Synchronous Permanent Magnet Machine Multi-Rotor Speed Control
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Solution Overview
Problem
Existing electric motors with multiple rotation speeds require separate gear mechanisms, leading to mechanical wear and increased complexity, while existing synchronous machines with two rotors are not designed for compact and cost-effective solutions for applications requiring both high and low rotation speeds.
Innovation Solution
A synchronous permanent magnet machine with a single stator and multiple rotors, each with different pole numbers and permanent magnets, generating distinct rotation speeds without a gear mechanism, utilizing a common frequency rotating field and innovative rotor designs for compactness and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a gear mechanism is used to generate multiple rotation speeds, then different rotation speeds can be achieved, but mechanical wear increases and reliability decreases
Solution Approach 1:
The patent replaces the mechanical gear mechanism with an electromagnetic field-based speed control system. The stator windings generate rotating magnetic fields at different frequencies to directly control the rotation speed of the rotor, eliminating mechanical gears and their associated wear problems. This substitution of mechanical system with electromagnetic system resolves the contradiction between achieving multiple speeds and maintaining reliability.
Solution Approach 2:
The patent changes the frequency parameter of the rotating magnetic field generated by the stator windings to achieve different rotation speeds. By varying the frequency of the supplied electrical current, the speed of the rotating magnetic field changes, which directly controls the rotor speed without any mechanical transmission components. This parameter-based control eliminates mechanical wear while providing versatile speed adjustment.
2Adaptability or versatility
If separate motors are used for high speed and low speed operations, then appropriate speeds can be generated, but device complexity and cost increase
Solution Approach 1:
The patent designs a single synchronous motor that can operate at multiple rotation speeds by controlling the frequency of the rotating magnetic field. The same motor structure serves both high-speed and low-speed operations, making the motor universal for different speed requirements. This eliminates the need for separate motors and reduces overall system complexity and cost.
Solution Approach 2:
The patent combines the functionality of multiple motors into a single motor design. Instead of having separate motors for high-speed and low-speed operations, the invention merges these functions into one motor that can dynamically adjust its speed through electrical control of the rotating magnetic field frequency, thereby simplifying the overall system architecture.
3Adaptability or versatility
If a single stator with multiple rotors is used, then multiple rotation speeds can be generated without gears, but the machine design becomes more complex
Solution Approach 1:
The patent segments the rotor into multiple independent rotors, each with different pole configurations optimized for different speed ranges. Each rotor can be independently controlled by the stator windings, allowing the system to achieve multiple rotation speeds without mechanical gears. This segmentation of the rotor enables speed versatility while maintaining a relatively simple stator design.
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 the generation of multiple rotation speeds in a compact and cost-effective manner, reducing mechanical wear and complexity, suitable for applications like radial blower and centrifugal separators, with the ability to adjust speeds through pole number variations.
Implementation Method 1
a single stator carrying stator windings; at least two rotors for at least two rotation speeds of the machine, each of said rotors defining a separate rotation speed, and each of said rotors carrying permanent magnets with different numbers of poles
Implementation Method 2
means connected to said windings for subjecting the armature windings to a rotating field of a common frequency
Implementation Method 3
at least one permanent magnet segment and at most p/2 permanent magnet segments of the same polarity are replaced by segments comprising a dia- or ferromagnetic material of high permeability
Implementation Method 4
segments comprising a dia- or ferromagnetic material of high permeability
Data Source
AI summary
A synchronous permanent magnet machine for at least two rotation speeds has a single stator and at least two rotors. For each rotation speed there is provided a separate rotor with a different numbers of poles. The armature windings on the stator extend across all of the rotors and the windings are subjected to a rotating field with the same frequency.