Variable Torque Electric Motor Assembly With Controllable Magnetic Device
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Solution Overview
Problem
Conventional Permanent Magnet DC Motors (PMDCMs) are limited in power delivery due to the fixed magnetic field strength, requiring larger sizes or stronger magnets, which restricts their ability to provide maximum power under varying conditions and faults.
Innovation Solution
Incorporating a controllable magnetic device, such as an electromagnet with rotating windings, coupled to the rotor assembly, allowing for adjustable magnetic flux through electric current control, enabling increased or decreased torque based on conditions, thereby enhancing power delivery without increasing motor size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the magnetic field strength is increased to deliver maximum power, then the power delivery capability is improved, but the rotor size or magnet strength must be increased which increases device complexity and size
Solution Approach 1:
The patent applies dynamics by making the magnetic field strength variable rather than fixed. An electromagnet with rotating windings is introduced to dynamically adjust the magnetic flux in the rotor assembly based on operating conditions, allowing the motor to deliver maximum power when needed without requiring a permanently larger rotor or stronger permanent magnets.
Solution Approach 2:
The patent changes the magnetic flux parameter dynamically through the controllable magnetic device. By adjusting the electric current to the electromagnet, the magnetic flux density in the rotor can be varied to optimize power delivery for different operating conditions, resolving the contradiction between fixed design constraints and variable performance requirements.
2Power
If the rotor size is increased to provide more magnetic flux, then the power delivery is improved, but the device size and cost increase
Solution Approach 1:
Instead of increasing rotor size to get more magnetic flux, the patent changes the magnetic flux parameter through electrical control of the electromagnet. This allows a compact rotor to provide high power output when needed by temporarily increasing magnetic flux through the controllable magnetic device, avoiding the need for a permanently larger rotor.
Solution Approach 2:
The patent replaces the mechanical approach of increasing rotor size with an electromagnetic approach. By using an electromagnet with controllable windings, the system achieves higher power output through field control rather than through mechanical enlargement of the rotor, thereby reducing device volume while maintaining power delivery capability.
3Power
If stronger magnets are used to increase magnetic flux, then the power delivery is improved, but the device cost and weight increase
Solution Approach 1:
The patent avoids using stronger permanent magnets by instead changing the magnetic flux parameter through an electromagnet. The controllable magnetic device provides the necessary additional flux through electrical current control, eliminating the need for heavy, expensive high-strength permanent magnets while achieving the same power delivery improvement.
Solution Approach 2:
The patent substitutes permanent magnets with an electromagnetic field generation system. By using an electromagnet with rotating windings coupled to the rotor, the system achieves variable magnetic flux without relying on heavy permanent magnet materials, thereby reducing weight and cost while maintaining power delivery capability.
4Device complexity
If the magnetic flux is fixed in conventional PMDCMs, then the device simplicity is maintained, but the adaptability to varying conditions and faults is reduced
Solution Approach 1:
The patent introduces dynamics to the previously static magnetic field system. The controllable magnetic device with electric current control allows the magnetic flux to be dynamically adjusted in response to varying operating conditions and faults, providing adaptability while adding minimal complexity through the controlled electromagnetic component.
Solution Approach 2:
The controllable magnetic device serves multiple functions: it can increase magnetic flux for maximum power delivery, maintain normal flux for standard operation, and potentially reduce flux for fault tolerance. This multi-functionality provides adaptability to various conditions without requiring separate systems for each operating mode.
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 power adjustment and fault tolerance, reducing the need for redundant systems and minimizing size and cost, while maintaining high power density and efficiency, particularly beneficial in applications like aircraft systems.
Implementation Method 1
a controllable magnetic device coupled to the rotor assembly... applying a second electric current to a controllable magnetic device coupled to the rotor assembly, the second electric current causing an amount of torque provided by the electric motor to change by adjusting the magnetic flux in the rotor assembly
Implementation Method 2
an electric motor including a rotor assembly and a stator assembly configured to be actuated to cause the rotor assembly to rotate based on an amount of magnetic flux in the rotor assembly
Implementation Method 3
the rotor assembly and the stator assembly form at least part of a brushless direct current (DC) motor
Data Source
AI summary
An actuator assembly includes an electric motor including a rotor assembly and a stator assembly configured to be actuated to cause the rotor assembly to rotate based on an amount of magnetic flux in the rotor assembly is disclosed. The assembly also includes a controllable magnetic device coupled to the rotor assembly, an actuator coupled to the rotor assembly; and a controller configured to apply electric current to the controllable magnetic device to adjust an amount of torque provided by the electric motor by adjusting the magnetic flux in the rotor assembly.