Composite Permanent Magnet
A hard disk drive includes composite magnet as voice coil motor magnet, where a composite permanent magnet comprising: a first magnet (M1), a second magnet (M2) and a third magnet (M3). M1, M2 and M3 are deposited, bonded, sintered, glued or assembled together and next to each other. The directions of the saturation magnetization of M1 and M3 are opposite to each other. The direction of the saturation magnetization of M2 is substantially perpendicular to the direction of saturation magnetization of M1 and M3.
The present disclosure relates to a novel permanent magnet technology and its use in high efficiency voice coil motors (VCM), particular for the application utilized in hard disk drive.
BACKGROUND OF THE INVENTIONPermanent magnets (PM) create their own persistent magnetic fields and are typically used in electromagnetic induction devices such as motors and generators. Permanent magnets are made from a magnetic material such as ferrite. Additional magnetic materials from rare earth metals, such as Samarium-Cobalt (SmCo), or Neodymium-Iron-Boron (NdFeB) have also been used. While an NdFeB magnet is stronger (e.g., according to maximum energy product (BH)max than an SmCo magnet which is stronger than ferrite, it becomes difficult to increase the magnetic strength even further and Neodymium magnets are much more expensive than ferrite due to the scarcity of Neodymium.
Moreover, a magnet is typically strongest at the surface of the magnet. The magnetization at the magnet surface then decreases with distance from the magnet surface due to a large self-demagnetization field generated by surface magnetic charges, thereby reducing the strength of the magnet away from the surface, such that the magnetic flux density decreases with distance from the magnet. Other various magnetic properties such as magnetic anisotropy, magnetic moment and thus magnetic flux density, etc. may decline as the operating temperature increases. Additionally, there are several grades of NdFeB, SmCo, ferrite, etc. magnets, where higher grades indicate stronger magnets. However, the cost of the magnet may increase in proportion with the grade. The torque generated in an electromagnetic induction device, such as a motor is proportional to the magnetic flux density produced by a permanent magnet in the stator. As the magnetic flux density increases, the efficiency of the motor increases. For the case of hard disk drive, permanent magnets are utilized in the motors to rotate magnetic disks and the head stack assembly that host the magnetic recording heads to perform read and write operations. A higher magnetic field gradient provided by the permanent magnet will lead to an increased efficiency for drive random access operation or a reduced power consumption.
SUMMARY OF THE INVENTIONThe presently disclosed embodiments address many of the issues described above with respect to permanent magnets. The permanent magnets described herein address these disadvantages, having a high magnetic flux density, thereby increasing the efficiencies of motors and generators that implement the permanent magnets. The embodiments disclosed herein are suitable for use in hard disk drive VCM in which permanent magnets are presently employed.
In an embodiment, a composite permanent magnet comprises a first magnet (M1), a second magnet (M2) and a third magnet (M3). M1, M2 and M3 are deposited, bonded, glued or assembled together and next to each other. The directions of the saturation magnetization of M1 and M3 are opposite to each other. The direction of the saturation magnetization of M2 is substantially perpendicular to the direction of saturation magnetization of M1 and M3. Further in an embodiment, the composite permanent magnet is attached to a soft magnetic yoke. In practice, the soft magnetic yoke can be a flat piece or a flat plate with in a predefined shape. The soft magnetic yoke may further include mounting holes.
In another embodiment, a composite permanent magnet comprising: a first magnet (M1), a second magnet (M2), a third magnet (M3), a fourth magnet (M4) and a fifth magnet (M5). M1, M2, M3, M4 and M5 are deposited or assembled together and next to each other. The directions of the saturation magnetization of M2 and M4 are opposite to each other. The direction of the saturation magnetization of M1 and M5 is substantially antiparallel to the direction of the saturation magnetization of M3. The directions of saturation magnetization of M1, M3 and M5 are substantially perpendicular to the direction of saturation magnetization of M2 and M4.
Moreover, the width of M1, M3 and M5 may be ⅓ of the width of M2 and M4, the length and the height of M1, M2, M3, M4 and M5 are approximately the same.
