The present invention relates generally to a magnetic shear force transfer device. More particularly, the present invention relates to magnetic shear force transfer devices comprising multi-pole correlated magnetic structures that enable couplings and gears having high ratios of torque to magnetic material volume.
The shortcomings of traditional mechanical couples and gears are often overlooked since they are ubiquitous and frequently represent the only means of getting the right torque and rotation speed from, as an example, a motor to a propeller shaft. Gear teeth run into and rub against one another. This wastes energy, generates heat, emits vibration and sound, generates abrasive particles, wears gear teeth, makes lubrication essential, limits the service life of gears, and necessitates maintenance. In addition, incorporating fluid flow, maintenance access and heat transfer characteristics increases the complexity and cost of gears and transmissions. A gear that operated with interlocking magnetic fields, on the other hand, would not require physical contact between teeth. Despite a long list of potential advantages, magnetic couples and gears have heretofore been extremely limited in their application by their low torque densities (i.e., torque per volume of couple or gear mechanism). Higher torque densities would translate directly into broader applications for magnetic gears and couples.
Briefly, according to one embodiment of the invention, a magnetic shear force transfer device for transferring shear forces across a non-magnetic gap includes a first magnetic structure comprising a first plurality of magnetic sources magnetically printed into a first magnetizable material in accordance with a first pattern and a second magnetic structure comprising a second plurality of magnetic sources magnetically printed into a second magnetizable material in accordance with a second pattern. The first and second patterns define the print location and polarity of each magnetic source of the first and second pluralities of magnetic sources. The first pattern corresponds to a first plurality of concentric circular tracks and the second pattern corresponds to a second plurality of concentric circular tracks. Each concentric circular track of the first plurality of concentric circular tracks has an even number of magnetic sources and each concentric circular track of the second plurality of concentric circular tracks has an even number of magnetic sources. Adjoining magnetic sources alternate in polarity in each circular track of said first plurality of concentric circular tracks and said plurality of concentric circular tracks. One or more tracks of the first plurality of concentric circular tracks are rotated relative to one or more tracks of the second plurality of concentric circular tracks such that a maximum torque condition coincides to one angular orientation between the first and second magnetic structures.
In accordance with one aspect of the invention, the distances between print positions of adjoining magnetic sources and the amounts of magnetizing current used to generate H fields that create adjoining opposite polarity B fields in said first and second magnetizable material are selected to produce a desired force profile that may correspond to a force versus distance curve or a torque versus a rotation of said first magnetic structure relative to said second magnetic structure.
Shear forces can be transferred as torque and the non-magnetic gap can be an air gap.
A first shunt plate can be positioned on a back side of the first magnetic structure and a second shunt plate can be positioned on a back side of the second magnetic structure.
An intermediate layer can be located between the first magnetic structure and the second magnetic structure, where the intermediate layer is a non-magnetic material.
In accordance with a second embodiment of the invention, a method for manufacturing a magnetic shear force transfer device for transferring shear forces across a non-magnetic gap includes producing a first magnetic structure by magnetically printing a first plurality of magnetic sources into a first magnetizable material in accordance with a first pattern and producing a second magnetic structure by magnetically printing a second plurality of magnetic sources into a second magnetizable material in accordance with a second pattern, where the first and second patterns define the print location and polarity of each magnetic source of said first and second pluralities of magnetic sources. The first pattern corresponds to a first plurality of concentric circular tracks and the second pattern corresponds to a second plurality of concentric circular tracks. Each concentric circular track of said first plurality of concentric circular tracks has an even number of magnetic sources and each concentric circular track of said second plurality of concentric circular tracks has an even number of magnetic sources. Adjoining magnetic sources alternate in polarity in each circular track of said first plurality of concentric circular tracks and said second plurality of concentric circular tracks. One or more tracks of the first plurality of concentric circular tracks are rotated relative to one or more tracks of the second plurality of concentric circular tracks such that a maximum torque condition coincides to one angular orientation between said first and second magnetic structures.
The method may also include determining a desired distance between print positions of adjoining magnetic sources and desired amounts of magnetizing current used to generate H fields that create adjoining opposite polarity B fields in a magnetizable material that produce a desired force profile, wherein distances between print positions of adjoining magnetic sources substantially correspond to the desired distance and the amounts of magnetizing current used to generate H fields that create adjoining opposite polarity B fields in said first and second magnetizable material substantially correspond to the desired amounts of magnetizing current.
The shear forces are transferred as torque.
The non-magnetic gap is an air gap.
The desired force profile corresponds to a force versus distance curve or to a torque versus a rotation of said first magnetic structure relative to said second magnetic structure.
The method may include providing a first shunt plate on a back side of the first magnetic structure and providing a second shunt plate on a back side of the second magnetic structure.
The method may also include providing an intermediate layer between the first magnetic structure and the second magnetic structure, where the intermediate layer is a non-magnetic material.
The present invention is described with reference to the accompanying drawings. In the drawings, like reference numbers indicate identical or functionally similar elements. Additionally, the left-most digit(s) of a reference number identifies the drawing in which the reference number first appears.
The present invention will now be described more fully in detail with reference to the accompanying drawings, in which the preferred embodiments of the invention are shown. This invention should not, however, be construed as limited to the embodiments set forth herein; rather, they are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art.
The behavior of magnets is well understood and, aside from materials improvements such as rare-earth materials, magnets have been used in much the same way for the more than a century. During this time, machines have been designed to work with the fixed behavior of permanent magnets that have a North Pole and a South Pole, where the field magnitude decreases with the square of the separation distance between two magnets.
Larry Fullerton, a prolific inventor and founder of Correlated Magnetics Research (CMR), made a series of discoveries in magnetism beginning in 2008. Those discoveries and later inventions stemmed from his application of signal processing and coding theories to magnetic structures such as is described in U.S. Pat. No. 8,179,219, which is incorporated herein by reference. Fullerton discovered that magnetic fields interfere in space similar to the way radio signals, or sound, interfere. He further discovered that geometric patterns of mixed magnetic poles (each called a maxel, for magnetic pixel) create many new behaviors. A multi-pole correlated magnetic structure, trademarked by CMR as a “Polymagnet®”, can be designed or “programmed” to have desired functionality, instead of applications being designed around the limited functionality of conventional magnets. For an example of how signal processing brings new functionality to magnets, one can consider Barker codes (http://en.wikipedia.org/wiki/Barker_code), which refers to a family of codes traditionally used to define communications and radar radio frequency (RF) signals that constructively interfere only when the signals are precisely in phase, or in other words, when they are correlated. When Barker codes or other such codes having desirable autocorrelation properties are emulated in multi-pole magnetic structures, “constructive interference” becomes attraction (or repulsion) forces that are present between the structures only when they are aligned.
A two-dimensional code would constructively interfere with correlation in two dimensions simultaneously. Such a code has been printed into the surface of magnetic material 102a 102b to produce a pair of magnetic structures where constructive interference refers to force between the structures and correlation translates to spatial alignment of the magnetic structure pair.
