945results about "Magnetic bearings" patented technology

An apparatus and method for a centrifugal fluid pump for pumping sensitive biological fluids, which includes (i) an integral impeller and rotor which is entirely supported by an integral combination of permanent magnets and electromagnetic bearings and rotated by an integral motor, (ii) a pump housing and arcuate passages for fluid flow and containment, (iii) a brushless driving motor embedded and integral with the pump housing, (iv) a power supply, and (v) specific electronic sensing of impeller position, velocity or acceleration using a self-sensing method and physiological control algorithm for motor speed and pump performance based upon input from the electromagnetic bearing currents and motor back emf-all fitly joined together to provide efficient, durable and low maintenance pump operation. A specially designed impeller and pump housing provide the mechanism for transport and delivery of fluid through the pump to a pump output port with reduced fluid turbulence.

A pump assembly 1, 33, 200 adapted for continuous flow pumping of blood. In a particular form the pump 1, 200 is a centrifugal pump wherein the impeller 100, 204 is entirely sealed within the pump housing 2, 201 and is exclusively hydrodynamically suspended therein as the impeller rotates within the fluid 105 urged by electromagnetic means external to the pump cavity 106, 203. Hydrodynamic suspension is assisted by the impeller 100, 204 having deformities therein such as blades 8 with surfaces tapered from the leading edges 102, 223 to the trailing edges 103, 224 of bottom and top edges 221, 222 thereof.

A blood pump has an impeller rotatably disposed and magnetically suspended within a cavity of a stator by a plurality of magnetic bearings (passive permanent and active electromagnetic) having impeller magnets on the impeller and stator magnets or coils / poles on the stator. A motor includes impeller magnets on the impeller and coils / poles associated with the stator. A single, annular blood flow path extends axially through the cavity between the impeller and the stator, and between the impeller magnets on the impeller and the stator magnets or the coils / poles on the stator.

A blood pump has an impeller rotatably disposed and magnetically suspended within a cavity of a stator by a plurality of magnetic bearings (passive permanent and active electromagnetic) having impeller magnets on the impeller and stator magnets or coils / poles on the stator. A motor includes impeller magnets on the impeller and coils / poles associated with the stator. A single, annular blood flow path extends axially through the cavity between the impeller and the stator, and between the impeller magnets on the impeller and the stator magnets or the coils / poles on the stator.

A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

An energy conversion system may include a stationary structure, a rotatable structure configured to rotate relative to the stationary structure, wherein the rotatable structure defines an axis of rotation. The system may further include at least one blade member mounted to and extending radially outward from the rotatable structure, the at least one blade member being configured to interact with fluid currents flowing in a direction substantially parallel to the axis of rotation to cause the rotatable structure to rotate about the axis of rotation, and at least one bearing mechanism disposed to provide at least one of a radial and axial bearing between the rotatable structure and the stationary structure as the rotatable structure rotates about the stationary structure. The system may be configured to convert rotation of the rotatable structure to at least one of electricity and hydrogen production.

Since disruptive forces can be continuously exerted upon a rotor during a pulsatile flow through a pump with a magnetically mounted rotor (permanent magnets and addition control current coils), it is necessary to adjust position i.e. modify axial rotor position very quickly. The control current should only result in small amounts of losses. According to the invention, the current is pulse-width modulated by the control current coils by means of a set value predetermined by a controller which is arranged downstream from a position sensing system. If the set value is high, it is switched to a higher voltage level and the real value of the position sensing system is stored for a defined period of time, respectively beginning with the switching flank of the control current, and the position sensing system is disconnected during said period of time.

A magnetic levitation motor including a stator having magnetic bearing units and a motor unit, and a rotor provided to the stator. And the occurrence of an eddy current at a magnetic bearing is suppressed and the rotation loss of the rotor can be reduced, and also to provide a pump using such the magnetic levitation motor.

The bearing assembly comprises a radial foil bearing and an axial foil bearing, a control bearing preload device for controlling stiffness of the bearing under normal operating conditions, an electromagnetic unloading device for decreasing amplitude of rotor oscillations and an unloading means for increasing the ultimate bearing load without damaging bump foils. The radial foil bearing comprises a bushing 6 providing accommodating bearing misalignment with respect to the journal, an elastic member in the form of an elastic damping unit for increasing damping, which consists of a bump foil 20 and two smooth foils 16 and 22. The bump foils in the bearing have different heights and alternate in the axial direction to decrease wear under start / stop. A top foil 4 of the bearing is weldlessly retained within slots of mounting bars 70 and 80. The axial bearing has the bump foil with ridges circumferentially extended in order for the bearing to work in sealing mode. The top foils of the bearing are provided with circumferential slits in order to decrease thermal stress.

