Drum Brake Linkage Positioner Using Ball Ramp Clutch
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Solution Overview
Problem
Current linkage adjusters for drum brakes, particularly in heavy utility vehicles, face durability issues and are sensitive to friction conditions and production tolerances, leading to potential failure over time.
Innovation Solution
A linkage adjuster incorporating a ball ramp clutch preloaded by a pressure spring and a directional clutch as a clamping body freewheel, with components mounted on ball bearings, ensuring friction-independent functional behavior and robustness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Extent of automation
If a wrap spring one-way clutch is used in the linkage adjuster, then the adjuster can provide automatic adjustment functionality, but the component becomes susceptible to wear and friction conditions leading to failure over time
Solution Approach 1:
The patent changes the fundamental operating principle of the one-way clutch from friction-based (wrap spring) to geometry-based (ball ramp clutch). By using the ball ramp clutch with preloaded pressure spring, the adjustment mechanism achieves automatic adjustment functionality while eliminating friction wear on the clutch faces, thereby significantly improving reliability and durability over time.
2Device complexity
If traditional friction-based one-way clutch components are used, then the linkage adjuster can maintain simple structure, but the functional behavior becomes highly dependent on friction conditions and production tolerances
Solution Approach 1:
The invention transitions from friction-based clutch operation to geometry-based ball ramp clutch operation. The ball ramp clutch uses the geometric shape of the ramp surfaces and ball positioning to control clutch engagement and disengagement, making the functional behavior independent of friction conditions and production tolerances, thereby ensuring consistent and reliable operation.
Solution Approach 2:
The patent replaces the traditional friction-based mechanical clutch system with a ball ramp clutch system that utilizes geometric constraints and ball element positioning. This substitution eliminates the dependency on friction coefficients and allows for more precise control of clutch behavior through geometric design parameters.
3Reliability
If manual adjustment is performed at regular intervals, then the brake lining wear can be compensated, but the adjustment is not carried out according to requirements or continuously
Solution Approach 1:
The patent implements a self-service adjustment mechanism through the ball ramp clutch and associated automatic adjustment components. The system automatically detects and compensates for brake lining wear without requiring manual intervention, performing the adjustment continuously or as needed based on actual wear conditions rather than fixed intervals.
Solution Approach 2:
The linkage adjuster incorporates feedback mechanisms that monitor the position and wear state of brake linings. This feedback enables the automatic adjustment system to respond to actual wear conditions in real-time, ensuring adjustments are made according to requirements rather than predetermined schedules.
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 provides a linkage adjuster with precise, durable, and efficient operation, minimizing wear and maintaining functionality over time, with production benefits from non-cutting shaping processes.
Implementation Method 1
The overload clutch is configured as a ball ramp clutch that is preloaded by a pressure spring
Implementation Method 2
with components mounted on ball bearings, ensuring friction-independent functional behavior and robustness
Implementation Method 3
ensuring friction-independent functional behavior and robustness
Data Source
AI summary
A linkage positioner for a drum brake, which is used to compensate for braking-related wear, especially on the brake linings, has an overload clutch and a one-directionally rotating or one-way clutch. The overload clutch is embodied as a ball ramp clutch, which is biased by a pressure spring.