Motor Magnetic Shielding for Selective Regenerative Braking Control
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Solution Overview
Problem
Regenerative braking in electric vehicles and unintended counter electromotive forces in motors due to inertia driving lead to reduced fuel efficiency, decreased maximum movable distance, and driver discomfort, with existing solutions like dampers or clutches increasing costs and complexity.
Innovation Solution
A motor with a shield member that selectively screens the magnetic field between the stator and rotor using a moving member controlled by electromagnetic interaction, allowing for controlled magnetic field screening to prevent regenerative braking and counter electromotive forces.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If regenerative braking is activated to recover energy, then energy efficiency is improved, but traveling distance is reduced due to drag phenomenon
Solution Approach 1:
The shield member is positioned in advance to block the magnetic field between the stator and rotor during inertia driving, preventing the generation of regenerative torque before it can cause drag phenomenon. This preliminary blocking action eliminates the harmful regenerative braking effect while allowing energy recovery when desired.
Solution Approach 2:
The shield member is made movable along the axial direction, allowing its position to be dynamically adjusted. When moving in the first direction, it blocks the magnetic field to prevent regenerative braking; when moving in the second direction, it allows magnetic field passage for energy recovery. This dynamic positioning resolves the contradiction between preventing drag and enabling energy efficiency.
2Loss of energy
If regenerative braking is activated to recover energy, then energy efficiency is improved, but driver comfort deteriorates due to drag phenomenon
Solution Approach 1:
The shield member blocks the magnetic field in advance during inertia driving to prevent regenerative torque generation, eliminating the drag phenomenon that causes driver discomfort. By preventing the harmful effect before it occurs, both energy efficiency and driver comfort are optimized.
Solution Approach 2:
The movable shield member dynamically adjusts its position to control magnetic field passage. When positioned to block the field, it prevents regenerative braking and associated drag; when positioned to allow field passage, it enables energy recovery. This dynamic control eliminates driver discomfort while maintaining energy efficiency.
3Loss of energy
If shield member is added to control magnetic field, then energy efficiency is improved, but device complexity increases
Solution Approach 1:
The shield member is integrated with the motor structure, combining the magnetic field shielding function with the existing motor components. This merging approach adds the necessary energy control capability without significantly increasing overall device complexity.
Solution Approach 2:
The shield member is designed to move along the axial direction, utilizing simple linear motion to achieve dynamic magnetic field control. This dynamic design allows a single component to perform multiple functions (blocking and allowing magnetic field passage) without requiring complex mechanisms, thereby improving energy efficiency with minimal increase in device complexity.
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 enhances energy efficiency, extends the maximum driving distance, and improves drivability by selectively controlling electromagnetic interactions, preventing unwanted regenerative braking and counter electromotive forces during inertia-driven operations.
Implementation Method 1
a moving member that controls a position of the shield member based on an electromagnetic interaction with the stator such that screening of the magnetic field is selectively performed
Implementation Method 2
a shield member that screens a magnetic field between a stator and a rotor
Data Source
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AI summary
A motor may include a shield member that screens a magnetic field between a stator and a rotor, and a moving member that controls a position of the shield member in response to an electromagnetic interaction with the stator such that the screening of the magnetic field is configured to be selectively performed. The motor may prevent a generation of a counter electromotive force or regenerative braking.