To provide a sense of the state of magnetization technology development, a magnetization pattern of 120 2 mm outside diameter (OD) maxels can be printed into a standard N42, ⅛″ thick 1.5″ OD disc of Neodymium Iron Boron at room temperature in 10 to 15 seconds. CMR's, 4th Generation magnetic printer trademarked MagPrinter™ is shown in
A collection of magnetization technologies trademarked MaxField® have been developed by CMR that allow Polymagnets to be optimized for tensile force achieving a 500% mated force increase over conventional, un-coded pairs of magnets of the same material and size. These techniques specifically involve using a magnetizing circuit to magnetically print (i.e., spot magnetize) maxels into a particular grade and thickness of magnetizable material where an amount of magnetizing current is selected to produce an H field required to produce a B field in the magnetizable material such that adjoining opposite polarity maxels having a selected spacing will have a desired force profile. More generally, the strength of the magnetizing field and the maxel spacing can be selected based on the properties of the material being magnetized to achieve desired tensile and/or shear force profiles of adjoining opposite polarity maxels where force curves can be designed in multiple directions and along complex three-dimensional paths. For a latching device, higher forces provide the same performance with less magnetic material, or an opportunity to upgrade lower energy-product magnetic materials to replace rare-earth materials. As outlined in detail below, the CMR technologies support similar improvements in magnetic shear forces. These magnetization and related coding techniques are disclosed in U.S. patent application Ser. No. 13/240,355, filed Sep. 22, 2011, U.S. patent application Ser. No. 13/374,074, filed Dec. 9, 2011, and U.S. patent application Ser. No. 13/481,554, filed May 25, 2012, which are incorporated by reference herein in their entirety.
Other Polymagnets made to date include those that hover (trademarked HoverField® magnets), have tensile forces that fall to zero with certain rotations, align with low-micron (down to nanometer level) precision, and combine precise tensile forces, shear forces, and alignment functions into single magnet pairs. The CMR technologies introduce many new variables into the design of magnetic structures and machines. Maxels can have different sizes, shapes, polarities, dipole orientations, saturation levels and can be printed in many magnetic materials or formed from electromagnetic coils. The number of different maxel combinations is almost unlimited. More information about Correlated Magnetics Research's technology can be found on the company's web site: www.correlatedmagnetics.com.
CMR submitted a proposal and was awarded a Phase I Small Business Innovative Research (SBIR) contract to create improvements in shear forces and force densities between magnets using technologies invented by CMR. The proposal listed two goals: 1) quantify the potential of maxel arrays to increase the shear force between two magnetic structures and to improve the shear force to displacement curve, and 2) create maxel arrays that improve the torque/displacement curve by creating steeper torque onset and explore the potential for tailored torque/displacement behavior. The project included an extensive modeling effort aimed at understanding the nature of shear forces between magnets and magnetization patterns (sometimes also referred to as ‘codes’ or ‘arrays’) that provide high forces and force densities. This led to an exploration of the limits of magnetic torque transfer devices. The project was focused on devices that transfer forces directly between permanent magnets and not through modulating iron (like magnetic “shutter” gears) or via electromagnets. This project also resulted in the present invention.
The shear forces between magnets provide the dominant factor determining the torque density of magnet-to-magnet torque transfer devices. For couples (1:1 magnetic gears), the torque density is proportional to the shear area density between the magnets. The following equations, 1) illustrate how the torque density (T/V) is proportional to shear area density, or shear stress (τ) for disk-to-disk and concentric cylinder architectures, respectively. For the disk-to-disk equation ‘t’ refers to the thickness across both plates and ‘r’ to their radii.
Clutches are similar to magnetic couples and represent an important benchmark for their performance Carbon-carbon clutches used in various racing applications can provide a maximum of 100N of shear force for each square cm of plate area.
The shutter gear described by Atallah [IEEE Proc.-Electr. Power Appl., Vol. 151, No. 2, March 2004] has a torque density of 78 kN-m/m^3 as built (111 kN-m/m^3 as modeled). This corresponds to a shear area density (shear stress) of 3.9 N/cm^2 (5.5 N/cm^2 as modeled) at the low speed surface and is the highest experimentally verified torque-density magnetic gearbox that has been described in the literature.
The project objective was to produce a device that exceeds these numbers. CMR achieved this objective by developing a magnetic coupling that set a new standard for shear forces and torque densities.
A magnetic shear force transfer device according to the present invention includes a first magnetic structure comprising a first plurality of magnetic sources arranged in accordance with a first polarity pattern and a second magnetic structure comprising a second plurality of magnetic sources arranged in accordance with a second polarity pattern. Preferred embodiments of such a shear force transfer device include co-axial cylinders and pairs of concentric disks with gaps that can be substantially thinner than the magnetic materials. In a preferred embodiment comprising a pair of concentric disks, the first pattern and second pattern each comprise a plurality of concentric tracks each having an even number of magnetic source positions. In such an embodiment, the magnetic sources in the tracks of one magnet in the pair can be rotated so that all tracks reach a maximum torque condition at the same angular position, thereby creating a maximum torque for the structure. Angular shifting of the tracks can also be used to tune the maximum torque between the first and second magnetic structures or to control the angular stiffness between them. Other relevant variables available to tune the torque and torque curve include the distance between magnetic source positions of the first and second patterns, the size or strength of the magnetic sources and the shapes of the tracks. More generally, magnetic sources can be organized into a wide variety of patterns that can produce a wide variety of torque profiles between the first and second magnetic structures. In one embodiment, the pattern is selected to substantially match a preferred distance determined to produce a maximum force between adjoining opposite polarity magnetic sources. The distance between the center-line of adjacent tracks of the first and second patterns can also be selected to match the preferred distance.
The first and second magnetic structures of the present embodiment are referred to herein as plates or discs. Much of the disclosure describes a horizontal orientation of two plates such as shown in
Correlated Magnetic Coupling Development Overview
As part of the project, a variety of magnetic torque transfer devices in both patent and academic literature were reviewed. The purpose of this work was to establish benchmarks in terms of torque density performance and in terms of assembly and architecture guidelines.
To guide both the modeling and experimental portions of this project, several sources were reviewed to understand the fundamental nature of magnetic forces, and especially shear forces between magnetic structures. The main source was Furlani's “Permanent Magnet and Electromechanical Devices”, [2] since the charge model, p. 132, relates magnetization, emitted fields and forces between permanent magnets together.
Prior to the SBIR project, CMR developed an internal modeling software system to support the development of maxel patterns and the analysis of various magnetic structures. CMR's modeling software was used to support the development of appropriate maxel patterns for high shear and high torque magnets. CMR also used the Ansys Maxwell electromagnetic field simulation software.
The modeling work performed during this project was focused on the scaling of substrate thickness, feature size and aspect ratio, and magnetization patterns in terms of their influence the shear forces between magnets. The work focused on three main magnetization patterns: alternating blocks, a one-sided field structure formed from an array of triangles and a one-sided field structure consisting of a continuously rotating magnetization vector. Preliminary work was also directed toward examining the performance of maxel arrays.
The first modeling study used software developed by CMR to assemble substrates (digitally) from arrays of bars with alternating polarity aligned in the ‘z’ direction such as in
The blocks had different cross section ratios (in width ‘w’ versus thickness ‘t’) as viewed in the X-Z plane. The individual bars extended in the Y direction (into the page) to create square substrates. The shear forces versus displacement were calculated for different aspect ratios (t/w) of these blocks.
The next set of experiments focused on how the shear force varied with the feature size. The term feature size refers here to the width of the blocks, ‘w’. A square substrate 96 mm on a side was built from blocks with equal width and thickness. The blocks modeled were 8, 4, 2, 1 and 0.5 mm thick.
A similar scaling study was also performed using the Maxwell modeling software. Maxwell includes ferromagnetism, permeability and other magnetic material details that have not been integrated into the internally developed CMR software.