Furthermore, each of the magnetic material may be a ferrite (such as Barium-Iron-Oxygen (Ba—Fe—O), Barium-Nickel-Iron-Oxygen (Ba—Ni—Fe—O), Barium-Strontium-Nickel-Iron-Oxygen (Ba—Sr—Ni—Fe—O), etc.), alnico (such as Aluminum-Nickel-Cobalt (Al—Ni—Co), Aluminum-Nickel-Cobalt-Iron (Al—Ni—Co—Fe), Aluminum-Nickel-Cobalt-Iron-Copper (Al—Ni—Co—Fe—Cu), etc.), rare earth-transition metal-based permanent magnetic materials X-Y or X-Y-Z (where X includes rare-earth elements and their combinations, such as Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), Neodymium-Dysprosium (NdDy), Neodymium-Dysprosium-Terbium-Gadolinium (NdDyTbGd) and Neodymium-Dysprosium-Terbium (NdDyTb), etc.; Y includes transition metal elements and/or their combinations, such as Iron (Fe), Cobalt (Co), Manganese (Mn), Nickel (Ni), Iron-Cobalt (FeCo), Iron-Cobalt-Nickel (FeCoNi), Iron-Cobalt-Nickel-Manganese (FeCoNiMn), etc.; and Z includes non-metal elements and/or other doping elements and their combinations, such as Boron (B), Silicon (Si), Carbon (C), Nitrogen (N), Copper (Cu), Silver (Ag), Zirconium (Zr), etc.), Mn-based permanent magnetic materials X-Y or X-Y-Z (where X includes Mn, Fe, Manganese-Iron (MnFe), etc.; and Y includes Bismuth (Bi), Al, Gallium (Ga), and/or other doping elements such as Praseodymium (Pr), as well as the combination of these elements), transition metal-platinum-based magnetic material X-Y (where X includes transition metal elements and/or their combinations, such as Fe, Co, FeCo, etc.; and Y includes Platinum (Pt), Rhodium (Rh), Palladium (Pd), Zr, and/or their combinations with/without other doping elements), or Iron-Nitride (Fe—N). Specifically, each of the magnets can be Neodymium-Iron-Boron (NdFeB) based materials with different percentage of Neodymium (Nd) concentration.
In another embodiment, a composite permanent magnet comprising: a first magnet (M1), a second magnet (M2), a third magnet (M3), a fourth magnet (M4), a fifth magnet (M5) and a sixth magnet (M6). M1, M2, M3, M4, M5 and M6 are deposited or assembled together and next to each other. The directions of the saturation magnetization of M2 and M5 are opposite to each other. The direction of the saturation magnetization of M1, M3, M4 and M5 are not along the direction of the saturation magnetization of either M2 or M4.
Each of the above magnet material may be any of the above-mentioned magnetic materials. In an embodiment, each magnet utilized in the composite magnet are the same type of materials. In another embodiment, the materials for M1 and M3 use different materials from M2 for the composite permanent magnet with M1, M2 and M3. In another embodiment, the materials for M1, M3 and M5 use different materials from M2 and M4 for the composite permanent magnet with M1, M2, M3, M4 and M5.
The foregoing aspects and many of the attendant advantages described herein will become more fully understood from the detailed description and the accompanying drawings and tables. The drawings constitute a part of this specification and include exemplary embodiments of the invention, which may be embodied in various forms. It is to be understood that in some instances, various aspects of the invention may be shown exaggerated or enlarged to facilitate an understanding of the invention; therefore, the drawings are not necessarily to scale. In addition, in the embodiments depicted herein, like reference numerals in the various drawings refer to the conceptual design or structural elements represent each particular component or element of the apparatus.
Further areas of applicability of the present invention will become apparent from the detailed description provided hereinafter. It should be understood that the detailed description and specific examples, while indicating the preferred embodiment of the invention, are intended for purposes of illustration only and are not intended to limit the scope of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTSIn the following description, numerous specific details are disclosed to provide a thorough understanding of embodiments of the method, system and apparatus. One skilled in the relevant art will recognize, however, that embodiments of the method, system and apparatus described herein may be practiced without one or more of the specific details, or with other electronic devices, methods, components, and materials, and that various changes and modifications can be made while remaining within the scope of the appended claims. In other instances, well-known electronic devices, components, structures, materials, operations, methods, process steps and the like may not be shown or described in detail to avoid obscuring aspects of the embodiments. Embodiments of the apparatus, method and system are described herein with reference to figures.
Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, electronic device, method or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may refer to separate embodiments or may all refer to the same embodiment. Furthermore, the described features, structures, methods, electronic devices, or characteristics may be combined in any suitable manner in one or more embodiments.
As illustrated in
As illustrated in
In addition, when there are more platters added to each unit of hard disk drive, the total head stack assembly have an increased weight. Therefore, a stronger magnetic field and field gradient will help to overcome the penalty due to weight increase, and help to maintain efficiency of the operation, which reflect to an improved (reduced) seek time. In either approach, one other advantage of the composite magnet is to enable a faster rotation speed due to efficiency change. This will help to increase the hard disk drive number of read and write operations per second (R/Wops), which is a crucial performance metric. By optimizing the size of each magnet utilized in the composite magnet, the operation efficiency can be increased by more than 20%. Since the latency is the top contributor for random access input/output operations per second (iops), increase the magnet flux that can be utilized to drive head stack for the recording head will help to maintain or increase iops capability, reduce the seek time as compare to conventional approach.
The width of M1, M2, M3, M4 and M5 are W1, W2, W3, W4 and W5 respectively. The height of M1, M2, M3, M4 and M5 are H1, H2, H3, H4 and H5 respectively. In one embodiment, the width of M2 and M4 is approximately the same, and the width of M2 and M4 is larger than the width of M1, M3 and M5 respectively, i.e. W2=W4>W1=W3=W5 or W2≅W4>W1≅W3≅W5. The width of M1, M3 and M5 can be approximately the same. The height of M1, M2, M3, M4 and M5 is typically the same. The magnetization direction of M2 and M4 are along the height direction, and the magnetization direction of M1, M3 and M5 are along the width direction. The composite magnet can be bonded, or glued or pressed together, acting as one piece. The letter N and S represent the magnetic north and magnetic south pole. The dashed arrow illustrate the magnetization direction in each piece of the magnet. Each piece of magnet M1, M2, M3, M4 and M5 in the composite magnet is attached to the soft magnetic yoke 139a.
In another embodiment, the composite magnet is attached to the soft magnetic yoke 139a. The shape of the cross-section surface S1 and S2 is rectangular shape.
In another embodiment, the composite magnet is attached to the soft magnetic yoke 139a. The soft magnetic yoke 139a may further includes mounting holes 145. The shape of the cross-section surface S1 and S2 is rectangular shape, or can also be in trapezoid shape.
(M2), a third magnet (M3), a fourth magnet (M4), a fifth magnet (M5) and a sixth magnet (M6). The dashed arrows show the magnetization direction within each magnet. The + and − sign represent magnetic charge polarity. The second magnet (M2) and the fifth magnet (M5) has the magnetization direction to be opposite to each other. The second magnet (M2) and the fifth magnet (M4) also have the size and shape to be close to each other. The first magnet (M1) and the third magnet (M3) have magnetization direction with an acute angle with respect to the magnetization direction of the second magnet (M2). The fourth magnet (M4) and the sixth magnet (M6) have magnetization direction with an acute angle with respect to the magnetization direction of the fifth magnet (M5), as illustrated in
The above figures are examples of the individual composite magnet that can be utilized for VCM, particular for hard disk drive applications. Multiple composite permanent magnets can be utilized with particular periodic pattern and with different cross section shapes to form magnet structures for high efficiency motors and generators to improve power density. The magnet components to form composite magnet may not be all in rectangular shape, in some applications, as stated earlier, have trapezoid shape.
In another embodiment, a hard disk drive where the VCM is operated via a set of VCM magnet. Where at least one VCM magnet includes a composite magnet placed on the soft magnetic yoke. The composite magnet can be in any of the configurations described above.
The following list of aspects reflects a variety of the embodiments explicitly contemplated by the present application. Those of ordinary skill in the art will readily appreciate that the aspects below are neither limiting of the embodiments disclosed herein, nor exhaustive of all of the embodiments conceivable from the disclosure above, but are instead meant to be exemplary in nature.
