Variable Magnet Rotor for Electric Machine Efficiency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Permanent-magnet type electric rotating machines face inefficiencies in varying driving conditions, such as low-speed, high-torque and high-speed, low-torque modes, due to the inherent limitations of constant magnetized magnets and the complexity of assembling variable magnetomotive force motors, which result in a massive and complex design.
Innovation Solution
The design incorporates a rotor with both constant and variable magnetized magnets, where the variable magnets' magnetic force and direction are dynamically adjusted using magnetizing coils, allowing for a versatile and stable output control, enabling efficient operation across a wide range of driving modes without increasing the machine's size or complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If variable magnetized magnets are added to change magnetic force according to driving conditions, then efficiency in varying modes is improved, but device complexity and size increase
Solution Approach 1:
The patent merges the magnetizing coil with the stator core structure, integrating the variable magnetomotive force generation function into the existing stator rather than adding separate components. This reduces device complexity while maintaining the ability to adjust magnetic force for different driving modes
Solution Approach 2:
The stator is designed to serve multiple functions: it acts as both the structural support and houses the magnetizing coil that generates variable magnetomotive force. This multi-functionality eliminates the need for separate magnetizing structures, reducing overall machine complexity
2Adaptability or versatility
If magnetizing coil is arranged around the stator, then variable magnetomotive force is achieved, but stator length and machine size increase
Solution Approach 1:
The magnetizing coil is nested within the stator core structure rather than being arranged externally around it. This nested configuration allows the coil to be housed within the existing stator volume, avoiding any increase in stator axial length while still achieving variable magnetomotive force
3Device complexity
If constant magnetized magnets are used, then machine structure is simple, but efficiency in varying driving modes deteriorates
Solution Approach 1:
The patent introduces dynamic adjustability to the magnetic field through the magnetizing coil that can vary the magnetomotive force according to driving conditions. This dynamic capability allows the machine to maintain high efficiency across different operating modes while keeping the overall structure relatively simple by using the existing stator framework
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 configuration enhances the machine's versatility and efficiency by allowing direct control of magnetic forces, optimizing torque and speed, and simplifies assembly, enabling efficient operation from low-speed, high-torque to high-speed, low-torque modes without the need for increased size or complexity.
Implementation Method 1
The magnetic force and magnetization direction in the rotor are changed by the magnetic field generated by the magnetizing coil arranged around the stator as magnetizing pulse current flows in the magnetizing coil
Implementation Method 2
The stator has an armature coil configured to form a magnetic circuit for driving
Data Source
Figure 1~2
Figure 3
Figure 4A~4C
AI summary
According to one embodiment, a permanent-magnet type electric rotating machine has a stator (3), a magnetizing coil (504), a rotor (2) and a case (4). The stator (3) has an armature coil (302) configured to form a magnetic circuit for driving. The magnetizing coil (504) is configured to form a magnetic circuit for magnetizing. The rotor (2) has a constant magnetized magnet (2031), a rotor core (203) and a variable magnetized magnet (2022). The rotor core (203) holds the constant magnetized magnet (2031). The constant magnetized magnet (2031) is arranged closer to the magnetic circuit for driving than the variable magnetized magnet (2022). The variable magnetized magnet (2022) is arranged closer to the magnetic circuit for magnetizing than the constant magnetized magnet (2031).