Magneettiväli

Magneettiväli, often translated as "magnetic gap" or "air gap" in English, refers to the physical separation between two magnetic components, typically in a magnetic circuit. This separation is usually filled with a non-magnetic material, most commonly air, but it can also be a vacuum or other non-ferromagnetic substances. The presence of a magneettiväli significantly impacts the performance of magnetic devices.

In a magnetic circuit, magnetic flux lines tend to follow paths of low reluctance, which are generally ferromagnetic materials. When a magneettiväli is introduced, it creates a region of very high reluctance within the circuit. This means that a much larger magnetomotive force is required to drive the same amount of magnetic flux across the gap compared to driving it through a solid magnetic material. Consequently, the magnetic field strength across the magneettiväli is often weaker than in the surrounding ferromagnetic material, although the flux density itself can be maintained if the cross-sectional area is unchanged.

Magneettiväli is a critical design parameter in many electromagnetic devices. In transformers and inductors, it is carefully controlled to influence inductance values and prevent magnetic saturation of the core. In electric motors and generators, the magneettiväli between the stator and rotor is essential for generating torque and inducing voltage. In magnetic sensors and actuators, the variation in the magneettiväli is often the basis for their operation, as changes in the gap alter magnetic properties that can be measured or exploited. The precise dimensioning of the magneettiväli is therefore crucial for achieving the desired performance characteristics in these applications.