Planar Drive Rotor Gap Crossing With Local Magnetic Field Boost

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing planar drive systems face challenges in moving a rotor across gaps between stator modules due to the lack of magnetic field support, leading to instability and potential loss of control over the rotor's position.

Innovation Solution

A method involving the generation of magnetic fields with varying strengths by stator modules to maintain the rotor's vertical and horizontal positions, utilizing a first magnetic field with increased strength near the gap and reduced strength farther away to compensate for the lack of magnetic support, and dynamic field adjustments based on position detection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If stator modules are spaced apart to form a gap, then the rotor can be moved across the gap, but the magnetic field support is lost in the gap region causing instability

Engineering Contradiction:
Improve rotor movement capability across gapsVSAvoid rotor position stability
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent applies local quality by creating different magnetic field strengths in different spatial regions. Specifically, the first magnetic field has a first strength in a first region, a second greater strength in a second region adjacent to the gap, and a third lesser strength in a third region. This spatial variation in magnetic field properties ensures the rotor remains stable throughout its movement across the gap while maintaining controlled movement in other regions.

Inventive Principle:
Principle #3Local quality

2Reliability

If the magnetic field strength is increased near the gap to maintain rotor stability, then position control is improved, but energy consumption increases

Engineering Contradiction:
Improve rotor position controlVSAvoid energy consumption for magnetic field generation
Core Design Contradiction:
ReliabilityVSUse of energy by moving object

Solution Approach 1:

The magnetic field is concentrated with greater strength only in the second region adjacent to the gap where it is most needed for stability. The first and third regions have lesser field strengths, optimizing the balance between rotor control and energy efficiency by avoiding unnecessary high field strength in regions where it is not required.

Inventive Principle:
Principle #3Local quality

3Ease of operation

If the magnetic field is made homogeneous across the stator module, then the rotor movement is simplified, but the rotor cannot be stably held during gap crossing

Engineering Contradiction:
Improve rotor movement simplicityVSAvoid rotor stability during gap crossing
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The magnetic field is deliberately made inhomogeneous with three distinct strength regions. The second region adjacent to the gap has greater magnetic field strength to provide enhanced support during the critical gap-crossing phase, while other regions have standard field strengths. This localized variation ensures stable rotor holding during gap crossing while maintaining manageable operation elsewhere.

Inventive Principle:
Principle #3Local quality

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

Enables stable movement of the rotor across gaps by maintaining its position parallel to stator modules, compensating for magnetic field gaps, and adjusting magnetic forces to accommodate varying loads and positions.

Implementation Method 1

A first magnetic field can be generated by the first stator module. The first magnetic field can hold the rotor in a vertical position, spaced apart from a surface of the first stator module

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 2

The first magnetic field exhibits a second magnetic field strength in a first near-field region adjacent to the gap when the rotor moves across the gap. The second magnetic field strength is greater than the first magnetic field strength

Methodology Applied
Scientific EffectMagnetic force: Force

Implementation Method 3

A second magnetic field can be generated by the second stator module. The second magnetic field can hold the rotor in a vertical position, spaced apart from a surface of the second stator module

Methodology Applied
Scientific EffectMagnetic field: Magnetic Field

Implementation Method 4

The first magnetic field exhibits a third magnetic field strength in a first far-field region from the gap when the rotor moves across the gap. The third magnetic field strength is lower than the first magnetic field strength, thus compensating for any missing magnetic force on the rotor in the region of the gap

Methodology Applied
Scientific EffectMagnetic force compensation: Force

Data Source

PatentEP3818625B2Method for moving a rotor in a planar drive system
Publication Date: 2026.01.28 BECKHOFF AUTOMATION GMBH
  • EP3818625B2 patent drawingFigure 1
  • EP3818625B2 patent drawingFigure 2
  • EP3818625B2 patent drawingFigure 3

AI summary

The invention relates to a method for moving a rotor (20) in a planar drive system (1). The planar drive system (1) has a first stator module (11), a second stator module (12), and a rotor (20), and the first stator module (11) and the second stator module (12) are arranged in a mutually spaced manner, a gap (30) being formed between the first stator module (11) and the second stator module (12). A first magnetic field (91) can be generated by the first stator module (11), and a second magnetic field can be generated by the second stator module (12), wherein the first magnetic field (91) or the second magnetic field (92) can hold the rotor (20) in a vertical position at a distance to the surface of the first stator module (11) and/or the second stator module (12), and the first magnetic field (91) and/or the second magnetic field has a first magnetic field strength (93) in order to hold the rotor (20) in the vertical position. The first magnetic field (91) and/or the second magnetic field can additionally also be used to change the horizontal position of the rotor (20). The first stator module (11) has a first close-up region (71) adjacent to the gap (30), and the first magnetic field (91) has a second magnetic field strength (94) in the first close-up region (71) when the rotor (20) is moved over the gap (30), said second magnetic field strength (94) being greater than first magnetic field strength (93).