Linear Electromagnetic Machine Gas Bearings for Air Gap Stability
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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 incorporating a stator, translator, and bearing housings with gas bearings, magnet sections, and flexure assemblies to maintain motor air gaps and constrain translator motion, allowing for oil-less operation and improved mechanical stiffness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If gas bearings are used instead of traditional lubricated bearings, then friction is reduced and efficiency is improved, but device complexity increases due to the need for pressurized gas systems
Solution Approach 1:
The bearing housing and translator bearing surface form a gas bearing system that uses the relative motion between components to generate the necessary gas pressure for lubrication, eliminating the need for external pressurized gas supply systems while reducing friction and maintaining efficiency
Solution Approach 2:
The patent employs gas pressure generated within the bearing housing to create a gas bearing interface between the bearing housing and translator bearing surface, using pneumatic principles to reduce friction without requiring complex external gas supply infrastructure
2Adaptability or versatility
If the translator is allowed to move freely within the stator bore, then operational flexibility is improved, but mechanical stability and alignment deteriorate
Solution Approach 1:
The patent replaces traditional mechanical contact bearings with a gas bearing system that uses gas pressure to maintain alignment and stability of the translator within the stator bore, eliminating mechanical friction while preserving motion flexibility
Solution Approach 2:
The gas bearing system dynamically adjusts gas pressure parameters to maintain optimal alignment and stability of the translator during motion, allowing the system to adapt to varying operational conditions while maintaining precise positioning
3Reliability
If oil-less operation is implemented, then maintenance requirements are reduced and reliability is improved, but heat dissipation capability worsens
Solution Approach 1:
The patent extracts the lubrication function from the bearing system by implementing oil-less gas bearings, removing the need for lubricating oil while maintaining reliable operation through gas film separation between moving components
Solution Approach 2:
The patent introduces pressurized gas as an intermediary substance between the bearing housing and translator bearing surface, creating a protective gas film that prevents direct contact and heat generation while allowing efficient heat dissipation through the gas medium
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 ensures efficient operation, cost-effective construction, and reliable performance by maintaining motor air gaps and constraining translator motion, enhancing mechanical stiffness and reducing friction, thus achieving high efficiency and durability.
Implementation Method 1
The first bearing housing and the translator bearing surface are capable of forming a first bearing gap and the second bearing housing and the translator bearing surface are capable of forming a second bearing gap. For example, the first and second bearing gaps may be configured to contain a pressurized gas, and function as a gas bearing.
Implementation Method 2
The translator includes a magnet section. For example, the magnet section and the stator bore are capable of forming a motor air gap.
Implementation Method 3
Linear motors convert between electrical energy and kinetic energy of a moving element.
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.