Let’s talk about the Halbach Array. A phenomenon that was initially discovered in 1973, this arrangement of permanent magnets functions to make the magnetic field one side stronger while negating the opposite field to nearly zero. For comparison, with a single magnet, you will have equal strength on either end. It wasn’t until the 1980s that a physicist applied the Halbach array as a means to focus particle beams, electrons, and lasers.
Halbach For Electric Motors
Halbach arrays, or one-sided flux distributions have quite a few applications, perhaps most notably as a component in the maglev train system. Also, when configured cylindrically (with a field concentrated on either outer or inner diameter), a halbach array can be used to construct an electric motor. In this case, the magnetic field would be directed into the cylinder; windings would be inserted into the field. The array itself can be stationary or act as the rotating part of the configuration (also called an “inside out” design).
Halbach Means Less Iron
While electric motors based on the Halbach array are yet to become fully mainstream, they come with a lot of possibilities. For example, the Halbach doesn’t need back iron. This reduces eddy current losses and other losses called iron losses, thus reducing weight and inertia. That allows the motor to stop and start much faster. It can also reach much higher speeds. As of now, the major con to using Halbach arrays for electric motors is the cost. It takes a lot of money to manufacture the arrays. Arranging and assembling the magnets and making sure everything is done correctly requires a significant amount of labor.
Apex Magnets & Halbach Arrays
Magnet technology has all sorts of implications for the future of the auto industry, but sometimes it’s good to just get back to the basics. Check out our FAQ for answers to some basic magnetic questions. Remember, we’re here to help answer any questions you may have. Just give us a call or email us!
