Motorized Balanced Cryocooler Expander to Reduce Mechanical Vibrations
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional cryocoolers used in infrared cameras suffer from significant mechanical vibrations, which negatively impact their performance, size, and weight, making them less effective for compact applications such as spaceflight and high-sensitivity imaging.
Innovation Solution
A motorized and actively balanced expander system is integrated within the cryocooler, featuring a magnet ring and motor coil, which drives and balances the displacer motion while minimizing vibrations through an active spring system, allowing for reduced mechanical noise and increased compactness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional motors are used to drive the expander in a cryocooler, then the cooling function is achieved, but mechanical vibrations are generated that negatively impact performance and increase system complexity
Solution Approach 1:
The patent replaces the conventional mechanical motor-driven expander system with an electromagnetic linear motor system. The linear motor uses electromagnetic fields to directly drive the displacer without mechanical contact, eliminating mechanical vibrations while maintaining the cooling function. The electromagnetic force generated by the linear motor coil and magnet ring provides the driving force for the displacer motion.
Solution Approach 2:
The patent introduces an active spring system as an intermediary between the linear motor and the displacer. This spring system serves as a vibration isolation mechanism, further reducing mechanical vibrations transmitted to the cryocooler structure while allowing the displacer to perform its cooling function effectively.
2Object-affected harmful factors
If vibration mitigation techniques are applied to reduce mechanical vibrations, then vibration impact is reduced, but system weight and size increase
Solution Approach 1:
By replacing the mechanical motor system with an electromagnetic linear motor system, the patent inherently reduces vibrations at the source rather than requiring additional heavy vibration mitigation components. The electromagnetic driving mechanism produces minimal mechanical vibrations compared to conventional motors, eliminating the need for substantial vibration isolation hardware that would increase system weight.
Solution Approach 2:
The linear motor system is inherently self-balancing in terms of vibration reduction. The electromagnetic forces can be precisely controlled to minimize vibrations without requiring separate active vibration control systems or heavy passive isolation mechanisms, thus achieving vibration reduction without proportionally increasing system weight.
3Reliability
If conventional expanders are used, then the cooling function is provided, but the system size is large and not suitable for compact applications
Solution Approach 1:
The patent merges the motor function and expander function into a single integrated linear motor expander assembly. The linear motor coil, magnet ring, and displacer are combined in one compact unit, eliminating the need for separate motor and expander components. This integration significantly reduces the overall system volume while maintaining the cooling function.
Solution Approach 2:
The patent employs a nested arrangement where the magnet ring is positioned within the linear motor coil assembly, and the displacer is integrated within the same space. This nested configuration maximizes space utilization and minimizes the overall volume of the expander system, making it suitable for compact applications such as spaceflight and portable infrared cameras.
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 effectively reduces vibrations, maintaining or enhancing cooling performance while minimizing system size and weight, resulting in more accurate and reliable infrared imagery.
Implementation Method 1
a motorized and/or actively balanced expander configured to drive and/or balance motion of a displacer of the motorized and/or actively balanced expander. The motorized and/or actively balanced expander may include a magnet ring fixed to the displacer and a motor coil disposed within a cylinder head of the motorized and/or actively balanced expander
Implementation Method 2
A motorized and actively balanced expander system is integrated within the cryocooler, featuring a magnet ring and motor coil, which drives and balances the displacer motion while minimizing vibrations through an active spring system
Data Source
AI summary
Techniques are disclosed for systems and methods to reduce mechanical vibrations within a cryocooler/refrigeration system configured to provide cryogenic and/or general cooling of a device or sensor system. A cryocooler includes a motor driver controller configured to receive operational parameters and generate motor driver control signals and/or balancer system control signals based, at least in part, on the received operational parameters, and a motor driver configured to receive the control signals and generate drive signals to drive a motor and/or a balancer system of the cryocooler. The cryocooler includes a motorized and/or actively balanced expander configured to drive and/or balance motion of a displacer of the expander. The expander includes a magnet ring fixed to the displacer and a motor coil disposed within a cylinder head of the motorized and/or actively balanced expander.