IMPROVED MAGNETIC UNIT

Abstract

An improved liquid-cooled apparatus for magnetically transferring large torques, comprising a primary rotating member and a secondary rotating member, as set forth in US patent 7294947. The primary rotating member has permanent magnets, and the secondary rotating member has electrically conductive materials. Both rotors are enclosed in a liquid-tight housing and are liquid-cooled to enable power transfers exceeding 260 kW and torques of 1000 ft-lbs.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application claims priority over USA application number 16909989 filed on June 23, 2020. Field of Invention The present invention relates to an improvement on the prior art, more particularly set forth in U.S. Patent 7294947 and related patents in other jurisdictions, where said prior art was directed to a rotary magnetic torque transfer device using two coaxial cylinders superimposed on each other, where one cylinder contains one or more rows of permanent magnets and the other cylinder contains one or more rings of electro-conductive material, but the problem was that said prior art had a maximum energy transfer limit since the induction rotor bars were atmospherically air-cooled, said air-cooling causing both the induction rotor bars and the magnetic circuit materials to reach a temperature that would break the magnetic characteristics of the materials above a certain energy transfer evaluation point.The challenge is to develop a modified structure and geometric arrangement for the device that allows direct liquid injection cooling within the coaxial cylinders without increasing the reluctance of the magnetic circuit or short-circuiting the electrical conductors within the device. Prior art was limited to less than 1000 kW. -2 energy transfer, otherwise the internal operating temperature of the unit would cause the field of the permanent magnets to fail. Background of the Invention It is desirable to devise a liquid-cooled, permanent magnet-excited mechanism for transmitting variable torque in drive applications. Specifically, there is a need to couple constant-speed devices, such as motors or machines, to high-power, variable-torque and speed output devices, such as pump impellers, fans, propellers, wheels, etc. As stated in prior patent US 7294947, these devices, with their specific geometry of individual electro-conductive rotor bars, together with the similar geometry of analogous combined permanent magnets positioned directly opposite said electro-conductive rotor bars, create a torque transfer device that is not a traditional eddy current device. Eddy current devices produce circular-type eddy currents in relatively wide electro-conductive materials.The improvement over the narrow rotor electro-conducting rotor bars and narrow cross-section permanent magnets specific to device US 7294947 lies in devising a way to maintain this non-parasitic current rotor bar efficiency, but still developing a way to quickly remove the high heat generated and high energy transfers in such electro-conducting bars, in a way that will maintain the circuit / zoznn / cznz / q / uli. -3 efficient magnetic of the prior art (US 7294947). The invention describes and claims improvements that allow very large energy transfers through the direct injection of liquid into the electroconducting bars, after which the liquid comes out directly and impacts the rotor of the magnetic bar, the liquid does not interfere with the permeability of the magnetic field or magnetic circuit. The described device uses permanent magnets and conductors optimally arranged to generate magnetic flux in a power transmission unit, along with direct liquid injection for cooling both rotors. The described methods use a mechanical means to change the flux density between two rotating components to vary the transmitted torque and, consequently, the device's output speed. Summary of the Invention As described in prior art patent US 729947, the present invention uses permanent magnets to transmit a fixed or variable torque between two rotating elements. The permanent magnets mentioned above are located in only one of the two rotating elements (also called rotors or rotating members), and the other rotating member, in a particular embodiment, does not contain permanent magnets but has so-called electro-conducting elements. Furthermore, so-called magnetically permeable materials are also contained in said non-permanent magnet rotors, comprising said / zoznn / cznz / q / υιλι -4 Magnetically permeable materials are substances that allow the penetration of magnetic flux. The torque between the two rotating elements mentioned above is adjusted by varying the amount of magnetic flux passing between the elements by varying the degree to which the elements overlap axially. In a preferred embodiment of the apparatus, two concentric cylinders, one containing one or more rows of permanent magnets, move axially to progressively overlap a second cylindrical element containing electro-conducting and magnetically permeable elements, but not permanent magnets. This progressive axial overlap of the two cylinders allows for variation in the amount of magnetic flux intersecting the two concentric cylinders.This causes the amount of induced electrical current in the cylinder containing the electrically conductive elements to vary, which in turn causes the induced counter-magnetic forces to vary. The magnetic forces, and therefore the transmitted torque, will vary based on the amount of axial overlap. The previous technique relied solely on air cooling by the existing atmospheric air surrounding the two rotors. The electrically conductive rotor has an induced current that increases as the difference in relative angular velocity between the two rotors increases; this current generated heat, thus limiting the unit to transferring approximately 260 kW (at a torque of 1000 ft-lbs). Therefore, in order to transfer thousands of kilowatts of power, a liquid cooling system was devised where the coolant would circulate. -5extremely close to the surface of the electro-conducting / heat-generating rotor bar, and where the amount of liquid flow through each rotor bar could be adjusted with threaded end plugs at the end of each coolant channel of the electro-conducting rotor bar. Furthermore, to cool the surface of the magnetic rotors that run very close to the inducing rotor bars through a very narrow space, when said coolant reaches said threaded flow-adjusting plug, the coolant is directed radially to the magnetic rotor in such a way that the liquid coolant impinges directly on the surface of the magnetic bars.The proposed invention overcomes the prior limitation of the invention described in US patent 7294947 in that there is no limit to the amount of energy the device can