| Device to relieve thrust load in a rotor-bearing system using permanent magnets -> Monitor Keywords |
|
|
  Device to relieve thrust load in a rotor-bearing system using permanent magnetsUSPTO Application #: 20070040464Title: Device to relieve thrust load in a rotor-bearing system using permanent magnets Abstract: The present invention provides a device and a method to enhance thrust load capacity in a rotor bearing system. The load-enhancing device comprises a stator and a rotor arranged in such as way as to achieve a magnetic thrust load capacity enhancement by employing a number of permanent magnets, which produce an attracting force of an expulsing force between the rotor and the stator. (end of abstract)
Agent: Schnader Harrison Segal & Lewis, LLP - Philadelphia, PA, US Inventors: LIN SUN, HUAI LIN USPTO Applicaton #: 20070040464 - Class: 310090500 (USPTO) The Patent Description & Claims data below is from USPTO Patent Application 20070040464. Brief Patent Description - Full Patent Description - Patent Application Claims
FIELD OF THE INVENTION [0001] The present invention relates to rotor-bearing systems. More specifically, the present invention is concerned with a device and a method to enhance thrust load capacity in a rotor-bearing system. BACKGROUND OF THE INVENTION [0002] In applications of high-speed rotor-bearing systems with significant thrust load, i.e. where there exists a significant load parallel to the axis of rotation and tending to push the shaft in the axial direction, the design of thrust bearings that receive the longitudinal thrust or pressure of the shaft especially in so-called oil-free bearings systems, is generally a challenging task. [0003] Magnetic bearings, which may be dimensioned to withstand the worst possible operating conditions, as well as gas bearings, are often the favorite candidates for such high-speed oil free applications. [0004] However, a number of design difficulties has to be solved in order to obtain a high load capacity in the thrust bearing of a magnetic bearing system involves such as the following for example: [0005] a high load capacity means a large thrust area in the shaft, but the thrust area is limited by a maximum outer diameter ("OD") due to a rotor material strength limit [0006] a high load capacity often requires large size coils and magnetic flux path in a stator, resulting in a large axial dimension of the stator, thus in turn requiring a longer rotor, but the rotor length is limited by shaft mode frequencies; and [0007] a high current is generally required in the coils, but it is limited by the temperature rise in the winding. Moreover, high current involves costly power electronics. [0008] In gas bearing systems, such as hydrostatic or hydrodynamic systems, a high thrust load bearing requires a very large thrust area, which oftentimes results unrealistic to build. In such systems, the main problems are due to a low viscosity of the gas, a low relative speed between rotor and bearings near the center of rotation, and a limited pressure supply. [0009] In rolling element thrust bearing systems and fluid bearing systems, a high load causes an increased system loss, consequently resulting in low efficiency, and even overheating of the systems. [0010] From the foregoing, there is obviously a need for a compact and high efficiency device and method to enhance thrust load capacity In a rotor-bearing system. OBJECTS OF THE INVENTION [0011] An object of the present invention is therefore to provide an improved device and a method to enhance thrust load capacity in a rotor-bearing system. SUMMARY OF THE INVENTION [0012] More specifically, in accordance with the present invention, there is provided a thrust load enhancement device for a rotor-bearing system comprising: [0013] a stator mounted on a rotation axis of the rotor-bearing system; [0014] a rotor separated from the stator by a first air gap on the rotation axis; and [0015] at least one permanent magnet separated from the rotor by a second air gap, [0016] wherein the at least one permanent magnet, the stator and the rotor form a magnetic circuit characterized by a flux path so that a flux in the first and second air gaps generates a compensation force between the rotor and the stator that opposes an external force F.sub.ext. [0017] There is further provided a method for thrust load enhancement for a rotor-bearing system comprising the steps of: [0018] providing a stator on a rotation axis of the rotor-bearing system; [0019] providing a rotor separated on the rotation axis from the stator by a first air gap; and [0020] providing at least one permanent magnet separated from the rotor by a second air gap, [0021] whereby the at least one permanent magnet, the stator and the rotor form a magnetic circuit characterized by a flux path so that a flux in the first and second air gaps generates a compensation force between the rotor and the stator that opposes an external force F.sub.ext. [0022] Other objects, advantages and features of the present invention will become more apparent upon reading of the following non-restrictive description of embodiments thereof, given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS [0023] In the appended drawings: [0024] FIG. 1 is a cross-section of a load enhancement device according to a first embodiment of a first aspect of the present invention; [0025] FIG. 2 is a cross-section of a load enhancement device according to a second embodiment of the first aspect of the present invention; [0026] FIG. 3 is a cross-section of a load enhancement device according to a third embodiment of the first aspect of the present invention; [0027] FIG. 4 is a cross-section of a load enhancement device according to a first embodiment of a second aspect of the present invention; and [0028] FIG. 5 is a cross-section of a load enhancement device according to a further embodiment of the present invention. DESCRIPTION OF SPECIFIC EMBODIMENTS [0029] Generally stated, the present invention provides a device and a method to enhance thrust load capacity in a rotor-bearing system. Continue reading... Full patent description for Device to relieve thrust load in a rotor-bearing system using permanent magnets Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Device to relieve thrust load in a rotor-bearing system using permanent magnets patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Device to relieve thrust load in a rotor-bearing system using permanent magnets or other areas of interest. ### Previous Patent Application: Drive for the adjustment of flaps Next Patent Application: Alternator assembly Industry Class: Electrical generator or motor structure ### FreshPatents.com Support Thank you for viewing the Device to relieve thrust load in a rotor-bearing system using permanent magnets patent info. IP-related news and info Results in 0.50537 seconds Other interesting Feshpatents.com categories: Accenture , Agouron Pharmaceuticals , Amgen , AT&T , Bausch & Lomb , Callaway Golf |
||
