METHOD AND AN APPARATUS FOR THE SEGMENTATION OF ND-FE-B MAGNETS

Abstract

A method of segmenting a cured NdFeB magnet includes providing a first and a second NdFeB magnet. The surface of the NdFeB magnets is cleaned. An insulating adhesive is deposited on the surface of the first NdFeB magnet. Then, the first NdFeB magnet is cured. Next, a layer of the insulating adhesive is deposited on the surface of the NdFeB magnets. Then, the first NdFeB magnet and the second NdFeB magnet are stacked to produce a stacked NdFeB magnet. After stacking, a predetermined clamping pressure is applied to the stacked NdFeB magnet. The stacked NdFeB magnet is then cured to produce a cured NdFeB magnet. The cured NdFeB magnet is then machined into a plurality of small NdFeB magnets. The step of depositing the insulating adhesives is further defined as depositing a plurality of beads of the insulating adhesive onto the surface of the first NdFeB magnet.

Claims

1. A method of segmenting a stacked NdFeB magnet, said method comprising the steps of: providing a first NdFeB magnet and a second NdFeB magnet with the first NdFeB magnet and the second NdFeB magnet including rust and grease disposed on a surface of the first NdFeB magnet and the second NdFeB magnet; cleaning the surface of the first NdFeB magnet and the second NdFeB magnet to remove the rust and the grease from the first NdFeB magnet and the second NdFeB magnet; depositing an insulating adhesive onto the surface of the first NdFeB magnet; curing the first NdFeB magnet including the insulating adhesive; cleaning the surface of the first NdFeB magnet including the insulating adhesive; depositing a layer of the insulating adhesive on the surface of the first NdFeB magnet and the second NdFeB magnet; stacking the first NdFeB magnet and the second NdFeB magnet to sandwich the layer of the insulating adhesive on the surface of the second NdFeB magnet and the layer of insulating adhesive and the beads of the first adhesive on the surface of the first NdFeB magnet between the first NdFeB magnet and the second NdFeB magnet to produce a staked NdFeB magnet; applying a predetermined clamping pressure to the stacked NdFeB magnet; curing the stacked NdFeB magnet to produce a cured NdFeB magnet; machining the cured NdFeB magnet to divide the cured NdFeB magnet into a plurality of small NdFeB magnets; and said step of depositing the insulating adhesives being further defined as depositing a plurality of beads of the insulating adhesive onto the surface of the first NdFeB magnet.

2. The method as set forth in claim 1 wherein said step of depositing the plurality of beads is further defined as depositing at least three beads of the insulating adhesive spaced from one another onto the surface of the first NdFeB magnet.

3. The method as set forth in claim 1 wherein said step of depositing the plurality of beads is further defined as depositing the plurality of beads of the insulating adhesive of an epoxy resin onto the surface of the first NdFeB magnet.

4. The method as set forth in claim 1 wherein said step of providing the first NdFeB magnet and the second NdFeB magnet is further defined as providing the first NdFeB magnet and the second NdFeB magnet with the first NdFeB magnet and the second NdFeB magnet being permanent NdFeB magnets or permanent NdFeB magnets containing Terbium or Dysprosium diffused therein.

5. The method as set forth in claim 1 wherein said step of curing the first NdFeB magnet including the insulating adhesive is further defined as heating the first NdFeB magnet including the insulating adhesive in a furnace under a curing temperature of between 20 C. to 200 C. for a curing duration of between 0.1 hour and 24 hours to solidify the insulating adhesive with the insulating adhesive having a thickness of between 0.03 mm and 0.5 mm.

6. The method as set forth in claim 1 wherein said step of machining the cured NdFeB magnet is further defined as using a wire-cutting tool, disc cutting tool, or a multi-wire cutting tool to divide the cured NdFeB magnet into the small NdFeB magnets.

7. The method as set forth in claim 6 further including a step of surface treating the small NdFeB magnets.

8. The method as set forth in claim 7 wherein said said step of surface treating is further defined as phosphating and spraying the small NdFeB magnets.

9. The method as set forth in claim 1 wherein said step of cleaning being further defined as acid washing, phosphating, or sand blasting the surface of the first NdFeB magnet and the second NdFeB magnet.

10. The method as set forth in claim 1 wherein said step of cleaning the surface of the first NdFeB magnet further including a step of removing the rust and the grease from the surface of the first NdFeB magnet and the second NdFeB magnet.

