Multimode Clutch With Cam-Actuated Pawls for Gear Shifts
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Solution Overview
Problem
Automatic transmission systems face challenges in ensuring reliable actuator performance and seamless mode transitions due to the complexity of managing multiple clutch modules for various gear ratios, which affects the reliability and cost-effectiveness of clutch operations.
Innovation Solution
A clutch design incorporating pivotable pawls and a cam actuator that allows for selective engagement and disengagement of rotating components in multiple directions, utilizing a torque spring and armature mechanism to control the pawls' position, enabling smooth transitions between locked and unlocked states.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If multiple clutch modules are used to accommodate multiple gear ratios, then the adaptability and versatility of the transmission system is improved, but the device complexity and actuator reliability concerns increase
Solution Approach 1:
The clutch assembly is segmented into multiple independent pawls (first pawl, second pawl, third pawl) that can operate independently to control different rotation directions. Each pawl can be engaged or disengaged separately, allowing complex rotational control functions to be achieved through simple, modular components rather than a single complex actuator system.
Solution Approach 2:
Instead of using a complex actuator system to directly control multiple clutch modules, the patent inverts the approach by using spring-loaded pawls that automatically engage with gear teeth through cam surfaces. The springs provide the actuating force, and the cam profiles control the engagement timing, eliminating the need for complex external actuators.
2Adaptability or versatility
If multiple clutch modules are used for automatic gear ratio changes, then the adaptability is improved, but the reliability of actuators decreases due to increased complexity
Solution Approach 1:
The pawl assembly is designed to be self-actuating through spring forces and cam surface geometry. As the gear rotates, the cam surface automatically pushes the pawl into engagement or disengagement positions without requiring external actuators. The spring provides continuous pressure to maintain engagement, and the system self-regulates based on the gear's rotational position.
Solution Approach 2:
The pawls are designed with pivot points that allow them to dynamically adjust their position during gear engagement and disengagement. This dynamic movement allows for smooth transitions between gear ratios without sudden shocks or binding, improving reliability by avoiding forced engagements that could damage components.
3Ease of operation
If clutch modules are designed to smoothly transition between operating modes, then the ease of operation is improved, but the device complexity increases
Solution Approach 1:
The cam surfaces are designed with curved profiles that guide the pawls through smooth, continuous motion during gear transitions. The curved cam surfaces ensure that the pawls engage and disengage gradually rather than abruptly, creating smooth transitions between operating modes without requiring complex control mechanisms.
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 design enhances actuator reliability and cost-effectiveness by providing precise control over rotational movement, allowing for smooth transitions between locked and unlocked states, improving operational efficiency and reducing wear and tear.
Implementation Method 1
a torque spring biasing the common member to rotate toward the first pawl and away from the second pawl
Implementation Method 2
an armature return spring biasing the armature toward the first armature position
Implementation Method 3
a pawl spring connected to the armature or a clutch housing and biasing the first pawl and the second pawl toward engagement with the rotating component
Data Source
AI summary
A clutch for selectively preventing rotation of a rotating component may include a first and second pawls pivotable between engagement and disengagement with the rotating component to selectively prevent or allow rotation of the rotating component in one or both directions. An armature moveable between a first and second armature positions may have a common member pivotally connected thereto and engaging the first and second pawls, with a torque spring biasing the common member to rotate toward the first pawl and away from the second pawl. In an intermediate armature position, the common member may disengage the first pawl from the rotating component while engaging the second pawl to allow rotation in one direction while preventing rotation in the opposite direction. In embodiments, a clutch may include a cam actuator rotating to selectively control engagement of the pawls with the rotating component and locking in one or both directions.