Electromagnetic Actuator Passive Damping Integration

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Solution Overview

Problem

Existing electromagnetic actuators for vehicle suspension systems rely heavily on active control, which can fail due to electric failures or other malfunctions, leading to inadequate damping.

Innovation Solution

An electromagnetic actuator design incorporating a ferromagnetic structure and control current conductors, with additional damping current conductors made of high-conductivity non-magnetic materials, providing a passive damping force that is independent of active control and linearly dependent on relative velocity, ensuring consistent performance even in case of control circuit failures.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If electromagnetic actuators rely heavily on active control for damping, then damping performance can be adjusted dynamically, but the system becomes vulnerable to electric failures and malfunctions

Engineering Contradiction:
Improvedamping performance reliabilityVSAvoidactive control system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent incorporates a passive damping mechanism using eddy currents as a backup system before active control fails. The ferromagnetic structure with conductive layers is pre-configured to automatically provide damping force through electromagnetic induction when the actuator moves, ensuring continuous damping protection without requiring complex active control systems.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

2Reliability

If passive damping is added to electromagnetic actuators, then reliability improves through backup damping capability, but device complexity increases

Engineering Contradiction:
Improvedamping backup capabilityVSAvoidactuator structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The ferromagnetic structure serves dual functions: it provides the magnetic path necessary for active electromagnetic control while simultaneously acting as the passive damping element through embedded conductive layers. This multi-functionality eliminates the need for separate passive damping components, maintaining structural simplicity while improving reliability.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the active control conductors and passive damping conductors into a single integrated ferromagnetic structure. Both sets of conductors are embedded within the same magnetic path material, allowing the structure to perform both active electromagnetic actuation and passive eddy current damping without requiring separate components.

Inventive Principle:
Principle #5Merging (Combining)

3Force

If the magnetic field strength is increased to improve active control performance, then force generation improves, but passive damping from eddy currents increases unintentionally

Engineering Contradiction:
Improveactive control forceVSAvoidunintentional passive damping
Core Design Contradiction:
ForceVSObject-generated harmful factors

Solution Approach 1:

The patent applies different conductor configurations to different regions of the ferromagnetic structure. Active control conductors are positioned and dimensioned to maximize electromagnetic force generation, while passive damping conductors are strategically placed and sized to provide controlled eddy current damping only where needed, allowing independent optimization of both functions.

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

The actuator achieves linear dependence of force on control current and relative velocity, enabling effective passive damping as a safety feature and allowing for optimized design specifications without compromising active control performance.

Implementation Method 1

each respective one thereof forming a respective closed loop of an electrically conductive material, different from the ferromagnetic material, for providing a respective damping force induced by relative movement

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Implementation Method 2

an electric charge moving in a magnetic field experiences a force, referred to as the Lorentz force. In the actuator, the Lorentz force acts on the conductors

Methodology Applied
Scientific EffectLorentz force: Lorentz Force

Data Source

PatentEP2435726B1Electromagnetic actuator with integrated passive damper
Publication Date: 2019.11.27 SKF BV
  • EP2435726B1 patent drawingFigure 1
  • EP2435726B1 patent drawingFigure 2~4
  • EP2435726B1 patent drawingFigure 5

AI summary

An electromagnetic actuator (100) comprises magnets (109, 111, 113, 115, 11), and a ferromagnetic structure (103) accommodating control conductors (118, 121, 123, 125). The magnets and the structure can move with respect to one another under control of control currents in the control conductors. The magnetic field in a gap (107) between the magnets and the ferromagnetic structure is oriented perpendicular to the direction of relative movement. The structure (103) accommodates damping conductors (127) that form closed loops of an electrically conductive material, different from the ferromagnetic material. The damping conductors (127) provide a damping force induced by the relative movement.