Segmented Stator Motor with Nested Windings
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Solution Overview
Problem
Electric motors experience a significant drop in efficiency when operating away from their optimum frequency, and existing solutions that use gearing systems to address this issue increase costs and reduce efficiency further.
Innovation Solution
The motor is designed with a stator split into multiple components, each with protrusions and windings, where the windings on one component fit into gaps between the other, allowing for efficient operation at reduced power and frequency while maintaining a saturated magnetic field, and the stator components are rotationally offset to enhance compactness and reduce torque fluctuations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If the motor operates at reduced power to achieve lower rotational frequency, then the operating frequency range is extended, but the magnetic field becomes unsaturated and efficiency drops dramatically
Solution Approach 1:
The stator is divided into multiple independent stator components, each with its own windings that can be independently controlled. This segmentation allows selective activation of stator components based on the desired rotational frequency, enabling the magnetic field to remain saturated in active components even at reduced overall power levels.
Solution Approach 2:
Instead of reducing power to all windings uniformly, the invention applies partial action by activating only the necessary number of stator components based on the target rotational frequency. This ensures sufficient current density in active windings to maintain magnetic saturation while consuming less total power.
2Loss of energy
If the stator is divided into multiple components with separate windings, then the motor can operate efficiently at reduced power, but the winding configuration becomes more complex and less efficient due to increased end portions
Solution Approach 1:
The windings on adjacent stator components are arranged such that the end portions of windings on one stator component are nested within the gaps between windings on adjacent stator components. This nesting arrangement minimizes the exposed end portions, reducing their negative impact on magnetic field generation while maintaining the benefits of segmented stator control.
Solution Approach 2:
The invention addresses the winding complexity issue by utilizing the axial dimension to offset stator components rotationally. This dimensional approach allows the end portions of windings to be positioned in gaps of adjacent components, effectively utilizing space that would otherwise be wasted and reducing the overall impact of end portions on motor efficiency.
3Speed
If gearing systems are added to extend the efficient operating range, then the motor can drive axles at different speeds, but the system cost increases and efficiency is reduced
Solution Approach 1:
The invention replaces the mechanical gearing system with an electrical control system that selectively activates stator components based on the desired output speed. This substitution eliminates the need for physical gears, reducing mechanical complexity, cost, and efficiency losses associated with gear friction and mechanical wear.
Solution Approach 2:
Instead of changing the mechanical transmission ratio through gears, the invention changes the electrical operating parameters by selectively activating different numbers of stator components. This allows the motor to maintain optimal current density and magnetic saturation across a range of output speeds, achieving variable speed operation without mechanical gearing.
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 allows for efficient operation at lower power and frequency with reduced torque fluctuations, improving the motor's performance and reducing costs by minimizing the need for complex control systems.
Implementation Method 1
In this regard in an electric motor where there are windings that generate an electric field, the motor operates most efficiently if the magnetic field generated within the body that the windings are mounted on is saturated.
Implementation Method 2
said rotor being mounted within said at least two stator components on a rotational mounting such that said rotor can rotate about a longitudinal central axis with respect to said stator
Data Source
AI summary
An electric motor apparatus comprises a rotor and a stator formed of at least two stator components, each of the at least two stator components having a substantially hollow cylindrical form. The rotor is mounted within the at least two stator components on a rotational mounting such that the rotor can rotate about a longitudinal central axis with respect to the stator. Each of the at least two stator components has at least two protrusions arranged at different circumferential points on an inner surface of the at least two stator components. Each protrusion has a winding mounted thereon. Control circuitry generates control signals to control power supplied to the windings on each stator component such that power can be controlled to each stator component independently. The stator components are mounted adjacent to each other along the longitudinal central axis and rotationally offset with respect to each other such that the two protrusions on one of the stator components are offset with respect to the protrusions on an adjacently mounted stator component, such that a portion of each winding that extends beyond a longitudinal end of the protrusions on one of the stator components fits within a gap between windings mounted on the adjacently mounted stator component.