Stator Tooth Groove Geometry for Lower Cogging Torque
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Solution Overview
Problem
Existing motors experience cogging torque, which causes noise and vibration, and the performance and quality are affected by the shape of the grooves in the stator teeth, necessitating a design that reduces cogging torque while maintaining performance.
Innovation Solution
The design incorporates grooves in the stator teeth with specific dimensions and orientations to alter the magnetic flux distribution, reducing cogging torque by adjusting the width and depth of the grooves relative to the slot openings and protrusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If grooves are formed in the stator teeth to reduce cogging torque, then noise and vibration are reduced, but the motor performance may deteriorate
Solution Approach 1:
The patent applies parameter changes by precisely controlling the width and depth of grooves formed in the stator teeth. The groove width is set to 0.5mm to 1.5mm and depth to 0.3mm to 1.0mm, which optimizes the reduction of cogging torque while preserving motor performance. This quantitative parameter optimization resolves the contradiction between reducing harmful cogging torque and maintaining necessary motor power output.
Solution Approach 2:
The patent implements local quality by forming grooves only in specific regions of the stator teeth rather than uniformly across the entire stator structure. The grooves are positioned at the tooth tips and have controlled dimensions, creating localized modifications that reduce cogging torque at critical areas while leaving the rest of the motor structure intact to maintain performance.
2Object-affected harmful factors
If the width and depth of grooves are increased to further reduce cogging torque, then noise and vibration decrease, but the motor output and efficiency may be affected
Solution Approach 1:
The patent establishes optimal parameter ranges for groove dimensions to balance noise reduction and motor output. The groove width is limited to 0.5mm to 1.5mm and depth to 0.3mm to 1.0mm, preventing excessive groove sizes that would harm motor productivity. These parameter constraints ensure sufficient noise and vibration reduction while preserving adequate motor output and efficiency.
3Measurement precision
If grooves are formed in the stator teeth, then the main cogging order increases, but the structural complexity of the stator increases
Solution Approach 1:
The patent applies segmentation by dividing the stator tooth structure into distinct regions with and without grooves. The grooves are segmented features formed only at specific locations (tooth tips) rather than throughout the entire tooth structure. This segmented approach increases cogging order precision while minimizing the overall structural complexity of the stator.
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 approach significantly reduces cogging torque, improving motor quality by minimizing noise and vibration, particularly in high-speed conditions, and enhances the motor's performance by optimizing the cogging order.
Implementation Method 1
owing to a difference in permeability between the stator made of a metal material and air of the SO which is an empty space while the rotor rotates, a cogging torque may occur
Implementation Method 2
owing to a difference in permeability between the stator made of a metal material and air of the SO which is an empty space
Data Source
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AI summary
An embodiment provides a stator comprising a stator core having a plurality of teeth and coils wound around the teeth, wherein the tooth includes a body around which the coil is wound and a shoe connected to the body, the shoe includes a plurality of grooves and a curvature center of the inner peripheral surface of the shoe is the same as the center of the stator core.