Linear Compressor Decoupled Bearing Design to Reduce Side-Load Wear
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Solution Overview
Problem
Linear moving magnet or reluctance motors face significant side loads due to misalignment of motor components and non-uniform magnetization, leading to wear and rapid deterioration of the cylinder wall and rider, which is costly and unreliable to address with tight dimensional tolerances and alignment methods.
Innovation Solution
A linear motor design featuring a piston and bearing decoupled from side-load bearing functions, with ferromagnetic rods positioned to counteract side loads by generating auxiliary forces perpendicular to the longitudinal axis, allowing for adjustable placement to minimize side loads and maintain efficient operation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If tight dimensional tolerances and alignment methods are used to center the magnet ring, then motor side loads are reduced, but manufacturing cost and assembly complexity increase significantly
Solution Approach 1:
A ferromagnetic rod is introduced as an intermediary component between the magnet ring and the bearing. This rod interacts with the magnetic field to generate an auxiliary force that counteracts side loads, serving as a mediator that eliminates the need for tight alignment between the magnet ring and bearing while still achieving side load reduction
Solution Approach 2:
The patent replaces the mechanical alignment system (which requires precise dimensional tolerances and alignment procedures) with a magnetic field-based system. The ferromagnetic rod utilizes electromagnetic interaction to generate the necessary auxiliary forces, substituting complex mechanical alignment requirements with a more forgiving magnetic field-based solution
2Productivity
If the piston diameter is reduced to achieve target resonant frequency, then operational efficiency is improved, but bearing surface area is reduced leading to increased bearing load per surface area
Solution Approach 1:
The patent segments the bearing load support function from the piston. Instead of relying solely on the piston's bearing surface to support side loads, the ferromagnetic rod is introduced as a separate component that provides magnetic support. This segmentation allows the piston diameter to be reduced for resonant frequency optimization while the ferromagnetic rod compensates for the reduced bearing capacity
Solution Approach 2:
The ferromagnetic rod generates an auxiliary force that acts as a counterbalancing force to offset the bearing load. This magnetic counterforce compensates for the reduced bearing surface area, allowing the system to maintain acceptable bearing load levels even with a smaller piston diameter optimized for resonant frequency
3Duration of action of stationary object
If ferromagnetic rods are added to counteract side loads, then bearing load is reduced and lifespan is extended, but device complexity increases
Solution Approach 1:
The ferromagnetic rod serves multiple functions: it acts as a structural support element, a magnetic field interaction component for generating auxiliary forces, and a side load counterbalancing mechanism. By consolidating these functions into a single component, the patent minimizes the increase in device complexity while achieving the desired lifespan extension through reduced bearing loads
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 design extends the lifespan of the linear compressor by reducing bearing load per surface area, allowing for independent selection of resonant frequency and enhancing operational efficiency while reducing assembly costs and complexity.
Implementation Method 1
A ferromagnetic feature interacts with the electromagnetic field generated by the motor stator to impart linear force on the piston
Implementation Method 2
ferromagnetic rods positioned to counteract side loads by generating auxiliary forces perpendicular to the longitudinal axis
Data Source
AI summary
A linear motor includes a piston cylinder having a first diameter and extending along a first cylindrical axis. The piston cylinder includes a first side wall. A piston is disposed within the piston cylinder and the piston is movable along the first cylindrical axis within the piston cylinder. The linear motor includes a bearing cylinder having a second diameter and extending along a second cylindrical axis. The bearing cylinder includes a second side wall. A bearing is disposed within the bearing cylinder, and the bearing is movable along the second cylindrical axis within the piston cylinder. A linkage mechanically couples the piston to the bearing. A motor stator generates an electromagnetic field. A ferromagnetic feature interacts with the electromagnetic field generated by the motor stator to impart linear force on the piston. The second diameter is greater than the first diameter.