One-Way Clutch Off-Axis Coupling for Hybrid Engine Starting
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Solution Overview
Problem
Existing internal combustion engine starting systems face challenges with noise, vibration, and harshness due to clutch positioning and heat generation, which affect energy efficiency and require additional machining, and existing clutches are not suitable for hybrid vehicles that frequently start and stop the engine.
Innovation Solution
A sealed high-capacity overrunning roller clutch system that includes a pinion gear, drive plate, and a one-way clutch assembly with an inner and outer race, rollers, and a spring mechanism to align teeth, allowing for efficient torque transfer and minimizing friction losses, enabling frequent engine starting without the need for lubrication.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the clutch is positioned immediately adjacent to or partially within the engine block to utilize lubricant, then lubrication is provided to the clutch, but additional special machining is required to the engine block to provide passageways for lubricant
Solution Approach 1:
The clutch assembly is extracted from the engine block and mounted on the external surface of the engine block, eliminating the need for internal lubricant passageways and special machining while maintaining lubrication through external oil supply
2Adaptability or versatility
If the clutch operates in an overrunning mode, then the clutch allows temporary driving interconnection, but heat is generated and efficiency is lost
Solution Approach 1:
The clutch is designed to minimize heat generation and energy loss during overrunning operation, converting the previously harmful heat dissipation into a more efficient energy management system suitable for frequent engine starting and stopping in hybrid vehicles
3Adaptability or versatility
If the outer race axis is misaligned with the drive plate axis, then the clutch can accommodate misalignment, but additional teeth engagement mechanisms are required
Solution Approach 1:
The clutch incorporates a dynamic teeth engagement mechanism where the spring urges the first and second sets of teeth into alignment, allowing the system to adapt to misalignment conditions while maintaining functional simplicity
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 low-cost, energy-efficient torque transfer mechanism with high torque capacity in a compact design, reducing noise, vibration, and harshness while eliminating the need for lubrication, thus enhancing the efficiency and reliability of hybrid vehicle starting systems.
Implementation Method 1
A spring engages the drive plate and the outer race to urge the first and second sets of teeth into alignment with one another
Implementation Method 2
A plurality of rollers positioned radially between an inner race fixed for rotation with the crankshaft and an outer race coupled for rotation with the drive plate
Data Source
AI summary
A starting system for a hybrid vehicle includes a pinion gear driven by a starter motor and a drive plate having a set of teeth in constant meshed engagement with the pinion gear. A one-way clutch assembly drivingly interconnects the drive plate and an engine crankshaft and includes an inner race fixed for rotation with the crankshaft, an outer race coupled for rotation with the drive plate and a plurality of rollers positioned radially therebetween. The outer race includes a first set of teeth drivingly engaging a second set of teeth on the drive plate and arranged to allow the outer race to rotate about an axis misaligned with an axis of rotation of the drive plate. A spring engages the drive plate and the outer race to urge the first and second sets of teeth into alignment with one another.