Selectable One-Way Clutch Notch Plate Inserts for Engine Disconnect
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Solution Overview
Problem
Current hybrid electric vehicle powertrains face challenges with rotational backlash and noise during transient operations, leading to inefficiencies in fuel economy and increased emissions, due to the mechanical connection between the internal combustion engine and electric motor.
Innovation Solution
The implementation of pawl-type selectable one-way clutches (SOWC) with floating notch plate inserts and hydraulic control systems to manage torque transfer between the engine and torque converter, reducing backlash and noise, and improving engine disconnect response time.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a mechanical connection is maintained between the internal combustion engine and electric motor, then power transfer reliability is improved, but rotational backlash and noise increase during transient operations
Solution Approach 1:
The patent employs a selectable one-way clutch mechanism that dynamically switches between engaged and disengaged states based on operating conditions. The clutch allows torque transmission in one direction while permitting free rotation in the opposite direction, eliminating backlash during transient operations while maintaining reliability during steady-state power transfer.
Solution Approach 2:
The invention extracts the harmful mechanical connection during specific transient operations by disengaging the one-way clutch, allowing the engine and electric motor to decouple temporarily. This eliminates rotational backlash and noise during mode transitions while preserving the mechanical connection during normal operation for reliability.
2Loss of energy
If the engine is disconnected from the torque converter during transient operations, then fuel economy is improved and emissions are reduced, but engine disconnect response time increases
Solution Approach 1:
The one-way clutch is pre-positioned in an engaged state during steady-state operation, allowing for rapid disengagement when transient conditions occur. The mechanical readiness of the clutch mechanism enables quick response time while still achieving fuel economy benefits during transient operations.
Solution Approach 2:
The dynamic nature of the selectable one-way clutch allows it to transition quickly between engaged and disengaged states based on real-time operating conditions. This dynamic response capability reduces the time penalty associated with engine disconnection while maintaining energy efficiency during transient operations.
3Object-affected harmful factors
If floating notch plate inserts are used in the one-way clutch, then rotational backlash is reduced, but device complexity increases
Solution Approach 1:
The one-way clutch is segmented into modular components including the notch plate, floating inserts, and pawls. This segmentation allows the floating inserts to independently adjust and eliminate backlash while keeping each component relatively simple in design, balancing backlash reduction with manufacturing complexity.
Solution Approach 2:
The floating notch plate inserts act as intermediary elements between the notch plate and the pawls. These inserts absorb dimensional variations and wear, maintaining precise engagement without requiring complex adjustment mechanisms, thus reducing backlash while controlling overall device 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
This configuration enhances fuel economy, reduces emissions, and minimizes packaging space while maintaining efficient powertrain performance with reduced noise and vibration.
Implementation Method 1
the spring-biased wedge insert is configured to push the notch plate insert in a circumferential direction to thereby take-up any backlash space between the pawl and the notch plate
Implementation Method 2
A pawl is pivotally mounted on the notch plate insert for engaging a pocket plate to which an output shaft of the engine is drivingly coupled
Data Source
AI summary
Presented are clutch-type engine disconnect devices, methods for making/using such disconnect devices, and motor vehicles equipped with such disconnect devices. An engine disconnect device includes a notch plate, which has multiple notches and attaches to a torque converter, and a pocket plate, which has multiple pockets and attaches to an engine's crankshaft. A pawl is movably mounted within each notch; these pawls selectively engage the notches with the pockets. A notch plate insert is nested within each notch, supporting thereon one of the pawls. A selector plate interposed between the pocket and notch plates moves from a first position, to shift the pawls out of engagement with the pockets, and a second position, to move the notch plate inserts within the notches and allow the pawls to engage the notches with the pockets to thereby lock the notch plate to the pocket plate to rotate in unison with each other.