Integrated Motor Encoder Teeth for Linear Drive Commutation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing linear drive motors face challenges in maintaining accurate commutation and positioning due to manufacturing variations, requiring complex and costly Hall Effect sensors and lengthy setup times, especially in sinusoidally commutated motors with separate encoder scales.
Innovation Solution
A thin sheet of magnetic permeable material with slots and recesses is used to form motor teeth, encoder teeth, and commutation teeth simultaneously, eliminating the need for Hall Effect sensors by synchronizing these features for precise alignment and standardized electrical angle, allowing flexible programming and reduced setup times.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If Hall Effect sensors and separate encoder scales are used for commutation and positioning, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent combines motor teeth, encoder teeth, and commutation teeth into a single integrated secondary structure. The slots extending through the magnetic permeable material simultaneously form all three tooth types, eliminating the need for separate Hall Effect sensors and encoder scales. This merging maintains measurement precision while significantly reducing device complexity and cost.
Solution Approach 2:
The integrated secondary structure serves multiple functions: it provides motor teeth for force generation, encoder teeth for position feedback, and commutation teeth for electrical angle reference. This multi-functional design eliminates the need for separate sensing systems while maintaining all required measurement capabilities.
2Ease of manufacture
If separate encoder scales are attached after motor teeth are created, then manufacturing flexibility is improved, but manufacturing precision deteriorates due to alignment variances
Solution Approach 1:
The encoder teeth and commutation teeth are formed simultaneously with the motor teeth during the initial slotting process, rather than being added later. This preliminary formation ensures precise alignment from the start, eliminating alignment variances that would occur with post-assembly attachment methods.
Solution Approach 2:
By integrating all tooth formations into a single manufacturing step, the patent eliminates the sequential attachment process that causes alignment issues. The slots are cut through the entire secondary structure in one operation, ensuring consistent spacing and precise alignment between all tooth types.
3Ease of operation
If conventional Hall Effect devices are used for commutation, then ease of operation is improved, but setup and calibration times increase
Solution Approach 1:
The integrated commutation teeth provide inherent reference features that enable the motor system to self-establish commutation without requiring external Hall Effect sensors or manual calibration procedures. The standardized electrical angle is built into the structure itself, allowing the system to automatically determine its reference position.
Solution Approach 2:
The patent removes the need for Hall Effect sensors and separate encoder scales by extracting their functions into the integrated tooth structure. The commutation teeth directly provide the electrical angle reference that would otherwise require separate sensing devices, eliminating the time-consuming setup and calibration processes.
4Ease of manufacture
If manufacturing variations are present in separate components, then ease of manufacture is improved, but reliability deteriorates due to inconsistent commutation
Solution Approach 1:
By forming motor teeth, encoder teeth, and commutation teeth as a single integrated structure, the patent eliminates cumulative manufacturing variations that would occur with separate components. All teeth are created from the same magnetic permeable material in one slotting operation, ensuring consistent spacing and reliable commutation across all motors using this secondary design.
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 enables predictable and repeatable commutation, reduces setup and calibration times, and allows for interchangeable motor components, improving the flexibility and efficiency of linear drive motors by eliminating the need for Hall Effect sensors and phase searching.
Implementation Method 1
A thin sheet of magnetic permeable material with slots extending through the material to form teeth of the secondary
Data Source
AI summary
A primary for a linear drive motor has a stage with stacks made from solid steel. Each stack has inner and outer teeth made that form a generally u-shaped cross-section for the stack. A magnet is disposed between the first and second stacks and a a coil wrapped between the first and second stacks. The stacks may be placed in a housing or may be formed as a housingless stage. The stacks and/or housing may be modified to selectively skew motor alignment to reduce motor cogging. The stacks may be contoured to follow various secondary forms. The stack inner and outer teeth lengths may be adjusted to help balance or optimize the magnetic circuit, to increase tooth surface area for increasing force, to allow more motor windings in the coil of the stack assembly, and to help locate the magnet and coil near the tooth surface.