Telescopic Adjusting Spindle for Compact Disc Brakes
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Solution Overview
Problem
Existing disc brakes for commercial vehicles are bulky and heavy due to long adjusting spindles required for maintaining a constant air gap between the brake lining and disc, leading to inefficient adjustment speed and potential operational issues.
Innovation Solution
A disc brake design featuring a telescopic adjusting spindle with an outer and inner tube, where the inner tube is held in a torsion-proof manner, allowing for shorter spindle length and improved adjustment speed, and a synchronizing device with drive wheels for synchronized adjustment, reducing the overall size and weight.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If long adjusting spindles are used to maintain constant air gap during brake lining wear, then the air gap remains stable, but the disc brake becomes bulky and heavy
Solution Approach 1:
The adjusting spindle is designed as a telescopic structure with movable sections that can extend and retract. During braking operation, the spindle automatically adjusts its length to maintain the constant air gap between brake lining and disc, while in non-operational state it retracts to minimize space and weight. This dynamic adjustment mechanism eliminates the need for permanently long spindles.
Solution Approach 2:
The adjusting spindle is divided into multiple sections or segments that can move relative to each other. These segmented parts allow the spindle to extend when adjustment is needed and retract when not in use, providing the functionality of a long spindle without the permanent weight and space penalty.
2Strength
If small pitch thread is used in adjusting spindle, then adequate hold in bridge is achieved, but adjustment speed becomes relatively low
Solution Approach 1:
The telescopic adjusting spindle incorporates a dynamic thread mechanism where the effective pitch can vary during operation. The spindle uses a differential thread design with different pitch sections - a fine pitch section for strong engagement with the bridge and a coarse pitch section for rapid adjustment movement, optimizing both strength and speed requirements simultaneously.
Solution Approach 2:
The thread structure is segmented into multiple zones with different pitch characteristics. The first zone has a small pitch for strong holding capability when engaged with the bridge, while subsequent zones have progressively larger pitches that enable faster adjustment movement, thus combining both strength and productivity requirements in a single threaded connection.
3Force
If pressure pieces rotate relative to brake components, then braking force transmission occurs, but indeterminable operating behavior and functionality restriction risk arise
Solution Approach 1:
A synchronization device acts as an intermediary mechanism between the adjusting spindle and the pressure pieces. This device includes drive wheels that engage with the adjusting spindle threads and transmit rotational motion to the pressure pieces in a controlled manner, ensuring predictable and deterministic operation while maintaining effective braking force transmission.
Solution Approach 2:
The synchronization device incorporates a feedback mechanism through engaged drive wheels that monitor and control the rotational position of pressure pieces relative to the adjusting spindle. This feedback ensures that the pressure pieces rotate only to the extent required for proper braking force transmission, preventing indeterminate operating behavior and maintaining system reliability.
4Weight of stationary object
If minimizing disc brake size is pursued, then weight reduction occurs, but adequate spindle hold length becomes difficult to achieve
Solution Approach 1:
The adjusting spindle uses a telescopic design that dynamically adjusts its effective length based on operational requirements. When the disc brake is compact and not in adjustment mode, the spindle retracts to its minimum length, achieving weight reduction and space savings. When adjustment is required, the spindle extends to provide adequate hold length for maintaining the constant air gap, thus resolving the contradiction between size minimization and functional requirements.
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 results in a more compact, lighter disc brake with enhanced adjustment speed and increased service life, reducing fuel consumption and operational risks.
Implementation Method 1
The adjusting spindles have an external thread and are each screwed into a threaded hole in the bridge
Implementation Method 2
The corresponding threads of the outer and inner tubes are preferably in the opposite direction to the corresponding threads of the outer tube/bridge
Implementation Method 3
to prevent rotation, only the frictional forces occurring between the threads in the circumferential direction have to be held
Data Source
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AI summary
A disc brake for a commercial vehicle comprising a) a brake caliper overlapping a brake disc, b) a clamping device arranged in the brake caliper for pressing brake pads against the brake disc, c) at least one adjusting spindle (3) which is rotatably mounted in a bridge (1) on which the clamping device engages by means of a corresponding thread, d) an adjusting device positioned in the brake caliper with which a wear-related change in the clearance between the brake pad and the brake disc can be substantially compensated by means of an axial adjustment of the adjusting spindle (3), is designed such that e) the adjusting spindle (3) is designed as a telescopic spindle.