transfer, limited only by the structural strength of the various materials. There is no longer any limitation due to the heat generated in the conductive bars of the conductive rotor. The liquid coolant does not interfere with the magnetic flux flow of the magnetic field circuit, nor does it allow for internal short circuits in the components in and around the conductive elements. Furthermore, the rotation of the induction rotor itself acts as a second centrifugal booster pump to help circulate the liquid coolant.In order to properly regulate the amount of liquid coolant flow needed for adequate cooling and not allow excessive liquid coolant flow that would reduce the net energy transfer efficiency. -6 unit, the new geometry of the new liquid-cooled induction rotor has adjustment screw plugs at the end of each electro-conductive rotor bar (504). The proposed invention overcomes previous limitations by taking advantage of new technologies in magnetic materials and provides a stable means of mechanically varying large amounts of transmitted torque without the need for large external current controls. / zoznn / cznz / q / υιλι Brief Description of the Figures of the Invention The drawings form part of this specification and include exemplary embodiments of the invention, which can be implemented in various ways. It should be understood that, in some cases, several aspects of the invention may be exaggerated or enlarged to facilitate understanding. The description of the selected embodiments of the invention included herein is listed below: Figure 1 is an isometric view of the exterior of a preferred embodiment of the invention. Figure 2 is an exploded isometric view of Figure 1. Figure 3 is an exploded isometric view of the liquid-cooled electro-conductive rotor of the preferred embodiment of the invention. Figure 4 is an isometric view of the liquid-cooled electroconducting rotor. Figure 5 is an isometric view of the detail of the channels for the flow of coolant immediately adjacent and parallel along the bars of the electro-conducting rotor of Figure 4. Detailed Description of the Invention Detailed descriptions of preferred embodiments are provided herein. It should be understood, however, that the present invention can be implemented in various ways. Therefore, the specific details set forth herein should not be construed as limiting, but rather as a basis for the claims and as a representative basis for teaching a person skilled in the art to employ the present invention in virtually any appropriately detailed system, structure, or manner. With reference to Figures 1 through 5, the preferred embodiment of the invention is shown and described as applied to a liquid-cooled, high-power variable-speed drive application. The two coaxial rotors [one rotor having axially positioned electroconductive bars (201) and one rotor having axially positioned permanent magnetic bars (202)] together with their respective support bearing cartridge systems [(200 and 203) are shown in an exploded view outside their housing (100). Also shown is the automatic control system actuator (204) that moves one of the two rotors relative to the other to adjust the axial overlap of the two rotors as they rotate, thereby varying the amount of torque and power transferred through the drive.The housing (100) of the mode when assembled is completely liquid-tight to capture the coolant that is pumped through the coolant conduits (501) located directly / zoznn / cznz / q / uli. -8 adjacent to the electro-conducting rotor bars (504). The bearing support cartridges (200 and 203) are oil-lubricated, cooled, and sealed from both the outside and the housing to prevent mixing of the oil and rotor coolant. The purpose of using magnetically permeable material is to provide a continuous magnetic flux path between the magnetic pole surfaces, allowing for optimal magnetic flux arrangements. The magnetically permeable material need not be ferromagnetic. The cooling system is a closed system consisting of an external liquid storage tank, a centrifugal circulation pump, a heat exchanger to reject the heat collected in the magnetic drive unit, temperature gauges, pressure gauges, filters, and interconnecting piping. The coolant may consist of a mixture of distilled water and a glycol compound. The previous technique relied solely on air cooling by the existing atmospheric air surrounding the two rotors. The electrically conductive rotor has an induced current that increases as the relative angular velocity difference between the two rotors increases; this current generated heat, thus limiting the unit to transferring approximately 260 kW (at a torque of 1000 ft-lbs). Therefore, in order to transfer thousands of kilowatts of power, a liquid cooling system was devised where the coolant travels extremely close to the surface of the current-carrying / heat-generating rod of the electrically conductive rotor. -9 and wherein the amount of liquid flow through each rotor bar could be adjusted by threaded end plugs at the end of each coolant channel of the electro-conducting rotor bar (502 and 503). Furthermore, to cool the surface of the magnetic rotors running very close to the inductor rotor bars through a very narrow space, when said coolant reaches said threaded flow-adjusting plug (503), the coolant is directed radially toward the magnetic rotor so that the liquid coolant impinges directly on the surface of the magnetic bars. The proposed invention overcomes the prior limitation of the invention described in US 7294947 in that there is no limit to the amount of energy that the device can transfer, limited only by the structural strength of the various materials.There are no longer any limitations due to the heat generated in the conductive bars of the conductive rotor. The liquid coolant does not interfere with the magnetic flux flow of the magnetic field circuit, nor does it allow for internal short circuits in the components in and around the conductive elements. Furthermore, the rotation of the induction rotor itself acts as a second centrifugal booster pump to help circulate the liquid coolant. In order to properly regulate the amount of liquid coolant flow required for adequate cooling and to prevent excessive liquid coolant flow that would reduce the net power transfer efficiency of the unit, the new geometry of the liquid-cooled induction rotor has adjusting screw plugs (502 and 503) at the end of each bar of the conductive rotor (504). Although the invention has been described in relation to a preferred embodiment, it is not intended to limit the scope of the invention to the particular form stated, but rather to cover alternatives, modifications and equivalents that may be included within the spirit and scope of the invention as defined in the appended claims.

