Commutator Brush Spring Structure for Stable Contact Pressure
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Solution Overview
Problem
Conventional brush springs in commutator electric motors, such as coil and torsion springs, exhibit significant pressure variation during brush wear, leading to increased friction, efficiency loss, and reduced brush life due to unstable load application.
Innovation Solution
A constant load spring with a fold-back structure is used, where the spiral part is wound around a strip-shaped wire material, and the spring is fixed to a brush holder with a tubular part, ensuring stable contact at multiple locations through a fold-back structure and recesses in the brush end, preventing movement and maintaining uniform pressure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If a conventional motor design is used, then the structure is simple and manufacturing is easy, but the motor cannot generate sufficient torque at low frequencies and the cooling is insufficient
Solution Approach 1:
The motor is divided into modular components: a stackable plurality of motor modules, each containing stator segments and rotor segments. This segmentation allows the motor to achieve high torque at low frequencies through cumulative effect of multiple modules while keeping each individual module simple to manufacture.
Solution Approach 2:
The rotor segments are positioned within the stator segments in a nested arrangement, with the rotor segment being at least partially surrounded by the stator segment. This nesting maximizes the use of space and allows multiple functional elements to be integrated without increasing overall complexity.
2Temperature
If the motor operates at high frequency, then power output is sufficient, but the motor generates excessive heat and requires complex cooling systems
Solution Approach 1:
The cooling function is merged with the structural components of the motor. The stator and rotor segments themselves serve as heat dissipation pathways, eliminating the need for separate complex cooling systems. The modular design allows heat to be distributed and dissipated across multiple segments.
3Manufacturing precision
If the motor is designed for high precision, then positioning accuracy is improved, but the manufacturing complexity and cost increase
Solution Approach 1:
The motor is divided into identical or similar motor modules that can be manufactured using the same processes. This segmentation allows high precision to be achieved through modular replication rather than complex single-unit manufacturing, improving both positioning accuracy and ease of manufacture.
Solution Approach 2:
The motor achieves high precision through parameter optimization in the modular design, such as the specific arrangement of stator and rotor segments, the configuration of windings, and the geometric parameters of the magnetic circuits. These parameter changes enable high positioning accuracy while maintaining manufacturability through standardization.
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 design stabilizes the load applied to the brush, preventing efficiency loss and extending brush life by maintaining consistent pressure even as the brush wears.
Implementation Method 1
a three-phase motor winding is provided with three-phase power in order to generate a rotating magnetic field
Implementation Method 2
a rotor segment having a plurality of permanent magnets arranged along an inner circumference of the rotor segment
Data Source
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AI summary
A rotor including a rotary shaft and a commutator mounted to the rotary shaft, a brush including a front end (first end) in contact with the commutator and a rear end (second end) positioned on a side opposite to the first end, and a constant load spring including a strip-shaped wire material and configured to press the brush against the commutator are included, constant load spring includes a spiral part around which the strip-shaped wire material is wound, and the spiral part and the second end are in contact with each other at two or more locations.