Universal Motor Rotor Winding Segmentation for Commutation
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Solution Overview
Problem
Conventional universal motors suffer from poor commutation performance, especially when the number of rotor winding turns is large, leading to inefficiencies and reduced motor performance.
Innovation Solution
The design incorporates a rotor with multiple teeth and a commutator having segments, where each rotor winding unit is connected to a pair of adjacent segments and comprises multiple coils with subcoils connected in series, optimizing the magnetic coupling and winding configuration to improve commutation efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If the number of turns of rotor windings is increased to improve motor performance, then the motor can generate higher torque and power, but the commutation performance deteriorates significantly
Solution Approach 1:
The rotor winding is divided into multiple independent coils, each with multiple subcoils connected in series. Each coil is connected to a pair of adjacent commutator segments, creating a segmented winding structure that improves commutation by reducing the induced electromotive force in each individual coil while maintaining overall motor power through the series connection of multiple coils.
2Device complexity
If conventional rotor winding configuration is used, then the motor structure is simple, but the magnetic coupling efficiency is poor and commutation is inadequate
Solution Approach 1:
The patent applies different winding configurations to different local regions of the rotor. Each coil is positioned to optimize magnetic coupling with specific stator poles, and the series connection of subcoils within each coil creates localized magnetic fields that improve overall magnetic coupling efficiency while maintaining a relatively simple overall structure.
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 enhances commutation performance, reduces the induced electromotive force, and extends the motor's lifespan while minimizing material consumption and stator core requirements, resulting in a more efficient and cost-effective universal motor.
Implementation Method 1
each of the rotor winding units is connected to a pair of adjacent segments and at least one of the rotor winding units comprises at least two coils connected in series; each said coil comprises at least two subcoils directly connected in series and separated from each other by at least one tooth
Implementation Method 2
the stator is configured to form 2P magnetic poles... the rotor has m rotor winding units R1 ∼Rm and each rotor winding unit Rk is connected to a pair of adjacent segments Zk and Zk+1
Data Source
AI summary
An electric motor has a rotor, a stator and brushes. The rotor has a shaft, a rotor core fixed to the shaft and having a plurality of teeth, a commutator fixed to the shaft adjacent the rotor core and having a plurality of segments, and rotor winding units wound about the teeth and connected to the commutator segments. Each of the rotor winding units is connected to a pair of adjacent commutator segments. At least one of the rotor winding units has at least two coils connected in series. Each coil has at least two subcoils directly connected in series and separated from each other by at least one tooth. An initial subcoil and a final subcoil of each coil are respectively connected to a pair of segments.