Disc Brake Pad Clearance Control via Travel Limiting Arrangement
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Solution Overview
Problem
Existing disc brake systems for heavy-commercial vehicles face issues with brake pad wear and efficiency due to uneven rotor and pad wear, leading to unintentional contact between brake pads and the rotor, which increases fuel consumption and reduces brake pad life, and existing positive pad retraction systems are difficult to align and locate.
Innovation Solution
A disc brake system with a travel limiting arrangement that includes a locking element and guide rail to control the sliding of the brake pad assembly relative to the rotor, ensuring a predetermined clearance is maintained after a braking operation, thereby preventing unintended contact and optimizing pad wear.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If existing positive pad retraction systems are used to push brake pads away from the rotor, then pad clearance is improved, but the system becomes difficult to align and locate due to machining tolerances and cannot account for differential wear
Solution Approach 1:
The patent introduces an intermediate component (the adjustable positioning mechanism with locking element) that mediates between the brake pad assembly and the brake carrier. This intermediary allows for precise control of pad clearance while simplifying alignment requirements, as the mechanism can be adjusted to compensate for machining tolerances and differential wear between inboard and outboard pads.
2Power
If brake pads are allowed to slide freely on the rotor during braking operation, then braking effectiveness is improved, but unintentional contact occurs during non-braking operations due to vibration and cornering forces
Solution Approach 1:
The patent implements a dynamic positioning system where the brake pad assembly can slide freely during braking operations when force is applied, but automatically returns to and locks at a predetermined position during non-braking operations. The travel limiting arrangement with locking element enables this dynamic behavior, allowing full braking effectiveness while preventing unintentional contact during idle conditions.
3Ease of operation
If brake pads are pushed away from the rotor using rotor unevenness, then simple retraction is achieved, but unintentional contact occurs due to engine vibration and cornering forces
Solution Approach 1:
The patent employs a self-servicing mechanism where the brake pad assembly automatically returns to its rest position using the rotor's uneven surface during non-braking operations, and the travel limiting arrangement with locking element self-activates to prevent further movement. This maintains simplicity while reliably preventing unintentional contact, as the system uses existing operational forces rather than requiring additional active components.
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 system effectively inhibits excessive sliding of the brake pad assembly, maintaining optimal clearance and reducing wear, thus enhancing vehicle efficiency and extending brake pad life by preventing unintended contact between the brake pads and rotor.
Implementation Method 1
the first brake pad assembly being configured to slide relative to the guide surface in the axial direction
Implementation Method 2
a lock arrangement configured such that any sliding of the first brake pad assembly relative to the guide surface that is above a pre-determined amount, in the first direction, causes the lock arrangement to engage the guide surface and inhibit further sliding of the first brake pad assembly and the guide surface
Data Source
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AI summary
A disc brake (100) for a heavy commercial vehicle is provided. The disc brake comprises a brake carrier (101), a guide surface and a travel limiting arrangement (133a, 133b). The brake carrier receives a first brake pad assembly (103a) for contacting a rotor (104) having a central axis defining an inboard-outboard axial direction during a braking operation to slow the vehicle. The first brake pad assembly comprises a support plate (107a). The first brake pad assembly is configured to slide relative to the guide surface in the axial direction. The travel limiting arrangement (133a, 133b) engages the guide surface and is configured to inhibit any sliding of the first brake pad assembly relative to the guide surface that is above a pre-determined amount, in a first direction that is away from the rotor in the axial direction.