Parallel Dual Mass Flywheel Spiral Spring Damping
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Solution Overview
Problem
Existing dual mass flywheels struggle to achieve a compact configuration while effectively decoupling torque fluctuations and reducing torsional vibrations in compact internal combustion engines with limited cylinders, which requires improved performance to manage increased torque fluctuations.
Innovation Solution
A dual mass flywheel design featuring a parallel configuration of a resilient spiral spring unit and a damping unit, where the spiral spring is loaded differently based on torque direction and includes a gap that activates additional damping torque above a predefined level, with dry friction damping devices and abutments to manage torque transfer efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a dual mass flywheel uses a series configuration of elastic and damped stages, then the decoupling performance is improved, but the device complexity and manufacturing costs increase
Solution Approach 1:
The patent merges the elastic and damped stages into a parallel configuration where both stages work simultaneously rather than in series. This combines the functions of torque fluctuation dampening and vibration reduction in a single integrated structure, reducing the number of separate components and simplifying the overall device while maintaining effective decoupling performance.
Solution Approach 2:
The flywheel is segmented into distinct functional zones: the resilient unit with spiral springs for elastic deformation, the damping unit with friction elements for energy dissipation, and the connection elements. This segmentation allows each component to be optimized independently for its specific function while working together in parallel to achieve overall decoupling.
2Volume of moving object
If the flywheel is designed for compact configuration, then the space requirement is reduced, but the ability to dampen torque fluctuations and reduce torsional vibration is compromised
Solution Approach 1:
The spiral springs are arranged in a parallel configuration around the flywheel's axis, utilizing the radial and axial dimensions efficiently. This three-dimensional arrangement allows multiple spring elements to occupy compact space while collectively providing sufficient elastic compliance to dampen torque fluctuations without increasing the flywheel's overall volume.
Solution Approach 2:
The flywheel employs composite construction combining resilient materials for the spiral springs, damping materials for the friction elements, and rigid materials for the mass components. This composite approach allows each material to be optimized for its specific function while the combined structure achieves both compact size and effective vibration dampening within the same volume.
3Use of energy by moving object
If the number of cylinders is reduced to lower fuel consumption, then the engine efficiency is improved, but the torque fluctuations of the crankshaft are increased
Solution Approach 1:
The resilient unit with spiral springs is designed to anticipate and absorb torque fluctuations before they propagate through the drivetrain. The springs are pre-loaded and positioned to immediately respond to torque variations from the reduced-cylinder engine, dampening the force variations at their source rather than addressing them downstream.
Solution Approach 2:
The dual mass flywheel acts as an intermediary between the crankshaft and the drivetrain, with the resilient and damped units serving as mediators that decouple the direct connection. This intermediary structure absorbs and dissipates the increased torque fluctuations from the compact engine before they reach the transmission system, protecting the drivetrain while allowing the engine to operate with fewer cylinders for better fuel efficiency.
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 achieves efficient decoupling and damping of torsional vibrations, enhancing fatigue life and manufacturing simplicity while maintaining effective torque transfer, with improved damping during resonance conditions and reduced manufacturing costs.
Implementation Method 1
a spiral spring unit (6) to resiliently couple primary flywheel mass (2) to secondary flywheel mass (4)
Implementation Method 2
spiral spring unit (6) is constrained such to be loaded from a positive to a negative tension load depending from the torque direction
Implementation Method 3
a damping unit (7) arranged in parallel to spiral spring unit (6)
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A flywheel comprises a first flywheel mass (2) for connection with a crankshaft, a second flywheel mass (4) for connection with a gearbox, a spiral spring unit (6) for resiliently connecting primary and secondary flywheel mass (2, 4), a damping unit (7) in parallel to said spiral spring unit (6) with respect to second flywheel mass (4), and a gap (8) provided to increase the damping torque of damping unit (7) acting between said primary and secondary flywheel mass (2, 4) at a predefined angular displacement of primary flywheel mass (2) with respect to secondary flywheel mass (4).