Electrodynamic Drive With Soft-Magnetic Frame and Strain Relief
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromagnetic drives in pyrotechnical and pneumatic devices face limitations in force and efficiency due to insufficient force and working capacity per drive mass or volume, high wiring complexity, and low efficiency, particularly in highly dynamic applications like Thomson coils and railguns.
Innovation Solution
An electrodynamic drive comprising a first excitation coil, a soft-magnetic frame with a saturation flux density of at least 1.0 T, and a short circuit armature, where the frame is designed with strain relief mechanisms and materials like soft-magnetic composite materials to enhance force density and efficiency, and operated using a capacitor discharge.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If conventional electromagnetic drives are used in pyrotechnical devices, then the devices can operate, but the force and working capacity per drive mass or volume are insufficient
Solution Approach 1:
The patent employs soft-magnetic composite materials for the frame structure, combining materials with high saturation flux density (at least 1.0 T) and controlled electrical conductivity (not more than 10^6 S/m). This composite approach optimizes the balance between magnetic performance and eddy current losses, achieving higher force density without proportionally increasing drive mass
Solution Approach 2:
The invention optimizes key parameters including the saturation flux density of the frame material (Bs ≥ 1.0 T), electrical conductivity (σ ≤ 10^6 S/m), and geometric dimensions of the armature and frame. By carefully controlling these parameters, the drive achieves enhanced force constants while managing the weight-to-force ratio
2Force
If Thomson coils with flux concentrators are used, then magnetic field concentration is improved, but wiring expenditure and device complexity increase
Solution Approach 1:
The patent integrates the flux concentrator function directly into the frame structure itself, which is formed of soft-magnetic composite material. The frame serves dual purposes: providing structural support and concentrating magnetic flux. This merging eliminates separate flux concentrator components and reduces wiring complexity compared to conventional Thomson coil designs
Solution Approach 2:
The frame structure performs multiple functions simultaneously: it provides mechanical support, guides the armature movement, concentrates magnetic flux, and limits eddy currents through its composite material properties. This multi-functionality reduces the overall component count and wiring requirements
3Loss of energy
If conventional electromagnetic drives are used, then devices can function, but efficiency is too low
Solution Approach 1:
The soft-magnetic composite frame material with controlled electrical conductivity (σ ≤ 10^6 S/m) reduces eddy current losses while maintaining high magnetic permeability. This material optimization directly improves electric efficiency by minimizing parasitic energy losses in the frame structure
Solution Approach 2:
The invention optimizes the electrical conductivity parameter of the frame material to balance between magnetic flux conduction and eddy current suppression. By controlling σ ≤ 10^6 S/m, the design achieves reduced energy losses while maintaining efficient electromagnetic coupling
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 electrodynamic drive achieves higher force constants and electric efficiencies, enabling higher volume- or weight-specific work, addressing the limitations of existing electromagnetic drives by optimizing the design of the frame and armature for enhanced performance.
Implementation Method 1
an electrodynamic drive, comprising: a first excitation coil (30), a soft-magnetic frame (10), and a short circuit armature (40) mounted movably along an axis
Implementation Method 2
The electrodynamic drive achieves higher force constants and electric efficiencies
Implementation Method 3
the frame has a saturation flux density of at least 1.0 T
Implementation Method 4
a soft-magnetic frame (10)
Implementation Method 5
operated using a capacitor discharge
Data Source
AI summary
The invention relates to a highly dynamic electromagnetic drive in the manner of a Thomson coil with soft-magnetic frame, comprising a first excitation coil (30) whose winding height is greater than its length, which hence is flat; a soft-magnetic frame (10) in which the first excitation coil (30) is arranged and against which it abuts, and which in in the manner of a pot magnet constitutes an open magnetic circuit which includes an outer region (11), a bottom (12) and an inner region (13), and which is open on its end face, wherein the first excitation coil at least partly encloses the inner part (13) of the frame; a short circuit armature (40) preferably formed hollow cylindrical at least on its side facing the first excitation coil (30), which is movably mounted along an axis and which in its stroke starting position dips into the end-face opening of the frame (10) and thereby at least partly encloses the inner part of the frame (13), wherein the frame (10) entirely or predominantly is formed of a soft-magnetic composite material or one or more sheet stacks, which has a saturation flux density of at least 1.5 T and an effective specific electrical conductivity of not more than 106 S/m, and the first excitation coil (30) and/or the frame (10) include at least one means for strain relief, in particular in the form of an enclosure in order to at least partly absorb at least the radial forces occurring on the first excitation coil (30) during an actuating operation vertically to the direction of movement, and wherein the Lorentz force acting on the short circuit armature is used to perform work.