Motor Generator Accessory Drive System for Engine Start and Reverse Rotation
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Solution Overview
Problem
Existing power transmitting systems for engine-powered equipment face challenges in efficiently managing idle-stop and belt-alternator/generator-starter functionalities, particularly in maintaining operation of vehicle accessories when the engine is shut down, due to the need for costly and complex redundancy and large clutches.
Innovation Solution
A power transmitting system with a motor/generator and accessory drive system that operates in three modes: using engine rotary power, motor/generator rotary power in one direction, and motor/generator rotary power in the opposite direction to drive accessories independently of the engine, utilizing a clutch system to manage power transmission efficiently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If auxiliary electrically-driven units are employed to drive accessories when the engine is shut down, then accessory functionality is maintained, but device complexity and cost increase significantly
Solution Approach 1:
The motor/generator is designed to perform multiple functions: it acts as a starter motor to crank the engine, as an alternator to generate electricity when the engine runs, and as a motor to drive accessories when the engine is shut down. This multi-functionality eliminates the need for separate auxiliary units, reducing system complexity and cost while maintaining accessory functionality during engine shutdown.
2Reliability
If a large clutch is employed to de-couple the front end accessory drive system from the crankshaft, then the starter can drive accessories when the engine is shut down, but device complexity and cost increase
Solution Approach 1:
The patent combines the clutch mechanism with the motor/generator assembly into an integrated unit. The clutch is positioned between the motor/generator and the accessory drive system, allowing a single component to perform both power transmission and decoupling functions. This integration reduces the number of separate components and simplifies the overall system architecture.
3Use of energy by moving object
If the engine is shut down to save fuel, then energy efficiency improves, but accessory operation is lost
Solution Approach 1:
The motor/generator serves the system in multiple capacities without requiring external auxiliary systems. When the engine is shut down for fuel efficiency, the motor/generator automatically switches to motor mode to drive necessary accessories, ensuring continuous operation without additional energy-consuming auxiliary units. The system essentially serves itself across different operating conditions.
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 allows for efficient operation of vehicle accessories during engine shutdown by reducing redundancy and complexity, enhancing packaging efficiency and cost-effectiveness while maintaining accessory functionality.
Implementation Method 1
a generator, such as an alternator, is employed as a motor to turn the crankshaft via a belt
Implementation Method 2
a generator, such as an alternator
Data Source
AI summary
A device having an engine, a motor/generator and an accessory system having an accessory that is driven by rotary power. The device can be operated in a first mode in which the engine provides rotary power for driving the accessory and the motor/generator. The device can be operated in a second mode for starting the engine and driving the accessory in which rotary power is output from the motor/starter in a first rotational direction. The device can also be operated in a third mode in which the motor/generator outputs rotary power in a second, opposite rotational direction for driving the accessory while the engine is not operating. A method for operating the device is also provided.