11. The method as set forth in claim 10 wherein said step of removing the rust and the grease being further defined as washing the surface of the first NdFeB magnet and the second NdFeB magnet using a solution selected from at least one alcohol or acetone to remove the grease and the rust from the first NdFeB magnet and the second NdFeB magnet.

12. The method as set forth in claim 10 wherein said step of cleaning the surface of the first NdFeB magnet and the second NdFeB magnet further including a step of activating the surface of the first NdFeB magnet and the second NdFeB magnet following said step of washing.

13. The method as set forth in claim 12 wherein said step of activating is further defined as subjecting the surface of the first NdFeB magnet and the second NdFeB magnet to a plasma cleaning process using a low temperature plasma or a plasma flame.

14. The method as set forth in claim 1 wherein said step of applying the predetermined clamping pressure is further defined as disposing the stacked NdFeB magnet in a clamping tool and applying the predetermined clamping pressure of between 0.1 MPa and 20 MPa to the first NdFeB magnet and the second NdFeB magnet.

15. The clamping tool as set forth in claim 14 for applying the predetermined clamping pressure to the stacked NdFeB magnet, the clamping tool comprising: a housing of a generally U-shaped cross-section disposed on a center axis and extending between a first end and a second end; said housing including a lower plate disposed at said first end and a pair of side plates disposed spaced from one another and extending perpendicularly outwardly from said lower plate parallel to said center axis to said second end; a top plate disposed at said second end of said housing and defining a chamber extending between said lower plate and said side plates and said top plate for receiving the stacked NdFeB magnet; a platform having a convex surface disposed in said chamber and attached to said lower plate for engaging the stacked NdFeB magnet; a pair of magnet positioning members disposed in said chamber and attached to said side plates for engaging and positioning the stacked NdFeB magnet; a moving member disposed in said chamber and movable along said center axis for applying the predetermined clamping pressure to the stacked NdFeB magnet between said platform and said moving member; said moving member including a shaft of generally cylindrical shape extending from a primary end and a secondary end with said primary end being disposed outside said chamber and said secondary end being disposed in said chamber axially spaced from said primary end; a head portion of generally circular shape disposed in said chamber and attached to said secondary end of said shaft for axial movement with said shaft and engage the the stacked NdFeB magnet to sandwich the NdFeB magnets between said head portion and said platform; a spring disposed on said center axis in said chamber and extending helically between said head portion and said top plate for biasing said head portion toward said platform to apply the predetermined clamping pressure; and a handle disposed at said primary end of said shaft and attached to said primary end to allow a user to axially move said shaft and said head portion away from said platform and said lower plate.

16. A cured NdFeB magnet comprising: at least one first NdFeB magnet and at least one second NdFeB magnet disposed spaced and generally parallel to one another; a layer of an insulating adhesive disposed between said at least one first NdFeB magnet and said at least one second NdFeB magnet; and a plurality of cured beads of said insulating adhesive being dispose in said layer between said at least one first NdFeB magnet and said at least one second NdFeB magnet to space and insulate said at least one first NdFeB magnet from said at least one second NdFeB magnet.

17. The cured NdFeB magnet as set forth in claim 16 wherein said plurality of cured beads includes at least three cured beads of said insulating adhesive, spaced from one another, between said at least one first NdFeB magnet from said at least one second NdFeB magnet.

18. The cured NdFeB magnet as set forth in claim 17 wherein each of said cured beads and said layer of said insulating adhesive have a thickness of between 0.03-0.5 mm.

19. The cured NdFeB magnet as set forth in claim 16 wherein said insulating adhesive is made from an epoxy resin.

20. The cured NdFeB magnet as set forth in claim 16 wherein said at least one first NdFeB magnet and said at least one second NdFeB magnet are permanent NdFeB magnets or permanent NdFeB magnets containing Terbium or Dysprosium diffused therein.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Other advantages of the present invention will be readily appreciated, as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings wherein:

[0010] FIG. 1 is a schematic diagram of the method of segmentation of NdFeB magnets in accordance with one embodiment of the present invention;

[0011] FIG. 2 is cross-sectional perspective view of a cured NdFeB magnet in accordance with one embodiment of the present invention;

[0012] FIG. 3 is a side view of an apparatus for making the cured NdFeB magnet in accordance with one embodiment of the present invention; and

[0013] FIG. 4 is a schematic view of the method of segmentation of the NdFeB magnets.

