Wedge Drum Brake Transmission Element Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing brake systems for commercial vehicles, particularly expanding wedge drum brakes, face challenges with large size requirements, complex production, and high assembly/disassembly efforts due to the need for numerous components and rolling elements, which increase space and weight while reducing efficiency.
Innovation Solution
A brake system design featuring a transmission element and a piston element with an inclined transmission surface, where the piston element is supported directly on the transmission surface, eliminating rolling bodies and allowing for reduced installation space and weight, with rounded surfaces to minimize sliding friction and wear, and a non-linear geometry to optimize force transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If rolling bodies and rolling element cages are used for power transmission between the wedge-shaped transmission element and the brake shoes, then the braking force transmission is reliable, but the brake system requires a very large amount of space and has complex production and assembly
Solution Approach 1:
The patent removes the rolling element cage and rolling bodies from the brake system, replacing them with a direct sliding contact between the wedge-shaped transmission element and the brake shoe. This extraction of unnecessary components significantly reduces the space requirement while maintaining the power transmission function through the inclined transmission surface geometry.
Solution Approach 2:
The patent substitutes the rolling element mechanism with a sliding contact mechanism. Instead of using rolling bodies that require cages and complex arrangements, the inclined transmission surface directly converts the axial displacement of the wedge element into radial displacement of the brake shoe through sliding friction, eliminating the need for rolling elements and their supporting structures.
2Reliability
If rolling bodies and rolling element cages are used for power transmission, then the braking force transmission is reliable, but the production complexity and assembly/disassembly effort increase significantly
Solution Approach 1:
The patent extracts and eliminates the rolling element cage and rolling bodies from the system, reducing the number of components that need to be manufactured, assembled, and maintained. The simplified design uses only the wedge-shaped transmission element with an inclined transmission surface and the brake shoe with a sliding surface, removing the complex rolling element assembly entirely.
Solution Approach 2:
The patent merges the functions of the transmission element and brake shoe into a direct sliding contact interface. The inclined transmission surface of the wedge element and the sliding surface of the brake shoe work together as an integrated power transmission system, eliminating the need for separate rolling elements and cages, thereby reducing component count and assembly complexity.
3Object-generated harmful factors
If the transmission surface and piston surface are designed with rounded geometry, then the sliding friction and wear are reduced, but the manufacturing precision requirements increase
Solution Approach 1:
The patent applies rounded geometry to both the transmission surface of the wedge element and the sliding surface of the brake shoe. This curvature reduces the contact stress and sliding friction by distributing the load over a larger area and minimizing stress concentrations, thereby reducing wear. The rounded surfaces also facilitate smoother relative motion between the components.
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 solution reduces the size and weight of the brake system, simplifies assembly, and enhances braking force transmission with reduced wear and sliding friction, achieving improved performance and efficiency.
Implementation Method 1
a lubricating film is introduced between the piston surface and the transmission surface, which reduces the sliding friction between the piston surface and the transmission surface
Implementation Method 2
Due to the inclined alignment of the transmission surface with respect to the transmission axis, a displacement of the transmission element along the transmission axis leads to a displacement of the piston element transversely to the transmission axis
Data Source
Figure 1a~1b
Figure 2
Figure 3
AI summary
The invention relates to a brake system, in particular a wedge-type drum brake for utility vehicles, comprising a transmission element and a piston element, wherein the transmission element is displaceably guided along a transmission axis, wherein the piston element is guided transversely to the transmission axis, wherein the transmission element has a transmission surface which is inclined with respect to the transmission axis, wherein the piston element is supported with a piston surface on the transmission surface, and wherein a displacement of the transmission element along the transmission axis causes a displacement of the piston element essentially transversely to the transmission axis.