Rotor Module Pole Shift Layout for Lower Torque Ripple
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Solution Overview
Problem
Existing rotary electric machines with skewed rotor modules require different types of rotor modules for mechanical connections, leading to complex manufacturing and high costs due to the need for various manufacturing tools.
Innovation Solution
Implementing a rotor module design with a single type of rotor plate and specific shift angles between magnetic pole pairs, allowing for simplified assembly and reduced torque ripple while maintaining mechanical strength, using identical rotor modules to simplify manufacturing and reduce costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If rotor modules are skewed with different angular positions to reduce torque ripple, then torque ripple is reduced, but device complexity increases due to requiring different types of rotor modules
Solution Approach 1:
The rotor is divided into multiple identical rotor modules, each producing a fundamental torque wave. By segmenting the rotor into identical modular units with specific angular offsets, the patent achieves torque ripple reduction through superposition of torque waves while maintaining manufacturing simplicity through standardization of individual modules.
Solution Approach 2:
The patent introduces asymmetric angular positioning of identical rotor modules relative to the stator teeth. The first rotor module is positioned with a first angular offset and the second rotor module with a second angular offset, creating an asymmetric arrangement that produces destructive interference of torque ripple harmonics while using symmetric identical modules.
2Reliability
If different types of rotor modules are used for mechanical connections, then mechanical connection requirements are met, but manufacturing complexity increases due to requiring different manufacturing tools
Solution Approach 1:
The patent designs universal identical rotor modules that can be used in multiple positions and configurations within the rotor assembly. Each rotor module is designed with standardized mechanical features enabling consistent mounting and connection, allowing the same module type to fulfill multiple functional requirements while simplifying manufacturing through standardization.
Solution Approach 2:
Instead of changing the physical design of rotor modules to meet different mechanical connection requirements, the patent changes the angular position parameters of identical modules. By varying the angular offset parameters rather than the module design parameters, the patent achieves different mechanical configurations using the same standardized components.
3Adaptability or versatility
If multiple types of rotor modules are manufactured with different tools, then specific mechanical requirements are met, but production cost increases
Solution Approach 1:
The patent employs homogeneous identical rotor modules throughout the rotor assembly, all manufactured using the same tools and processes. This homogeneity in module design and manufacturing eliminates the need for multiple tooling setups and reduces production costs while maintaining the adaptability to achieve torque ripple reduction through standardized angular positioning of the identical modules.
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
The design achieves a significant reduction in torque ripple and manufacturing complexity, while using identical rotor modules to lower production costs and enhance mechanical strength.
Implementation Method 1
a plurality of permanent magnets defining a number of magnetic pole pairs comprising a first pole and a second pole... first poles being North poles and the second poles being South poles
Data Source
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AI summary
The invention relates to a rotor module (15) for a rotor (3) of a rotary electric machine (1) with an axis of rotation (A) comprising a stator (2) comprising a stator core (9) including radially oriented stator teeth, the rotor module (15) comprising: - a rotor module core (16), - a plurality of permanent magnets (17, 18) defining a number of magnetic pole pairs (24) comprising a first pole (22) and a second pole (23), the first pole (22) and the second pole (23) of each magnetic pole pair (24) being adjacent, the first poles (22) being North poles and the second poles (23) being South poles or the first poles (22) being South poles and the second poles (23) being North poles, the plurality of permanent magnets (17, 18) defining first magnet arrangements (25) defining each first pole (22) and second magnet arrangements (26) defining each second pole (23), the first magnet arrangements (25) and the second magnet arrangements (26) being distinct, a first angle (27) between the first pole (22) and the second pole (23) of each pairs is equal to 360° divided by two times the number of magnetic pole pairs (24), a second angle (28) between a second pole (23) of a first magnetic pole pair (29) and a first pole (22) of a second magnetic pole pair (30) adjacent to the second pole (23) of the first magnetic pole pair (29) is equal to the sum of the first angle (27) and a first shift angle, the first shift angle being greater than zero and less than or equal to a maximum shift angle, the maximum shift angle being equal to 360° divided by the number of stator teeth. 1. The invention also relates to a rotor (3) fitted with such a rotor module (15) and a rotary electric machine 1 fitted with such a rotor (3).