Linear Motor Coil Winding Configuration for Thrust Ripple Suppression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing linear motor design experiences a decrease in magnetic flux linkage at the end coils, leading to uneven thrust generation among phase components, resulting in thrust ripple and deteriorated controllability.
Innovation Solution
The linear motor is configured with a tubular body and rod, featuring a specific arrangement of teeth and slots, where the number of coil windings for the U phase coils is set to be smaller than for the V and W phase coils, ensuring equal thrust components and reducing thrust ripple.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If the coils are arranged with identical numbers of coil windings in all phases, then the manufacturing is simplified, but thrust ripple is generated due to unequal magnetic flux linkage at end positions
Solution Approach 1:
The patent applies local quality by setting different numbers of coil windings for different phase coils based on their positions. Specifically, the first and second phase coils (at end positions) have a different number of windings than the third through sixth phase coils (at central positions), allowing each coil to be optimized for its local magnetic flux linkage characteristics and eliminating thrust ripple
Solution Approach 2:
The patent changes the parameter of coil winding numbers to resolve the thrust ripple issue. By adjusting the number of coil windings for different phase coils, the magnetic flux linkage is equalized across all phases, transforming the uniform winding configuration into a non-uniform one that compensates for positional differences in magnetic flux
2Reliability
If the number of coil windings is increased to compensate for end position magnetic flux loss, then thrust balance is improved, but device complexity increases
Solution Approach 1:
The patent resolves this contradiction by applying local quality - different phase coils have different numbers of windings tailored to their specific positions. The first and second phase coils have fewer windings while the third through sixth phase coils have more windings, creating a localized optimization that balances thrust without requiring uniform increases across all coils
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 configuration equalizes the thrust components, suppressing thrust ripple and enhancing the controllability of the linear motor by adjusting the number of coil windings, particularly for the U phase coils.
Implementation Method 1
a moving magnetic field generated around a coil disposed on an inner peripheral surface of the yoke... force attracting the permanent magnet functions as thrust
Implementation Method 2
attracting a permanent magnet disposed on an outer peripheral surface of the rod using a moving magnetic field generated around a coil
Data Source
AI summary
A linear motor that displaces a tubular body and a rod relative to each other in an axial direction includes teeth arranged in the axial direction so as to project from an inner peripheral surface of the tubular body, slots formed between adjacent teeth, coils disposed in the slots, and permanent magnets provided in the rod and arranged in the axial direction. The coils are constituted by one or more first phase coils, one or more second phase coils, and one or more third phase coils. The first, second, and third phase coils are provided in the axial direction such that the first phase coil and the second phase coil are disposed at respective ends the tubular body. A total number of coil windings of the third phase coils is set to be smaller than a total number of coil windings of the first phase coils and a total number of coil windings of the second phase coils.