Stepped Piston Footing for Disk Brake Force Distribution
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Increasing the braking force in disk brake systems for larger and heavier vehicles poses challenges, such as uneven wear and operational problems due to increased pressure or piston diameter, and integrating a parking brake system with multiple pistons leads to issues like binding and uneven wear.
Innovation Solution
A piston design with a footing that distributes force over a larger area of the brake pad, utilizing a spindle, spindle nut, and ball ramp actuator to exert force, and incorporating a seal to prevent debris entry, which helps in maintaining uniform wear and reducing operational issues.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the piston diameter is increased to achieve greater braking force, then the braking force increases, but the width of the brake pad and other system dimensions limit further increases
Solution Approach 1:
The patent transitions from increasing piston diameter (2D area increase) to extending the footing length beyond the piston width (1D linear extension). This allows the force distribution area to increase in the longitudinal dimension rather than being constrained by the transverse dimension, effectively resolving the spatial limitation while maintaining force multiplication capability
Solution Approach 2:
The patent separates the force application function into two distinct components: the piston body (for force generation) and the extended footing (for force distribution). This segmentation allows the footing to extend beyond the piston boundaries to increase the contact area with the brake pad, thereby distributing the braking force over a larger area without requiring a larger piston diameter
2Force
If the pressure at the piston is increased to achieve greater braking force, then the braking force increases, but the brake pad becomes distorted due to highly localized force
Solution Approach 1:
The patent extends the footing in the longitudinal dimension beyond the piston width, transforming the force distribution from a concentrated circular area (piston cross-section) to an elongated rectangular area. This dimensional extension increases the force distribution area by a factor of 1.5 to 2 times, significantly reducing pressure concentration and preventing brake pad distortion while maintaining high braking force
Solution Approach 2:
The patent creates a localized extension (the footing) with different geometric properties than the piston body. This extended footing specifically addresses the local need for force distribution at the brake pad interface, while the piston body maintains its compact structure for hydraulic actuation. The footing's extended geometry provides the necessary force distribution capability without altering the piston's core function
3Force
If multiple pistons are used to increase braking force, then the braking force increases, but integrating a parking brake system becomes complex with issues like binding and uneven wear
Solution Approach 1:
The patent designs a single piston assembly that performs multiple functions: service braking (through hydraulic actuation) and parking brake application (through the ball ramp actuator mechanism). This multi-functional design eliminates the need for separate pistons for different brake functions, simplifying the overall system while maintaining the capability to generate sufficient braking force for both service and parking brake operations
Solution Approach 2:
The patent merges the service brake and parking brake actuation mechanisms into a single piston assembly. The ball ramp actuator is integrated within the piston structure, allowing both braking functions to be accomplished through one unified component rather than requiring multiple separate pistons. This integration reduces system complexity and eliminates issues associated with coordinating multiple pistons
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 piston design effectively increases braking force while minimizing uneven wear and operational problems, ensuring consistent brake performance and improved durability.
Implementation Method 1
ball ramp actuator located between the end wall and the spindle nut and configured to push against the end wall and the spindle nut during operation of the disk brake system
Implementation Method 2
incorporating a seal to prevent debris entry
Implementation Method 3
the footing distributes force over a larger area of the brake pad... the face having a length and a width, wherein the length is longer than an outside width of the body
Data Source
AI summary
A piston configured for use in a brake system is disclosed. The piston can comprise: a body; and a footing; the footing positioned adjacent an end of the body, and having a recess that receives a central portion of the end; during operation of the brake system, the footing extends along a brake pad, and is configured to exert force on the brake pad during actuation of the disk brake system; and the footing having a face configured to contact the brake pad, the face having a length and a width, wherein the length is longer than an outside width of the body, and the length is greater than the width, and/or the face having a cross-sectional area normal to a direction of travel of the piston that is larger than a cross-sectional area of the piston body that is normal to the direction of travel of the piston.