1. A composite permanent magnet comprises a first magnet (M1), a second magnet (M2), a third magnet (M3), a fourth magnet (M4) and a fifth magnet (M5). The M1, M2, M3, M4 and M5 are deposited or assembled together and next to each other. The volume of M2 and M4 are higher than the volume of M1, M3 and M5. The direction of the saturation magnetization of M2 and M4 are opposite to each other. The direction of the saturation magnetization of M1 and M5 is substantially antiparallel to the direction of the saturation magnetization of M3. The direction of saturation magnetization of M1, M3 and M5 is substantially perpendicular to the saturation magnetization of M2 and M4.
2. The composite permanent magnet as in aspect 1, wherein the width of M1, M3 and M5 are approximately the same.
3. The composite permanent magnet as in aspect 1, wherein the width of M2 and M4 are approximately the same.
4. The composite permanent magnet as in aspect 1, wherein the width of M1, M3 and M5 is smaller than the width of M2 and M4.
5. The composite permanent magnet as in aspect 1, wherein the length of M1, M2, M3, M4 and M5 are approximately the same.
6. The composite permanent magnet as in aspect 1, wherein the height of M1, M2, M3, M4 and M5 are approximately the same.
7. The composite permanent magnet as in aspect 1, wherein the materials of M1, M2, M3, M4 and M4 are selected from a ferrite (such as Barium-Iron-Oxygen (Ba—Fe—O), Barium-Nickel-Iron-Oxygen (Ba—Ni—Fe—O), Barium-Strontium-Nickel-Iron-Oxygen (Ba—Sr—Ni—Fe—O), etc.), alnico (such as Aluminum-Nickel-Cobalt (Al—Ni—Co), Aluminum-Nickel-Cobalt-Iron (Al—Ni—Co—Fe), Aluminum-Nickel-Cobalt-Iron-Copper (Al—Ni—Co—Fe—Cu), etc.), rare earth-transition metal-based permanent magnetic materials X-Y or X-Y-Z (where X includes rare-earth elements and their combinations, such as Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), Neodymium-Dysprosium (NdDy), Neodymium-Dysprosium-Terbium (NdDyTb), Neodymium-Dysprosium-Terbium-Gadolinium (NdDy TbGd), etc.; Y includes transition metal elements and/or their combinations, such as Iron (Fe), Cobalt (Co), Manganese (Mn), Nickel (Ni), Iron-Cobalt (FeCo), Iron-Cobalt-Nickel (FeCoNi), Iron-Cobalt-Nickel-Manganese (FeCoNiMn), etc.; and Z includes non-metal elements and/or other doping elements and their combinations, such as Boron (B), Silicon (Si), Carbon (C), Nitrogen (N), Copper (Cu), Silver (Ag), Zirconium (Zr), etc.), Mn-based permanent magnetic materials X-Y or X-Y-Z (where X includes Mn, Fe, Manganese-Iron (MnFe), etc.; and Y includes Bismuth (Bi), Al, Gallium (Ga), and/or other doping elements such as Praseodymium (Pr), as well as the combination of these elements), transition metal-platinum-based magnetic material X-Y (where X includes transition metal elements and/or their combinations, such as Fe, Co, FeCo, etc.; and Y includes Platinum (Pt), Rhodium (Rh), Palladium (Pd), Zr, and/or their combinations with/without other doping elements), or Iron-Nitride (Fe—N). Specifically, each of the magnets can be Neodymium-Iron-Boron (NdFeB) based materials with different percentage of Neodymium (Nd) concentration.
8. The composite permanent magnet as in aspect 1, wherein the width of M1, M3 and M5 is ⅓ of the width of M2 and M4, the length of each of the magnet is approximately equal to each other and the height of each of the magnet is approximately equal to each other.
9. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 materials are based on same materials selected from aspect 7.
10. The composite permanent magnet as in aspect 1, wherein M1, M3 and M5 are based on same material selected from aspect 7; M2 and M4 are based on the same material selected from aspect 7; wherein M2 and M4 material is different from M1, M3 and M5 material.
11. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 materials are based on Neodymium-Iron-Boron (NdFeB) materials.
12. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 materials are based on Neodymium-Iron-Boron (NdFeB) materials; M1, M3 and M5 has different percentage of Neodymium (Nd) concentration as compared to M2 and M4.