DESCRIPTION OF THE ENABLING EMBODIMENT

[0014] Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, it is one aspect of the present invention to provide a method of segmenting a cured NdFeB magnet 20.

[0015] As best illustrated in FIG. 1, the method in accordance with one embodiment of the present invention includes a first step of providing a first NdFeB magnet 22 and a second NdFeB magnet 24. The first NdFeB magnet 22 and the second NdFeB magnet 24 includes rust and grease disposed on a surface of the first NdFeB magnet 22 and the second NdFeB magnet 24. It should be appreciated that the rust and grease may be disposed on multiple surfaces of the NdFeB magnets. In one embodiment of the present invention, the first NdFeB magnet 22 and the second NdFeB magnet 24 are permanent NdFeB magnets or permanent NdFeB magnets containing Terbium or Dysprosium diffused therein.

[0016] The next step of the method is cleaning the surface of the first NdFeB magnet 22 and the second NdFeB magnet 24. It should be appreciated that the step of cleaning can be further defined as acid washing, phosphating, or sand blasting the surface of the first NdFeB magnet 22 and the second NdFeB magnet 24. The step of cleaning the surface of the first NdFeB magnet 22 and the second NdFeB magnet 24 includes a step of removing the rust and the grease from the surface of the first NdFeB magnet 22 and the second NdFeB magnet 24. The step of removing the rust and the grease is further defined as washing the surface of the first NdFeB magnet 22 and the second NdFeB magnet 24 using a solution to remove the grease and the rust from the first NdFeB magnet 22 and the second NdFeB magnet 24. It should be appreciated that the solution can be selected from at least one alcohol or acetone. After washing, the surface of the first NdFeB magnet 22 and the second NdFeB 24 is activated by subjecting the surface of the first NdFeB magnet 22 and the second NdFeB magnet 24 to a plasma cleaning process. It should be appreciated that the plasma cleaning process can be performed using a low temperature plasma or a plasma flame.

[0017] Then, an insulating adhesive is disposed onto the surface of the first NdFeB magnet 22. During the step of depositing the insulating adhesives, a plurality of beads 26 of the insulating adhesive are disposed onto the surface of the first NdFeB magnet 22. In one embodiment of the present invention, at least three beads 26 are disposed on onto the surface of the first NdFeB magnet 22. It should be appreciated that the insulating adhesive includes, but not limited to, an epoxy resin. Next, the first NdFeB magnet 22 including the insulating adhesive is cured by heating the first NdFeB magnet 22 including the insulating adhesive in a furnace under a curing temperature of between 20 C. to 200 C. for a curing duration of between 0.1 hour and 24 hours to solidify the beads 26 of the insulating adhesive. By solidifying the beads 26 of the insulating adhesive, the beads 26 hardens thereby allowing the beads 26 to properly space the first NdFeB magnet 22 from the second NdFeB magnet 24 when the first NdFeB magnet 22 and the second NdFeB magnet 24 are stacked together. At the same time, the beads 26 are also elastically deformable to prevent the beads 26 from being crushed when stacking the first NdFeB magnet 22 and the second NdFeB magnet 24. It should be appreciated that the beads 26 typically has a thickness T of between 0.03 mm and 0.5 mm to ensure effective insulation between the first NdFeB magnet 22 and the second NdFeB magnet 24.

[0018] Next, the surface of the first NdFeB magnet 22 including the insulating adhesive is further cleaned by acid washing, phosphating, or sand blasting the surface of the first NdFeB magnet 22. The step of cleaning the surface of the first NdFeB magnet 22 including the insulating adhesive can further include a step of washing the surface of the first NdFeB magnet 22 using the solution selected from at least one alcohol or acetone. After washing, the surface of the first NdFeB magnet 22 including the insulating adhesive is activated by subjecting the surface of the first NdFeB magnet 22 including the insulating adhesive to a plasma cleaning process.

