Brake Caliper Pivot Friction for Vibration-Induced Pad Contact

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Solution Overview

Problem

Brake calipers in railway vehicles and industrial vehicles are prone to undesired rotation due to vibrations, leading to unintended contact between brake pads and discs when no braking force is applied.

Innovation Solution

A brake caliper design featuring a pair of caliper levers, a body, a bracket, and a coupling pin with a friction applying unit that generates sliding friction at the contact surface to restrain rotation, preventing unintended contact between brake pads and discs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the brake caliper is rotatably attached to the bogie to maintain parallelism between the disc and brake pad, then the brake caliper can adapt to bogie inclination, but the body may be undesirably rotated by vibrations during traveling

Engineering Contradiction:
Improveadaptability to bogie inclinationVSAvoidstability of body rotation
Core Design Contradiction:
Adaptability or versatilityVSStability of the object's composition

Solution Approach 1:

The friction applying unit applies a preliminary frictional force in the opposite direction to the unwanted rotation caused by vibrations. This friction force acts before the vibration can cause significant rotation, counteracting the harmful effect and maintaining stable brake operation.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The friction applying unit converts the vibrational energy that causes harmful rotation into beneficial sliding friction at the contact surface. By allowing controlled sliding friction, the system dissipates vibration energy while preventing the body from rotating undesirably, transforming a harmful effect into a stabilizing mechanism.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Adaptability or versatility

If the body is made rotatable relative to the bracket to maintain parallelism, then the brake pad remains parallel to the disc during inclination, but unintended contact occurs due to vibration-induced rotation

Engineering Contradiction:
Improveparallelism maintenanceVSAvoidreliability of brake operation
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The friction applying unit creates a preliminary frictional barrier that prevents vibration-induced rotation before it can cause unintended brake pad contact. This ensures reliable brake operation by maintaining the intended gap between the brake pad and disc during normal traveling conditions.

Inventive Principle:
Principle #9Preliminary anti-action

Solution Approach 2:

The friction applying unit changes the friction parameter at the contact surface between the body and bracket. By increasing friction in the rotational direction while maintaining rotatability for inclination adaptation, the system achieves both parallelism maintenance and prevention of unintended contact through parameter optimization.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If friction is applied only at part of the body or bracket, then the structure is simpler, but the friction application is less stable

Engineering Contradiction:
Improvestructural simplicityVSAvoidstability of friction application
Core Design Contradiction:
Device complexityVSStability of the object's composition

Solution Approach 1:

The friction applying unit merges the friction application function into an integrated component that contacts both the body and bracket simultaneously. This combination of contact surfaces distributes the friction force more evenly and stabilizes the friction application, preventing localized wear and maintaining consistent friction characteristics.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The friction applying unit serves multiple functions: it applies friction to prevent rotation, maintains stable contact during vibration, and provides a wear-resistant interface. This multi-functionality achieves stable friction application without significantly increasing structural complexity, as the same component performs multiple protective roles.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design effectively prevents unintended contact between brake pads and discs by generating stable frictional forces, ensuring consistent brake operation and facilitating easy maintenance by replacing worn-out components.

Implementation Method 1

a friction applying unit penetrated by the coupling pin, the friction applying unit being configured to restrain rotation of the body by generating sliding friction at a contact surface of the friction applying unit where the friction applying unit touches the body or the bracket

Methodology Applied
Scientific EffectSliding friction: Friction

Implementation Method 2

a friction applying unit configured to restrain rotation of the coupling pin by generating sliding friction at a contact surface of the friction applying unit where the friction applying unit touches an end of the coupling pin in an axial direction

Methodology Applied
Scientific EffectSliding friction: Friction

Data Source

PatentEP3992485B1Brake caliper
Publication Date: 2025.06.25 NABTESCO CORP
  • EP3992485B1 patent drawingFigure 1
  • EP3992485B1 patent drawingFigure 2
  • EP3992485B1 patent drawingFigure 3

AI summary

Provided is a brake caliper capable of preventing unintended contact between brake pads and a disc when no braking is applied. The brake caliper includes a pair of caliper levers (40, 50), where each caliper lever (40, 50) retains a brake pad (12), a cylinder device (15) for outputting a force to rotate the caliper levers (40, 50) such that the caliper levers (40, 50) press a disc (11), a body (30) retaining the caliper levers (40, 50) in a rotatable manner and retaining the cylinder device (15), a bracket (21) fixedly attached to a bogie, a coupling pin (22) coupling the body (30) to the bracket (21) such that the body (30) and the bracket (21) are rotatable around a rotational axis extending in an axial direction in which the caliper levers (40, 50) extend when a brake is not in operation, and a friction applying unit (60) penetrated by the coupling pin (22), where the friction applying unit (60) is configured to generate sliding friction at a contact surface in the axial direction surrounding the coupling pin (22) against relative rotation between the body (30) and the bracket (21).