A 2D shear simulation of a well-known one-sided field emission structure having a triangle pattern, often emulated in refrigerator magnets, was assembled in Maxwell and is illustrated in
The next 2D model was setup only within the Maxwell software. It used a series of thin slices of material to approximate a substrate with a continuously rotating magnetization vector. The vector rotates counter-clockwise with increasing ‘x’. This model was used to explore the effect of a magnetization profile that was expected to have exceptional shear performance. To align with the other modeling efforts, the substrate was built to extend 96 mm in ‘x’, wavelengths of 1, 2, 4, and 8 mm were examined with the substrate thickness set to equal the wavelength. Instead of moving the top plate, which inherently changes the areas that are interacting in shear, the phase of the magnetization vector was shifted to a reach a maximum shear condition.
A variety of maxel patterns were “printed” (using CMR's proprietary MagPrinter magnetization tool) into nickel-plated N42 NIB material and most were 1″ square magnets ⅛″ thick. The shear forces were tested over a variety of offsets and displacements with an emphasis on understanding the effects of spatial frequency in ‘x’ and in ‘y’.
A shear force test apparatus is shown in
The results of the experimental magnetic shear force work were used to build high-torque codes for disk-to-disk couples. For these devices, ⅛″ thick×3″ OD N42 NIB magnets were used for the disks. In addition, a torque demonstration fixture was designed and built to help examine the performance of the couple magnets.
Magnetic Coupling Development Results and Conclusions
The nature of force development in magnetic coupling is a good starting point for understanding the shear force densities of unique magnetization patterns, since a coupling is a magnetic gear with a 1:1 transmission ratio. Lorimer, 1997 [3] analyzes the influence of magnetization patterns and shows that non-uniform patterns can produce higher torque than uniformly magnetized poles. No other references to shear force/torque development in non-uniformly magnetized couplings were found during this project.
Many types of magnetic gears have been invented involving conventional (i.e., uncoded) magnets and electromagnets. Some borrow their architecture from traditional spur or planetary gears, while others leverage the characteristics of magnetic fields and magnetic circuits, either axially or in concentric orientations. As shown in Table 1, these inventions span more than one hundred years and illustrate a variety of ways that magnets can be used to convert rotation speeds and torques without contact between gears.
Furlani, 2000 [13] and Jorgensen, 2005 [14] present analytical solutions for the torque transmission between parallel shaft multi-pole cylinders that are the magnetic equivalent of mechanical spur gears. These and other magnetic gear variants [15, 16] have torque densities significantly below commercially available mechanical gearboxes [especially, 17, 18], as shown in Table 2. Only the volume containing the gears and their interactions were used for the calculation of the torque densities in this table. For the commercially available standard gears, the dimensions of the gearbox housings were used to calculate the volume. Input and output shafts and other external materials were left out to facilitate the comparison of commercially available standard gearboxes with experimental magnetic gears. Thus, the differences in torque densities between magnetic gears and traditional gears are understated in this table Improved torque density is obtained when the coupling of permanent magnet material is maximized. One prevalent approach is the use of coaxial engagement of inner and outer rotors, such as those described in 13, 20, 21, 23 and 26.
There are two main contributors to shear force between magnets that have been demonstrated during this project. The first is that the spatial frequency of repeating patterns is an important factor in the shear force produced, and especially in terms of the shear force per volume of magnetic material. The other important factor is related to the pattern of magnetization within the substrate, including the creation of a one-sided field emission structure that maximizes the interaction between the two plates. The triangle and continuously varying patterns, outlined below, illustrate the role of magnetization in generating shear forces between magnets.
Furlani [2], introduces a very useful magnetic charge model which applies to the present discussion. The field of a permanent magnet can be expressed as an integral function of its magnetization, as shown in Equation 2. While the details of this equation are beyond the scope of the present discussion, it is the launching point for the analytical work that has become a part of this project and will form the first section of the shear force journal article that is being prepared based on the work outlined in this report.
Equation 3 defines a continuously rotating magnetization vector of a spatial frequency ‘f’ in a rectangular magnet having a length ‘2a’. This magnetization pattern was modeled and the results are described below.
Furlani's charge model can also be applied to the forces between two permanent magnets by integrating the field from the first magnet multiplied by the magnetization of the second, as shown in Equation 4. What is interesting is that the shear comes from the interaction of the gradient of B-field from magnet 1 (here “B1”), with the magnetization of the second magnet, M. By looking at only the force in the ‘x’ direction (the shear force in this case) the expression can be simplified to Equation 5. This provides a clearer picture of the source of shear force at each point in the second magnet: it is the gradient of the ‘x’ direction B field (from magnet 1) multiplied by the magnetization vector within magnet 2. Since the magnetization is limited to a maximum saturation point for the material, creating large gradients throughout the volume of a permanent magnet requires some kind of oscillation. Alternating fields, of course, create local magnetic circuits and tend to increase field gradients, but reduce the distances that fields propagate away from magnet surfaces. This is an effect illustrated by the field intensity surrounding a substrate with a continuously varying magnetization (similar to that described in Equation 3, above). The region above the substrate, according to Equation 5, is the one capable of producing shear forces in an upper magnet. It is interesting to note the thickness of the green region compared to the thickness of the substrate.
Another important discovery of the ‘alternating block’ study was the relationship between feature size and the decrease in force with distance. The same relationship was also found to apply to simulated maxels, as shown in
The CMR technologies grew from applying signal processing and coding theories to magnetic fields. One way of looking at the graph in
The 2D alternating block model built in the Maxwell simulation software shows several important differences with the results from the internally developed CMR software (with reference to
The maximum shear stress (48N/cm^2) of the triangle pattern as calculated by the CMR software is not significantly different from the alternating blocks or simulated maxel studies described above, and may stem from differences in the models themselves. The shear densities did change, but in an expected way. For alternating blocks, a 1 mm feature size led to a shear density of 160N/cc. The shear density calculated for 1 mm simulated maxels was 240N/cc. For the triangle study, a 1 mm feature size was calculated to have a shear density of 467N/cc. Since the substrates are scaled to ½ the feature size, the shear densities were nearly double that of the simulated maxel study.
However, the results of the triangle study in the CMR simulation software were ultimately not used to guide the development of maxel patterns. The 2 mm and 4 mm width triangle models did not follow curves with the same shape. There were also had challenges in terms of model convergence and handling the large gradients in the corners of the triangles. It was difficult to know to what extent the model was matching the behavior of a physical system in this case. Fortunately, a model built using the Maxwell software provided additional insight into this magnetization pattern.
A section of the Maxwell triangle pattern model oriented at a maximum shear condition is illustrated in
The shear stresses and shear densities for the triangle pattern are shown in
It is also interesting to compare the shear stresses for the alternating block model with those from the triangle model. At an offset of w/10 the shear stress from the alternating block model was 28N/cm2 for the same offset the triangle pattern was calculated to produce 55N/cm2. The differences in shear densities are more pronounced: 280N/cc for alternating blocks and 800N/cc for the triangle pattern.
Building a physical substrate from a series of triangular bars may not be practical. But, the behavior of this pattern shows how a one-sided field structure can improve shear forces between magnets.
The field intensity and field lines surrounding the continuously varying (CV) pattern are illustrated in
The discussion above included speculation that a single spatial frequency (rather than the family of harmonics that assemble the square-wave of the alternating block pattern) would fall off less rapidly with offset. This is not the case according to the results of the Maxwell modeling effort. The continuously varying pattern falls off slightly faster with increasing offset. At an offset of w/10, the alternating block pattern retains 58% of its zero-offset shear force, while the CV pattern retains 53% according to the Maxwell models.