13. The composite permanent magnet as in aspect 1, wherein the shape of M1, M2, M3, M4 and M5 is in cuboid or rectangular prism.
14. The composite permanent magnet as in aspect 1, wherein the surface of M1, M2, M3, M4 and M5 matches to each other in such a way they can be bonded, glued or pressed together into one composite magnet.
15. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 are glued, pressed, bonded or using other methods to connect together.
16. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 have smooth surface.
17. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 have curved or rough surface, can be joint at the interface when pressed together.
18. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 can be in rectangular shape from front view.
19. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 can be in rectangular shape from side view.
20. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 can be in trapezoid shape from front view.
21. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 can be in trapezoid shape from side view.
22. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 are bonded together and placed on a soft magnetic yoke.
22. The composite permanent magnet as in aspect 1, wherein M1, M2, M3, M4 and M5 are bonded together and placed on a soft magnetic yoke. The said yoke has predrilled mounting holes.
23. A composite permanent magnet comprises a first magnet (M1), a second magnet (M2) and a third magnet (M3). The M1, M2 and M3 are deposited or assembled together and next to each other. The direction of the saturation magnetization of M1 and M3 are opposite to each other. The direction of the saturation magnetization of M2 is substantially perpendicular to the direction of saturation magnetization of M1 and M3.
24. The composite permanent magnet as in aspect 23, wherein the width of the M1 and M3 are approximately same.
25. The composite permanent magnet as in aspect 23, wherein the width and the volume of M2 is smaller than the width of M1 and M3.
26. The composite permanent magnet as in aspect 23, wherein the length of M1, M2 and M3 are approximately the same.
27. The composite permanent magnet as in aspect 23, wherein the height of M1, M2 and M3 are approximately the same.
28. The composite permanent magnet as in aspect 23, wherein the materials of M1, M2 and M3 are selected from a ferrite (such as Barium-Iron-Oxygen (Ba—Fe—O), Barium-Nickel-Iron-Oxygen (Ba—Ni—Fe—O), Barium-Strontium-Nickel-Iron-Oxygen (Ba—Sr—Ni—Fe—O), etc.), alnico (such as Aluminum-Nickel-Cobalt (Al—Ni—Co), Aluminum-Nickel-Cobalt-Iron (Al—Ni—Co—Fe), Aluminum-Nickel-Cobalt-Iron-Copper (Al—Ni—Co—Fe—Cu), etc.), rare earth-transition metal-based permanent magnetic materials X-Y or X-Y-Z (where X includes rare-earth elements and their combinations, such as Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), Neodymium-Dysprosium (NdDy), Neodymium-Dysprosium-Terbium (NdDyTb), Neodymium-Dysprosium-Terbium-Gadolinium (NdDy TbGd), etc.; Y includes transition metal elements and/or their combinations, such as Iron (Fe), Cobalt (Co), Manganese (Mn), Nickel (Ni), Iron-Cobalt (FeCo), Iron-Cobalt-Nickel (FeCoNi), Iron-Cobalt-Nickel-Manganese (FeCoNiMn), etc.; and Z includes non-metal elements and/or other doping elements and their combinations, such as Boron (B), Silicon (Si), Carbon (C), Nitrogen (N), Copper (Cu), Silver (Ag), Zirconium (Zr), etc.), Mn-based permanent magnetic materials X-Y or X-Y-Z (where X includes Mn, Fe, Manganese-Iron (MnFe), etc.; and Y includes Bismuth (Bi), Al, Gallium (Ga), and/or other doping elements such as Praseodymium (Pr), as well as the combination of these elements), transition metal-platinum-based magnetic material X-Y (where X includes transition metal elements and/or their combinations, such as Fe, Co, FeCo, etc.; and Y includes Platinum (Pt), Rhodium (Rh), Palladium (Pd), Zr, and/or their combinations with/without other doping elements), or Iron-Nitride (Fe—N). Specifically, each of the magnets can be Neodymium-Iron-Boron (NdFeB) based materials with different percentage of Neodymium (Nd) concentration.
29. The composite permanent magnet as in aspect 23, wherein the width of M2 is ⅓ of the width of M1 and M3, the length of M1, M2 and M3 are approximately equal to each other and the height of M1, M2 and M3 are approximately equal to each other.
30. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 are based on same materials selected from aspect 28.
31. The composite permanent magnet as in aspect 23, wherein M1 and M3 are based on same material selected from aspect 28, M2 is based on another material selected from aspect 28.
32. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 materials are based on Neodymium-Iron-Boron (NdFeB) materials.
33. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 materials are based on Neodymium-Iron-Boron (NdFeB) materials with different percentage of Neodymium (Nd) concentration.
34. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 are glued, bonded, pressed or joint together.
35. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 have curved or rough surface, can be joint at the interface when pressed together.
36. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 can be in rectangular shape from front view.
37. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 can be in rectangular shape from side view.
38. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 can be in trapezoid shape from front view.
39. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 can be in trapezoid shape from side view.
40. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 are bonded together and placed on a soft magnetic yoke.
41. The composite permanent magnet as in aspect 23, wherein M1, M2 and M3 are bonded together and placed on a soft magnetic yoke. The said yoke has predrilled mounting holes.
42. The composite permanent magnet as in aspect 23, wherein further includes metallic or metallic alloy coating such as Ni, NiFe, or other materials coating on the surface of the composite magnet.
43. The composite permanent magnet as in aspect 23, wherein the magnetization direction of M1 and M3 are opposite to each other, and along the height of the magnet direction. The magnetization direction of M2 is perpendicular to the magnetization direction of M1 and M3, along the width of the composite magnet.
44. A composite permanent magnet comprises a first magnet (M1), a second magnet (M2), a third magnet (M3) and a fourth magnet (M4). The M1, M2, M3 and M4 are deposited or assembled together and next to each other. The direction of the saturation magnetization of M1 and M3 are opposite to each other. The direction of the saturation magnetization of M2 and M4 are opposite to each other. The direction of the saturation magnetization of M2 and M4 are substantially perpendicular to the direction of the saturation magnetization of M1 and M3.
45. The composite permanent magnet as in aspect 44, wherein the width of the M1 and M3 are approximately same.
46. The composite permanent magnet as in aspect 44, wherein the width and the volume of the M2 and M4 is smaller than M1 and M3.
47. The composite permanent magnet as in aspect 44, wherein the length of the M1, M2, M3 and M4 are approximately the same.
48. The composite permanent magnet as in aspect 44, wherein the height of M1, M2, M3 and M4 are approximately the same.
49. The composite permanent magnet as in aspect 44, wherein the materials of M1, M2, M3 and M4 are selected from a ferrite (such as Barium-Iron-Oxygen (Ba—Fe—O), Barium-Nickel-Iron-Oxygen (Ba—Ni—Fe—O), Barium-Strontium-Nickel-Iron-Oxygen (Ba—Sr—Ni—Fe—O), etc.), alnico (such as Aluminum-Nickel-Cobalt (Al—Ni—Co), Aluminum-Nickel-Cobalt-Iron (Al—Ni—Co—Fe), Aluminum-Nickel-Cobalt-Iron-Copper (Al—Ni—Co—Fe—Cu), etc.), rare earth-transition metal-based permanent magnetic materials X-Y or X-Y-Z (where X includes rare-earth elements and their combinations, such as Neodymium (Nd), Samarium (Sm), Gadolinium (Gd), Neodymium-Dysprosium (NdDy), Neodymium-Dysprosium-Terbium (NdDyTb), Neodymium-Dysprosium-Terbium-Gadolinium (NdDy TbGd), etc.; Y includes transition metal elements and/or their combinations, such as Iron (Fe), Cobalt (Co), Manganese (Mn), Nickel (Ni), Iron-Cobalt (FeCo), Iron-Cobalt-Nickel (FeCoNi), Iron-Cobalt-Nickel-Manganese (FeCoNiMn), etc.; and Z includes non-metal elements and/or other doping elements and their combinations, such as Boron (B), Silicon (Si), Carbon (C), Nitrogen (N), Copper (Cu), Silver (Ag), Zirconium (Zr), etc.), Mn-based permanent magnetic materials X-Y or X-Y-Z (where X includes Mn, Fe, Manganese-Iron (MnFe), etc.; and Y includes Bismuth (Bi), Al, Gallium (Ga), and/or other doping elements such as Praseodymium (Pr), as well as the combination of these elements), transition metal-platinum-based magnetic material X-Y (where X includes transition metal elements and/or their combinations, such as Fe, Co, FeCo, etc.; and Y includes Platinum (Pt), Rhodium (Rh), Palladium (Pd), Zr, and/or their combinations with/without other doping elements), or Iron-Nitride (Fe—N). Specifically, each of the magnets can be Neodymium-Iron-Boron (NdFeB) based materials with different percentage of Neodymium (Nd) concentration.
