Planetary Torque Converter Damper for Slip and NVH Reduction
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Solution Overview
Problem
Current torque converter assemblies in motor vehicle powertrains experience significant torsional vibrations and unwanted slip, leading to efficiency losses and increased noise, vibration, and harshness (NVH), which affect fuel economy and vehicle performance.
Innovation Solution
Integration of a planetary-type torsional vibration damper within the torque converter assembly, comprising a sun gear, ring gear, and planet carrier, which are securely attached to the turbine and clutch components, to mitigate torsional vibrations and reduce slip between the engine and transmission.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If a traditional torque converter assembly is used, then the basic torque transmission function is achieved, but significant torsional vibrations and unwanted slip occur leading to efficiency losses and increased NVH
Solution Approach 1:
The patent combines the torque converter and torsional vibration damper into a single integrated assembly. The damper is positioned between the impeller and turbine, merging two previously separate components (torque converter and damper) into one unified structure that simultaneously performs torque transmission and vibration damping functions, thereby reducing energy loss and NVH without requiring separate components
2Loss of energy
If a torque converter clutch is added to reduce slip, then mechanical lockup is achieved, but torsional vibrations are transmitted between engine and transmission
Solution Approach 1:
The integrated damper acts as an intermediary element positioned between the torque converter clutch and the turbine. When the clutch engages to reduce slip, the damper absorbs and attenuates the resulting torque-related vibrations, preventing them from being transmitted to the transmission. This intermediary damping mechanism allows the clutch to function effectively while blocking the transmission of harmful vibrations
3Object-generated harmful factors
If separate dampers are added to the torque converter assembly, then vibration damping is improved, but the size and complexity of the assembly increase
Solution Approach 1:
Rather than adding separate damper components to the torque converter assembly, the patent integrates the damping function directly into the torque converter structure. The damper is positioned within the existing assembly between the impeller and turbine, combining multiple functions into a single integrated unit that reduces vibration without increasing overall assembly 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 integrated damper effectively isolates and diminishes torque swings and vibrational excitation, reducing NVH, improving fuel efficiency, and minimizing the size and complexity of the damper assembly, while enhancing overall vehicle performance.
Implementation Method 1
a planetary-type torsional vibration damper... which are securely attached to the turbine and clutch components, to mitigate torsional vibrations and reduce slip between the engine and transmission
Data Source
AI summary
Presented are torque converters (TC) with planetary-type vibration dampers, methods for making/using such TC assemblies, and vehicles equipped with such TC assemblies. A TC assembly includes a TC housing drivingly connected to a prime mover to receive torque therefrom, and a TC output member drivingly connected to a transmission to transfer torque thereto. Rotatably mounted within an internal fluid chamber of the TC housing are juxtaposed turbine and impeller blades. The impeller blades are rotatably mounted to the housing. A TC clutch is operable to lock the TC housing to the TC output member. A torsional vibration damper, which is disposed within the internal fluid chamber, includes a sun gear attached to the TC output member for unitary rotation, a ring gear attached to the TC clutch for unitary rotation, and a planet carrier intermeshed with the ring and sun gears and attached to the turbine blades for unitary rotation.