Offset Protrusion Resolver Rotor Prevents Mounting Errors
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Solution Overview
Problem
Existing resolvers may be incorrectly mounted on rotary electric machines due to interchangeable designs, leading to faulty output signals if electrical characteristics differ, despite marking systems, as the protrusions and recesses' centerlines are often aligned with normal lines associated with tangent lines, allowing for potential misalignment.
Innovation Solution
A rotor design with a protrusion or recess that has a centerline offset in parallel to the normal line associated with the tangent line of the rotor or shaft, preventing incorrect mounting by ensuring precise alignment and preventing insertion into mismatched rotary shafts or resolvers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the protrusion centerline is aligned with the normal line associated with the tangent line of the rotor inner circumference, then the rotor can be easily manufactured with standard alignment, but the rotor may be incorrectly mounted on incompatible rotary shafts
Solution Approach 1:
The patent applies asymmetry by deliberately offsetting the protrusion centerline from the normal line associated with the tangent line of the rotor inner circumference. This asymmetric positioning creates a unique geometric relationship that prevents the rotor from being mounted on incompatible rotary shafts, while still allowing for straightforward manufacturing processes. The offset distance is specifically designed to ensure that only rotors with matching offset characteristics can be correctly mounted on corresponding rotary shafts.
2Ease of manufacture
If the recess centerline is aligned with the normal line associated with the tangent line of the rotary shaft outer circumference, then the rotary shaft can be manufactured with standard alignment, but the resolver may be incorrectly mounted with wrong types
Solution Approach 1:
The patent applies asymmetry by positioning the recess centerline at an offset from the normal line associated with the tangent line of the rotary shaft outer circumference. This asymmetric recess geometry complements the asymmetric protrusion on the rotor, creating a matched pair that ensures correct mounting. The offset distance of the recess is designed to correspond precisely with the protrusion offset, allowing only compatible rotor-shaft combinations to be assembled.
Solution Approach 2:
The patent applies inversion by reversing the traditional alignment approach. Instead of aligning both the protrusion and recess centerlines with their respective normal lines, the patent offsets both centerlines from their normal lines by corresponding distances. This inverted alignment strategy transforms the mounting interface from a symmetric, potentially mismatch-prone design to an asymmetric, uniquely compatible design.
3Reliability
If a marking system is implemented to determine the correct type of resolver, then mounting accuracy can be improved, but the complexity of the manufacturing process increases and human error may still occur
Solution Approach 1:
The patent replaces the marking system (information-based approach) with a mechanical interlocking system based on asymmetric geometry. The offset protrusion and offset recess create a physical compatibility mechanism that prevents incorrect mounting through geometric constraints rather than relying on markings and human verification. This substitution eliminates the need for complex marking systems and reduces reliance on human judgment, thereby reducing manufacturing process complexity while maintaining or improving mounting correctness.
Data Source
AI summary
A rotor in one embodiment includes an annular rotor main unit and a fitting portion that extends inward or outward one of an inner circumference and an outer circumference of the rotor main unit to be connected with a rotary shaft. The fitting portion is formed at a position at which a centerline of the fitting portion is offset in parallel with respect to a normal line that is associated with a tangent line of the one of the inner circumference and the outer circumference.