Stamped Aperture Assembly for Rotor Position Detection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The high cost of traditional 'all-in-one' injection molded photosensor systems in switched reluctance motors necessitates a more cost-effective solution for rotor position detection in brushless motors.
Innovation Solution
A stamped aperture assembly made from a thin, opaque, elongated sheet of plastic with an aperture window, a locking system, and an alignment system is used to secure and align an off-the-shelf infrared radiation emitting and detecting components, allowing for precise infrared radiation focusing and alignment without the need for an expensive injection molded assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an 'all-in-one' injection molded photosensor system is used, then the rotor position detection precision is maintained, but the manufacturing cost increases
Solution Approach 1:
The patent divides the photosensor system into separate functional components: an infrared emitting component, an infrared detecting component, and a stamped aperture assembly. These components are manufactured independently and then assembled together, replacing the integrated 'all-in-one' injection molded unit. This segmentation allows for simpler, more cost-effective manufacturing of individual parts while maintaining the overall detection precision through proper alignment features.
Solution Approach 2:
The patent employs a stamped aperture assembly made from a thin sheet of plastic material that is significantly cheaper to manufacture than the injection molded assembly. The stamped aperture serves the same optical function (focusing infrared radiation) but is produced through a lower-cost stamping process rather than complex injection molding, directly reducing manufacturing costs while preserving measurement precision.
2Ease of manufacture
If a stamped aperture assembly is used instead of injection molded assembly, then the manufacturing cost decreases, but the alignment precision may worsen
Solution Approach 1:
The stamped aperture assembly incorporates pre-formed alignment features (alignment slots and alignment pins) that are created during the stamping process itself. These features establish precise geometric relationships between the aperture window and the infrared components before assembly occurs, ensuring consistent alignment precision without requiring complex post-assembly adjustments or expensive tooling.
Solution Approach 2:
The alignment pins act as intermediary elements that physically connect the stamped aperture assembly to the infrared emitting and detecting components. These pins serve as precise locators that transfer the alignment geometry from the aperture assembly to the optical components, ensuring accurate positioning of the infrared radiation path while using simple, low-cost stamped features rather than complex molded alignment mechanisms.
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 solution provides a cost-effective rotor orientation and position detection system with similar capabilities to traditional 'all-in-one' units, offering substantial cost savings while maintaining precision and reliability.
Implementation Method 1
an alignment system to focus the infrared radiation beam
Implementation Method 2
an infrared radiation (IR) emitting component aligned across a gap with an infrared radiation (IR) detecting component
Implementation Method 3
the IR detecting component may be a phototransistor or a photodiode
Data Source
Figure 1
Figure 2A~2B
Figure 3~4
AI summary
A cost-effective photosensor system for rotor position detection includes securing an aperture assembly to an off-the-shelf infrared radiation-emitting component and/or an off-the shelf infrared radiation-detecting component. The application discloses an aperture assembly that may be stamped from a thin, opaque, elongated piece of plastic having an aperture window through which a radiation beam may pass and be focused. The aperture assembly also has a locking system for securing the assembly to the off-the-shelf photosensor system component, and an alignment system to direct the infrared radiation beam. A replaceable stamped aperture assembly for use in a rotor-sensing system and a method of providing a replaceable aperture assembly and securing it to an infrared component of a photosensor system are also disclosed.