Claims

1. A liquid-cooled, high-torque, high-power apparatus for magnetically transferring torque, comprising: a primary torque-driven rotating member and a secondary torque-driven rotating member; the primary rotating member axially overlapping said secondary rotating member; the secondary rotating member being surrounded by said primary member; the primary rotating member having permanent magnets installed therein; the secondary rotating member having electro-conducting elements and magnetically permeable materials; and not having permanent magnets; said electro-conducting elements being cooled by liquid coolant flowing in axial channels immediately adjacent to and parallel to the electro-conducting bars of the electro-conducting rotor; said liquid coolant being supplied to the apparatus by a closed-circuit liquid cooling system with an external storage tank, external pump, and external heat exchanger to reject the heat generated in the electro-conducting bars;wherein said secondary rotating member is axially superimposed on said primary rotating member wherein a means is provided for varying the axial position of said primary rotating member with respect to said secondary rotating member; and said primary rotating member is connected to and driven by a torque-producing device, and said secondary rotating member is connected to a device that utilizes; - 12 the torque, so the rotation of the primary rotating member causes the rotation of said secondary rotating member by some or all of the magnetic flux lines emanating from said permanent magnets installed in said 5 primary rotating member cutting through the electro-conductive material in said secondary rotating member thus generating torque and rotation in said secondary rotating member in relation to the percentage of the total area in which said secondary rotating member is axially overlapped 10 by said primary rotating member, and said permanent magnets being cooled by direct impact of the liquid coolant emanating from the ends of the cooling channels located immediately adjacent to the bars of the electro-conductive rotor. 15 2. The apparatus of claim 1, wherein said liquid refrigerant flow is further adjustable to optimize the liquid flow required for the best efficiency of the apparatus.

Images