Spring Loaded Gear Driven Resolver for Compact Electric Machines
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Solution Overview
Problem
Current bearingless high pole count electric machines require large diameter resolvers for accurate position sensing, which are costly and complex, and existing resolvers need to be fully removed for maintenance, increasing downtime and costs.
Innovation Solution
A spring-loaded gear driven resolver system where the resolver rotor drive shaft is coupled to a resolver driven gear, allowing for precise axial and radial alignment without the need for dedicated bearings, enabling easy replacement and maintaining zero backlash.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If large diameter resolvers are used for accurate position sensing in bearingless high pole count electric machines, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The resolver rotor drive shaft is made spring-loaded to dynamically accommodate radial displacement of the rotor while maintaining engagement with the driven gear. This dynamic adjustment allows the resolver to maintain accurate position sensing despite rotor movement, eliminating the need for large diameter resolvers and dedicated bearing support structures.
Solution Approach 2:
The spring-loaded drive shaft automatically adjusts to rotor radial displacement and maintains gear engagement without requiring external bearing support or complex alignment mechanisms. The system self-regulates to maintain measurement precision through the elastic deformation of the spring, reducing overall device complexity.
2Measurement precision
If dedicated rotor support bearings are used to maintain resolver alignment, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The dedicated rotor support bearings are completely removed from the system. Instead, the spring-loaded drive shaft directly accommodates rotor radial displacement and maintains resolver alignment through elastic deformation, eliminating the complex bearing support structure while preserving measurement precision.
Solution Approach 2:
The system changes from a rigid bearing-supported alignment mechanism to a flexible spring-loaded mechanism that allows radial displacement. The spring's elastic properties enable the drive shaft to absorb rotor movement while maintaining resolver-stator alignment, reducing device complexity.
3Volume of moving object
If resolvers are mounted on the rotor shaft to utilize unused space, then volume is reduced, but ease of repair worsens due to complete disassembly requirements
Solution Approach 1:
The resolver is segmented into separable components: the resolver stator remains mounted on the stator assembly while the resolver rotor on its spring-loaded drive shaft can be independently removed from the rotor shaft. This segmentation allows the resolver to be maintained or replaced without complete disassembly of the electric machine, improving ease of repair while maintaining compact volume.
4Device complexity
If spring-loaded gear driven system is used instead of bearing-supported system, then device complexity is reduced, but reliability may worsen due to gear mesh requirements
Solution Approach 1:
The spring-loaded drive shaft dynamically adjusts to rotor radial displacement, maintaining optimal gear mesh engagement between the drive gear and driven gear. This dynamic adjustment compensates for rotor movement, ensuring consistent gear engagement and maintaining reliability while reducing device complexity compared to rigid bearing-supported systems.
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 solution reduces the cost and complexity of resolver systems by allowing for the use of less expensive components while maintaining accuracy and enabling quick replacement without disassembling the electric machine, addressing the issues of high cost and maintenance complexity.
Implementation Method 1
the resolver rotor drive shaft is spring loaded to the resolver driven gear
Implementation Method 2
the spring loaded drive shaft accommodates radial displacement of the rotor
Implementation Method 3
a resolver driven gear in mesh engagement with a resolver drive gear
Data Source
AI summary
A resolver apparatus can include a resolver driven gear, a resolver stator, a resolver rotor coupled to the resolver stator and a resolver rotor drive shaft coupled to the resolver rotor, wherein the resolver rotor drive shaft is spring loaded to the resolver driven gear.