Active Differential Clutch for VDC Torque Biasing
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Solution Overview
Problem
Current four-wheel drive systems face a trade-off between maintaining compatibility with brake-based vehicle dynamic control (VDC) systems and achieving good traction and stability, while also striving for fuel efficiency, due to the passive nature of existing torque biasing systems.
Innovation Solution
A compact four-wheel drive powertrain coupling with a planetary gear set and a modulating biasing clutch assembly, featuring an electrical clutch operator and interleaved clutch plates, is designed to selectively couple input and output members, ensuring compatibility with VDC systems and maintaining beneficial torque biasing.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a passive friction based torque biasing system is used, then traction and stability are maintained, but compatibility with VDC systems deteriorates
Solution Approach 1:
The patent replaces the passive friction-based mechanical torque biasing system with an active electronically-controlled clutch assembly. The electrical operator (motor or solenoid) actuates the clutch to selectively engage and disengage the torque biasing mechanism, allowing dynamic control that is compatible with VDC systems while maintaining traction and stability when needed.
Solution Approach 2:
The invention transforms the static, passive torque biasing system into a dynamic, actively controlled system. The clutch assembly can be selectively engaged or disengaged based on driving conditions and VDC system requirements, enabling the torque biasing characteristic to change from fixed to variable, thus resolving the contradiction between maintaining traction and achieving VDC compatibility.
2Reliability
If a torque biasing system is added to maintain traction and stability, then vehicle control is improved, but fuel efficiency deteriorates
Solution Approach 1:
The active clutch-based torque biasing system operates periodically or intermittently rather than continuously. The clutch is engaged only when torque biasing is needed for traction or stability, and disengaged during normal operation to minimize energy consumption, thus improving fuel efficiency while maintaining vehicle control when required.
Solution Approach 2:
The system uses the vehicle's existing electrical system and control architecture to operate the clutch, leveraging available resources rather than requiring a dedicated continuous power source for torque biasing, thereby reducing overall energy consumption.
3Adaptability or versatility
If an active controlled torque biasing system is used, then compatibility with VDC systems is improved, but device complexity increases
Solution Approach 1:
The clutch assembly serves multiple functions: it provides torque biasing when engaged and acts as a disconnect coupling when disengaged. This multi-functionality reduces the need for separate components, thereby managing complexity while achieving VDC system compatibility through active control capability.
4Use of energy by moving object
If a compact four-wheel drive system is designed, then fuel efficiency is improved, but torque biasing capability deteriorates
Solution Approach 1:
The invention extracts the torque biasing function from a continuously operating mechanical system and implements it as an selectively activated feature through the clutch assembly. This allows the four-wheel drive system to operate in a fuel-efficient mode during normal conditions while providing torque biasing capability on-demand when traction or stability is needed.
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 provides a compact, lightweight system that enhances torque biasing compatibility with VDC systems, maintaining traction and stability while improving fuel efficiency by actively controlling the torque distribution between the front and rear axles.
Implementation Method 1
The clutch assembly includes an electrical operator and a plurality of clutch plates, including a first clutch plate and a second clutch plate
Implementation Method 2
The coupling device has an input member, a first output member, a second output member, and a planetary gear set having a plurality of gears and a planetary gear carrier
Implementation Method 3
The first and second clutch plate are disposed adjacent to each other
Data Source
AI summary
A coupling device (16) for use in a motor vehicle has an input member (45), a first and a second output member (46, 47), and a planetary gear set (54, 56, 58, 62) having gears (56, 58, 62) and a planetary gear carrier (54). Each of the input member (45) and the first and second output members (46, 47) are coupled to one of the planetary gear carrier (54) and a gear (56, 58, 62) of the planetary gear set (54, 56, 58, 62). A modulating biasing clutch assembly (70) selectively applies a biasing force to two of the three members. The modulating biasing clutch assembly (70) has an electrical clutch operator (72, 78, 84), a first clutch plate (92) coupled to one of the three members and a second clutch plate (94) coupled to another of the three members.