Electromagnetic One-Way Clutch with Ball Ramp Actuation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current overrunning coupling devices, such as one-way clutches and disconnect clutches in motor vehicle drivelines, lack control over their operational modes and exhibit high backlash angles, making them inefficient for advanced functionality like freewheeling and ratcheting in electric drive axles and transaxles.
Innovation Solution
A controllable one-way clutch with an electromagnetic actuator, featuring a clutch module with rotary components and power-operated struts, allows for selective engagement and disengagement via an electromagnetic actuator assembly, enabling both freewheeling and locking modes, reducing backlash and enhancing operational flexibility.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical coupling device (dog-clutch) is used to disconnect the electric motor from the geartrain, then the disconnect function is provided, but high backlash angles and very high release forces are required
Solution Approach 1:
The patent replaces the traditional mechanical dog-clutch system with an electromagnetic actuator assembly that uses magnetic fields to engage and disengage the clutch. The electromagnetic actuator eliminates the need for mechanical levers and springs, providing precise control with minimal backlash and significantly reduced release forces while maintaining reliable disconnect functionality.
2Reliability
If a mechanical coupling device (dog-clutch) is used to disconnect the electric motor from the geartrain, then the disconnect function is provided, but very high release forces are required
Solution Approach 1:
The electromagnetic actuator uses magnetic attraction and repulsion forces to engage and disengage the clutch, eliminating the need for high mechanical release forces. The magnetic field can be precisely controlled through electrical current, allowing for gentle engagement and disengagement without requiring very high force inputs.
3Adaptability or versatility
If a passive one-way clutch is used, then locked mode in one direction and freewheel mode in opposite direction are provided, but no independent control over operational modes is available
Solution Approach 1:
The patent transforms the static, passive one-way clutch into a dynamic, controllable system by introducing an electromagnetic actuator. This allows the clutch to actively switch between different operational modes (locked, freewheel, and disconnected) based on electrical control signals, providing independent control over when and how the clutch engages and disengages in either rotational direction.
4Adaptability or versatility
If a selectable one-way clutch with power-operated actuator is used, then additional functional modes are provided, but device complexity increases
Solution Approach 1:
The patent replaces complex mechanical actuation mechanisms (levers, springs, cam followers) with a compact electromagnetic actuator assembly. This substitution reduces the number of moving parts and mechanical linkages while providing the same or enhanced functional modes, thereby reducing overall device complexity despite the added capability for multiple operational states.
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 disconnect function with reduced backlash and additional operational modes, improving the efficiency and control of torque transfer in motor vehicle drivelines, particularly in electric drive axles and transaxles, by allowing selective disengagement and engagement of the electric motor with the geartrain.
Implementation Method 1
an electromagnetic actuator assembly having a stationary coil unit, an armature moveable relative to the coil unit between a first or 'engaged' position and a second or 'released' position
Implementation Method 2
a ball ramp mechanism integrated between the outer race assembly and the armature configured to convert movement of the armature relative to the coil unit into rotation of the armature
Data Source
AI summary
A controllable one-way clutch having a clutch module and a power-operated actuator module. The clutch module includes a first clutch component rotatably driven by an input member, a second clutch component rotatably driving an output member, struts disposed on the first clutch component for movement between a deployed position engaging ratchet teeth on the second clutch component and a non-deployed position disengaged from the ratchet teeth, and strut springs for biasing the struts toward their deployed position. The power-operated actuator module includes a coil unit, an armature moveable between an engaged position whereat the armature holds the struts in their non-deployed positions when the coil unit is powered-off and a released position where the armature releases the struts when the coil unit is powered-on, and a ballramp mechanism configured to move the armature along a helical path between its engaged and released positions.