Axially Movable Stator Control to Reduce Generator Drag
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Solution Overview
Problem
Hybrid vehicle motors functioning as generators impede engine rotation, leading to loss of driving force when electric power is not supplied, as they generate electric power even when not driven, causing inefficiency.
Innovation Solution
A control system that adjusts the overlap amount of a motor's rotor and stator by moving the stator axially, using an elastic member and a movement controller to minimize overlap when the motor is not driven, thereby preventing electric power generation and reducing driving force loss.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If the motor is designed to generate electric power when the rotor rotates, then electric power can be generated during engine operation, but the motor impedes the rotation of the output shaft causing loss of driving force
Solution Approach 1:
The patent applies the dynamics principle by making the stator movable in the axial direction rather than fixed. The stator can dynamically adjust its position to change the overlap amount with the rotor. When electric power generation is desired, the stator is positioned to maximize overlap; when driving force loss needs to be minimized, the stator is repositioned to reduce overlap, allowing the system to adapt to different operational requirements
Solution Approach 2:
The patent changes the physical parameter of stator position in the axial direction to control the overlap amount between stator and rotor. By adjusting this positional parameter, the system can control the degree of magnetic interaction and thereby regulate both electric power generation capability and driving force loss, transforming a fixed-parameter design into a variable-parameter system
2Power
If the stator and rotor maintain maximum overlap, then motor performance is optimized for driving, but electric power generation causes impedance to engine rotation
Solution Approach 1:
The stator is designed to be movable in the axial direction, enabling dynamic adjustment of the overlap amount. This dynamic capability allows the system to optimize motor performance when driving is required while minimizing rotation impedance when the motor functions as a generator, eliminating the need to choose between the two opposing requirements
3Use of energy by moving object
If the motor functions as a generator during engine rotation, then electric power can be recovered, but the induced electromotive force creates resistance to engine output shaft rotation
Solution Approach 1:
The movable stator design enables dynamic control of the overlap amount during generator operation. By adjusting the stator position to optimize the overlap amount, the system can maximize electric power recovery while minimizing the resistance force generated by induced electromotive force, achieving better energy efficiency without excessive drag on the engine
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 system effectively reduces the induced electromotive force and loss of driving force by minimizing the overlap between the rotor and stator when the motor is not in use, ensuring efficient engine rotation.
Implementation Method 1
a stator that generates a magnetic field for rotating the rotor
Implementation Method 2
When the output shaft rotates in a state where electric power is not supplied to a motor connected to the output shaft of the engine, the motor functions as a generator
Data Source
AI summary
A control system includes: a motor including (i) a rotor, connected to an output shaft of an engine, and (ii) a stator that is movable in an axial direction of the rotor, a moving member connected to the stator, a coil wound around the moving member, and a movement control part that changes an overlap amount of the rotor and the stator in the axial direction, by moving the stator in the axial direction of the rotor by causing a power source to apply a voltage to the coil.