Disc Brake Guide Pin Geometry for Low-Wear Sliding Contact
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The geometry of conventional guide pins and sliding bores in disc brakes results in limited line contact, leading to high stress, wear, noise, and material restrictions, which restricts the use of suitable materials and affects the sliding action of the brake caliper.
Innovation Solution
A guide assembly with a guide pin and sliding bore featuring a polygonal cross-sectional profile, providing multiple face mating interfaces to increase contact area, reduce stress and wear, and enhance sliding action, allowing for the use of lighter, cheaper materials with better noise damping characteristics.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a conventional circular guide pin and sliding bore arrangement is used, then the structure is simple and easy to manufacture, but the contact area is limited to line contact resulting in high stress and wear
Solution Approach 1:
The guide pin is designed with a polygonal cross-sectional profile (square, rectangular, triangular, hexagonal, or octagonal) instead of a conventional circular profile. This asymmetric geometry creates multiple flat pin faces that mate with corresponding bore faces in the sliding bore, transforming the contact from line contact to face-to-face contact. This increases the contact area between the guide pin and sliding bore, thereby reducing stress and wear while maintaining structural simplicity.
2Reliability
If a circular guide pin with line contact is used, then the manufacturing is simple, but the stress and wear rates are high
Solution Approach 1:
The polygonal cross-sectional profile with multiple flat faces increases the contact area from line contact to face-to-face contact. This distributes the load across larger surface areas, significantly reducing stress concentrations and wear rates. The increased contact area also improves damping characteristics and reduces noise from rattling, while the geometry remains simple enough for easy manufacturing using conventional processes.
3Stress or pressure
If a circular guide pin is used, then the structure is conventional and proven, but the contact geometry leads to high stress concentrations
Solution Approach 1:
The guide pin employs a polygonal cross-sectional profile (square, rectangular, triangular, hexagonal, or octagonal) instead of a circular profile. This creates multiple flat pin faces that provide face-to-face contact with the sliding bore, distributing stresses uniformly across larger contact areas. This eliminates the stress concentrations inherent in circular line-contact geometries, improving the reliability and service life of the disc brake assembly.
4Object-affected harmful factors
If line contact between guide pin and sliding bore is used, then the structure is simple, but the damping is insufficient leading to noise
Solution Approach 1:
The polygonal cross-sectional profile with multiple flat faces creates extensive face-to-face contact between the guide pin and sliding bore. This large contact area significantly increases damping capacity, reducing noise from rattling and vibration during brake operation. The flat faces provide stable mating surfaces that suppress unwanted vibrations while maintaining simple manufacturing processes.
Data Source
AI summary
A guide assembly for a disc brake and a method of arrangement. The guide assembly includes a guide pin and a sliding bore that receives the guide pin. A first face mating interface of the sliding bore may define a first sliding interface between the guide pin and the bore.