Two-Way Damper Tensioner for Engine Chain Timing Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional tensioners for closed loop power transmission systems in internal combustion engines fail to provide smooth transition from predominant tension conditions, leading to uneven load distribution and increased oscillations in cam and crankshaft timing, which can cause engine damage and performance issues.
Innovation Solution
A dual arm tensioner with a two-way damper that applies equal slip torque in both rotational directions, ensuring symmetrical tensioning of both strands of the chain by pivotally mounting the lower end of each tensioning arm to the engine and connecting the upper end via a linkage to a pivotally mounted tensioner between the arms, thereby maintaining uniform tension throughout the chain system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional tensioner is used to maintain chain tension, then chain tension is maintained, but oscillations in cam and crankshaft timing increase and load distribution becomes uneven
Solution Approach 1:
The tensioner is divided into two separate arms (first and second arms) that independently engage with different strands of the chain. Each arm can move independently to accommodate tension variations in its respective strand, allowing the tensioner to maintain stable timing while distributing load evenly across both chain strands.
Solution Approach 2:
Each arm of the tensioner is designed with specific engagement characteristics for its respective chain strand. The first arm engages the first strand while the second arm engages the second strand, allowing localized adaptation to the specific tension and motion requirements of each strand, thereby reducing overall oscillations and improving timing stability.
2Reliability
If a hydraulic tensioner is used to maintain chain tension, then chain tension is maintained, but the device complexity increases
Solution Approach 1:
The invention extracts and eliminates the hydraulic system from the tensioner design. Instead of using hydraulic pressure to maintain chain tension, the design relies on the mechanical properties of the two arms and their engagement with the chain strands, significantly reducing device complexity while maintaining tension control functionality.
Solution Approach 2:
The tensioner arms automatically adjust and maintain chain tension through their own mechanical movement and engagement with the chain strands. The system is self-regulating, requiring no external hydraulic power source or complex control mechanisms, thereby reducing device complexity while maintaining reliable tension control.
3Reliability
If a blade spring tensioner is used to control chain tension, then chain tension is maintained, but the mounting means increase device complexity and reduce adaptability
Solution Approach 1:
The invention removes the complex mounting bracket structure from the tensioner design. Instead of using a fixed bracket with multiple mounting points, the tensioner arms are directly engaged with the chain strands and pivot about a single axis, eliminating the need for complex mounting means and reducing device complexity.
Solution Approach 2:
The two-arm tensioner design can accommodate both chain strands simultaneously and adapt to different tension conditions in each strand. The same basic arm structure serves multiple functions: engaging the chain, maintaining tension, and accommodating tension variations, thereby reducing the need for additional mounting components and increasing adaptability.
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 two-way damper tensioner minimizes oscillations in cam and crankshaft timing, reduces wear on engine components, and maintains consistent tension, improving engine performance and extending engine life by balancing load distribution across the chain system.
Implementation Method 1
The tensioner acts as a two way damper in that it applies an equal amount of slip torque in both rotational directions of the tensioner
Data Source
AI summary
A tensioner for a power transmission system includes two tensioning arms operatively engaged with the strand of the chain or the belt of the power transmission system. The upper end of each tensioning arm is connected to a two way damper which is pivotally mounted between the upper ends of the tensioning arms. When a pre-determined chain tension overload threshold is reached, the amount of torque required to overcome the coefficient of friction the damper allows the tensioner to adjust the tension in the chain with minimal oscillations and minimal phase change variation.