[0019] After cleaning, a layer 28 of the insulating adhesive is deposited on the surface of the first NdFeB magnet 22 and the second NdFeB magnet 24. Then, the first NdFeB magnet 22 and the second NdFeB magnet 22 are stacked to produce a stacked NdFeB magnet. During stacking, the layer 28 of the insulating adhesive on the surface of the second NdFeB magnet 22 and the layer 28 of insulating adhesive and the beads 26 of the first adhesive on the surface of the first NdFeB magnet 22 are sandwiched between the first NdFeB magnet 22 and the second NdFeB magnet 24. A predetermined clamping pressure is then applied to the stacked NdFeB magnet. To apply the predetermined clamping pressure, the stacked NdFeB magnet is placed in a clamping tool and the predetermined pressure of between 0.1 MPa and 20 MPa is applied to the stacked NdFeB magnet. This is to ensure that the layer 28 of insulating adhesive is evenly spread, i.e. having a uniform thickness, between the first NdFeB magnet 22 and the second NdFeB magnet 24. It should be appreciated that, in one embodiment of the present invention, the thickness of the layer 26 is equivalent to the thickness of the beads 28, e.g. between 0.03 mm and 0.5 mm. In one embodiment of the present invention, the stack NdFeB magnet only includes a first NdFeB magnet 22 and the second NdFeB magnet 24, i.e. the stacked NdFeB magnets includes two NdFeB magnets being stacked together. It should be appreciated that the method of the present invention can be used to stack between 2 to 50 NdFeB magnets together.

[0020] Then, the stacked NdFeB magnet is cured by heating the stacked NdFeB magnet in the clamping tool under the predetermined clamping pressure in a furnace at a predetermined temperature of between 20 C. and 250 C. for a predetermined duration of between 0.1 hr and 24 hr to produce a cured NdFeB magnet 20. In other words, during the curing of the stacked NdFeB magnet, both the clamping tool and the stacked NdFeB magnet are subjected to the heat treatment. The cured NdFeB magnet 20 is then machined into a plurality of small NdFeB magnets. In other words, during the machining step, the cured NdFeB magnet 20 is divided into a plurality of small NdFeB magnets 30. To machine the cured NdFeB magnet 20, a wire cutting tool, a disc cutting tool, or a multi-wire cutting tool is used to cut and divide the cured NdFeB magnet 20 into the small NdFeB magnets 30. In addition, the machining step can also be used to dispose excessive insulating adhesive, if any, around the cured NdFeB magnets 20. After dividing the cured NdFeB magnet 20, the small NdFeB magnets 30 are subjected to a surface treatment process by phosphating and spraying the small NdFeB magnets to protect the surfaces of the small NdFeB magnets 30.

[0021] It is another aspect of the present invention to provide a cured NdFeB magnet 20. The cured NdFeB magnet 20, as best shown in FIG. 2, includes at least one first NdFeB magnet 22 and at least one second NdFeB magnet 24 disposed generally spaced and parallel to one another. It should be appreciated that the at least one first NdFeB magnet 22 and the at least one second NdFeB magnet 24 can be permanent NdFeB magnets or permanent NdFeB magnets containing Terbium or Dysprosium diffused therein. A layer 28 of an insulating adhesive is disposed between the at least one first NdFeB magnet 22 and the at least one second NdFeB magnet 24. A plurality of cured beads 26 of the insulating adhesive is dispose in the layer 28 between the at least one first NdFeB magnet 22 and the at least one second NdFeB magnet 24 to space and insulate the at least one first NdFeB magnet 22 from the at least one second NdFeB magnet 24. The plurality of cured beads 26 includes at least three cured beads 26 of the insulating adhesive, spaced from one another, between the at least one first NdFeB magnet 22 from the at least one second NdFeB magnet 24. It should be appreciated that, in one embodiment of the present invention, the insulating adhesive can be made from an epoxy resin and that each of the cured beads 26 and the layer 28 of the insulating adhesive can have a thickness T of between 0.03-0.5 mm.

[0022] It is a further aspect of the present invention to provide clamping tool 32 for applying the predetermined clamping pressure to the stacked NdFeB magnet. The clamping tool 32, as best shown in FIG. 3, includes a housing 34, having a generally U-shaped cross-section, disposed on a center axis A. The housing 34 extends between a first end 36 and a second end 38. The housing 34 includes a lower plate 40 and a pair of side plates 42. The lower plate 40 is disposed at the first end 36 of the housing 34. The pair of side plates 42, spaced from one another, extends perpendicularly outwardly from the lower plate 40, parallel to the center axis, to the second end 38. The housing 34 further includes a top plate 44 disposed at the second end 38 of the housing 34 to define a chamber 46 extending between the lower plate 40, the side plates 42, and the top plate 44 for receiving the stacked NdFeB magnet. It should be appreciated that the chamber 46 can be configured to receive a stacked NdFeB magnet made from up to 50 individual NdFeB magnets. A platform 48, having a generally convex surface 50, is disposed in the chamber 46 and attached to the lower plate 40 for engaging the stacked NdFeB magnet. A pair of magnet positioning members 52 disposed in the chamber 46 and attached to the side plates 42 for engaging and positioning the stacked NdFeB magnet in the chamber 46. It should be appreciated that the magnet positioning members 52 can include a plurality of protrusions 53 extending outwardly from the magnet positioning members 52 perpendicular to the center axis A for engaging the stacked NdFeB magnet.

