Classifications

• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K49/00—Dynamo-electric clutches; Dynamo-electric brakes
  • H02K49/02—Dynamo-electric clutches; Dynamo-electric brakes of the asynchronous induction type
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K49/00—Dynamo-electric clutches; Dynamo-electric brakes
  • H02K49/10—Dynamo-electric clutches; Dynamo-electric brakes of the permanent-magnet type
  • H02K49/104—Magnetic couplings consisting of only two coaxial rotary elements, i.e. the driving element and the driven element
  • H02K49/106—Magnetic couplings consisting of only two coaxial rotary elements, i.e. the driving element and the driven element with a radial air gap
• • H—ELECTRICITY
  • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
  • H02K—DYNAMO-ELECTRIC MACHINES
  • H02K51/00—Dynamo-electric gears, i.e. dynamo-electric means for transmitting mechanical power from a driving shaft to a driven shaft and comprising structurally interrelated motor and generator parts

Definitions

• An apparatus for transferring torque magnetically An apparatus for transferring torque magnetically.
• Patent application number 10/790,571 which has a priority filing date of March 1,
• the present invention relates to rotational magnetic torque transfer devices utilizing two coaxial cylinders overlapping one another wherein one cylinder contains a row(s) of permanent magnets and the other cylinder contains a ring(s) of electroconductive material.
• Eddy current clutches that use DC current to generate and vary the flux density in a fixed gap mechanism. These devices are available in a wide range of horse power but are expensive, complicated and require a DC current and control to induce the torque. There are applications where the DC current is not desirable or where the apparatus for controlling the torque producing currents are unreliable.
• the apparatus described utilizes recent developments in magnetic material technology, in conjunction with architecture designed for mechanically stable operation. This will allow the apparatus to be used in a full range of power transmission applications including high horsepower applications.
• the configuration of the device also makes it stable and able to operate at higher input speeds, which are natively present in some motors and engines.
• the described apparatus is a device that uses permanent magnets and conductors arranged in an optimal manner to generate the magnetic flux in a power transmission drive.
• a number of the embodiments described utilize a mechanical means for changing the flux density between two rotating components to vary the torque transmitted by and thereby the output speed of the apparatus.
• the present invention utilizes permanent magnets to transmit variable or fixed torque between two rotating elements.
• the torque between the elements may be adjusted by mechanically varying the amount of magnetic flux passing between the elements. This is accomplished by varying the extent to which the elements are axially overlapped.
• two concentric cylinders one containing one or more rows of permanent magnets, is moved axially in order to progressively axially overlap a second cylindrical element containing electrically conductive and magnetically conductive elements. This progressive axial overlapping of the two cylinders allows variation in the amount of magnetic flux intersecting the two concentric cylinders.
• the proposed invention overcomes previous limitations by taking advantage of new technologies in magnet materials and provides a stable means of mechanically varying large amounts of transmitted torque without the need for large external current controls.
• Figure 1 is an isometric view of the exterior of a preferred embodiment of the invention.
• Figure 2 is a sectioned isometric view of the preferred embodiment of the invention.
• Figure 3 is section view through the preferred embodiment of the invention.
• Figure 4 is an exploded section view showing the various major parts of the described preferred embodiment of the invention.
• Figure 5 is a section view of an alternate form of electrically conductive cylinder as described in the alternate embodiment of the invention.
• Figure 6 is an isometric of an alternate embodiment of the invention.
• Figure 7 is a cut away through the isometric of the alternate embodiment of the invention.
• Figure 8 is an isometric of a second alternate embodiment of the invention.
• Figure 9 is a cut away through the isometric of the second alternate embodiment of the invention.
• the first part of the variable speed' torque transfer apparatus described in this preferred embodiment consists of a primary rotary member comprising an input shaft rotor (2), a support cylinder (3), and a magnet-carrying rotor (4), all mechanically connected together, and constrained to rotate at the same angular velocity together.
• the second part of the variable speed torque transfer apparatus described in this preferred embodiment consists of a secondary rotary member comprising an output shaft rotor (1), magnetically permeable ferrous wheels (7) which support and back the electro-conductive rings (6), all mechanically connected together, and constrained to rotate at the same angular velocity together.
• the input shaft (2) is connected directly to a concentric support cylinder (3), which is constrained to rotate with the input shaft (2).
• the support cylinder (3) and input shaft (2) are supported by two input shaft support bearings (12) located at each end of the support cylinder (3). These two bearings (12) are in turn, supported by the apparatus exterior protective enclosure (30), which has mounting feet (31) on its underside section. These mounting feet are then attached to a type of machinery a foundation (not shown).
• a separate magnet- carrying rotor (4) is mounted concentrically within the support cylinder (3) and is constrained to rotate with the support cylinder (3).
• the magnet-carrying rotor (4) is also constrained to move axially with respect to the support cylinder (3) while maintaining its rotational and concentric relationship with the support cylinder (3).
• the constraints are comprised of four pairs of rollers (14) whose axles are radially positioned on the magnetic carrying cylinder and disposed to engage and run in longitudinal slots (15) in the support cylinder (3). It is noted that those skilled in the art could conceive of other means for supporting and constraining the magnet-carrying rotor (4).
• the interior surface of the magnet-carrying rotor (4) contains one or more annular arrays, each array consisting of a plurality of magnets (5) which are arrayed radially around the internal periphery of the magnet-carrying rotor (4).
• the poles of the magnets (5) are geometrically positioned to be radial and are magnetically arranged so that the polarity varies at each successive magnet, i.e. north then south, or alternately, in groups, so that the polarity alternates only after a plurality of magnets of a particular polarity (north or south) are grouped together.
