Frictionless X-Y Stage with Magnetic Grid Actuation
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Solution Overview
Problem
Existing X-Y stages in milling machines and CNC equipment suffer from positioning errors due to play in mechanical connections, friction, and dimensional changes, which affect desired velocity and torque, and often require motor movement for multiple axes.
Innovation Solution
A frictionless X-Y stage system with a puck that moves on a magnetic base, utilizing a checkerboard pattern of north and south poles, allowing for simultaneous X-Y translation and rotation, with electromagnets on the puck providing bipolar force vectors for 10 possible motions, including translation, diagonal motion, and rotation, without the need for moving parts other than the stage.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If electric motors are mechanically connected to the stage for each axis, then the stage can be driven and positioned, but positioning errors occur due to play in connections, friction, and dimensional changes
Solution Approach 1:
The patent replaces traditional mechanical motor-stage connections with magnetic field-based actuation. Electromagnets mounted on the stage interact with a magnetic grid on the base to produce motion forces, eliminating mechanical couplings, gears, and belts that cause play and friction. This substitution of mechanical systems with electromagnetic systems directly resolves the positioning accuracy problem while reducing mechanical complexity.
Solution Approach 2:
The invention extracts and removes the mechanical transmission components (motors, gears, belts, couplings) from the positioning system. By using electromagnetic forces directly applied to the stage through interaction with the magnetic grid, the system eliminates the intermediate mechanical elements that generate positioning errors, achieving direct-drive motion without mechanical play or friction.
2Device complexity
If a motor for one axis moves both portions of the stage, then device complexity is reduced, but positioning precision deteriorates due to coupled movements and interference
Solution Approach 1:
The patent segments the actuation system by providing independent electromagnetic control for each axis. Electromagnets are selectively activated on the stage to produce forces in specific directions (X-axis, Y-axis, or both simultaneously), allowing independent and precise control of each degree of freedom. This segmentation enables multi-axis motion with a single stage platform while maintaining positioning precision through selective electromagnetic activation.
3Ease of manufacture
If traditional mechanical connections are used between motor and stage, then the system is easier to manufacture, but positioning errors increase due to friction and dimensional changes
Solution Approach 1:
The patent replaces friction-prone mechanical connections with contactless electromagnetic actuation. Electromagnets on the stage interact with the magnetic grid on the base through magnetic fields, eliminating physical contact points that generate friction, wear, and dimensional changes. This substitution maintains ease of manufacture through modular electromagnetic components while dramatically improving positioning accuracy by eliminating mechanical error sources.
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 system achieves high-resolution, frictionless motion with minimal positioning errors, enabling precise control and reduced mechanical complexity, as the puck can move in multiple directions with optimal force vectors without the need for separate motor movements for each axis.
Implementation Method 1
The surface on which the puck moves is called herein a base. The puck is able to move simultaneously in X-Y translation and can rotate relative to the base. A stage system comprises: (i) a flat base comprising north pole and south pole magnets arranged in a checkerboard pattern.
Implementation Method 2
In a simple embodiment, four nodes on the puck are electromagnetics, which may be powered off, but for puck motion, are typically configured to have a north or south magnetic field.
Implementation Method 3
each corner node is energized with either a north or south field, at a variable strength, or off, which then either attracts or repels some combination of the base magnets, most strongly interacting with the nearest base magnets.
Data Source
AI summary
An X-Y movable stage with rotation and tilt is described. A fixed base comprises a magnetic bed with a checkerboard, hexagonal or pseudo-random pattern of alternating north and south poles on a grid. A movable puck moves, rotates and tilts on the base. The base and puck system is free of any other moving parts. The puck comprises three or more nodes where each node may be energized for a north, south, or off magnetic field, with varying field strength. Embodiments include use in a vacuum or fluid. Light from the base to the puck may be used to charge or power a puck. Methods of mapping node locations, controllers, and applications are described. Embodiments for specific applications are described.