Pivoting Blade Spring Chain Tensioner for Vibration Damping
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Solution Overview
Problem
Existing chain tensioning mechanisms in internal combustion engines face challenges in maintaining consistent chain tension due to temperature fluctuations, wear, and torsional vibrations, leading to potential slippage and timing issues.
Innovation Solution
A compliant pivoting tensioning device with a resilient chain guide element and blade springs is used, where the blade springs are placed in a channel cut groove on the bracket body, applying a separating force to the chain guide element to maintain constant contact with the chain, and the device pivots to absorb energy waves, ensuring tension is maintained across the chain's design life.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydraulic tensioner with a rigid piston and pressure chamber is used, then the chain tension can be maintained under normal conditions, but the device cannot adequately respond to rapid fluctuations in chain tension caused by torsional vibrations and temperature variations
Solution Approach 1:
The patent replaces the rigid hydraulic piston system with a dynamic blade spring mechanism that can rapidly adapt to changing chain tension conditions. The blade spring's flexible structure allows it to dynamically respond to torsional vibrations and temperature-induced tension variations, providing both stability and adaptability simultaneously.
Solution Approach 2:
The invention changes the physical state of the tensioning element from a rigid, incompressible hydraulic system to a compliant elastic blade spring. This parameter change enables the system to absorb and respond to rapid tension fluctuations while maintaining reliable chain tension under normal operating conditions.
2Reliability
If a rigid lever arm is used to push against the chain, then the chain tension is maintained when slack, but the device cannot absorb energy waves and rapid tension increases
Solution Approach 1:
The blade spring is positioned and pre-loaded to provide cushioning before rapid tension increases occur. This beforehand cushioning allows the spring to absorb energy waves and impact forces from torsional vibrations before they can cause harmful effects on the chain tensioning system.
Solution Approach 2:
The patent employs a flexible blade spring instead of a rigid lever arm. This flexible element can deform to absorb energy waves and impact forces while maintaining chain tension control, directly addressing the harmful effects of torsional vibrations and rapid tension fluctuations.
3Reliability
If check valves are used to regulate fluid flow in the pressure chamber, then the no-return function is achieved, but the device complexity increases and response time to tension changes is delayed
Solution Approach 1:
The patent extracts and eliminates the complex valve mechanism from the tensioning system. By removing the check valves and hydraulic fluid regulation system, the invention achieves the one-way tensioning function through the inherent elasticity and geometry of the blade spring, significantly reducing device complexity and improving response time.
Solution Approach 2:
The invention replaces the hydraulic valve control system with a purely mechanical blade spring mechanism. The spring's elastic deformation and geometric configuration naturally provide the one-way tensioning function without requiring complex valve mechanisms, thereby reducing device complexity while maintaining reliability.
4Reliability
If a hydraulic tensioner with multiple components (piston, chamber, valves, fluid) is used, then chain tension can be regulated, but the device complexity and potential failure points increase
Solution Approach 1:
The patent merges multiple hydraulic components (piston, pressure chamber, valves, and fluid) into a single integrated blade spring element. This consolidation maintains the tension regulation capability while dramatically reducing the number of components and potential failure points in the system.
Solution Approach 2:
The blade spring performs multiple functions that were previously distributed across several hydraulic components: it provides tensioning force, absorbs energy waves, responds to rapid tension changes, and maintains one-way tensioning. This multi-functionality reduces device complexity while preserving reliability.
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 effectively maintains chain tension across new and worn chains, preventing slippage and tooth jumping by ensuring the chain guide element remains in contact with the chain, even under varying conditions, thus ensuring consistent engine operation.
Implementation Method 1
at least one blade spring, placed in the channel cut groove, applying a separating force to the chain guide element
Implementation Method 2
the device pivots to absorb energy waves, ensuring tension is maintained across the chain's design life
Data Source
AI summary
A tensioner for imparting tension to a chain having a body, a resilient chain guide element, at least one blade spring, and at least one bracket. The body of the tensioner has a surface with a profile of the path of a new chain and a groove found longitudinally along the length of the surface. The resilient chain guide element, on the surface of the body has a chain contact surface and two ends wrapped around the ends of the body, with the chain guide being sufficiently larger than the body, such that the chain contact surface is capable of being biased away from the body. The blade spring is present in the groove with its end in the containments means of the groove, biasing the chain guide out and away from the body. At least one bracket is fixedly attached to the body and has a pivot.