Frustoconical Air Gap Electromagnetic Drive for High-Pressure Actuation

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Solution Overview

Problem

Existing electromagnetic drives for high-pressure systems are large, costly, and lack the necessary force to handle high-pressure applications efficiently, while smaller drives fail to provide sufficient power reserves against pressure medium contaminants.

Innovation Solution

An electromagnetic drive with a coil, core, and armature featuring a frustoconical air gap and a magnetizable web for compact design, enhanced magnetic force, and precise positioning, along with a magnetic field sensor for force measurement and control, and damping fluid for reduced acceleration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If electromagnetic drives are made smaller for cost optimization and space saving, then device size and cost are reduced, but the force required for high-pressure systems is insufficient

Engineering Contradiction:
Improveactuator sizeVSAvoidlifting force
Core Design Contradiction:
Volume of moving objectVSForce

Solution Approach 1:

The patent applies parameter changes by modifying the air gap geometry from a conventional uniform shape to a frustoconical shape with legs at specific angles (30°-70°) to the axis of symmetry. This geometric parameter change increases the magnetic force generation efficiency, allowing smaller actuators to produce the required lifting force for high-pressure systems (65-200 bar) while maintaining compact dimensions.

Inventive Principle:
Principle #35Parameter changes

2Ease of manufacture

If conventional uniform air gap geometry is used, then manufacturing is simpler, but lateral forces and positioning precision are worsened

Engineering Contradiction:
Improveair gap manufacturingVSAvoidarmature positioning precision
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The patent employs asymmetry by designing the air gap with a frustoconical shape where the legs are angled at 30°-70° relative to the axis of symmetry. This asymmetric geometry generates magnetic forces that naturally counteract lateral forces during armature movement, significantly improving positioning precision and reducing transverse force effects without complicating the manufacturing process.

Inventive Principle:
Principle #4Asymmetry

3Volume of moving object

If actuator size is reduced for high-pressure systems, then space and cost are optimized, but power reserve against contaminants is insufficient

Engineering Contradiction:
Improveactuator dimensionsVSAvoidpower reserve
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The patent utilizes parameter changes in the air gap geometry (frustoconical shape with angled legs) to enhance the magnetic force density. This allows the compact actuator to generate sufficient magnetic force to overcome contamination forces in high-pressure systems, providing adequate power reserve while maintaining reduced dimensions for space and cost optimization.

Inventive Principle:
Principle #35Parameter changes

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 compact, cost-efficient, and flexible operation with exact positioning and optimized extension speed in high-pressure systems, while minimizing lateral forces and ensuring reliable operation.

Implementation Method 1

an electromagnet with a coil (3), a core (4) and an armature (6) which can be moved in a linear fashion

Methodology Applied
Scientific EffectMagnetic field generation: Electromagnet

Implementation Method 2

The armature of the electromagnet is ferromagnetic and is attracted by the magnetic field generated by the coil and amplified by the core

Methodology Applied
Scientific EffectMagnetic attraction: Magnetism

Data Source

PatentEP3356711B1Electromagnetic actuating drive for carrying out a linear movement
Publication Date: 2020.08.26 VOITH PATENT GMBH
  • EP3356711B1 patent drawingFigure 1
  • EP3356711B1 patent drawingFigure 2
  • EP3356711B1 patent drawingFigure 3

AI summary

The invention relates to an electromagnetic drive (1) for carrying out a linear movement, comprising an electromagnet (2) with a coil (3), a core (4), and an armature (6) which can be linearly moved along an axis of symmetry (5) of the core (4), wherein an air gap (7) is formed between the core (4) and the armature (6). The aim of the invention is an electromagnetic drive which can be used in a simple, compact, cost-efficient, and flexible manner with high-pressure systems while simultaneously allowing an exact positioning of the piston at any position with an optimized extension speed. This is achieved in that the air gap (7) has a base (8), two limbs (9, 10) which run symmetrically relative to the axis of symmetry (5), and a substantially truncated cone-shaped cross-section in the longitudinal section, and the limbs (9, 10) are arranged relative to the axis of symmetry (5) of the core (4) so as to form an angle α.