The shear stress and shear density graph for the CV pattern (see
The effect on shear density of moving from the alternating block magnetization pattern to the CV pattern, which introduces both a one-sided field and a smoothly varying magnetization, is illustrated in
There is additional work necessary to understand how the CV pattern changes the way that the field from the lower plate interacts with the magnetization of the upper plate at a more fundamental and complete level. This work would guide the synthesis of a repeating magnetization pattern that would maximize this interaction. In turn, this work would guide the development of maxel patterns to produce even higher shear force magnets and higher torque density couples and gears than the prototypes developed during the course of this project.
A simulation of spot magnetization was built using a dipole model and a simplified magnetization model of the substrate. The setup of that model is illustrated in
As illustrated in
It is difficult, however to determine what additional guidance this model establishes for the design of high-shear maxel arrays. The ‘z’ direction field profile above a single maxel in this simulation did not match the near-gaussian profile tested above printed maxels. The field profile around the proprietary magnetization head developed by CMR is different from a single dipole. Further, CMR is pushing the limits of high-speed magnetization into areas of magnetization dynamics that are not yet well understood. As one example of the complexity of this process, NIB material has been observed to have a variable ferromagnetism that is dependent on the magnetization condition. From observations, including several from the experimental work during this project, there are significant interactions between magnetized regions and maxel printing. This means that overlap between maxels and the order the maxels are magnetized influence the fields emitted from, and the forces between, maxel arrays. The results of this model follow the basic behavior of other models developed during this project, but ultimately the simulation results come from an over simplification of the magnetization head, the magnetic material, and the magnetization process.
In order to acquire the most accurate characterization data possible, CMR produced a 3D field probe apparatus with a 40μ, 3-axis Hall-effect probe. This device enables a far more comprehensive exploration of the fields emitted from individual maxels, and arrays of maxels created under a variety of conditions. This capability, combined with the development of a more representative magnetization model in Maxwell, will support improvements to the CMR magnetization process, to include speed, maxel profiles, and more accurate assessment, and allow maxel arrays to be designed to make better use of the magnetic material.
A large variety of maxel patterns were designed, printed, and tested during this project. This led to the development of codes that demonstrate substantially higher shear forces and force densities compared to the literature. A single pass of shear force data for a selection of codes is shown in
Another interesting deviation from expectations is illustrated by comparing the MS, 31 and MF codes. The expectation was that the 31 Code would exhibit shear forces that sat between the MF and MS codes since the MF varies in both X and Y and the MS only in X. The 31 Code varies more slowly in Y, which should place it in an intermediate position. That the 31 Code falls below these other two codes indicates that there may be two competing effects. The modeling work focused on magnetization variation only in X. The comparison between the MF, MS and 31 Codes shows that the variation of magnetization in two directions is more complex. Variation in both X and Y has the effect of increasing the effective spatial frequency of the substrate, which should reduce the shear force at a particular offset. However, the benefits of reducing the spatial frequency illustrated in several of the graphs of model data above were tied to also increasing the thickness of the substrate. So the effect of decreasing spatial frequency without increasing substrate thickness is to reduce the amount of shear force available, which is an effect illustrated by
Another important comparison in
At these same displacements, the Maxwell models predict far higher shear forces for both the alternating block and CV patterns. Additional work will be necessary to determine the sources of these differences and more importantly, to find available techniques for increasing the forces exhibited by maxel arrays.
Based on the results of the shear force experiments, a series of high torque (HT) codes were developed for printing onto commercially available 3″ OD, Nickel-plated, N42, NIB disks, ⅛″ thick. Several different strategies were used to design the codes. As an example, the code illustrated in
In accordance with another embodiment of the invention depicted in
The spatial layouts for the six maxel tracks of the codes of
The polarity patterns and maxel positions for the maxel tracks of the two-magnet codes of
The torque density versus offset of a magnet pair printed with this code is shown in
While particular embodiments of the invention have been described, it will be understood, however, that the invention is not limited thereto, since modifications may be made by those skilled in the art, particularly in light of the foregoing teachings.
This Nonprovisional Patent Application claims the benefit of U.S. Provisional Patent Application 61/573,462, filed Sep. 6, 2011, titled “High Torque Magnetic Gears”.
This invention was made with government support under contract number N00014-11-M-0150 awarded by the Office of Naval Research. The government has certain rights in the invention.
Number | Name | Date | Kind |
---|---|---|---|
93931 | Westcott | Aug 1869 | A |
361248 | Winton | Apr 1887 | A |
