Disc Brake Operating Shaft Layout for Angled Wear-Adjuster Drive

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Solution Overview

Problem

Existing air disc brake systems face challenges in accommodating a manual adjuster shaft while maintaining effective transmission of the adjuster drive to the wear adjuster mechanism, leading to space constraints and complexity in manufacturing and assembly.

Innovation Solution

The design incorporates an operating shaft with opposed arcuate surfaces and a recess that accommodates a pin extending at a non-zero angle, allowing the manual adjuster shaft to be positioned within the recess while enabling the pin to engage the input driving portion over the full range of motion, simplifying manufacturing and enhancing durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If the manual adjuster shaft is accommodated within the recess of the operating shaft, then space is saved and the design becomes more compact, but the pin must be arranged at a non-zero angle to engage the input driving portion over the full range of motion, increasing manufacturing complexity

Engineering Contradiction:
Improvespace utilizationVSAvoidmanufacturing complexity
Core Design Contradiction:
Volume of moving objectVSEase of manufacture

Solution Approach 1:

The pin is arranged at a non-zero angle (e.g., 45 degrees) relative to the axis of rotation, transitioning from a conventional axial arrangement to an angular orientation. This angular arrangement allows the pin to engage the input driving portion (such as a slot or gear tooth) while accommodating the manual adjuster shaft within the recess, effectively utilizing three-dimensional space to resolve the conflict between compactness and manufacturability

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The operating shaft is segmented into distinct functional zones: the recess area for accommodating the manual adjuster shaft, the pin engagement area for torque transmission, and the arcuate surfaces for actuation. This segmentation allows each component to be optimized independently, with the pin serving as a separate detachable component that can be manufactured and hardened separately before assembly

Inventive Principle:
Principle #1Segmentation

2Reliability

If the pin is made as a separate component and press-fitted into the operating shaft, then the pin can be separately hardened to enhance durability, but the assembly process becomes more complex

Engineering Contradiction:
ImprovedurabilityVSAvoidassembly complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The pin is pre-hardened through heat treatment or surface hardening processes before being press-fitted into the operating shaft. This preliminary action ensures the pin has the required durability and wear resistance before assembly, and the press-fit connection provides a secure permanent joint that eliminates the need for additional fastening operations during final assembly

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The pin is integrated with the operating shaft through a press-fit connection, merging two separate components into a unified assembly. This combining approach provides the benefits of separate manufacturing and hardening while achieving a compact, reliable connection that functions as a single unit during operation

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3862591B1An actuation mechanism
Publication Date: 2022.12.14 MERITOR HEAVY VEHICLE BRAKING SYSTEMS (UK) LIMITED
  • EP3862591B1 patent drawingFigure 1
  • EP3862591B1 patent drawingFigure 2
  • EP3862591B1 patent drawingFigure 3~4

AI summary

An operating shaft for a disc brake, the operating shaft comprising: opposed pairs of arcuate surfaces arranged with offset axes of rotation, one arcuate surface of each pair adapted to be grounded to a housing of the disc brake and the other arcuate surface of each pair adapted to transmit an actuating force to a brake pad of the disc brake upon rotation of the operating shaft; a recess intermediate the pairs of arcuate surfaces for accommodating a portion of a wear adjuster mechanism; and a pin adapted to engage a corresponding input driving portion of the wear adjuster mechanism, the pin extending from the operating shaft at a non-zero angle with respect to the axes of rotation and a direction of force transmission.