[0023] A moving member 54 is disposed in the chamber 46 and movable along the center axis A for applying the predetermined clamping pressure to the stacked NdFeB magnet in the chamber 46 between the platform 48 and the moving member 54. The moving member 54 includes a shaft 56, having a generally cylindrical shape, extending through the top plate 44 along the center axis A between a primary end 58 and a secondary end 60. The primary end 58 of the moving member 54 is disposed outside the chamber 46 and spaced from the housing 34. The secondary end 60 is disposed in the chamber 46 axially spaced from the primary end 58. A head portion 62, having a generally circular shape, is disposed in the chamber 46 and attached to the secondary end 60 of the shaft 56 for axial movement with the shaft 56 and engage the stacked NdFeB magnet to sandwich the stacked NdFeB magnet between the head portion 62 and the platform 48. A spring 64 is disposed on the center axis A, in the chamber 46, and extends helically between the head portion 62 and the top plate 44 for biasing the head portion 62 toward the platform 48 to apply the predetermined clamping pressure. A handle 66, disposed at the primary end 58 of the shaft 56, is attached to the primary end 58 to allow a user to axially move the shaft 56 and the head portion 62 away from the platform 48 and the lower plate 40.

[0024] In operation, a user first pulls on the handle 66 to move the head portion 62 axially away from the platform 48. Next, the stacked NdFeB is disposed in the chamber 46 between the magnet positioning members 52, the platform 48, and the head portion 62. This is to ensure that, during the process of applying the predetermined clamping pressure, there will be no movement of the stacked NdFeB magnet in the chamber 46. After the stacked NdFeB magnet is properly positioned in the chamber 46, the handle 66 is released and the stacked NdFeB magnet is sandwiched between the head portion 62 and the platform 48. The spring 64 biases the head portion 62 toward the platform 48 and applies the predetermined clamping pressure of 0.1-20 MPa onto the stacked NdFeB magnet to spread the insulating adhesive evenly between the NdFeB magnets in the stacked NdFeB magnet.

[0025] Implementing examples are set forth below to provide a better illustration of the present invention. The implementing examples are used for illustrative purposes only and do not limit the scope of the present invention.

Implementing Example 1

[0026] FIG. 2 best illustrates the clamping tool 32 in accordance with one embodiment of the present invention for applying the predetermined clamping pressure to the stacked NdFeB magnet. The clamping tool 32, as best shown in FIG. 3, includes a housing 34, having a generally U-shaped cross-section, disposed on a center axis A. The housing 34 extends between a first end 36 and a second end 38. The housing 34 includes a lower plate 40 and a pair of side plates 42. The lower plate 40 is disposed at the first end 36 of the housing 34. The pair of side plates 42, spaced from one another, extends perpendicularly outwardly from the lower plate 40, parallel to the center axis, to the second end 38. The housing 34 further includes a top plate 44 disposed at the second end 38 of the housing 34 to define a chamber 46 extending between the lower plate 40, the side plates 42, and the top plate 44 for receiving the stacked NdFeB magnet. It should be appreciated that the chamber 46 can be configured to receive a stacked NdFeB magnet made from up to 50 individual NdFeB magnets. A platform 48, having a generally convex surface 50, is disposed in the chamber 46 and attached to the lower plate 40 for engaging the stacked NdFeB magnet. A pair of magnet positioning members 52 disposed in the chamber 46 and attached to the side plates 42 for engaging and positioning the stacked NdFeB magnet in the chamber 46. The magnet positioning members 52 include a plurality of protrusions 53 extending outwardly from the magnet positioning members 52 perpendicular to the center axis A for engaging the stacked NdFeB magnet.

