Segmented Stator with Misaligned Teeth for Cogging Torque Reduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional electric machines suffer from high cogging torque due to stator slot openings, leading to unsmooth rotation, noise, and reduced efficiency, with existing solutions either being costly or complex in manufacturing.
Innovation Solution
The electric machine features a novel stator design with adjacently disposed and misaligned stator units, eliminating stator slot openings and allowing coils to be wound in advance, which reduces magnetic flux variation and cogging torque, simplifying the structure and manufacturing process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If stator slot openings are configured between stator teeth for winding coils, then coil winding is enabled, but cogging torque increases causing unsmooth rotation
Solution Approach 1:
The patent extracts and eliminates the stator slot openings from the stator structure. By removing these openings, the source of cogging torque is eliminated while coils are wound in advance on stator teeth and then assembled, achieving both smooth rotation and manufacturability
Solution Approach 2:
The patent applies preliminary action by winding coils on stator teeth before assembly. This allows coils to be pre-positioned and secured on individual stator teeth, eliminating the need for slot openings during final assembly while maintaining proper coil placement
2Object-generated harmful factors
If casting procedure is used to fabricate stator teeth to minimize gaps, then cogging torque is reduced, but manufacturing cost increases
Solution Approach 1:
The patent segments the stator into multiple independent stator teeth that can be manufactured separately using conventional, cost-effective methods. Each stator tooth is equipped with coils before assembly, eliminating the need for expensive casting while maintaining tight spacing to reduce cogging torque
Solution Approach 2:
Coils are wound on stator teeth before assembly, allowing conventional manufacturing methods to be used for stator teeth while still achieving the goal of minimizing gaps between teeth through precise assembly of pre-equipped modules
3Object-generated harmful factors
If staggered winding is placed over multiple stator teeth, then cogging torque is reduced, but coil complexity and manufacturing difficulty increase
Solution Approach 1:
The patent divides the stator into separate teeth, each with its own coil winding. This segmentation allows each coil to be wound independently on a single tooth using simple, conventional methods, while the overall staggered arrangement is achieved through the spatial arrangement of teeth themselves rather than complex winding patterns
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 effectively minimizes cogging torque and magnetic loss, enhancing the efficiency and reducing production costs while allowing for easier assembly and faster manufacturing.
Implementation Method 1
the rotor can be driven to rotate by the magnetic flux between the stator and rotor so as to generate the required mechanical energy
Implementation Method 2
When the coil disposed on the stator slot is applied with current, each stator tooth will generate a corresponding magnetic pole, thereby generating the expected magnetic attraction
Data Source
Figure 1A
Figure 1B
Figure 1C
AI summary
An electric machine includes a stator and a rotor. The stator is disposed near to the rotor and has at least one first stator unit and at least one second stator unit. The first stator unit has a first tooth and a second tooth, and the second stator unit has a third tooth and a fourth tooth. The rotor has a rotating direction or a moving direction with respect to the stator. The first tooth and the third tooth are adjacently disposed to each other along the rotating direction or the moving direction. The protruding directions of the first tooth and the third tooth respectively form a first angle and a third angle with the radial direction of the rotor, and the first angle and the third angle are different.