Overrunning Decoupler Helical Spring Torsional Damping
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Solution Overview
Problem
Existing over-running decouplers in drive systems fail to effectively inhibit resonant conditions and provide adequate torsional damping, especially during acceleration or deceleration of the source of rotary power relative to the driven component, leading to torsional loads and vibrations.
Innovation Solution
A decoupler design incorporating a one-way clutch and torsional damper formed by a single helical coil spring, which allows for the decoupling and recoupling of driven components to manage torsional loads and inhibit resonant conditions by using a helical coil spring that expands and contracts in response to torque changes, providing both damping and clutch functionality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a conventional over-running decoupler with torsionally resilient coupling is used, then decoupling functionality is provided, but resonant conditions are not effectively inhibited and torsional damping is inadequate
Solution Approach 1:
The patent combines the one-way clutch mechanism and torsional damper into a single integrated decoupler assembly. The clutch assembly includes clutch plates, springs, and damping elements that work together to provide both decoupling and torsional damping functions simultaneously, resolving the contradiction by merging multiple functions into one device rather than using separate components.
Solution Approach 2:
The patent employs adjustable damping parameters through selectable spring rates and damping coefficients. The decoupler includes multiple springs with different rate characteristics and damping elements that can be configured to change the torsional damping parameters, allowing optimization of resonant inhibition while maintaining decoupling functionality without increasing structural complexity.
2Device complexity
If the decoupler uses a single helical coil spring for both clutch and damping, then device complexity is reduced, but manufacturing precision requirements increase
Solution Approach 1:
The single helical coil spring is designed to perform multiple functions simultaneously: it acts as both the clutch spring and the torsional damper. The spring's geometry, material properties, and placement are optimized to provide clutch engagement forces and torsional damping in one component, reducing device complexity while the patent specifies precise manufacturing parameters to ensure both functions are achieved with adequate precision.
3Reliability
If the natural frequency is tuned below engine firing frequency to prevent resonance, then resonant conditions are inhibited, but the torque capacity range is limited
Solution Approach 1:
The decoupler employs dynamic elements including progressive spring rates and variable damping characteristics that allow the system to adapt to different operating conditions. The natural frequency is tuned below engine firing frequency to prevent resonance, while the progressive spring rate and multiple damping elements enable the torque capacity to increase with operating conditions, resolving the contradiction between resonance inhibition and torque capacity range.
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 decoupler effectively reduces torsional vibrations and prevents resonance by tuning the natural frequency of the system below the engine's firing frequency, enhancing the torque capacity and operational stability of the drive system.
Implementation Method 1
a one-way clutch and torsional damper formed by a single helical coil spring that is disposed coaxially about the rotational axis of the decoupler between the first drive member and the second drive member
Implementation Method 2
The single helical coil spring is configured to engage the first and second drive surfaces and to expand and contract in response to torque changes
Implementation Method 3
an over-running decoupler is employed to dampen fluctuations in the torsional load transmitted from the source of rotary power to the driven component
Data Source
AI summary
A decoupler having an input member, an output member and a combination one-way clutch and torsional isolator that couples the input and output members. The combination one-way clutch and torsional isolator includes a single helical coil spring. The decoupler being designed to provide torsional damping through a range of torque transmitted through the decoupler, the range including a maximum rate torque for the decoupler.