Belt Integrated Starter Generator Clutch Control for Cabin Comfort
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Solution Overview
Problem
Conventional Integrated Starter Generator (ISG) based micro-hybrids in automotive vehicles cannot maintain interior climate comfort when the engine is shut off, as the air conditioning compressor, part of the Front End Accessory Drive system, ceases to run, forcing a trade-off between fuel economy and cabin temperature comfort in hot conditions.
Innovation Solution
The Belt Integrated Starter Generator (BISG) system allows selective mechanical coupling of an electric motor with the crankshaft and accessory components via a belt and clutches, enabling the electric motor to drive the air conditioning compressor independently when the engine is not spinning, using existing FEAD belt and clutch systems.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the engine is shut off to improve fuel economy, then fuel consumption is reduced, but the air conditioning compressor ceases to run and interior climate comfort deteriorates
Solution Approach 1:
The system separates the engine's functions into two independent power sources: the engine for propulsion and the electric motor for accessory power. This allows the engine to be shut off for fuel economy while the electric motor independently powers the air conditioning compressor to maintain cabin comfort.
Solution Approach 2:
The electric motor is designed to perform multiple functions: it can start the engine when needed and independently power accessory components like the air conditioning compressor. This multi-functionality resolves the contradiction by providing both fuel economy benefits and climate comfort without requiring the engine to run continuously.
2Temperature
If the engine runs continuously to maintain air conditioning operation, then cabin temperature comfort is maintained, but fuel economy benefits are lost
Solution Approach 1:
The system divides power delivery into separate pathways: the engine connects to the crankshaft for propulsion, while the electric motor connects to accessory components. This segmentation allows the engine to be decoupled from accessory power delivery, enabling it to shut off for fuel economy while the electric motor maintains air conditioning operation.
Solution Approach 2:
The electric motor acts as an intermediary power source between the battery and accessory components. It mediates the power delivery to the air conditioning compressor, allowing the compressor to operate independently of engine operation, thus maintaining comfort while enabling fuel economy through engine shutdown.
3Speed
If a conventional ISG system is used, then rapid engine start capability is achieved, but independent accessory power delivery while engine is off is not possible
Solution Approach 1:
The system segments the ISG's mechanical connections by using two separate clutches: one coupling the electric motor to the crankshaft for engine starting, and another coupling the electric motor to accessory components. This segmentation enables independent control of engine starting and accessory power delivery, allowing accessories to operate while the engine is off.
Solution Approach 2:
The system dynamically controls the engagement and disengagement of two separate clutches to adapt power flow to different operating conditions. The first clutch engages for engine starting, while the second clutch engages for accessory power delivery. This dynamic control provides versatility, allowing the electric motor to independently power accessories while the engine remains stationary.
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 enables continued interior comfort by allowing the air conditioning compressor to operate while the engine is off, maintaining fuel economy benefits and ensuring cabin temperature control during hot ambient temperatures.
Implementation Method 1
a belt and clutches... allowing the electric motor to drive the air conditioning compressor
Data Source
AI summary
A belt integrated starter generator may selectively drive accessory components while an engine is off. The belt integrated starter generator may also selectively drive a crankshaft of the engine. Clutches are used to access rotational power from the belt.