'', 70a'''',b'''') is shaped such that the surface of the saddle support (12', 12'') and the end sections (64a',b', 64a'',b'') do not have completely flat surfaces between which the clearance (70a,b, 70a',b', 70a'',b'', 70a''',b'''') is formed.
  5. Brake (1, 1', 1'', 1''', 1'''') after Claim 4 , wherein the free space (70a,b, 70a,b', 70a,b'', 70a'''',b'''') in a cross-sectional plane parallel to the axis of rotation (42) has an angle α greater than 0.5°, which is enclosed by the end sections (64a,b, 64a',b', 64a'',b'', 64a''',b''') and the saddle support (12, 12', 12'').
  6. Brake (1, 1', 1'', 1'''', 1'''') according to one of the preceding claims, wherein the length of the middle section (62) is at least 50%, in particular at least 65% of the length of the support element (60, 60', 60'', 60'''', 60'''').
  7. Brake (1, 1', 1'', 1''', 1'''') after one of the Claims 1 until 5 , wherein the length of the middle section (62''') is at most 20% of the length of the support element (60, 60', 60'', 60'''', 60''''), the middle section (62''') gradually transitions into the end sections (64a''',b''''), and the support element (60, 60', 60'', 60''', 60'''') has a convexly curved surface (68'') opposite the surface of the saddle support (12) along the axis of rotation (42).
  8. Brake (1'''') according to one of the preceding claims, wherein the rolling element (50) is partially cylindrical or cylindrical, and the support element (60'''') has a negative curvature in a cross-sectional plane perpendicular to the axis of rotation (42) corresponding to the curvature of the rolling element (50).
  9. Brake (1'', 1'''') according to one of the preceding claims, wherein the support element (60'', 60'''') is integrally formed on the brake caliper (10'', 10'') and the free space (70a,b, 70a',b', 70a'',b'', 70a''',b''') is formed in a projection of the brake caliper (10'', 10''').
  10. Brake (1, 1', 1''') after one of the Claims 1 until 8 , wherein the support element (60, 60', 60'''') is designed as a separate part of the brake caliper (10, 10', 10'''') and has a mounting interface (66) for attachment to a corresponding mounting interface (14) of the brake caliper (10, 10', 10'''').
  11. Brake caliper (10, 10', 10'', 10'''') for a brake, (1, 1', 1'', 1'''') according to one of the preceding claims, wherein the brake comprises: - a pressure piece (20) movably mounted in the brake caliper (10, 10', 10'', 10''''), - a lever (40) pivotably mounted in the brake caliper (10, 10', 10'', 10'''') for transmitting a braking force from a brake cylinder to the pressure piece (20), - a rolling element (50, 50') which guides the lever (40) along the axis of rotation (42) and pivotably supports it, and - a support element (60, 60', 60'', 60''', 60''''), wherein the brake caliper (10, 10', 10'', 10'''') comprises a caliper support (12, 12', 12'') and the support element (60, 60', 60'', 60'''', 60'''') is configured to support the rolling element (50, 50') against the caliper support (12', 12'') of the brake caliper (10, 10', 10'', 10''''), characterized in that the support element (60, 60', 60'', 60''', 60'''') has a central section (62) and two end sections (64a',b', 64a'',b'',) adjacent to the central section (62), wherein the caliper support (12', 12'') is shaped such that between the end sections (64a',b', 64a'',b'') and the saddle support (12', 12'') in an unloaded state of the brake each form a free space (70a',b', 70a'',b'').
  12. brake caliper (10, 10', 10'', 10''') after Claim 11 , wherein the support element (60, 60', 60'', 60'''', 60'''') has a mounting interface (66), and the brake caliper (10, 10', 10', 10'''') has a corresponding mounting interface (14) for coupling with the mounting interface (66) of the support element (60, 60', 60'', 60'''', 60'''').
  13. brake caliper (10, 10', 10', 10''') after Claim 11 , wherein the support element (60, 60', 60'', 60''', 60'''') for supporting the rolling element (50, 50') is formed as an integral part of the brake caliper (10, 10', 10', 10''') and the clearance (70a',b', 70a'',b'') is formed in a projection of the brake caliper (10, 10', 10', 10''').
