Dual Mass Flywheel Variable Stiffness Decoupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing dual mass flywheels face challenges in achieving a balance between decoupling angular fluctuations from the crankshaft and damping vibrations during resonance, particularly at the first natural frequencies of the drivetrain components, which affects the efficiency and fatigue life of drivetrain components like the clutch and gearbox.
Innovation Solution
A dual mass flywheel design featuring a torsionally resilient element with a spiral spring and compression coil springs arranged in series, along with a damping device, which provides variable stiffness and damping torque to effectively decouple and dampen vibrations, with specific geometrical features and configurations to optimize performance across different operating conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a dual mass flywheel uses a decoupling element with high torsional stiffness to effectively transmit torque, then the torque transmission efficiency is improved, but the decoupling performance deteriorates because angular fluctuations from the crankshaft are transmitted to the drivetrain components
Solution Approach 1:
The decoupling element is divided into multiple independent torsionally resilient elements (spiral springs) arranged circumferentially. Each spring independently contributes to torque transmission while providing decoupling, allowing the system to achieve both high torque transmission efficiency and effective angular fluctuation isolation through the combined action of multiple segmented elements.
Solution Approach 2:
The torsionally resilient elements are designed with optimized geometric parameters (wire diameter, mean coil diameter, active coils) to provide variable torsional stiffness characteristics. The springs exhibit nonlinear elastic behavior that adapts to different operating conditions, maintaining optimal decoupling performance across varying torque levels while ensuring efficient torque transmission.
2Object-affected harmful factors
If a dual mass flywheel uses a decoupling element with low torsional stiffness to improve decoupling performance, then angular fluctuations are better isolated, but the torque transmission efficiency deteriorates
Solution Approach 1:
Multiple torsionally resilient spiral springs are combined in parallel within the decoupling element. This merging of multiple elastic elements increases the overall torsional stiffness and torque transmission capacity while maintaining the decoupling function, as the combined action of multiple springs provides both isolation and efficient power transfer.
Solution Approach 2:
The decoupling element combines multiple spiral spring elements with different geometric characteristics to create a composite torsional system. This composite structure achieves an optimized balance between decoupling performance and torque transmission by leveraging the synergistic effects of multiple elastic elements with varying stiffness contributions.
3Reliability
If a dual mass flywheel adds a damping device to reduce vibrations during resonance, then the fatigue life of drivetrain components is improved, but the device complexity increases
Solution Approach 1:
The damping device is integrated with the existing spring loader and decoupling element structure. The damping mechanism is merged into the torsional vibration transmission path, allowing vibration damping functionality to be added without creating a completely separate system, thereby reducing the overall device complexity while maintaining effective vibration control.
Solution Approach 2:
A damping element is introduced as an intermediary component between the primary and secondary flywheel masses. This mediator absorbs and dissipates vibrational energy during resonance conditions, protecting drivetrain components from excessive vibrations while being integrated into the existing decoupling mechanism to minimize structural complexity.
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 design enhances decoupling performance below a predefined torque limit and provides efficient damping above this limit, reducing oscillation amplitudes and extending the fatigue life of drivetrain components by optimizing the design of stops, gaps, and spring rates, ensuring effective damping across the entire working range of the drivetrain.
Implementation Method 1
a torsionally resilient element (5) arranged in series between said primary flywheel mass (2) and said plurality of compression coil springs (4)... configured to transfer torsional load from springs attached to the primary flywheel mass to the springs attached to the secondary flywheel mass
Implementation Method 2
a plurality of compression coil springs (4) circumferentially arranged to obtain a torsional action on secondary flywheel mass
Implementation Method 3
compression coil springs torsionally connecting the primary flywheel mass with an intermediate spring loader
Implementation Method 4
a damping device is provided to dampen vibrations during torsional resonances occurring
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A flywheel (1) comprises a primary flywheel mass (2) suitable for being connected to a crankshaft of an internal combustion engine, a secondary flywheel mass (3), a decoupling spring unit (5) coupled to said primary flywheel mass (2), a spring loader (6) coupled to said decoupling spring unit (5) and a plurality of compression coil springs (4) arranged circumferentially to be loaded when said spring loader (6) and said secondary mass (3) angularly displace relative to each other, the overall torsional spring rate of said compression coil springs (4) being higher than that of said decoupling spring unit (5).