[0027] A moving member 54 is disposed in the chamber 46 and movable along the center axis A for applying the predetermined clamping pressure to the stacked NdFeB magnet in the chamber 46 between the platform 48 and the moving member 54. The moving member 54 includes a shaft 56, having a generally cylindrical shape, extending through the top plate 44 along the center axis A between a primary end 58 and a secondary end 60. The primary end 58 of the moving member 54 is disposed outside the chamber 46 and spaced from the housing 34. The secondary end 60 is disposed in the chamber 46 axially spaced from the primary end 58. A head portion 62, having a generally circular shape, is disposed in the chamber 46 and attached to the secondary end 60 of the shaft 56 for axial movement with the shaft 56 and engage the stacked NdFeB magnet to sandwich the stacked NdFeB magnet between the head portion 62 and the platform 48. A spring 64 is disposed on the center axis A, in the chamber 46, and extends helically between the head portion 62 and the top plate 44 for biasing the head portion 62 toward the platform 48 to apply the predetermined clamping pressure. A handle 66, disposed at the primary end 58 of the shaft 56, is attached to the primary end 58 to allow a user to axially move the shaft 56 and the head portion 62 away from the platform 48 and the lower plate 40.

[0028] In operation, a user first pulls on the handle 66 to move the head portion 62 axially away from the platform 48. Next, the stacked NdFeB is disposed in the chamber 46 between the magnet positioning members 52, the platform 48, and the head portion 62. This is to ensure that, during the process of applying the predetermined clamping pressure, there will be no movement of the stacked NdFeB magnet in the chamber 46. After the stacked NdFeB magnet is properly positioned in the chamber 46, the handle 66 is released and the stacked NdFeB magnet is sandwiched between the head portion 62 and the platform 48. The spring 64 biases the head portion 62 toward the platform 48 and applies the predetermined clamping pressure of 0.1-20 MPa onto the stacked NdFeB magnet to spread the insulating adhesive evenly between the NdFeB magnets in the stacked NdFeB magnet.

Implementing Example 2

[0029] In Implement Example 2, square shaped NdFeB permanent magnets including grease on a surface of the NdFeB permanent magnets are first provided. The surface of the NdFeB permanent magnets is first cleaned using a solution containing 5% nitric acid. After washing the NdFeB permanent magnets, the surface of the NdFeB permanent magnets is phosphatized. Then, the surface of the NdFeB permanent magnets is washed using an alcohol to remove the grease. After washing, the surface of the NdFeB permanent magnets are activated using a plasma flame for 1 minute.

[0030] After activating the surface, a plurality of four beads of the insulating adhesive are disposed onto the surface of the NdFeB permanent magnets. Then, the NdFeB permanent magnets including the four beads are cured in a furnace under a curing temperature of 20 C. and for a curing duration of 24 hrs. After curing the NdFeB permanent magnets including the four beads, the thickness of the beads are 0.03 mm. It should be appreciated that the curing temperature, the curing duration, and the thickness of the beads can be varied and controlled based on specific requirements.

[0031] The surface of the NdFeB permanent magnets including the cured beads is then washed using the alcohol to remove the grease. After washing, the surface of the NdFeB permanent magnets including the cured beads are activated using a plasma flame for 1 minute. Next, a layer of the insulating adhesive is deposited on the surface of the NdFeB permanent magnets. Then, as best shown in FIG. 3, a plurality of six NdFeB permanent magnets including the layer of the insulating adhesive is stacked to form the stacked NdFeB magnet. A predetermined clamping pressure is then applied to the stacked NdFeB magnet. To apply the predetermined clamping pressure, the stacked NdFeB magnet is placed in the clamping tool and the predetermined pressure of between 0.1 MPa is applied to the stacked NdFeB magnet. Then, the stacked NdFeB magnet, disposed in the clamping tool, is cured by heating the stacked NdFeB magnet in a furnace at a predetermined temperature of between 20 C. for a predetermined duration of 24 hr to produce a cured NdFeB magnet. As best shown in FIG. 4, the cured NdFeB magnet is then machined into a plurality of six equal sized small NdFeB magnets using a disc cutting tool. After machining the cured NdFeB magnet, the small NdFeB magnets are subjected to a surface treatment process of phosphating.

