Linear Motor Capacitive Power Transfer for Consistent Air Gaps

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Solution Overview

Problem

Existing linear motors face challenges with complex stator designs, heat generation, and mechanical contact risks due to small air gaps, particularly in applications requiring contactless power transfer and efficient operation on complex tracks with bends.

Innovation Solution

The linear motor design incorporates capacitive power transfer electrodes parallel to the motor air gap, maintaining consistent air gaps and efficiency through bends, allowing for efficient power and data communication on complex track geometries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Force

If the air gap between drive coils and drive magnets is reduced to improve propulsion efficiency, then the propulsion force increases, but the risk of mechanical contact between stator and shuttle increases

Engineering Contradiction:

Improvepropulsion forceVSAvoidrisk of mechanical contact

Core Design Contradiction:

ForceVSReliability

Solution Approach 1:

The patent introduces a capacitive power transfer arrangement with electrodes as an intermediary system between stator and shuttle. This allows power transfer through the air gap without requiring the shuttle to carry heavy power supply equipment, enabling the use of smaller air gaps for improved propulsion efficiency while maintaining reliability through contactless power transfer.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Device complexity

If drive coils are arranged on the stator in a long stator linear motor design, then the stator structure is simplified, but heat generation increases and requires active cooling

Engineering Contradiction:

Improvestator structure complexityVSAvoidheat generation

Core Design Contradiction:

Device complexityVSTemperature

Solution Approach 1:

The patent extracts the power supply function from the moving shuttle and places it on the stationary stator through the capacitive power transfer arrangement. This allows the drive coils to be arranged on the stator without the heat management issues associated with active cooling systems, as the power transfer is contactless and efficient.

Inventive Principle:

Principle #2Taking out (Extraction)

3Reliability

If contactless power transfer is implemented to avoid mechanical contact, then reliability improves, but the complexity of the power transfer system increases

Engineering Contradiction:

Improveavoidance of mechanical contactVSAvoidpower transfer system complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The capacitive power transfer arrangement serves multiple functions simultaneously: it transfers power contactlessly from stator to shuttle, enables bidirectional data communication between control and shuttle, and provides a simple structure that does not require complex active cooling systems. This multi-functionality reduces overall system complexity while maintaining high reliability.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Adaptability or versatility

If the stator is designed with complex geometry to accommodate bends and switches, then adaptability to complex tracks improves, but manufacturing precision requirements increase

Engineering Contradiction:

Improvetrack geometry adaptabilityVSAvoidair gap consistency

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent addresses the manufacturing precision challenge by orienting the capacitive power transfer electrodes parallel to the motor air gap. This dimensional orientation ensures that both air gaps are equally affected by bends in the track geometry, allowing the system to maintain consistent performance on complex tracks without requiring extremely precise manufacturing tolerances.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

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

Ensures consistent propulsion and power transfer efficiency on complex track geometries, reducing mechanical contact risks and heat generation, while enabling bidirectional data communication.

Implementation Method 1

the at least one primary electrode and the at least one secondary electrode form a power transfer capacitor with the power transfer air gap as dielectric for capacitive power transfer for transferring electrical energy from the stator to the shuttle

Methodology Applied

Scientific EffectCapacitive power transfer: Capacitance

Implementation Method 2

the drive coils are energized by applying a drive coil voltage to the drive coils for generating an electromagnetic drive field. This electromagnetic drive field interacts with the magnetic field of the drive magnets on the shuttle for producing a propulsion force acting on the shuttle

Methodology Applied

Scientific EffectElectromagnetic interaction: Electromagnetic Induction

Data Source

PatentEP4624225A1Linear motor with capacitive power transfer

Publication Date: 2025.10.01 ABB (SCHWEIZ) AG

Figure 1~2
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Figure 4~5

AI summary

For providing a linear motor with improved capacitive power transfer from the stator to the shuttle of the motor, the linear motor (1) comprises a capacitive power transfer arrangement (10) with a power transfer capacitor (CPT) with a power transfer air gap (13) as dielectric in between a primary electrode (11) and a secondary electrode (12), wherein the motor air gap (6) of the linear motor (1) and the power transfer air gap (13) are parallel and are arranged in transverse direction (y) next to each other.