• the magnetic poles face radially inward around the periphery of the cylinder. In the preferred embodiment described, three such arrays of alternating magnets are included.
• the invention is not limited by the length of the magnets, quantity of magnets in each annular ring and the number of annular magnetic rings.
• the support cylinder (3) immediately surrounding and supporting the magnets is made from a magnetically permeable material, preferably iron or steel.
• the purpose of using magnetically permeable material is to provide a continuous magnetic flux path between the magnetic pole faces, thereby allowing optimum magnetic flux arrangements to exist.
• the electro- conductive rings (6) are separated from the faces of the magnets (5) by a small radial gap, which allows clearance for the primary and secondary rotary members to rotate independently of each other.
• Each such cylinder consists of an external ring of material with a good electrical conductivity (6), manufactured from a conductive material such as copper or aluminum, and interior support wheels (7) manufactured from a magnetically permeable material such as iron or steel.
• the magnetically permeable material be constructed from thin laminated pieces of ferrous material, in which the laminated pieces are coated with an electrically insulative material with a high dielectric value. These laminated pieces are stacked together to form the cylindrical support for the electro-conductive material rings (6). It is the purpose of the magnetic material to allow for a complete magnetic path through the electro-conductive layer and back the magnets. The laminations will reduce large scale undesirable eddy currents from being induced in the magnetically permeable material.
• the electro- conductive rings (6), their support wheels (7), and the output shaft (1) are supported by two output shaft support bearings (11) located at each end of the output shaft (1).
• the poles of the magnets (5) mounted to the magnet- carrying rotor (4) pass over the electro-conductive material, as the magnet- carrying rotor (4) rotates. This action will induce electrical currents in the electro- conductive rings (6) and the induced magnetic forces produced by the currents in these rings (6) will cause magnetic interaction between the rotors, and thereby cause torque to be transmitted between the magnet ring (5) and the rings (6), their support wheels (7), and attached output shaft (1).
• the torque will vary based on the relative rotational speed of primary rotary member and the secondary rotary member, and the amount of axial overlap between the magnet rings (5) and the electro-conductive rings (6).
• the number of annular arrays of magnets (5) with corresponding wheels of electro-conductive rings (6) used can vary from one to a plurality, and the invention is not limited by the number of these rings selected or utilized.
• the magnetic-carrying rotor (4) being movable axially within the support cylinder (3), allows for the amount of axial overlap of the rings of magnets (5) to the electro-conductive rings (6) to be adjustable by means of this variable axial motion.
• control of the axial position of the magnetic-carrying rotor (4) relative to the electro-conductive rings (6) is provided by motion transmitted from an exterior linkage (9) which positions a trunnion and ring (13) carrying the outer race of a thrust transmitting bearing (8).
• the inner race of the thrust bearing (8) is attached directly to the magnet- carrying rotor (4).
• the inner race of the thrust bearing (8) is supported at protruding attachment locations (29) which extend radially outward through slots (21) in support cylinder (3).
• the mechanism described will position the magnet- carrying rotor (4) by virtue of motion of the exterior linkage.
• An individual skilled in the art will realize that a number of alternate means internal and external are also available for the positioning of the magnet-carrying rotor (4).
• a means is provided for moving and positioning the magnet-carrying rotor (4) via the mechanism (9).
• the means shown is a hydraulic cylinder (10), but the invention is not restricted to this means solely.
• Other means may be used to move the magnet-carrying rotor (4) axially.
• Other means include, but are not limited to, manual actuation by a mechanical lever, electromechanical self-synchronous devices, or an actuator with a drive screw arrangement. Other applicable means of adjustment would be selected largely depending on the intended application of the apparatus.
• open slots are included through the apparatus end caps (26), the wheels (7), and the end caps (28) of the support cylinder (3). These slots allow for the passage of cooling air through the apparatus. It is recognized that heat will be generated as a result of the electrical currents generated in the rotors of the apparatus. As such, means may be provided for the removal of excessive heat. These means can include ventilation as shown in the embodiment of Figures 2 and 4, forced air convective heat transfer (not shown), sealed direct refrigerant cooling (not shown), or forced liquid cooling (not shown). An alternative embodiment is depicted in figure 5, 6 and 7.
• the first part of the variable speed torque transfer apparatus described in this alternative embodiment consists of a primary rotary member comprising an input shaft rotor (118) and a magnet-carrying rotor (120), mechanically connected together, and constrained to rotate at the same angular velocity together.
• the second part of the variable speed torque transfer apparatus described in this alternative embodiment consists of a secondary rotary member comprising an output shaft rotor (117), magnetically permeable ferrous cylinder (122), which supports and backs an electro-conductive ring (116), all mechanically connected together, and constrained to rotate at the same angular velocity.
• a magnet-carrying rotor (120) is attached directly to the input shaft (118).
• the array of magnets (119) rotate with the magnet-carrying rotor (120) and are constrained by the rotor to move concentrically about the center of rotation of the shaft (118) and to move synchronously with the shaft (118).
• the poles of the magnets (119) are geometrically positioned to be radial and are magnetically arranged so that the polarity varies at each successive magnet, i.e. north then south, or alternately, in groups, so that the polarity alternates only after a plurality of magnets of a particular polarity (north or south) are grouped together.
• the poles point radially inward toward the axis of rotation.
• An output shaft (117) is constrained to rotate coaxially with the input shaft (118) by bearings (125).
• a rotor cylinder (122) is mounted on the output shaft (117) and is constrained to rotate synchronously with the output shaft (117) by means of a male spline machined into the output shaft (117).
• a mating female spline on the rotor cylinder (122) constrains the cylinder to rotate in unison with the output shaft (117) and allows the magnet-carrying rotor (120) to move axially along the output shaft (117).