381968 | Tesla | May 1888 | A |
493858 | Edison | Mar 1893 | A |
675323 | Clark | May 1901 | A |
687292 | Armstrong | Nov 1901 | A |
996933 | Lindquist | Jul 1911 | A |
1081462 | Patton | Dec 1913 | A |
1171351 | Neuland | Feb 1916 | A |
1236234 | Troje | Aug 1917 | A |
1252289 | Murray, Jr. | Jan 1918 | A |
1301135 | Karasick | Apr 1919 | A |
1312546 | Karasick | Aug 1919 | A |
1323546 | Karasick | Aug 1919 | A |
1554236 | Simmons | Jan 1920 | A |
1343751 | Simmons | Jun 1920 | A |
1624741 | Leppke et al. | Dec 1926 | A |
1784256 | Stout | Dec 1930 | A |
1895129 | Jones | Jan 1933 | A |
2048161 | Klaiber | Jul 1936 | A |
2147482 | Butler | Dec 1936 | A |
2186074 | Koller | Jan 1940 | A |
2240035 | Catherall | Apr 1941 | A |
2243555 | Faus | May 1941 | A |
2269149 | Edgar | Jan 1942 | A |
2327748 | Smith | Aug 1943 | A |
2337248 | Koller | Dec 1943 | A |
2337249 | Koller | Dec 1943 | A |
2389298 | Ellis | Nov 1945 | A |
2401887 | Sheppard | Jun 1946 | A |
2414653 | lokholder | Jan 1947 | A |
2438231 | Schultz | Mar 1948 | A |
2471634 | Vennice | May 1949 | A |
2475456 | Norlander | Jul 1949 | A |
2508305 | Teetor | May 1950 | A |
2513226 | Wylie | Jun 1950 | A |
2514927 | Bernhard | Jul 1950 | A |
2520828 | Bertschi | Aug 1950 | A |
2565624 | phelon | Aug 1951 | A |
2570625 | Zimmerman et al. | Oct 1951 | A |
2690349 | Teetor | Sep 1954 | A |
2694164 | Geppelt | Nov 1954 | A |
2964613 | Williams | Nov 1954 | A |
2701158 | Schmitt | Feb 1955 | A |
2722617 | Cluwen et al. | Nov 1955 | A |
2770759 | Ahlgren | Nov 1956 | A |
2837366 | Loeb | Jun 1958 | A |
2853331 | Teetor | Sep 1958 | A |
2888291 | Scott et al. | May 1959 | A |
2896991 | Martin, Jr. | Jul 1959 | A |
2935352 | Heppner | May 1960 | A |
2935353 | Loeb | May 1960 | A |
2936437 | Fraser et al. | May 1960 | A |
2962318 | Teetor | Nov 1960 | A |
3055999 | Lucas | Sep 1962 | A |
3089986 | Gauthier | May 1963 | A |
3102314 | Alderfer | Sep 1963 | A |
3151902 | Ahlgren | Oct 1964 | A |
3204995 | Teetor | Sep 1965 | A |
3208296 | Baermann | Sep 1965 | A |
3238399 | Johanees et al. | Mar 1966 | A |
3273104 | Krol | Sep 1966 | A |
3288511 | Tavano | Nov 1966 | A |
3301091 | Reese | Jan 1967 | A |
3351368 | Sweet | Nov 1967 | A |
3382386 | Schlaeppi | May 1968 | A |
3408104 | Raynes | Oct 1968 | A |
3414309 | Tresemer | Dec 1968 | A |
3425729 | Bisbing | Feb 1969 | A |
2932545 | Foley | Apr 1969 | A |
3468576 | Beyer et al. | Sep 1969 | A |
3474366 | Barney | Oct 1969 | A |
3500090 | Baermann | Mar 1970 | A |
3521216 | Tolegian | Jul 1970 | A |
3645650 | Laing | Feb 1972 | A |
3668670 | Andersen | Jun 1972 | A |
3684992 | Huguet et al. | Aug 1972 | A |
3690393 | Guy | Sep 1972 | A |
3696258 | Anderson et al. | Oct 1972 | A |
3790197 | Parker | Feb 1974 | A |
3791309 | Baermann | Feb 1974 | A |
3802034 | Bookless | Apr 1974 | A |
3803433 | Ingenito | Apr 1974 | A |
3808577 | Mathauser | Apr 1974 | A |
3836801 | Yamashita et al. | Sep 1974 | A |
3845430 | Petkewicz et al. | Oct 1974 | A |
3893059 | Nowak | Jul 1975 | A |
3976316 | Laby | Aug 1976 | A |
4079558 | Gorham | Mar 1978 | A |
4117431 | Eicher | Sep 1978 | A |
4129846 | Yablochnikov | Dec 1978 | A |
4209905 | Gillings | Jul 1980 | A |
4222489 | Hutter | Sep 1980 | A |
4296394 | Ragheb | Oct 1981 | A |
4340833 | Sudo et al. | Jul 1982 | A |
4352960 | Dormer et al. | Oct 1982 | A |
4355236 | Holsinger | Oct 1982 | A |
4399595 | Yoon et al. | Aug 1983 | A |
4416127 | Gomez-Olea Naveda | Nov 1983 | A |
4451811 | Hoffman | May 1984 | A |
4453294 | Morita | Jun 1984 | A |
4517483 | Hucker et al. | May 1985 | A |
4535278 | Asakawa | Aug 1985 | A |
4547756 | Miller et al. | Oct 1985 | A |
4629131 | Podell | Dec 1986 | A |
4645283 | MacDonald et al. | Feb 1987 | A |
4680494 | Grosjean | Jul 1987 | A |
4764743 | Leupold et al. | Aug 1988 | A |
4808955 | Godkin et al. | Feb 1989 | A |
4837539 | Baker | Jun 1989 | A |
4849749 | Fukamachi et al. | Jul 1989 | A |
4862128 | Leupold | Aug 1989 | A |
H693 | Leupold | Oct 1989 | H |
4893103 | Leupold | Jan 1990 | A |
4912727 | Schubert | Mar 1990 | A |
4941236 | Sherman et al. | Jul 1990 | A |
4956625 | Cardone et al. | Sep 1990 | A |
4980593 | Edmundson | Dec 1990 | A |
4993950 | Mensor, Jr. | Feb 1991 | A |
4994778 | Leupold | Feb 1991 | A |
4996457 | Hawsey et al. | Feb 1991 | A |
5013949 | Mabe, Jr. | May 1991 | A |
5020625 | Yamauchi et al. | Jun 1991 | A |
5050276 | Pemberton | Sep 1991 | A |
5062855 | Rincoe | Nov 1991 | A |
5123843 | Van der Zel et al. | Jun 1992 | A |
5179307 | Porter | Jan 1993 | A |
5190325 | Doss-Desouza | Mar 1993 | A |
5213307 | Perrillat-Amede | May 1993 | A |
5302929 | Kovacs | Apr 1994 | A |
5309680 | Kiel | May 1994 | A |
5345207 | Gebele | Sep 1994 | A |
5349258 | Leupold et al. | Sep 1994 | A |
5367891 | Furuyama | Nov 1994 | A |
5383049 | Carr | Jan 1995 | A |
5394132 | Poil | Feb 1995 | A |
5399933 | Tsai | Mar 1995 | A |
5425763 | Stemmann | Jun 1995 | A |
5440997 | Crowley | Aug 1995 | A |
5461386 | Knebelkamp | Oct 1995 | A |
5485435 | Matsuda et al. | Jan 1996 | A |
5492572 | Schroeder et al. | Feb 1996 | A |
5495221 | Post | Feb 1996 | A |
5512732 | Yagnik et al. | Apr 1996 | A |
5570084 | Ritter et al. | Oct 1996 | A |
5582522 | Johnson | Dec 1996 | A |
5604960 | Good | Feb 1997 | A |
5631093 | Perry et al. | May 1997 | A |
5631618 | Trumper et al. | May 1997 | A |
5633555 | Ackermann et al. | May 1997 | A |
5635889 | Stelter | Jun 1997 | A |
5637972 | Randall et al. | Jun 1997 | A |
5730155 | Allen | Mar 1998 | A |
5759054 | Spadafore | Jun 1998 | A |
5788493 | Tanaka et al. | Aug 1998 | A |
5852393 | Reznik et al. | Dec 1998 | A |
5935155 | Humayun et al. | Aug 1999 | A |
5956778 | Godoy | Sep 1999 | A |
5983406 | Meyerrose | Nov 1999 | A |
6000484 | Zoretich et al. | Dec 1999 | A |
6039759 | Carpentier et al. | Mar 2000 | A |
6047456 | Yao et al. | Apr 2000 | A |
6072251 | Markle | Jun 2000 | A |
6074420 | Eaton | Jun 2000 | A |
6104108 | Hazelton et al. | Aug 2000 | A |
