Method for permanent magnet protection

1. A method for manufacturing of a permanent magnet pole piece including a magnet fixed to a base plate, a protective cover and a filling mass, comprising:

fixing of the protective cover to the base plate so that the protective cover covers the magnet such that an interior cavity between the protective cover and the base plate are framed and such that the protective cover and the base plate are hermetically sealed;

evacuating the interior cavity through a first opening;

injecting the filling mass through a second opening into the interior cavity; and

curing the filling mass,

wherein the evacuating generates a vacuum inside the interior cavity causing the filling mass to be sucked into the interior cavity.

2. The method as claimed in claim 1 , wherein the protective cover is fixed to the base plate by gluing, welding or soldering.

3. The method as claimed in claim 1 , wherein the first opening that the interior cavity is evacuated is arranged in the base plate.

4. The method as claimed in claim 1 , wherein the second opening that the filling mass is injected is arranged in the base plate.

5. The method as claimed in claim 1 , wherein a fibreglass mat is placed on at least a part of a surface of the magnet before fixing the protective cover to the base plate.

6. The method as claimed in claim 1 , wherein the protective cover comprises a fibreglass mat.

7. The method as claimed in claim 1 , wherein the magnet is demagnetized.

8. The method as claimed in claim 7 , wherein the demagnetized magnet is magnetised after the filling mass is cured.

9. The method as claimed in claim 1 , wherein the base plate is made of steel.

10. The method as claimed in claim 1 , wherein the protective cover is made of steel or stainless steel.

11. The method as claimed in claim 1 , wherein the filling mass is epoxy resin or silicone rubber.

12. The method as claimed in claim 1 , wherein the protective cover is glued to the base plate.

13. The method as claimed in claim 1 , wherein the protective cover is welded to the base plate.

14. The method as claimed in claim 1 , wherein the protective cover is soldered to the base plate.

15. The method as claimed in claim 1 , wherein the first opening that the interior cavity is evacuated is arranged in the base plate or in the protective cover.

16. The method as claimed in claim 1 , wherein the second opening that the filling mass is injected is arranged in the base plate or in the protective cover.

17. A method for manufacturing of a permanent magnet pole piece having a magnet fixed to a base plate, a protective cover and a filling mass, comprising:

fixing of the protective cover to the base plate so that the protective cover covers the magnet and forming an interior cavity between the protective cover and the base plate so that the protective cover and the base plate are hermetically sealed;

evacuating the interior cavity through an opening;

injecting the filling mass through an opening into the interior cavity; and

curing the filling mass;

wherein the protective cover is fixed to the base plate by gluing, welding or soldering;

wherein the opening that the interior cavity is evacuated is arranged in the base plate or in the protective cover;

wherein the opening that the filling mass is injected is arranged in the base plate or in the protective cover;

wherein a fibreglass mat is placed on at least a part of a surface of the magnet before fixing the protective cover to the base plate;

wherein the protective cover comprises a fibreglass mat;

wherein the protective cover is glued to the base plate by the injected filling mass.