• the axial overlap between the ring of magnets (119) and the electro-conductive cylinder (116) of the rotor can be varied by this means.
• the inner cylinder (122) supports and backs an electro- conductive cylinder (116).
• the electrico- conductive cylinder (116) is in the alternate form of a circumferential ladder type of arrangement with conductive bars joined to conductive end rings. This type of geometry is useful in shaping the direction of the electrical current flow generated by the passing proximity of a magnetic field of the magnet-carrying rotor (120).
• the electro-conductive ring (116) may also have the geometric form of a smooth solid cylindrical ring. Either embodiment, the smooth cylindrical ring, or the circumferential ladder arrangement, or variations of either, can be used dependeng on the specified properties of the application. The invention is not limited by the choice of this geometric form.
• the magnet-carrying rotor (120) is made up of magnetically permeable material to lower the reluctance of the magnetic circuit.
• the cylindrical rotor (122) supporting the electro-conductive cylinder (116), is fabricated with magnetically permeable material, which completes the magnetic field circuit extending from the rotating magnet ring (119) through the electro-conductive ring (116).
• the rotor cylinder's (122) magnetically permeable material extends up through the openings in the electro-conductive ring (116).
• the yoke allows axial positioning of the rotor (122), thereby changing the amount of axial overlap with the magnetic ring (119) of the magnet-support rotor (120).
• the amount of magnetic flux transmitted and thus torque transferred, is dependent of the amount of axial overlap of the two rotors.
• a means is provided for positioning the yoke and rotor cylinder.
• axial thrust to actuate and move the electro-conductive ring rotor (116) axially is provided mechanically through the rod (124).
• the means to axially move this rod (124) are not shown in this alternate embodiment, but one skilled in the art would recognize the various options for axially moving the electro-conductive ring (116) rotor relative to the magnet-carrying rotor (120), as described in the first embodiment.
• One skilled in the art will also recognize that other arrangements of the elements described in the embodiments above are also covered in another embodiment (not shown), the function of the input shaft rotor and output shaft rotors can be functionally exchanged, and the operation of the invention will still work properly.
• the rings of magnets are mounted in the inner cylindrical rotor with the electro-conductive ring on the exterior cylinder. In these cases, the apparatus would still function as described.
• the invention is not limited by the number of arrays of magnet rings (119) with corresponding electro-conductive rings (116), nor is the invention limited by the means chosen to axially move or actuate these two rings relative to one another.
• a second alternative embodiment, or third embodiment, is depicted in figures 8 and 9.
• the relative axial position of the two co-axial cylinders remains fixed at what ever axial position the end user desires. This is a mechanically simpler embodiment than the previously described embodiments, and is used in services that do not require the output rotating shaft's angular velocity to vary appreciably from the input rotating shaft's angular velocity while operating.
• the first part of this torque transfer apparatus described in this second alternative embodiment consists of a primary rotary member comprising an input shaft rotor (218) and a magnet-carrying rotor (220), mechanically connected together, and constrained to rotate at the same angular velocity together.
• the second part of this torque transfer apparatus described in this second alternative embodiment consists of a secondary rotary member comprising an output shaft rotor (217), magnetically permeable ferrous cylinder (222), which supports and backs an electro-conductive ring (216), all mechanically connected together, and constrained to rotate at the same angular velocity.
• a magnet-carrying rotor (220) is attached directly to the input shaft (218).
• the array of magnets (219) rotate with the magnet- carrying rotor (220) and are constrained by the rotor to move concentrically about the center of rotation of the shaft (218) and to move synchronously with the shaft (218).
• the poles of the magnets (219) are geometrically positioned to be radial and are magnetically arranged so that the polarity varies at each successive magnet, i.e. north then south, or alternately, in groups, so that the polarity alternates only after a plurality of magnets of a particular polarity (north or south) are grouped together.
• An output shaft (217) is constrained to rotate coaxially with the input shaft (218) by bearings (not shown).
• a rotor cylinder (222) is mounted on the output shaft (217) and is constrained to rotate synchronously with the output shaft (217) by means of a collet type conical collar (221) placed onto the output shaft (217). Similar mechanical means (221) are used for mounting the magnet-carrying rotor (220) onto the input shaft (218). Other mechanical means may be used for mounting the rotor cylinder (222) to the output shaft (217).
• the inner cylinder (222) supports and backs an electro- conductive cylinder (216).
• the electro-conductive cylinder (216) is in the alternate form of a circumferential ladder type of arrangement with conductive bars joined to conductive end rings. This type of geometry is useful in shaping the direction of the electrical current flow generated by the passing proximity of a magnetic field of the magnet- carrying rotor (220).
• the electro-conductive ring (216) may also have the geometric form of a smooth solid cylindrical ring. Either embodiment, the smooth cylindrical ring, or the circumferential ladder arrangement, or variations of either, can be used depending on the specified properties of the application. The invention is not limited by the choice of this geometric form.
• the magnet-carrying rotor (220) is made up of magnetically permeable material to lower the reluctance of the magnetic circuit.
• the cylindrical rotor (222) supporting the electro-conductive cylinder (216) is fabricated with magnetically permeable material, which completes the magnetic field Circuit extending from the rotating magnet ring (219) through the electro- conductive ring (216).
• the rotor cylinder's (222) magnetically permeable material extends up through the openings in the electro-conductive ring (216).
• the rings of magnets are mounted in the inner cylindrical rotor with the electro-conductive ring on the exterior cylinder. In these cases, the apparatus would still function as described. As in the first two embodiments described herein, the invention is not limited by the number of arrays of magnet rings (219) with corresponding electro- conductive rings (216).