6115849 | Meyerrose | Sep 2000 | A |
6118271 | Ely et al. | Sep 2000 | A |
6120283 | Cousins | Sep 2000 | A |
6125955 | Zoretich et al. | Oct 2000 | A |
6142779 | Siegel et al. | Nov 2000 | A |
6170131 | Shin | Jan 2001 | B1 |
6187041 | Garonzik | Feb 2001 | B1 |
6188147 | Hazelton et al. | Feb 2001 | B1 |
6205012 | Lear | Mar 2001 | B1 |
6210033 | Karkos, Jr. et al. | Apr 2001 | B1 |
6224374 | Mayo | May 2001 | B1 |
6234833 | Tsai et al. | May 2001 | B1 |
6273918 | Yuhasz et al. | Aug 2001 | B1 |
6275778 | Shimada et al. | Aug 2001 | B1 |
6285097 | Hazelton et al. | Sep 2001 | B1 |
6387096 | Hyde, Jr. | May 2002 | B1 |
6422533 | Harms | Jul 2002 | B1 |
6457179 | Prendergast | Oct 2002 | B1 |
6467326 | Garrigus | Oct 2002 | B1 |
6535092 | Hurley et al. | Mar 2003 | B1 |
6540515 | Tanaka | Apr 2003 | B1 |
6561815 | Schmidt | May 2003 | B1 |
6599321 | Hyde, Jr. | Jul 2003 | B2 |
6607304 | Lake et al. | Aug 2003 | B1 |
6652278 | Honkura et al. | Nov 2003 | B2 |
6653919 | Shih-Chung et al. | Nov 2003 | B2 |
6720698 | Galbraith | Apr 2004 | B2 |
6747537 | Mosteller | Jun 2004 | B1 |
6821126 | Neidlein | Nov 2004 | B2 |
6841910 | Gery | Jan 2005 | B2 |
6842332 | Rubenson et al. | Jan 2005 | B1 |
6847134 | Frissen et al. | Jan 2005 | B2 |
6850139 | Dettmann et al. | Feb 2005 | B1 |
6862748 | Prendergast | Mar 2005 | B2 |
6864773 | Perrin | Mar 2005 | B2 |
6913471 | Smith | Jul 2005 | B2 |
6927657 | Wu | Aug 2005 | B1 |
6936937 | Tu et al. | Aug 2005 | B2 |
6954938 | Emberty et al. | Oct 2005 | B2 |
6954968 | Sitbon | Oct 2005 | B1 |
6971147 | Halstead | Dec 2005 | B2 |
7009874 | Deak | Mar 2006 | B2 |
7016492 | Pan et al. | Mar 2006 | B2 |
7031160 | Tillotson | Apr 2006 | B2 |
7033400 | Currier | Apr 2006 | B2 |
7038565 | Chell | May 2006 | B1 |
7065860 | Aoki et al. | Jun 2006 | B2 |
7066739 | McLeish | Jun 2006 | B2 |
7066778 | Kretzschmar | Jun 2006 | B2 |
7097461 | Neidlein | Aug 2006 | B2 |
7101374 | Hyde, Jr. | Sep 2006 | B2 |
7135792 | Devaney et al. | Nov 2006 | B2 |
7137727 | Joseph et al. | Nov 2006 | B2 |
7186265 | Sharkawy et al. | Mar 2007 | B2 |
7224252 | Meadow, Jr. et al. | May 2007 | B2 |
7264479 | Lee | Sep 2007 | B1 |
7276025 | Roberts et al. | Oct 2007 | B2 |
7311526 | Rohrbach et al. | Dec 2007 | B2 |
7339790 | Baker et al. | Mar 2008 | B2 |
7344380 | Neidlein et al. | Mar 2008 | B2 |
7351066 | DiFonzo et al. | Apr 2008 | B2 |
7358724 | Taylor et al. | Apr 2008 | B2 |
7362018 | Kulogo et al. | Apr 2008 | B1 |
7364433 | Neidlein | Apr 2008 | B2 |
7381181 | Lau et al. | Jun 2008 | B2 |
7402175 | Azar | Jul 2008 | B2 |
7416414 | Bozzone et al. | Aug 2008 | B2 |
7438726 | Erb | Oct 2008 | B2 |
7444683 | Prendergast et al. | Nov 2008 | B2 |
7453341 | Hildenbrand | Nov 2008 | B1 |
7467948 | Lindberg et al. | Dec 2008 | B2 |
7498914 | Miyashita et al. | Mar 2009 | B2 |
7583500 | Ligtenberg et al. | Sep 2009 | B2 |
7637746 | Lindberg et al. | Dec 2009 | B2 |
7645143 | Rohrbach et al. | Jan 2010 | B2 |
7658613 | Griffin et al. | Feb 2010 | B1 |
7715890 | Kim et al. | May 2010 | B2 |
7762817 | Ligtenberg et al. | Jul 2010 | B2 |
7775567 | Ligtenberg et al. | Aug 2010 | B2 |
7796002 | Hashimoto et al. | Sep 2010 | B2 |
7799281 | Cook et al. | Sep 2010 | B2 |
7808349 | Fullerton et al. | Oct 2010 | B2 |
7812697 | Fullerton et al. | Oct 2010 | B2 |
7817004 | Fullerton et al. | Oct 2010 | B2 |
7828556 | Rodrigues | Nov 2010 | B2 |
7832897 | Ku | Nov 2010 | B2 |
7837032 | Smeltzer | Nov 2010 | B2 |
7839246 | Fullerton et al. | Nov 2010 | B2 |
7843297 | Fullerton et al. | Nov 2010 | B2 |
7868721 | Fullerton et al. | Jan 2011 | B2 |
7871272 | Firman, II et al. | Jan 2011 | B2 |
7874856 | Schriefer et al. | Jan 2011 | B1 |
7889037 | Cho | Feb 2011 | B2 |
7901216 | Rohrbach et al. | Mar 2011 | B2 |
7903397 | McCoy | Mar 2011 | B2 |
7905626 | Shantha et al. | Mar 2011 | B2 |
7982568 | Fullerton et al. | Jul 2011 | B2 |
7997906 | Ligenberg et al. | Aug 2011 | B2 |
8002585 | Zhou | Aug 2011 | B2 |
8009001 | Cleveland | Aug 2011 | B1 |
8050714 | Fadell et al. | Nov 2011 | B2 |
8078224 | Fadell et al. | Dec 2011 | B2 |
8078776 | Novotney et al. | Dec 2011 | B2 |
8087939 | Rohrbach et al. | Jan 2012 | B2 |
8099964 | Saito et al. | Jan 2012 | B2 |
8138869 | Lauder et al. | Mar 2012 | B1 |
8143982 | Lauder et al. | Mar 2012 | B1 |
8143983 | Lauder et al. | Mar 2012 | B1 |
8165634 | Fadell et al. | Apr 2012 | B2 |
8177560 | Rohrbach et al. | May 2012 | B2 |
8187006 | Rudisill et al. | May 2012 | B2 |
8190205 | Fadell et al. | May 2012 | B2 |
8242868 | Lauder et al. | Aug 2012 | B2 |
8253518 | Lauder et al. | Aug 2012 | B2 |
8264310 | Lauder et al. | Sep 2012 | B2 |
8264314 | Sankar | Sep 2012 | B2 |
8271038 | Fadell et al. | Sep 2012 | B2 |
8271705 | Novotney et al. | Sep 2012 | B2 |
8297367 | Chen et al. | Oct 2012 | B2 |
8344836 | Lauder et al. | Jan 2013 | B2 |
8348678 | Hardisty et al. | Jan 2013 | B2 |
8354767 | Pennander et al. | Jan 2013 | B2 |
8390411 | Lauder et al. | Mar 2013 | B2 |
8390412 | Lauder et al. | Mar 2013 | B2 |
8390413 | Lauder et al. | Mar 2013 | B2 |
8395465 | Lauder et al. | Mar 2013 | B2 |
8398409 | Schmidt | Mar 2013 | B2 |
8435042 | Rohrbach et al. | May 2013 | B2 |
8454372 | Lee | Jun 2013 | B2 |
8467829 | Fadell et al. | Jun 2013 | B2 |
8497753 | DiFonzo et al. | Jul 2013 | B2 |
8514042 | Lauder et al. | Aug 2013 | B2 |
8535088 | Gao et al. | Sep 2013 | B2 |
8576031 | Lauder et al. | Nov 2013 | B2 |
8576034 | Bilbrey et al. | Nov 2013 | B2 |
8616362 | Browne et al. | Dec 2013 | B1 |
8648679 | Lauder et al. | Feb 2014 | B2 |
8665044 | Lauder et al. | Mar 2014 | B2 |
8665045 | Lauder et al. | Mar 2014 | B2 |
8690582 | Rohrbach et al. | Apr 2014 | B2 |
8702316 | DiFonzo et al. | Apr 2014 | B2 |
8734024 | Isenhour et al. | May 2014 | B2 |
8752200 | Varshavsky et al. | Jun 2014 | B2 |
8757893 | Isenhour et al. | Jun 2014 | B1 |
8770857 | DiFonzo et al. | Jul 2014 | B2 |
8774577 | Benjamin et al. | Jul 2014 | B2 |
8781273 | Benjamin et al. | Jul 2014 | B2 |
