Linear Motor Stator Tooth Layout for Anti-Clocking Gas-Bearing Alignment
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Solution Overview
Problem
Existing linear motors face challenges in achieving efficient operation, cost-effective construction, and reliability, particularly in matching the efficiency of rotary generators, while requiring high-efficiency materials, geometry optimization, and high copper slot fill.
Innovation Solution
A linear electromagnetic machine (LEM) design featuring a stator with windings, a translator with magnet sections, and bearing housings that form gas-bearing gaps for oil-less operation, along with flexure assemblies for mechanical stiffness, ensuring alignment and efficient motion.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional contact bearings are used in linear motors, then mechanical support is provided, but friction and wear increase reducing efficiency and reliability
Solution Approach 1:
The patent replaces traditional mechanical contact bearings with a gas bearing system that uses a thin film of pressurized gas (typically air) to support the translator. This substitution eliminates direct metal-to-metal contact, thereby eliminating friction and wear associated with contact bearings while providing the necessary mechanical support and alignment.
Solution Approach 2:
The patent employs pneumatic principles by introducing pressurized gas into the bearing gap between the translator and stator. The gas pressure creates a lifting force that supports the translator's weight and provides radial support, replacing the function of mechanical bearings without the associated friction and wear problems.
2Object-generated harmful factors
If oil-lubricated bearings are used, then friction is reduced, but contamination and maintenance requirements increase
Solution Approach 1:
The patent substitutes oil-lubricated mechanical bearings with a gas bearing system that uses compressible gas (typically air) as the lubricating medium. This substitution maintains low friction while eliminating the contamination risks associated with oil lubrication, as gas does not leak, attract dust, or require the same level of maintenance.
Solution Approach 2:
The patent creates an inert gas environment in the bearing gap that prevents contamination. The pressurized gas acts as a protective barrier, preventing external contaminants from entering the bearing interface and eliminating the need for oil lubrication that would otherwise be required to reduce friction.
3Ease of manufacture
If stator teeth are arranged with uniform azimuthal gaps, then manufacturing is simplified, but anti-clocking force is insufficient
Solution Approach 1:
The patent introduces asymmetry in the stator tooth arrangement by creating a non-uniform azimuthal gap pattern. Specifically, one gap between adjacent stator teeth is made larger than the others, forming an azimuthal gap asymmetry. This asymmetric configuration generates a net anti-clocking force that prevents the translator from rotating azimuthally while maintaining relatively simple manufacturing requirements.
4Force
If magnet axial length is increased, then electromagnetic force is improved, but motor air gap maintenance becomes more difficult
Solution Approach 1:
The patent introduces gas bearings as an intermediary mechanism between the translator (with longer magnets) and the stator. The gas bearing film acts as a compliant intermediary that can accommodate variations in air gap length while maintaining stable operation, thereby enabling the use of longer magnets for increased electromagnetic force without compromising air gap maintenance precision.
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 LEM design achieves efficient energy conversion, maintains motor air gaps, and provides reliable operation with reduced friction and wear, enhancing performance and durability.
Implementation Method 1
The translator is configured to electromagnetically interact with the stator and is arranged to move axially within the stator bore substantially along the axis
Implementation Method 2
The first and second bearing gaps may be configured to contain a pressurized gas, and function as a gas bearing
Data Source
AI summary
A linear electromagnetic machine includes a stator, a translator, and a bearing system. The bearing system maintains alignment against lateral displacement of the translator relative to the stator, as the translator reciprocates axially. More particularly, the bearing system maintains a motor air gap between the stator and a magnetic section of the translator. The stator includes a plurality of stator teeth and windings, which form a plurality of phases. The stator teeth and windings are arranged using a hoop stack with spines to form a stator bore and define the motor air gap. The bearing system can include bearing housings that are configured to form a bearing interface with a surface of the translator. The bearing interface can include a contact bearing or a non-contact bearing, such as a gas bearing. Current is controlled in the phases to convert between electrical energy and kinetic energy of the translator.