Rotor Bore Alignment Tool for Sub-Micron Motor Shaft Concentricity
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Solution Overview
Problem
Radial misalignment of rotor shafts in electric motors leads to asymmetric loading, reduced operational lifespan, and acoustic noise due to manufacturing deviations, which existing technologies struggle to accurately compensate for.
Innovation Solution
A rotor bore alignment tool with expandable members is used to radially align motor components, achieving sub-micron end-to-end deviation by transitioning extendable mandrels to an extended position, ensuring precise concentric alignment of the rotor shaft within the motor bore.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If traditional manufacturing methods are used for motor assembly, then manufacturing simplicity is maintained, but radial alignment precision deteriorates with deviations exceeding 10 microns
Solution Approach 1:
The patent introduces a bore alignment tool as an intermediary device between the housing portions and rotor assembly. This tool includes a shaft with extendable members that can be inserted into the rotor bore to establish precise radial alignment. The extendable members engage with the housing portions to maintain sub-10 micron alignment precision during assembly, effectively mediating the alignment between components that would otherwise be difficult to achieve with traditional methods.
Solution Approach 2:
The alignment tool is designed to perform preliminary alignment actions before final motor assembly. The extendable members are configured to be inserted into the rotor bore first, establishing the radial alignment reference. This preliminary positioning ensures that subsequent assembly steps maintain the precise alignment, preventing misalignment issues that would require complex post-assembly adjustments.
2Reliability
If radial alignment precision is improved to sub-10 micron levels, then motor lifespan is extended, but manufacturing complexity increases
Solution Approach 1:
The alignment tool incorporates dynamic extendable members that can transition between retracted and extended states. During assembly, the members are extended to establish precise radial alignment. After alignment is achieved and components are secured, the members are retracted to allow tool removal. This dynamic capability enables the tool to perform its alignment function without permanently complicating the motor structure or requiring complex manufacturing processes for the final product.
Solution Approach 2:
The patent utilizes parameter changes in the extendable members' dimensional state to achieve the alignment function. The members transition from a compact state during insertion to an extended state during alignment establishment. This parameter change allows the same component to serve multiple functions: insertion, alignment establishment, and then retraction for removal, thereby achieving high precision alignment without permanently increasing manufacturing complexity.
3Manufacturing precision
If extendable members are used for radial alignment, then alignment precision reaches sub-10 microns, but device structure becomes more complex
Solution Approach 1:
The extendable members are designed with a nested structure where segments can be contained within one another during the retracted state. This nesting allows the members to be compact during storage and transport, and only extend when needed for alignment. The nested design minimizes the overall structural complexity of the alignment tool while maintaining the capability to achieve sub-10 micron precision when extended.
Data Source
AI summary
The present disclosure is generally directed to techniques for radial alignment of motor components relative to each other to achieve a motor with a rotor bore having sub-micron end-to-end deviation. In an embodiment, a rotor bore alignment tool is disclosed herein that can be inserted between motor components, and more particularly, apertures/through holes defined by each of the motor components such as housing sections and a stator assembly. The rotor bore alignment tool includes expandable members that can be selectively transitioned to an extended position to cause each of the motor components to be radially aligned prior to securely coupling the same in a so-called “stack” to form a motor. Once the motor components are coupled together, the resulting motor includes a rotor shaft extending from end-to-end that preferably includes a sub-micron deviation of less than 10 microns, and more preferably less than or equal to 5 microns, for example.