20020125977 | VanZoest | Sep 2002 | A1 |
20030170976 | Molla et al. | Sep 2003 | A1 |
20030179880 | Pan et al. | Sep 2003 | A1 |
20030187510 | Hyde | Oct 2003 | A1 |
20040003487 | Reiter | Jan 2004 | A1 |
20040155748 | Steingroever | Aug 2004 | A1 |
20040244636 | Meadow et al. | Dec 2004 | A1 |
20040251759 | Hirzel | Dec 2004 | A1 |
20050102802 | Sitbon et al. | May 2005 | A1 |
20050196484 | Khoshnevis | Sep 2005 | A1 |
20050231046 | Aoshima | Oct 2005 | A1 |
20050240263 | Fogarty et al. | Oct 2005 | A1 |
20050263549 | Scheiner | Dec 2005 | A1 |
20060066428 | McCarthy et al. | Mar 2006 | A1 |
20060189259 | Park et al. | Aug 2006 | A1 |
20060198047 | Xue et al. | Sep 2006 | A1 |
20060214756 | Elliott et al. | Sep 2006 | A1 |
20060290451 | Prendergast et al. | Dec 2006 | A1 |
20060293762 | Schulman et al. | Dec 2006 | A1 |
20070072476 | Milan | Mar 2007 | A1 |
20070075594 | Sadler | Apr 2007 | A1 |
20070103266 | Wang et al. | May 2007 | A1 |
20070138806 | Ligtenberg et al. | Jun 2007 | A1 |
20070255400 | Parravicini et al. | Nov 2007 | A1 |
20070267929 | Pulnikov et al. | Nov 2007 | A1 |
20080119250 | Cho et al. | May 2008 | A1 |
20080139261 | Cho et al. | Jun 2008 | A1 |
20080174392 | Cho | Jul 2008 | A1 |
20080181804 | Tanigawa et al. | Jul 2008 | A1 |
20080186683 | Ligtenberg et al. | Aug 2008 | A1 |
20080218299 | Arnold | Sep 2008 | A1 |
20080224806 | Ogden et al. | Sep 2008 | A1 |
20080272868 | Prendergast et al. | Nov 2008 | A1 |
20080282517 | Claro | Nov 2008 | A1 |
20090021333 | Fiedler | Jan 2009 | A1 |
20090209173 | Arledge et al. | Aug 2009 | A1 |
20090250576 | Fullerton et al. | Oct 2009 | A1 |
20090251256 | Fullerton et al. | Oct 2009 | A1 |
20090254196 | Cox et al. | Oct 2009 | A1 |
20090278642 | Fullerton et al. | Nov 2009 | A1 |
20090289090 | Fullerton et al. | Nov 2009 | A1 |
20090289749 | Fullerton et al. | Nov 2009 | A1 |
20090292371 | Fullerton et al. | Nov 2009 | A1 |
20100033280 | Bird et al. | Feb 2010 | A1 |
20100126857 | Polwart et al. | May 2010 | A1 |
20100167576 | Zhou | Jul 2010 | A1 |
20110026203 | Ligtenberg et al. | Feb 2011 | A1 |
20110210636 | Kuhlmann-Wilsdorf | Sep 2011 | A1 |
20110234344 | Fullerton et al. | Sep 2011 | A1 |
20110248806 | Michael | Oct 2011 | A1 |
20110279206 | Fullerton et al. | Nov 2011 | A1 |
20120007704 | Nerl | Jan 2012 | A1 |
20120085753 | Fitch et al. | Apr 2012 | A1 |
20120235519 | Dyer et al. | Sep 2012 | A1 |
20130001745 | Iwaki | Jan 2013 | A1 |
20130186209 | Herbst | Jul 2013 | A1 |
20130186473 | Mankame et al. | Jul 2013 | A1 |
20130186807 | Browne et al. | Jul 2013 | A1 |
20130187538 | Herbst | Jul 2013 | A1 |
20130192860 | Puzio et al. | Aug 2013 | A1 |
20130207758 | Browne et al. | Aug 2013 | A1 |
20130252375 | Yi et al. | Sep 2013 | A1 |
20130256274 | Faulkner | Oct 2013 | A1 |
20130270056 | Mankame et al. | Oct 2013 | A1 |
20130305705 | Shivaram et al. | Nov 2013 | A1 |
20130341137 | Mandame et al. | Dec 2013 | A1 |
20140044972 | Menassa et al. | Feb 2014 | A1 |
20140072261 | Isenhour et al. | Mar 2014 | A1 |
20140152252 | Wood et al. | Jun 2014 | A1 |
20140205235 | Benjamin et al. | Jul 2014 | A1 |
20140221741 | Wang et al. | Aug 2014 | A1 |
Number | Date | Country |
---|---|---|
1615573 | May 2005 | CN |
2938782 | Apr 1981 | DE |
0 345 554 | Dec 1989 | EP |
0 545 737 | Jun 1993 | EP |
823395 | Jan 1938 | FR |
1 495 677 | Dec 1977 | GB |
60-091011 | May 1985 | JP |
WO-0231945 | Apr 2002 | WO |
WO-2007081830 | Jul 2007 | WO |
WO-2009124030 | Oct 2009 | WO |
WO-2010141324 | Dec 2010 | WO |
Entry |
---|
International Search Report and Written Opinion of the International Searching Authority issued in Application No. PCT/US12/61938 dated Feb. 26, 2013. |
International Search Report and Written Opinion of the International Searching Authority issued in Application No. PCT/US2013/028095 dated May 13, 2013. |
Mi, “Magnetreater/Charger Model 580” Magnetic Instruments Inc. Product specification, May 4, 2009, http://web.archive.org/web/20090504064511/http://www.maginst.com/specifications/580—magnetreater.htm, 2 pages. |
United States Office Action issued in U.S. Appl. No. 13/104,393 dated Apr. 4, 2013. |
United States Office Action issued in U.S. Appl. No. 13/236,413 dated Jun. 6, 2013. |
United States office Action issued in U.S. Appl. No. 13/246,584 dated May 16, 2013. |
United States Office Action issued in U.S. Appl. No. 13/374,074 dated Feb. 21, 2013. |
United States Office Action issued in U.S. Appl. No. 13/470,994 dated Jan. 7, 2013. |
United States Office Action issued in U.S. Appl. No. 13/530,893 dated Mar. 22, 2013. |
United States Office Action issued in U.S. Appl. No. 13/855,519 dated Jul. 17, 2013. |
United States Office Action issued in U.S. Appl. No. 13/470,994 dated Aug. 8, 2013. |
United States Office Action issued in U.S. Appl. No. 13/430,219 dated Aug. 13, 2013. |
BNS 33 Range, Magnetic safety sensors, Rectangular design, http://www.farnell.com/datasheets/36449.pdf, 3 pages, date unknown. |
Series BNS, Compatible Series AES Safety Controllers, http://www.schmersalusa.com/safety—controllers/drawings/aes.pdf, pp. 159-175, date unknown. |
Series BNS-B20, Coded-Magnet Sensorr Safety Door Handle, http://www.schmersalusa.com/catalog—pdfs/BNS—B20.pdf, 2pages, date unknown. |
Series BNS333, Coded-Magnet Sensors with Integral Safety Control Module, http://www.schmersalusa.com/machine—guarding/coded—magnet/drawings/bns333.pdf, 2 pages, date unknown. |
International Search Report and Written Opinion dated Jun. 1, 2009, directed to counterpart application No. PCT/US2009/002027. (10 pages). |
International Search Report and Written Opinion, dated Apr. 8, 2011 issued in related International Application No. PCT/US2010/049410. |
International Search Report and Written Opinion, dated Aug. 18, 2010, issued in related International Application No. PCT/US2010/036443. |
International Search Report and Written Opinion, dated Jul. 13, 2010, issued in related International Application No. PCT/US2010/021612. |
