How to mount and align magnets

Motor Drivers/Sensors
1

I am considering using an MPS magnet and magnetic sensor in a beside-the-shaft application. This is my first time using a target magnet in an application and the website has poor details on actual implementation of such a system. Therefore, I have several questions, hopefully these are all really easy to answer (and probably obvious for someone who has done a lot of these systems).

  1. The datasheets for the magnets include a blue arrow showing the direction of feild, is this arrow actually printed on the magnet too?
  2. Similar to question 1 - Are there any alignment markings on the magnets, if not, then what is the best way to mount the magnets so that they are at a repeatable angular position on the shaft?
  3. I am really amazed that there are no ring magnets that have either a “D” shaped opening or a threaded screw so that they could be mounted on a D shaft with highly repeatable position. Does such a magnet exist?
  4. Overall, do you have any application notes that show real photos (not drawings) of actual magnets mounted on actual shafts? If not, I would suggest that this could be a really helpful application note to create, showing a bunch of commonly accepted industry options for mounting the magnets.

Thanks!

2

Hello stevec,

  1. No. Anyway, there is a chance you can get some kind of marking if you contact a magnet manufacturer to get customized magnets.
  2. No. There are several strategies, but the more accurate would be to use a magnetic angle or linear sensor to detect the magnet direction when it is being
    mounted.
  3. From my experience, there are no such standardized magnets with diametral magnetization. I suggest to look for magnet manufacturers in your area and contact them to see if they can make such magnets. It is likely they can.
  4. I could not find any. But maybe you will find this article useful: Using MagAlpha Rotary Magnetic Sensors in Side Shaft Mode | Article | MPS (monolithicpower.com)

Best,

Carmine