  14. Support element (60, 60', 60'', 60''', 60'''') for a brake (1, 1', 1'', 1'''') according to one of the preceding claims, wherein the brake comprises: - a brake caliper (10, 10', 10', 10'''') with a caliper support (12, 12''), - a pressure piece (20) movably mounted in the brake caliper (10, 10', 10', 10'''), - a lever (40) pivotably mounted in the brake caliper (10, 10', 10'', 10''') for transmitting a braking force from a brake cylinder to the pressure piece (20), - a rolling element (50, 50') which guides the lever (40) along the axis of rotation (42) and pivotably supports it, and - a support element (60, 60', 60'', 60'''', 60'''') for supporting the rolling element (50, 50') against the saddle support (12, 12'') of the brake caliper (10, 10', 10', 10''''), characterized in that the support element (60, 60', 60'', 60'''', 60'''') has a central section (62, 62') and two end sections (64a,b, 64a'',b'', 64a''',b''') adjacent to the central section (62, 62') and opposite end sections, wherein the support element (60, 60', 60'', 60'''', 60'''') is shaped such that between the end sections (64a,b, 64a'',b'', 64a''',b''') and the saddle support (12, 12'') in an unloaded state of the brake a free space (70a,b, 70a'',b'', 70a'''', b'''') is formed.

Description

The present invention relates to a brake, in particular an electromechanical disc brake for a commercial vehicle, comprising: a brake caliper with a caliper support, a pressure piece movably mounted in the brake caliper, a lever pivotably mounted in the brake caliper about an axis of rotation, which is configured to transmit a braking force from a brake cylinder to the pressure piece, a rolling element which guides the lever along the axis of rotation and pivotably supports it, and a support element for supporting the rolling element against the caliper support of the brake caliper. The invention relates in particular to electromechanical disc brakes that operate according to the single-piston principle, i.e., that have only one pressure piston for moving the brake shoes. The technical advantages of the so-called single-piston actuation are generally considered to be its weight-saving design and compact form. In brakes of the type mentioned above, a braking force is transmitted from a brake cylinder to a pressure piece movably mounted in the brake caliper via a lever. The lever is typically guided along its axis of rotation by a rolling element and pivotally supported against the brake caliper. When the brake is under load, with a braking force acting on the lever from the brake cylinder, the brake caliper deforms. This deformation subjects the end regions of the rolling element opposite the axis of rotation to considerable stress. This inhomogeneous force application to the rolling element leads to increased wear. (See page 2 and page 2a (final version)) of the edge areas, resulting in a reduced service life. Furthermore, the considerable stress on the edge areas of the rolling element leads to a significant increase in contact pressure, thus causing work hardening and an increase in the stiffness of these edge areas. Due to the increased stiffness of the rolling element, the brake caliper experiences a considerable stress concentration when force is applied through these edge areas. Brakes are known in which the pressure on the outer areas of the rolling element is counteracted by a convex shape of the rolling element. DE 10 2015 100 322 A1 This is revealed, for example, by such a brake. The manufacturing costs of a convex rolling element are significantly higher compared to cylindrical or semi-cylindrical rolling elements. To ensure a more homogeneous force transmission in the brake caliper and thus avoid stress concentrations, a rolling element with a partially cylindrical shape was chosen in the past, which comprised a contact surface that was essentially flat and corresponded to the caliper mounting surface. Such a brake is used, for example, in the US 7 506 732 B2 revealed. Furthermore, from the DE 296 23 621 U1 a brake with a pivot and lever mechanism known which has a rolling element as a support element for guiding and supporting forces against a brake housing. The DE 60 2004 007 576 T2 This describes a lever assembly that can be equipped with a roller bearing, the lever of which is inserted through an opening in the brake caliper and clipped into place. A snap ring ensures locking, and a longitudinal keyway combination prevents incorrect alignment. The DE 44 30 258 C1 The device features a brake with a compact clamping mechanism in which the clamping shaft is decoupled via two differently positioned axes and a rolling element, allowing the pressure piece to be displaced only axially without oscillating laterally. This results in precise, low-wear, and consistently effective brake actuation. While this design method has proven itself in principle, there is still a need for further improvements. In particular, there is a need to further increase the service life of the brake, to enable a more homogeneous force transmission into the brake caliper, and to avoid stress concentrations. Furthermore, there is a need to reduce manufacturing costs without compromising the lifespan of the brake. Accordingly, the invention was based on the objective of providing an improved brake. In particular, the invention was based on the objective of providing a brake with an increased service life while maintaining or reducing manufacturing costs. The invention solves the underlying problem in a brake of the type described above by providing the support element with a The middle section has two end sections adjacent to the middle section and opposite each other at the ends, wherein the support element and/or the saddle support are shaped such that a free space is formed between the end sections and the saddle support at least in an unloaded state of the brake. An unloaded state of the brake is understood here to be a state in which no force acts through the brake cylinder on the lever or any other part of the brake. Preferably, the central section of the support element is in contact with the corresponding saddle surface of the brake caliper, ensuring that the rolling element is reliably compressed, particularly along