International Search Report and Written Opinion, dated May 14, 2009, issued in related International Application No. PCT/US2009/038925. |
Pill-soo Kim, “A future cost trends of magnetizer systems in Korea”, Industrial Electronics, Control, and Instrumentation, 1996, vol. 2, Aug. 5, 1996, pp. 991-996. |
United States Office Action, dated Aug. 26, 2011, issued in counterpart U.S. Appl. No. 12/206,270. |
United States Office Action, dated Feb. 2, 2011, issued in counterpart U.S. Appl. No. 12/476,952. |
United States Office Action, dated Mar. 12, 2012, issued in counterpart U.S. Appl. No. 12/206,270. |
United States Office Action, dated Mar. 9, 2012, issued in counterpart U.S. Appl. No. 13/371,280. |
United States Office Action, dated Oct. 12, 2011, issued in counterpart U.S. Appl. No. 12/476,952. |
Wikipedia, “Barker Code”, Web article, last modified Aug. 2, 2008, 2 pages. |
Wikipedia, “Bitter Electromagnet”, Web article, last modified Aug. 2011, 1 page. |
Wikipedia, “Costas Array”, Web article, last modified Oct. 7, 2008, 4 pages. |
Wikipedia, “Gold Code”, Web article, last modified Jul. 27, 2008, 1 page. |
Wikipedia, “Golomb Ruler”, Web article, last modified Nov. 4, 2008, 3 pages. |
Wikipedia, “Kasami Code”, Web article, last modified Jun. 11, 2008, 1 page. |
Wikipedia, “Linear feedback shift register”, Web article, last modified Nov. 11, 2008, 6 pages. |
Wikipedia, “Walsh Code”, Web article, last modified Sep. 17, 2008, 2 pages. |
United States Office Action issued in U.S. Appl. No. 13/529,520 dated Sep. 28, 2012. |
Atallah et al., 2004, “Design, analysis and realisation of a high-performance magnetic gear”, IEE Proc.-Electr. Power Appl., vol. 151, No. 2, Mar. 2004. |
Atallah et al., D. 2001, “A Novel High-Performance Magnetic Gear”, IEEE Transactions on Magnetics, vol. 37, No. 4, Jul. 2001, p. 2844-46. |
Bassani, 2007, “Dynamic Stability of Passive Magnetic Bearings”, Nonlinear Dynamics, V. 50, p. 161-68. |
Boston Gear 221S-4, One-stage Helical Gearbox, http://www.bostongear.com/pdf/product—sections/200—series—helical.pdf, referenced Jun. 2010. |
Chau et al., 2008, “Transient Analysis of Coaxial Magnetic Gears Using Finite Element Comodeling”, Journal of Applied Physics, vol. 103. |
Charpentier et al., 2001, “Mechanical Behavior of Axially Magnetized Permanent-Magnet Gears”, IEEE Transactions on Magnetics, vol. 37, No. 3, May 2001, p. 1110-17. |
Choi et al., 2010, “Optimization of Magnetization Directions in a 3-D Magnetic Structure”, IEEE Transactions on Magnetics, vol. 46, No. 6, Jun. 2010, p. 1603-06. |
Correlated Magnetics Research, 2009, Online Video, “Innovative Magnetics Research in Huntsville”, http://www.youtube.com/watch?v=m4m81JjZCJo. |
Correlated Magnetics Research, 2009, Online Video, “Non-Contact Attachment Utilizing Permanent Magnets”, http://www.youtube.com/watch?v=3xUm25CNNgQ. |
Correlated Magnetics Research, 2010, Company Website, http://www.correlatedmagnetics.com. |
Furlani 1996, “Analysis and optimization of synchronous magnetic couplings”, J. Appl. Phys., vol. 79, No. 8, p. 4692. |
Furlani 2000, “Analytical analysis of magnetically coupled multiple cylinders”, J. Phys. D: Appl. Phys., vol. 33, No. 1, p. 28-33. |
Furlani 2001, “Permanent Magnet and Electromechanical Devices”, Academic Press, San Diego, pp. 131-136. |
General Electric DP 2.7 Wind Turbine Gearbox, http://www.gedrivetrain.com/insideDP27.cfm, referenced Jun. 2010. |
Ha et al., 2002, “Design and Characteristic Analysis of Non-Contact Magnet Gear for Conveyor by Using Permanent Magnet”, Conf. Record of the 2002 IEEE Industry Applications Conference, p. 1922-27. |
Huang et al., 2008, “Development of a Magnetic Planetary Gearbox”, IEEE Transactions on Magnetics, vol. 44, No. 3, p. 403-12. |
Jian et al., “Comparison of Coaxial Magnetic Gears With Different Topologies”, IEEE Transactions on Magnetics, vol. 45, No. 10, Oct. 2009, p. 4526-29. |
Jian et al., 2010, “A Coaxial Magnetic Gear With Halbach Permanent-Magnet Arrays”, IEEE Transactions on Energy Conversion, vol. 25, No. 2, Jun. 2010, p. 319-28. |
Jørgensen et al., 2005, “Two dimensional model of a permanent magnet spur gear”, Conf. Record of the 2005 IEEE Industry Applications Conference, p. 261-5. |
Jørgensen et al., “The Cycloid Permanent Magnetic Gear”, IEEE Transactions on Industry Applications, vol. 44, No. 6, Nov./Dec. 2008, p. 1659-65. |
Krasil'nikov 2008, “Calculation of the Shear Force of Highly Coercive Permanent Magnets in Magnetic Systems With Consideration of Affiliation to a Certain Group Based on Residual Induction”, Chemical and Petroleum Engineering, vol. 44, Nos. 7-8, p. 362-65. |
Krasil'nikov 2009, “Torque Determination for a Cylindrical Magnetic Clutch”, Russian Engineering Research, vol. 29, No. 6, pp. 544-47. |
Liu et al., 2009, “Design and Analysis of Interior-magnet Outer-rotor Concentric Magnetic Gears”, Journal of Applied Physics, vol. 105. |
Lorimer et al., A., 1997, “Magnetization Pattern for Increased Coupling in Magnetic Clutches”, IEEE Transactions on Magnetics, vol. 33, No. 5, Sep. 1997. |
Mezani et al., 2006, “A high-performance axial-field magnetic gear”, Journal of Applied Physics vol. 99. |
Neugart PLE-160, One-Stage Planetary Gearbox, http://www.neugartusa.com/ple—160—gb.pdf, referenced Jun. 2010. |
Tsurumoto 1992, “Basic Analysis on Transmitted Force of Magnetic Gear Using Permanent Magnet”, IEEE Translation Journal on Magnetics in Japan, Vo 7, No. 6, Jun. 1992, p. 447-52. |
C. Pompermaier, L. Sjoberg, and G. Nord, Design and Optimization of a Permanent Magnet Transverse Flux Machine, XXth International Conference on Electrical Machines, Sep. 2012, p. 606, IEEE Catalog No. CFP1290B-PRT, ISBN: 978-1-4673-0143-5. |
V. Rudnev, An Objective Assessment of Magnetic Flux Concentrators, Het Trating Progress, Nov./Dec. 2004, p. 19-23. |
Number | Date | Country | |
---|---|---|---|
20140062241 A1 | Mar 2014 | US |
Number | Date | Country | |
---|---|---|---|
61573462 | Sep 2011 | US |