Switchable Clutch Assembly Wedge Segments Hybrid Torque Transfer
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Solution Overview
Problem
In hybrid vehicles, the fixed connection between the torque converter, flexplate, and engine prevents the electric motor from driving the transmission without backdriving the engine, reducing efficiency, as the engine is always connected to the torque converter.
Innovation Solution
A switchable clutch assembly is integrated between the engine and torque converter, featuring a wedge clutch with radially expandable and contractable wedge segments, allowing selective disconnection and reconnection of torque transfer, enabling the electric motor to drive the transmission without backdriving the engine.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the engine is fixedly connected to the torque converter via flexplate, then torque transfer is reliable and simple in structure, but the electric motor cannot drive the transmission independently, reducing vehicle efficiency
Solution Approach 1:
The clutch assembly transitions from a static fixed connection to a dynamic switchable connection. The wedge clutch mechanism can selectively engage or disengage torque transfer between the engine and torque converter, allowing the system to adapt between different operating modes (engine-driven, motor-driven, or combined). This dynamic capability enables the electric motor to drive the transmission independently when the clutch is disengaged.
Solution Approach 2:
The clutch assembly acts as an intermediary device between the engine and torque converter. By introducing this intermediate component, the system gains the ability to control torque flow selectively. The wedge clutch segments serve as the mediating element that can either transmit or block torque, enabling independent motor operation while maintaining the option for engine connection when needed.
2Productivity
If a switchable clutch is added between engine and torque converter, then the electric motor can drive the transmission independently, but the device complexity increases
Solution Approach 1:
The clutch mechanism is segmented into multiple wedge-shaped segments that can independently engage or disengage. This segmentation allows for a compact design where multiple functional elements are distributed around the torque transfer path. The segmented structure enables controlled torque transfer while maintaining relative simplicity in each individual segment's design.
Solution Approach 2:
The traditional multi-component friction clutch mechanism is replaced with a wedge-based mechanical system. The wedge segments utilize geometric shape and mechanical advantage to achieve engagement and disengagement with simpler actuation. This substitution reduces the number of friction surfaces, springs, and adjustment mechanisms typically found in conventional clutches, thereby improving efficiency while controlling 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 clutch assembly allows for efficient operation by enabling the electric motor to drive the transmission independently of the engine, improving vehicle efficiency by allowing torque to be selectively transferred between the engine and torque converter.
Implementation Method 1
The wedge segments are configured to collectively radially expand and contract to selectively transfer torque between the first plate and the second plate
Data Source
AI summary
A clutch assembly for selectively transmitting torque between an engine and a torque converter is provided. A first plate is non-rotatably connected to a torque converter cover. A second plate is configured to receive a torque input from an engine. A wedge clutch is disposed axially between the first and second plates and is configured to selectively transfer torque between the first plate and the second plate. The wedge clutch includes wedge segments that are configured to collectively radially expand and contract to selectively transfer torque between the first plate and the second plate.