Electromagnet Guide Sleeve Minimizes Parasitic Air Gap
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electromagnets suffer from suboptimal magnetic force-stroke characteristics due to significant parasitic air gaps, which are difficult to minimize without risking contact and increased hysteresis, especially in complex designs with radial play and large air gaps.
Innovation Solution
The magnetic piston is mounted on a guide sleeve with a sliding fit, where the pole piece forms a bushing part that overlaps the coil body, allowing for an optimal parasitic air gap width by adjusting the inner and outer diameters, and using identical pole pieces to minimize costs and ensure precise coaxiality, avoiding contact and friction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If the parasitic air gap is minimized to improve magnetic force, then magnetic force increases, but the risk of contact between piston and pole piece increases leading to increased hysteresis
Solution Approach 1:
The guide sleeve acts as an intermediary component between the magnetic piston and the pole piece. It provides a precisely fitted sliding guide that maintains the required clearance while preventing direct contact, thus allowing minimal parasitic air gap without risking piston-pole piece contact and associated hysteresis losses
Solution Approach 2:
The invention replaces complex mechanical alignment systems (such as roller bearings with play) with a precision sliding fit guide sleeve. This eliminates radial play and ensures consistent coaxiality, allowing the parasitic air gap to be minimized to less than 0.1 mm without risking contact during piston movement
2Manufacturing precision
If complex alignment systems like roller bearings are used to ensure concentric alignment, then alignment accuracy improves, but device complexity and radial play increase
Solution Approach 1:
The invention extracts and eliminates the complex roller bearing mounting system from the design. Instead, it uses a simple guide sleeve with sliding fit that provides both alignment and guidance functions, significantly reducing device complexity while maintaining manufacturing precision through the precision fit alone
3Adaptability or versatility
If the pole piece is designed with adjustment capability for subsequent alignment, then alignment flexibility improves, but the pole air gap must be increased
Solution Approach 1:
The guide sleeve with its precisely fitted sliding fit provides self-alignment during assembly. The interference fit of the bushing part into the hollow cylinder automatically ensures correct coaxial positioning, eliminating the need for subsequent adjustment mechanisms while maintaining minimal parasitic air gap for optimal magnetic force
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
This configuration achieves an optimal force-stroke characteristic with minimized parasitic air gaps, reducing hysteresis and enabling cost-effective production while maintaining precise alignment and high magnetic force with a compact design.
Implementation Method 1
Contact between the magnetic piston and the pole piece would lead to increased hysteresis in the magnetic force-stroke characteristic due to friction and must therefore be avoided at all costs.
Implementation Method 2
an electromagnet, in particular a switching magnet, with an exciter winding located on a coil former
Implementation Method 3
The magnetic yoke between the pole piece and the magnetic piston is of great importance for the operating properties of such magnets
Implementation Method 4
a parasitic air gap is formed between the inner wall of the hollow cylinder and the circumference of the piston
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The invention relates to an electromagnet, in particular a switching magnet, having a field winding (11) which is located on a coil former (7), and having a pole piece (23) which forms a part of the magnetic return path, wherein a pole core (17) and an axially movable magnet piston (19) are provided within the coil former (7), the pole piece (23) forms an aperture opening (25) for the magnet piston (19) on the area opposite the pole core (17), and said magnet piston (19) is borne for its movement in its guide in the pole core (17), characterized in that the pole piece (23) has a flange part (27) which at least partially engages over the coil former (7) at its axial end, and has a bush part (29) which extends axially therefrom and, within the coil former (7), forms a hollow cylinder which engages over a longitudinal section of the magnet piston (19) between the inner wall of which hollow cylinder and the circumference of the magnet piston (19) a parasitic air gap (30) is formed.