Brake Rotor Tone Ring Rivet Attachment
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Solution Overview
Problem
Securing a tone ring to a brake rotor is challenging due to different thermal expansion rates and coefficients of thermal expansion between materials, leading to disengagement issues from press-fit, snap-fit, or threaded fasteners, and increased manufacturing complexity and cost.
Innovation Solution
A brake rotor assembly using a rivet to fixly secure the tone ring, where the rivet is inserted through aligned holes in the mounting flange and tone ring, and then upset to expand and create a secure contact with both the brake rotor and tone ring, providing a robust and vibration-resistant attachment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If press-fit or snap-fit is used to secure the tone ring, then assembly is simple, but the tone ring is susceptible to disengagement due to thermal growth differences
Solution Approach 1:
The tone ring is segmented into multiple sections with individual fasteners, allowing each segment to be independently secured to the brake rotor. This segmentation enables the fasteners to distribute thermal and mechanical stresses, preventing disengagement while maintaining assembly simplicity through modular installation
Solution Approach 2:
The patent employs fasteners with specific material properties and geometric parameters designed to accommodate thermal expansion differences between the tone ring and brake rotor. The fasteners are engineered with controlled elasticity and thermal characteristics that allow them to maintain clamping force across temperature variations, securing the tone ring reliably without complex assembly procedures
2Strength
If threaded fasteners are used to secure the tone ring, then clamp load can be increased, but the fasteners are susceptible to loosening due to vibration and thermal loading
Solution Approach 1:
The patent extracts the threading function from the fastener design, using smooth-bored fasteners without threads. Instead of relying on threaded engagement, the fasteners create friction-based clamping through precise bore fitting and controlled deformation during installation. This eliminates the loosening susceptibility of threaded fasteners while maintaining adequate clamp load through optimized fastener geometry and material properties
Solution Approach 2:
The fasteners feature rounded or curved contact surfaces that distribute clamping forces more uniformly across the tone ring and brake rotor interfaces. The curved geometry helps accommodate thermal expansion and vibration-induced movements, preventing stress concentration that would lead to fastener loosening while maintaining consistent clamp load
3Strength
If welding is used to secure the tone ring, then structural strength is improved, but package space and weight increase
Solution Approach 1:
The patent replaces the welding process with a mechanical fastening system using precision-bored fasteners. This substitution eliminates the need for additional weld material and the associated weight increase, while achieving comparable or superior structural strength through optimized mechanical interlocking. The fasteners are designed to distribute loads effectively without adding the excess weight of weld deposits and reinforcement structures
4Reliability
If complex tolerancing and machining are used to prevent disengagement, then tone ring retention is improved, but manufacturing cost and complexity increase
Solution Approach 1:
The patent designs the fasteners to serve multiple functions simultaneously: securing the tone ring, accommodating thermal expansion, distributing mechanical loads, and compensating for manufacturing tolerances. This multi-functionality is achieved through carefully selected material properties and geometric features that provide retention reliability without requiring complex tolerancing or specialized machining processes
Solution Approach 2:
The patent applies localized quality enhancements at critical interfaces, such as precision-bored holes in the brake rotor and corresponding features in the tone ring. Rather than requiring complex tolerancing throughout the entire assembly, only the fastener interface areas require precise machining, while other areas can use standard tolerances. This localized approach maintains tone ring retention while significantly reducing overall manufacturing complexity and cost
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 rivet-based attachment method effectively secures the tone ring to the brake rotor, resisting mechanical, thermal, and vibration loads, while avoiding the limitations of other fastening techniques, such as loosening and oxide jacking, and simplifying manufacturing processes.
Implementation Method 1
The rivet is upset to expand and create a secure contact with both the brake rotor and tone ring
Data Source
AI summary
A brake rotor assembly and a method of assembly. The brake rotor assembly includes a brake rotor, a tone ring, and a rivet. The rivet is disposed in a hole in the brake rotor and a hole in the tone ring and fixedly secures the tone ring to the brake rotor.