Implementing Example 3

[0032] In Implement Example 3, permanent NdFeB magnets containing Terbium or Dysprosium diffused therein are first provided. The surface of the permanent NdFeB magnets is first cleaned using a solution containing 3% nitric acid. After washing the permanent NdFeB magnets, the surface of the permanent NdFeB magnets is phosphatized. Then, the surface of the permanent NdFeB magnets is washed using an acetone to remove the grease. After washing, the surface of the permanent NdFeB magnets are activated using a low temperature plasma for 10 minutes.

[0033] After activating the surface, a plurality of six beads of the insulating adhesive are disposed onto the surface of the permanent NdFeB magnets. Then, the permanent NdFeB magnets including the six beads are cured in a furnace under a curing temperature of 200 C. and for a curing duration of 0.1 hr. After curing the permanent NdFeB magnets including the six beads, the thickness of the beads are 0.5 mm.

[0034] The surface of the permanent NdFeB magnets including the cured beads is then washed using the acetone to remove the grease. After washing, the surface of the permanent NdFeB magnets including the cured beads are activated using a plasma flame for 10 minute. Next, a layer of the insulating adhesive is deposited on the surface of the NdFeB permanent magnets. Then, a plurality of 50 permanent NdFeB magnets including the layer of the insulating adhesive is stacked to form the stacked NdFeB magnet. A predetermined clamping pressure is then applied to the stacked NdFeB magnet. To apply the predetermined clamping pressure, the stacked NdFeB magnet is placed in the clamping tool and the predetermined pressure of between 20 MPa is applied to the stacked NdFeB magnet. Then, the stacked NdFeB magnet, disposed in the clamping tool, is cured by heating the stacked NdFeB magnet in a furnace at a predetermined temperature of between 200 C. for a predetermined duration of 0.1 hr to produce a cured NdFeB magnet. The cured NdFeB magnet is then machined into two equal sized small NdFeB magnets using a multi-wire cutting tool. After machining the cured NdFeB magnet, the small NdFeB magnets are subjected to a surface treatment process of spraying.

Implementing Example 4

[0035] In Implement Example 4, square shaped NdFeB permanent magnets including grease on a surface of the NdFeB permanent magnets are first provided. The surface of the NdFeB permanent magnets is first cleaned using a solution containing 5% nitric acid. After washing the NdFeB permanent magnets, the surface of the NdFeB permanent magnets is phosphatized. Then, the surface of the NdFeB permanent magnets is washed using an acetone to remove the grease. After washing, the surface of the NdFeB permanent magnets are activated using a low temperature plasma for 5 minutes.

[0036] After activating the surface, a plurality of four beads of the insulating adhesive are disposed onto the surface of the NdFeB permanent magnets. Then, the NdFeB permanent magnets including the four beads are cured in a furnace under a curing temperature of 150 C. and for a curing duration of 1.5 hrs. After curing the NdFeB permanent magnets including the four beads, the thickness of the beads are 0.1 mm.

[0037] The surface of the NdFeB permanent magnets including the cured beads is then washed using an alcohol to remove the grease. After washing, the surface of the NdFeB permanent magnets including the cured beads are activated using a low temperature plasma for 5 minutes. Next, a layer of the insulating adhesive is deposited on the surface of the NdFeB permanent magnets. Then, a plurality of two NdFeB permanent magnets including the layer of the insulating adhesive is stacked to form the stacked NdFeB magnet. A predetermined clamping pressure is then applied to the stacked NdFeB magnet. To apply the predetermined clamping pressure, the stacked NdFeB magnet is placed in the clamping tool and the predetermined pressure of between 1 MPa is applied to the stacked NdFeB magnet. Then, the stacked NdFeB magnet, disposed in the clamping tool, is cured by heating the stacked NdFeB magnet in a furnace at a predetermined temperature of between 150 C. for a predetermined duration of 1.5 hr to produce a cured NdFeB magnet. The cured NdFeB magnet is then machined into a plurality of 50 equal sized small NdFeB magnets using a wire cutting tool. After machining the cured NdFeB magnet, the small NdFeB magnets are subjected to a surface treatment process of phosphating.

[0038] Obviously, many modifications and variations of the present invention are possible in light of the above teachings and may be practiced otherwise than as specifically described while within the scope of the appended claims. These antecedent recitations should be interpreted to cover any combination in which the inventive novelty exercises its utility. The use of the word said in the apparatus claims refers to an antecedent that is a positive recitation meant to be included in the coverage of the claims whereas the word the precedes a word not meant to be included in the coverage of the claims.