Rotary Electrical Machine With Movable Stator Portion
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Solution Overview
Problem
Conventional radial and axial gap type electric motors require bulkier designs to vary output characteristics, which contradicts the desire for smaller, more efficient machines.
Innovation Solution
A rotary electrical machine with a stator divided into at least two portions, where one portion is fixed and the other is movable in the rotational direction relative to the first, allowing for variable magnetic resistance and flux control without increasing the machine's size.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the gap between rotor and stator is increased to vary output characteristics, then the output characteristics can be varied, but the machine becomes bulkier
Solution Approach 1:
The stator is divided into two independent portions (first stator portion and second stator portion) that can move relative to each other. This segmentation allows the gap between rotor and stator to be varied without increasing the overall machine volume, as the portions slide within the existing stator structure rather than requiring external expansion.
Solution Approach 2:
The second stator portion is made movable relative to the first stator portion through a sliding mechanism. This dynamic configuration allows the gap between rotor and stator to be adjusted during operation, enabling output characteristic variation while maintaining a compact fixed external dimensions.
2Speed
If field magnet weakening control is used to control output, then speed control is achieved, but torque is reduced and efficiency decreases
Solution Approach 1:
Instead of changing the magnetic field strength through field magnet weakening (which causes torque loss), the invention changes the physical gap parameter between rotor and stator. By sliding the second stator portion to increase or decrease the gap, the magnetic flux linkage is controlled, allowing speed variation while maintaining optimal torque production and efficiency.
3Adaptability or versatility
If a movable portion is added to vary the gap, then output control is improved, but device complexity increases
Solution Approach 1:
The second stator portion is designed to slide along the rotational direction within the stator structure. This sliding mechanism provides a simple dynamic adjustment capability that varies the gap and controls output characteristics without requiring complex actuators, motors, or control systems.
Solution Approach 2:
The sliding mechanism allows the second stator portion to be positioned by the interaction of magnetic forces and mechanical constraints itself, rather than requiring an external drive system. The structure uses the magnetic field and mechanical geometry to guide and maintain the position of the movable portion.
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
Enables efficient control of output characteristics across a wide range of torque and speed operations, maintaining a compact design and reducing mechanical loss, without consuming non-torque contributing electric power.
Implementation Method 1
one portion is movable in a rotational direction or a reverse rotational direction of the rotor relative to another such portion so that a gap to form a magnetic resistance between the first portion and the second portion is variable
Data Source
AI summary
A rotary electrical machine has a mechanism capable of varying an output characteristic, without increasing mechanical loss, or without consuming the electric power that does not contribute to increasing torque. The rotary electrical machine has a rotor with N pole and S pole magnets alternately and fixedly disposed thereon. An end surface, (which opposes the rotor), of each of a plurality of first teeth positioned on a first stator section is broader than that of the opposite surface thereof, and a winding is wound around a portion between both of the end surfaces. A second stator section has second teeth, corresponding the number of the first teeth, and which has no winding. The second teeth are disposed to oppose the end surfaces of the respective first teeth, and each second tooth is reciprocally movable between a reference position at which the second tooth directly opposes the respective first tooth and a maximum movable position located at the right center position between the respective end surfaces. At the reference position, a strong magnetic flux flows into the entire first tooth from each magnet. At the maximum movable position, a weak magnetic flux flows over the end surface of each first tooth. A middle amount of the magnetic flux flow occurs at a middle moved position.