Outer-Rotor Motor-Generator Inertia for Flywheel-Less Noise Reduction
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Solution Overview
Problem
Existing flywheel-less connections between internal combustion engines and motor-generators result in larger motor-generator sizes due to the need for increased torque compensation, making installation challenging and generating noise.
Innovation Solution
A motor-generator configuration with an outer rotor connected directly to the engine without a flywheel, where the rotor's inertia is adjusted to reduce torque ripples and rotational fluctuations, thereby reducing noise and size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Weight of stationary object
If a flywheel-less connection is used between the internal combustion engine and motor-generator, then the size and weight of the drive system are reduced, but the motor-generator becomes larger due to the need for large torque compensation
Solution Approach 1:
The patent merges the flywheel function into the motor-generator rotor, creating a combined structure where the rotor serves both as the electromagnetic component and the inertial energy storage element. This integration eliminates the need for a separate flywheel while providing both motor generation functionality and torque ripple compensation, thereby reducing overall system size and weight.
Solution Approach 2:
The rotor is designed to perform multiple functions simultaneously: it acts as the electromagnetic rotor for motor generation operation and as an inertial element for torque compensation. This multi-functionality allows the motor-generator to compensate for torque ripples without requiring additional components, resolving the contradiction between system compactness and torque compensation capability.
2Reliability
If large torque is generated for compensating torque ripples in a flywheel-less connection, then torque ripple compensation is improved, but the motor-generator becomes larger in size
Solution Approach 1:
The patent optimizes the rotor's moment of inertia as a key parameter to achieve effective torque ripple compensation. By carefully selecting and adjusting the inertia parameter within a specific range, the system achieves adequate torque compensation without requiring excessive rotor size, thereby maintaining compact dimensions while ensuring reliable torque ripple mitigation.
3Object-affected harmful factors
If the rotor inertia is increased to reduce rotational fluctuations, then noise reduction is improved, but the motor-generator size increases
Solution Approach 1:
The patent establishes an optimal range for rotor inertia that simultaneously achieves noise reduction through rotational fluctuation suppression and maintains compact motor-generator dimensions. By parameter optimization rather than simple increase, the system achieves the beneficial effect of reduced noise without the penalty of excessive size increase.
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 achieves a compact motor-generator design that effectively reduces noise and size by utilizing an outer rotor with adjusted inertia to compensate for torque ripples and rotational fluctuations, eliminating the need for a flywheel.
Implementation Method 1
The outer rotor servers as alternative to the flywheel and is configured to reduce noise due to at least one of torque ripples of the internal combustion engine and rotational fluctuations of the motor-generator
Data Source
AI summary
In a motor-generator configured to use no flywheel connection to an internal combustion engine, an inner stator is provided. An outer rotor is arranged to surround the inner stator. The outer rotor is connected to the internal combustion engine without a flywheel and is configured to reduce noise due to at least one of torque ripples of the internal combustion engine and rotational fluctuations of the motor-generator.