Floating Caliper Brake with Dual-Piston Pad Retraction
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Solution Overview
Problem
Floating caliper disc brakes experience residual drag torque due to the inability to actively control the position of the second pad relative to the brake disc, leading to unwanted contact and increased energy consumption, wear, and emissions.
Innovation Solution
A floating caliper disc brake design with independently actuable pistons allows for selective and sequential rearward movement to detach both friction pads from the brake disc, ensuring complete separation and minimizing residual drag torque.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If only the first pad position is controlled by elastic seal configuration, then the piston position can be passively adjusted (roll-back effect), but the second pad on the reaction side cannot be actively positioned and remains in contact with the disc generating residual drag torque
Solution Approach 1:
The single piston system is segmented into two independent pistons: a first piston for actuating the first friction pad and a second piston for positioning the second friction pad. This segmentation allows independent control of each pad's position relative to the brake disc, enabling complete detachment of both pads to eliminate residual drag torque while maintaining manageable system complexity through modular design
Solution Approach 2:
The second piston serves multiple functions: it positions the second friction pad relative to the brake disc, enables complete detachment of the second pad, and works in coordination with the first piston for synchronized pad retraction. This multi-functionality addresses the limitation of the conventional single-piston system while avoiding the need for entirely separate positioning mechanisms
2Reliability
If the second pad remains in contact with the disc to maintain braking force, then braking performance is ensured, but residual drag torque increases causing energy consumption and pad wear
Solution Approach 1:
The brake system implements periodic action by completely detaching both friction pads from the brake disc after braking events. The pistons are actuated to maintain contact during braking, then retracted to create separation afterward. This periodic engagement and disengagement ensures braking performance when needed while eliminating residual drag torque and associated energy losses during non-braking periods
Solution Approach 2:
The system dynamically changes the contact parameter between the friction pads and brake disc. During braking, the pistons are actuated to maintain pad-disc contact for reliable braking performance. After braking, the pistons retract to change the contact parameter to zero, completely separating the pads from the disc and eliminating residual drag torque, thereby reducing energy consumption and pad wear
3Productivity
If the caliper body slides to position pads opposite the brake disc, then clamping is achieved, but the second pad cannot be actively positioned to ensure complete detachment when braking is not required
Solution Approach 1:
The positioning function is segmented between two independent pistons rather than relying solely on caliper body sliding. The first piston maintains braking efficiency by actuating the first pad, while the second piston provides dedicated positioning control for the second pad. This segmentation enables complete detachment of both pads by allowing independent adjustment of each pad's position relative to the brake disc
Solution Approach 2:
The second piston acts as an intermediary element between the caliper body and the second friction pad. It provides the missing active positioning capability for the second pad that the floating caliper mechanism alone cannot achieve. By introducing this intermediary actuating element, the system gains precise control over the second pad's position while maintaining the simplicity of the floating caliper design
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
This design reduces pad wear, energy consumption, pollutant emissions, and enhances vehicle range while maintaining brake performance by eliminating residual drag torque.
Implementation Method 1
the position of the first pad on the piston side can be controlled to a given extent by the configuration and positioning of the elastic seal and its housing in the caliper body, which positions the (unbiased) piston elastically relative to the caliper (roll-back effect)
Implementation Method 2
one or more first and second friction pads supported by the supporting bracket and/or the caliper body on the first and second sides of the brake disc
Data Source
AI summary
A floating disc brake has a supporting bracket, a caliper body connected to the supporting bracket, a first friction pad on a first side of the caliper body, a second friction pad on a second side of the caliper body, fixed to the caliper body, a first piston connected to the first friction pad and a second piston that can freely rest on the first friction pad forming a positioning surface which can abut against a resting surface of the supporting bracket. The first and second pistons can be actuated independently so that a rearward movement of the first piston towards the first side detaches the first friction pad from the brake disc, and a rearward movement of the second piston towards the first side, with the positioning surface abutting against the resting surface moves the caliper body together with the second friction pad towards the second side and detaches the second friction pad from the brake disc.