Linear Actuator Magnetic Pre-Compression Anti-Chatter
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Solution Overview
Problem
Conventional linear actuators face challenges in preventing chattering/backlash between guide rails and slide tables due to high machining and assembly precision requirements, complex structures, and increased frictional forces, especially when using spherical rolling bodies in gothic arch or circular grooves, which complicates miniaturization.
Innovation Solution
A linear actuator design featuring projections on the guide rail with arcuate-shaped rolling grooves and a magnetic attractive force from bipolar magnets to support rolling bodies, reducing the need for precise machining and assembly and minimizing differential slippage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the diameter of rolling bodies is increased to apply pre-compression and prevent chattering/backlash, then chattering/backlash is prevented, but machining accuracy requirements increase to a few μm level
Solution Approach 1:
The patent replaces the mechanical pre-compression method (increasing rolling body diameter) with a magnetic field-based solution. A magnet is positioned between the rolling bodies and the guide rail to apply magnetic attractive force, creating the necessary pre-compression without requiring high-precision machining of the rolling bodies or guide grooves. This substitution of mechanical adjustment with magnetic field control resolves the contradiction between preventing chattering and maintaining manufacturing feasibility.
2Ease of operation
If gothic arch rolling grooves are used to support rolling bodies, then displacement is enabled, but differential slippage increases causing higher frictional forces
Solution Approach 1:
The patent introduces a magnetic field-based retention mechanism that supplements the mechanical groove structure. The magnetic attractive force acts on the rolling bodies to prevent differential slippage during displacement, reducing frictional forces while maintaining the displacement capability provided by the rolling grooves. This hybrid approach combines mechanical guidance with magnetic stabilization.
3Object-generated harmful factors
If four rows of rolling grooves are used in circular structure to reduce differential slippage, then differential slippage is reduced, but device complexity increases and miniaturization becomes difficult
Solution Approach 1:
The patent replaces the complex four-row circular groove structure with a simpler single-row or dual-row groove configuration supplemented by magnetic retention. The magnetic attractive force provides the additional stabilization needed to control differential slippage without requiring multiple rows of grooves, thereby simplifying the overall structure and enabling miniaturization of the linear actuator.
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 solution effectively prevents chattering/backlash and suppresses differential slippage while simplifying the structure and enabling miniaturization of the linear actuator by using a magnetic attractive force to apply pressure to the rolling bodies, reducing the complexity and precision requirements of the grooves.
Implementation Method 1
a magnet that generates a bipolar magnetic field having two poles
Implementation Method 2
the first rolling grooves and the second rolling grooves apply a pressure on the rolling bodies, caused by a magnetic attractive force of a magnet
Data Source
AI summary
A linear actuator displaces a relative position between a guide rail and a slide table, which is arranged in confronting relation to the guide rail. Projections are formed on opposite end sides of the guide rail, the projections extending along a direction of displacement and projecting toward the slide table. The slide table is disposed between the projections on the opposite end sides of the guide rail, with rigid balls being interposed therebetween. Guide grooves and guide grooves, which rollably support the balls, are provided on the projections on the opposite end sides of the guide rail and on the slide table. The guide grooves and the guide grooves apply, on the balls, a pressure caused by a magnetic attractive force of permanent magnets.