Variable Stiffness Torsion Damper for Automatic Transmission Vibration
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Solution Overview
Problem
Transmissions with automatic gear change in motor vehicles face inefficiencies due to the size, mass, and high inertia of hydraulic torque converters, leading to increased fuel consumption and performance loss, along with higher costs.
Innovation Solution
A vibration filter with a variable stiffness torsion damper, incorporating helical springs and a torque limiter, is integrated into the transmission to filter vibrations and torque, reducing the need for large inertial components while maintaining efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydraulic torque converter is used to filter vibrations and multiply starting torque, then vibration filtering and torque multiplication are achieved, but the size, mass, and high inertia increase leading to higher fuel consumption and performance loss
Solution Approach 1:
The patent extracts the vibration filtering function from the hydraulic torque converter by implementing a separate torsion damper with elastic means. This separates the vibration damping function from the torque multiplication function, allowing the torque converter to be smaller and lighter while maintaining effective vibration filtering through the dedicated torsion damper assembly.
Solution Approach 2:
The patent employs a torsion damper with variable stiffness characteristics through its elastic means that can dynamically adapt to different operating conditions. The damper's stiffness varies with the amplitude of vibrations, providing optimal damping across different engine speeds and load conditions, thereby maintaining effective vibration filtering with reduced mass compared to a fixed-stiffness hydraulic torque converter.
2Reliability
If a hydraulic torque converter is used to filter vibrations, then vibration filtering is achieved, but the high inertia leads to increased fuel consumption
Solution Approach 1:
The patent extracts the vibration filtering function from the hydraulic torque converter by implementing a separate torsion damper with elastic means. This separates the vibration damping function from the torque multiplication function, allowing the torque converter to be smaller and lighter while maintaining effective vibration filtering through the dedicated torsion damper assembly.
Solution Approach 2:
The patent employs a torsion damper with variable stiffness characteristics through its elastic means that can dynamically adapt to different operating conditions. The damper's stiffness varies with the amplitude of vibrations, providing optimal damping across different engine speeds and load conditions, thereby maintaining effective vibration filtering with reduced mass compared to a fixed-stiffness hydraulic torque converter.
3Reliability
If a hydraulic torque converter is used to filter vibrations, then vibration filtering is achieved, but performance is lost due to size and mass
Solution Approach 1:
The patent extracts the vibration filtering function from the hydraulic torque converter by implementing a separate torsion damper with elastic means. This separates the vibration damping function from the torque multiplication function, allowing the torque converter to be smaller and lighter while maintaining effective vibration filtering through the dedicated torsion damper assembly.
Solution Approach 2:
The patent employs a torsion damper with variable stiffness characteristics through its elastic means that can dynamically adapt to different operating conditions. The damper's stiffness varies with the amplitude of vibrations, providing optimal damping across different engine speeds and load conditions, thereby maintaining effective vibration filtering with reduced mass compared to a fixed-stiffness hydraulic torque converter.
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 filters vibrations and torque, reducing fuel consumption, performance loss, and costs associated with hydraulic torque converters, while allowing for precise matching of inertias for engine balancing and gear ratios.
Implementation Method 1
a torsion damper (30) which comprises deformable elastic elements such as helical springs (34)
Implementation Method 2
a friction ring (40), which is applied, in the known way, by means of a spring ring on the face of the primary flywheel (10)
Implementation Method 3
The flexible flywheel versions lead to an upward change in the natural frequencies of the crankshaft, and, due to a reduced mass beyond excitation frequencies of order 2 produced by the engine rotating at high speeds
Data Source
AI summary
In a vibration filter for a transmission with automatic gear changing for a motor vehicle, including a torsion damper disposed between an input or driving element arranged to be driven in rotation by the crankshaft of the motor vehicle engine, and an output or driven shaft arranged to be coupled to an input shaft or driven shaft of the transmission, the torsion damper includes elastic means: the stiffness of the damper is variable and is obtained by virtue of the said elastic means, which are in the form of helical springs oriented substantially radially; the input element is a primary flywheel (10) which has at its radially inner periphery an axial flange (12) for supporting a bearing (13) which centers and guides in rotation a secondary inertial flywheel (20) constituting the output element.