Rotor Magnet Positioning to Balance Torque and Dynamic Unbalance
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Solution Overview
Problem
Conventional rotor structures in motors suffer from dynamic unbalance and motor characteristic deterioration due to the magnet's center of gravity deviating from the rotor's central position, leading to inefficient magnetic flux contribution and potential motor performance issues.
Innovation Solution
A motor design featuring a rotor with a magnet positioned on its outer peripheral part, flanked by axial holders to restrict movement, where the lengths between the holders and the magnet are carefully calibrated to maintain the magnet's central position between the stator and rotor cores, ensuring optimal dynamic balance and magnetic flux alignment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the magnet moves toward the end surface side of the rotation shaft, then the magnet can be positioned to generate magnetic field, but the center of gravity moves away from the central position of the rotation shaft causing large dynamic unbalance
Solution Approach 1:
The patent intentionally creates asymmetric positioning where the magnet's central position is deliberately deviated from the rotor core's central position in the axial direction. This asymmetric arrangement allows the magnet to be positioned for effective magnetic flux contribution while the holders and spacing compensate for the imbalance. The asymmetric design resolves the contradiction by accepting controlled positional deviation as the solution to achieve both magnetic performance and dynamic balance.
Solution Approach 2:
The patent uses the rotor core and holders as counterbalancing elements to offset the gravitational effect of the magnet's displaced position. By carefully designing the rotor core structure and holder positioning, the system creates a counterweight effect that compensates for the magnet's axial displacement, thereby maintaining dynamic balance despite the magnet not being centered on the rotation shaft.
2Stability of the object's composition
If the center of gravity of the magnet is moved toward the central position of the rotor, then dynamic unbalance is reduced, but the central position of the magnet deviates from the axial central position of the stator causing deterioration in motor characteristics
Solution Approach 1:
The patent employs asymmetric positioning where the magnet's central position is deliberately deviated from the rotor core's central position. The deviation amount is precisely controlled through the holder positioning and spacing relationships. This asymmetric design allows the magnet to maintain optimal alignment with the stator for effective magnetic flux contribution while the overall rotor structure maintains dynamic balance through compensating mass distribution.
3Power
If the magnet is positioned to optimize magnetic flux contribution, then motor characteristics are improved, but the magnet may move axially causing dynamic unbalance
Solution Approach 1:
The patent implements preliminary positioning action by pre-establishing the magnet's axial position through the holders before the motor operates. The holders are designed with specific spacing relationships to the rotor core that predeterminedly set the magnet's central position at the optimal deviation point. This preliminary positioning ensures that the magnet maintains its optimized position for magnetic flux contribution throughout operation, preventing axial movement that would cause dynamic unbalance.
Solution Approach 2:
The holders serve as intermediary elements between the magnet and the rotor core, mediating the positional relationship. The holders are positioned at specific distances from the rotor core's central position, and this intermediate positioning allows the magnet to be held at the optimal axial deviation while being mechanically supported. The holders act as the mediating structure that enables both the optimized magnetic positioning and the prevention of axial movement.
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 effectively suppresses dynamic unbalance and maintains motor performance by ensuring the magnet's effective contribution to rotational torque, thereby preventing motor characteristic deterioration.
Implementation Method 1
when electric power is supplied to the winding, a predetermined magnetic field is formed in the stator, and in response to this magnetic field, a magnetic attractive or repulsive force is generated between the magnetic field and the magnet, whereby the rotor continuously rotates
Implementation Method 2
a predetermined magnetic field is formed in the stator, and in response to this magnetic field, a magnetic attractive or repulsive force is generated
Data Source
AI summary
Provided is a motor including a stator and a rotor. The rotor includes a rotor core rotating integrally with an rotation shaft and having a core base end part fixed to the rotation shaft and core protrusions protruding outward in a radial direction from the core base end part; and a magnet disposed between the core protrusions adjacent to each other in a circumferential direction on an outer peripheral surface of the core base end part. A central position of the stator core in the axial direction, a central position of the rotor core in the axial direction, and a central position of the magnet in the axial direction are deviated from each other. The central position of the magnet in the axial direction is located between the central position of the stator core in the axial direction and the central position of the rotor core in the axial direction.