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• Engineering & Computer Science (AREA)
• Power Engineering (AREA)
• Dynamo-Electric Clutches, Dynamo-Electric Brakes (AREA)

Priority Applications (9)

Applications Claiming Priority (2)

Related Child Applications (2)

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Citations (4)

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• 2004
  • 2004-03-01 US US10/790,571 patent/US7294947B2/en not_active Expired - Lifetime
• 2005
  • 2005-02-26 NZ NZ586326A patent/NZ586326A/en not_active IP Right Cessation
  • 2005-02-26 CA CA2557807A patent/CA2557807C/en not_active Expired - Fee Related
  • 2005-02-26 EP EP05723864A patent/EP1761996A4/en not_active Withdrawn
  • 2005-02-26 KR KR1020067020498A patent/KR101324954B1/ko not_active Expired - Fee Related
  • 2005-02-26 US US10/591,366 patent/US7990007B2/en not_active Expired - Fee Related
  • 2005-02-26 AU AU2005219946A patent/AU2005219946C1/en not_active Ceased
  • 2005-02-26 NZ NZ550168A patent/NZ550168A/en not_active IP Right Cessation
  • 2005-02-26 JP JP2007501863A patent/JP2007526738A/ja active Pending
  • 2005-02-26 WO PCT/US2005/006179 patent/WO2005086330A1/en not_active Ceased
• 2010
  • 2010-06-24 AU AU2010202633A patent/AU2010202633B2/en not_active Ceased
  • 2010-12-15 JP JP2010279932A patent/JP2011092000A/ja active Pending
• 2013
  • 2013-06-07 JP JP2013121323A patent/JP2013192449A/ja active Pending

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