V-Shaped Permanent Magnet Rotor Contour for Lower Torque Ripple
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Solution Overview
Problem
Existing rotors for electric machines experience undesirable torque fluctuations due to complex air gap arrangements, leading to manufacturing challenges and data transfer issues, which are not easily manageable by all machine types.
Innovation Solution
The rotor core is described using a simple outer contour defined by a limited number of radii with specific center points, allowing for straightforward data transfer and production, while reducing torque fluctuations through controlled air gap variation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the air gap is varied around the circumference to reduce torque fluctuations, then torque fluctuations are reduced, but the outer contour becomes complex and difficult to manufacture
Solution Approach 1:
The rotor core is divided into multiple sectors, each containing permanent magnet arrangements with specific V-shaped configurations. This segmentation allows the complex air gap variation to be achieved through discrete, manufacturable sector elements rather than a continuously complex outer contour
Solution Approach 2:
The air gap is varied locally by positioning permanent magnets at different radial distances from the rotation axis in different sectors, rather than changing the overall outer contour. This allows torque fluctuation reduction through localized magnetic field adjustments while maintaining a simple global rotor shape
2Reliability
If the outer contour is made complex to reduce torque fluctuations, then torque fluctuations are reduced, but data transfer and production become problematic
Solution Approach 1:
The rotor design segments the air gap variation into discrete permanent magnet positions in different sectors, which can be described using simple geometric parameters rather than complex continuous contour data. This reduces data transfer complexity while achieving the desired torque characteristics
Solution Approach 2:
Instead of defining the outer contour through complex mathematical calculations, the invention uses parameter changes in permanent magnet positioning (radial distances, angular positions) to achieve torque fluctuation reduction. These parameters are simpler to communicate and less prone to interpretation errors
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 simplifies the description and production of the rotor, reduces torque fluctuations, and ensures compatibility across various machine types, enhancing operational smoothness and manufacturing efficiency.
Implementation Method 1
each of which contains a permanent magnet arrangement comprising two first permanent magnets
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A rotor (3) for an electric machine (1) is described, comprising a rotor lamination stack (6) subdivided into several sectors (B), each containing a permanent magnet arrangement (4) with two V-shaped permanent magnets (13a, 13n) positioned symmetrically with respect to a plane of symmetry (C) dividing the sector (B) into two half-sectors (D, D'). An outer contour (E) of the rotor lamination stack (6) is symmetrical with respect to the plane of symmetry (C) in each sector (B) and is formed in each half-sector (D, D') by at least three different radii with as many different centers. The invention further relates to an electric machine (1) with such a rotor (3) and a vehicle (17) with such an electric machine (1).