50. The composite permanent magnet as in aspect 44, wherein the width of M2 and M4 is ⅓ of the width of M1 and M3, the length of each of the magnets is approximately equal to each other and the height of each of the magnets is approximately equal to each other.
51. The composite permanent magnet as in aspect 44, wherein M1, M2, M3 and M4 are based on the same material selected from aspect 49.
52. The composite permanent magnet as in aspect 44, wherein M1 and M3 are based on same material selected from aspect 49, M2 is based on another material selected from aspect 49.
53. The composite permanent magnet as in aspect 44, wherein M1, M2, M3 and M4 materials are based on Neodymium-Iron-Boron (NdFeB) materials.
54. The composite permanent magnet as in aspect 44, wherein M1, M2, M3 and M4 materials are based on Neodymium-Iron-Boron (NdFeB) materials with different percentage of Neodymium (Nd) concentration.
55. The composite permanent magnet as in aspect 44, wherein M1, M2, M3 and M4 are glued, bonded, pressed or joint together.
56. The composite permanent magnet as in aspect 44, wherein further includes metallic or metallic alloy coating such as Ni, NiFe, or other materials coating on the surface of the composite magnet.
57. The composite permanent magnet as in aspect 44, wherein the magnetization direction of M1 and M3 are opposite to each other, and along the height of the magnet. The magnetization direction of M2 and M4 are perpendicular to the magnetization direction of M1 and M3, along the width of the composite magnet.
58. A hard disk drive includes two VCM magnets, where at least one of the VCM magnets includes a composite magnet, where at least three or more pieces of magnets are glued or bond together. Where two of the magnets have the saturation magnetization direction to be in opposite direction. At least one of the magnets have the saturation magnetization direction to be perpendicular to the other two magnets.
59. The hard disk drive as in aspect 58, wherein the composite magnet is placed on the soft magnetic yoke.
60. The hard disk drive as in aspect 59, wherein the soft magnetic yoke has predrilled mounting holes.
61. The hard disk drive as in aspect 58, wherein the VCM magnet has metallic coating, such as Ni plated coat.
62. A composite magnet system includes multiple magnets connect to each other or to a magnet holder, where each of the magnet is comprise of composite magnet structure in aspect 1.
63. A composite magnet system includes multiple magnets connect to each other or to a magnet holder, where each of the magnet is comprise of composite magnet structure in aspect 23.
64. A composite magnet system includes multiple magnets connect to each other or to a magnet holder, where each of the magnet is comprise of composite magnet structure in aspect 44.
The embodiments were chosen and described to best explain the principles of the invention and its practical application to persons who are skilled in the art. As various modifications, could be made to the exemplary embodiments, as described above with reference to the corresponding illustrations, without departing from the scope of the invention, it is intended that all matter contained in the foregoing description and shown in the accompanying drawings shall be interpreted as illustrative rather than limiting. Thus, the breadth and scope of the present invention should not be limited by any of the above-described exemplary embodiments, but should be defined only in accordance with the following claims appended hereto and their equivalents. Modifications and variations may be made to the disclosed embodiments while remaining within the spirit and scope of the method, system and apparatus. The implementations described above and other implementations are within the scope of the following claims.
Claims
1. A hard disk drive includes composite magnet as voice coil motor magnet, where a composite permanent magnet comprising: a first magnet (M1), a second magnet (M2) and a third magnet (M3). M1, M2 and M3 are deposited, bonded, glued or assembled together and next to each other. The directions of the saturation magnetization of M1 and M3 are opposite to each other. The direction of the saturation magnetization of M2 is substantially perpendicular to the direction of saturation magnetization of M1 and M3.
