MR Fluid Clutch Coupling for Smooth Human-Hybrid Powertrains
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional human-hybrid powertrains face challenges in seamlessly integrating human power with additional power sources, particularly due to low bandwidth and high inertia issues, leading to inefficient torque transmission and discomfort during use.
Innovation Solution
The implementation of magnetorheological (MR) fluid actuators and clutches to selectively connect and disconnect power sources, allowing for variable torque transmission and adaptation to user input, thereby enhancing the powertrain's bandwidth and responsiveness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If conventional clutch systems (centrifugal or one-way) are used to connect additional power source to human power, then the system can provide power assistance, but the engagement and disengagement is not smooth causing user discomfort and the system has low bandwidth
Solution Approach 1:
The patent replaces conventional mechanical clutch systems (centrifugal or one-way clutches) with a magnetorheological (MR) fluid-based clutch system. The MR fluid clutch uses magnetic field control to vary the coupling between input and output shafts, enabling smooth and continuous engagement/disengagement without the abrupt transitions characteristic of mechanical clutch systems. This substitution provides both smooth operation and high bandwidth responsiveness.
Solution Approach 2:
The patent implements a dynamic clutch system where the coupling characteristics can be continuously adjusted in real-time based on operating conditions. The MR fluid clutch allows the connection between the additional power source and human power to be dynamically modulated, adapting to varying torque demands and speeds, thereby achieving both smooth operation and high responsiveness.
2Use of energy by moving object
If high inertia components are used in the powertrain to store energy, then energy storage capacity increases, but the system bandwidth and responsiveness to user input decreases
Solution Approach 1:
The patent replaces high-inertia mechanical energy storage components with an MR fluid-based power transmission system. Instead of relying on large rotating masses for energy storage and delivery, the system uses magnetorheological fluid to transmit and modulate power, dramatically reducing the moment of inertia while maintaining energy delivery capability. This enables rapid response to user input while preserving sufficient energy storage through the MR fluid's controllable coupling characteristics.
3Power
If the additional power source is always connected to provide assistance, then power availability is maximized, but the human user cannot disengage the assistance when not needed
Solution Approach 1:
The patent implements a dynamically controllable clutch system that allows real-time engagement and disengagement of the additional power source. The MR fluid clutch can be controlled to provide power assistance when needed and completely disengage when not needed, giving the user full control over power availability while maintaining the capability for immediate power delivery when required.
Solution Approach 2:
The patent employs a control system that monitors operating conditions and user input to dynamically adjust the clutch engagement. Sensors detect parameters such as torque demand, speed, and user effort, and the controller modulates the MR fluid clutch accordingly, ensuring the additional power source is engaged only when assistance is needed and disengaged when the user can operate independently.
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
This solution improves the integration of human and additional power sources, reducing induced torque and enhancing the powertrain's ability to match user input, resulting in smoother and more efficient operation.
Implementation Method 1
magnetorheological (MR) fluid actuators and clutches to selectively connect and disconnect power sources, allowing for variable torque transmission
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
A system for assisting a user in moving a device relative to a structure comprises a magnetorheological (MR) fluid actuator unit including at least one torque source and at least one MR fluid clutch apparatus having an input coupled to the at least one torque source to receive torque from the at least one torque source, the MR fluid clutch apparatus controllable to transmit a variable amount of assistance force via an output thereof. An interface is configured for coupling the output of the at least one MR fluid clutch apparatus to the device or surrounding structure. At least one sensor provides information about a movement of the device. A processor unit for controlling the at least one MR fluid clutch apparatus in exerting the variable amount of assistance force as a function of said information, wherein the system is configured for one of the MR fluid actuator unit and the interface to be coupled to the structure, and for the other of the MR fluid actuator unit and the interface to be coupled to the device for the assistance force from the MR fluid actuator unit to assist in moving the device.