Self-Energizing Disconnect Actuator for Fast AWD Shaft Decoupling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Traditional AWD vehicles suffer from reduced fuel efficiency due to continuously engaged driveline components, and existing disconnect systems require high current, are complex, and have slow response times, often needing external power sources.
Innovation Solution
A self-energizing electromagnetic disconnect system using a coil and cam mechanism that converts rotational motion into axial motion to engage and disengage driveline components, eliminating the need for external motors and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If spring force is used to return the arm to the open position, then the mechanism can reset automatically, but the spring force may be insufficient to overcome friction and ensure reliable resetting
Solution Approach 1:
The system uses the electromagnetic force generated during normal operation to perform the resetting function. The electromagnetic actuator generates sufficient force to overcome spring force and friction, pushing the arm back to the open position without requiring a separate powerful spring mechanism.
Solution Approach 2:
The system dynamically switches between two modes: during normal operation, the electromagnetic actuator provides controlled force; during resetting, the same actuator dynamically generates high force to overcome the spring and ensure reliable arm return, adapting its output based on operational requirements.
2Device complexity
If a simple electromagnetic actuator is used, then the device complexity is reduced, but the actuator may not generate sufficient force to push the arm against a powerful spring
Solution Approach 1:
The electromagnetic actuator serves dual functions: normal position control and high-force resetting. By utilizing the existing electromagnetic infrastructure to generate resetting force, the system avoids adding separate high-force mechanisms, maintaining simplicity while achieving sufficient force through self-reinforcement.
Solution Approach 2:
The patent combines the resetting function with the existing electromagnetic actuator rather than using a separate mechanism. The same electromagnetic components that control normal operation are also used to generate the high force needed for resetting, merging two functions into one system.
3Reliability
If high spring force is used to ensure reliable arm return, then resetting reliability improves, but the force required to close the switch during normal operation increases
Solution Approach 1:
The system dynamically adjusts force requirements: during normal operation, only minimal force is needed to close the switch; during resetting, the electromagnetic actuator dynamically generates high force to overcome the spring. This dynamic capability allows reliable arm return without permanently increasing normal operation force requirements.
Solution Approach 2:
The electromagnetic actuator operates in periodic cycles: normal operation mode for most of the time requiring minimal force, and resetting mode periodically when high force is needed to overcome the spring and return the arm. This periodic high-force action ensures reliability without continuous high force requirements.
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 system achieves fast engagement and disengagement of AWD components, reducing power consumption, complexity, and package size while enhancing fuel efficiency by utilizing vehicle power and inertia.
Implementation Method 1
an electromagnetic actuator that generates electromagnetic force to push the arm against the spring force, thereby opening the switch
Implementation Method 2
a spring that biases the arm toward the closed position
Data Source
Figure 1
Figure 2A
Figure 2B
AI summary
A disconnect system (32) for selectively engaging and disengaging one or more shafts of a power train unit. The disconnect system includes a plurality of cam members (40, 42) and an electromagnetic coil (36). At least one cam member rotates at the same speed as an input shaft. At least one cam member rotates at variable speeds. In operation, the electromagnetic coil is energized by rotation of the input shaft (46) for selectively activating a clutch (38) to engage one or more of the cams (40, 42) to connect and disconnect one or more output shafts (48).