2. The composite permanent magnet of claim 1, wherein the width of M1 and M3 are approximately the same.
3. The composite permanent magnet of claim 1, wherein the width of M2 is smaller than the width of M1 and M3.
4. The composite permanent magnet of claim 1, wherein the magnet further placed on a soft magnetic yoke.
5. The composite permanent magnet of claim 1, wherein the shape of M1, M2 and M3 in trapezoid shape as seen in front view or side view.
6. The composite permanent magnet of claim 1, wherein the height of M1, M2 and M3 are approximately the same.
7. The composite permanent magnet of claim 1, wherein: M1, M2 and M3 materials is at least one of: alnico, ferrite, a rare earth-transition metal-based permanent magnetic material, a manganese-based permanent magnetic material, a transition metal-platinum-based magnetic material, or Iron-Nitride (Fe—N), a neodymium-based permanent magnetic material, such as neodymium-iron-boron.
8. The composite permanent magnet of claim 1, wherein M1, M2 and M3 materials are same.
9. The permanent magnet of claim 1, wherein M1, M2 and M3 are attached to each other via at least one of: injection molding, compression molding, adhesion, high pressure compression, high pressure annealing, sintering, gluing or direct bonding.
10. A composite permanent magnet comprises a first magnet (M1), a second magnet (M2), a third magnet (M3) and a fourth magnet (M4). M1, M2, M3 and M4 are deposited or assembled together and next to each other. The direction of the saturation magnetization of M1 and M3 are opposite to each other. The direction of the saturation magnetization of M2 and M4 are opposite to each other. The direction of the saturation magnetization of M2 and M4 are substantially perpendicular to the direction of the saturation magnetization of M1 and M3.
11. The composite permanent magnet of claim 10, wherein: M1, M2, M3 and M4 materials is at least one of: alnico, ferrite, a rare earth-transition metal-based permanent magnetic material, a manganese-based permanent magnetic material, a transition metal-platinum-based magnetic material, or Iron-Nitride (Fe—N), a neodymium-based permanent magnetic materials, such as neodymium-iron-boron.
12. The composite permanent magnet of claim 10, wherein M1 and M3 materials are the same.
13. The composite permanent magnet of claim 10, wherein M1, M2, M3 and M4 are attached to each other via at least one of: injection molding, compression molding, adhesion, high pressure compression, high pressure annealing, sintering, gluing or direct bonding.
14. The composite permanent magnet of claim 10, wherein further includes other magnet pieces with periodic structure of claim 10.
15. A hard disk drive includes composite magnet as voice coil motor magnet, where a composite permanent magnet comprising: a first magnet (M1), a second magnet (M2), a third magnet (M3), a fourth magnet (M4) and a fifth magnet (M5). M1, M2, M3, M4 and M5 are deposited or assembled together and next to each other. The directions of the saturation magnetization of M2 and M4 are opposite to each other. The direction of the saturation magnetization of M1 and M5 is substantially antiparallel to the direction of the saturation magnetization of M3. The directions of saturation magnetization of M1, M3 and M5 are substantially perpendicular to the direction of saturation magnetization of M2 and M4.
16. The composite permanent magnet of claim 15, wherein: M1, M2, M3, M4 and M5 materials is at least one of: alnico, ferrite, a rare earth-transition metal-based permanent magnetic material, a manganese-based permanent magnetic material, a transition metal-platinum-based magnetic material, or Iron-Nitride (Fe—N), a neodymium-based permanent magnetic materials, such as neodymium-iron-boron.
17. The composite permanent magnet of claim 15, wherein the magnet further placed on a soft magnetic yoke.
18. The composite permanent magnet of claim 15, wherein the shape of M1, M2, M3, M4 or M5 can be in trapezoid or other none rectangular shape as seen from front or side view.
19. The composite permanent magnet of claim 15, wherein the volume of M2 and M4 are higher than the volume of M1, M3 and M5 respectively.
20. The composite permanent magnet of claim 15, wherein M1, M2, M3, M4 and M5 are attached to each other via at least one of: injection molding, compression molding, adhesion, high pressure compression, high pressure annealing, sintering, gluing or direct bonding.
Type: Application
Filed: Dec 9, 2020
Publication Date: May 5, 2022
Inventor: Kaizhong Gao (North Oaks, MN)
Application Number: 17/117,093