A magnetic levitation system for supporting an object against gravity by a supporting force includes a permanent-magnet dipole aligned in a vertical position and coupled to the object, a supporting-field generator and a stabilization system. The supporting-field generator generates a supporting force on the permanent-magnet dipole via a supporting field. The supporting field is a two-dimensional or three-dimensional magnetic quadrupole field so that the supporting force is independent of a position of the dipole. The stabilization system constrains the dipole against movements in at least one horizontal direction, and includes a diamagnetic element coupled to the dipole and arranged below the dipole, and a stabilizing-field generator generating a second two-dimensional or three-dimensional stabilizing field to restore said diamagnetic element to a position where the field strength of the stabilizing field has a local minimum.

This invention relates to rotary pumps adapted, but not exclusively, for use as artificial hearts or ventricular assist devices and, in particular, discloses in preferred forms a seal-less shaft-less pump featuring open or closed (shrouded) impeller blades with the edges of the blades used as hydrodynamic thrust bearings and with electromagnetic torque provided by the interaction between magnets embedded in the blades and a rotating current pattern generated in coils fixed relative to the pump housing.

A combined externally pressurized gas and magnetic bearing assembly (3) includes an externally pressurized gas bearing (9) and a magnetic bearing (8) that are integrated together so as to have component parts common to both of the externally pressurized gas bearing (9) and the magnetic bearing (8). The externally pressurized gas bearing (9) or the magnetic bearing (8) may be disposed within an axial extent of the magnetic bearing (8) or the externally pressurized gas bearing (9), respectively. A spindle device (1) utilizing the combined externally pressurized gas and magnetic bearing assembly (3) is also provided which includes a housing (2) for supporting a main shaft (4) rotatably through the combined externally pressurized gas and magnetic bearing assembly (3). This combined externally pressurized gas and magnetic bearing assembly (3) can be applied not only to the radial bearing, but also to the axial bearing.

Motor-compressor comprising a compressor, an electric motor directly connected to said compressor, wherein the compressor and the electric motor are integrated in a single unit, housed in a single box or casing.

A radial, active magnetic bearing apparatus comprising at least three electromagnets which are distributedly arranged is excited by a three-phase rotary current controller.

The jacketed active magnetic bearing is applied to a rotary machine having a rotor in contact with a process gas and placed in a leaktight enclosure. The magnetic stator is protected by a first jacket of magnetic anti-corrosion material that constitutes a portion of the leaktight enclosure and that is secured to the bearing stator, and the detector stator is protected by a second jacket of non-magnetic anti-corrosion material that constitutes a portion of the leaktight enclosure and that is secured to the detector stator. The bearing armature and the detector armature can be made of a laminated magnetic identical to that of the first jacket.

A flywheel system has an approximately toroidal flywheel rotor having an outer radius, the flywheel rotor positioned around and bound to a hub by stringers, the stringers each of a radius slightly smaller than the outer radius of the flywheel rotor. The hub is suspended from a motor-generator by a flexible shaft or rigid shaft with flexible joint, the flywheel rotor having a mass, substantially all of the mass of the flywheel rotor comprising fibers, the fibers in large part movable relative to each other. The motor-generator is suspended from a damped gimbal, and the flywheel rotor and motor-generator are within a chamber evacuatable to vacuum. An electrostatic motor / generator can also be within the same vacuum as the flywheel.

A simple permanent-magnet-excited maglev geometry provides levitation forces and is stable against vertical displacements from equilibrium but is unstable against horizontal displacements. An Inductrack system is then used in conjunction with this system to effect stabilization against horizontal displacements and to provide centering forces to overcome centrifugal forces when the vehicle is traversing curved sections of a track or when any other transient horizontal force is present. In some proposed embodiments, the Inductrack track elements are also employed as the stator of a linear induction-motor drive and braking system.

A magnetic bearing for centering and controlling tilting of a first body relative to a second body includes centering members adapted to center the first body magnetically relative to the second body at least in the direction transverse to the reference axis, two permanently magnetized rings carried by a first ferromagnetic armature fastened to the first body, an annular plurality of (at least three) tilt windings fastened to the second body and each including two groups of circumferential strands respectively adapted to face each of the permanently magnetized rings regardless of the orientation of the hollow outer part, and an excitation circuit adapted to apply excitation currents to the tilt windings adapted to generate tilting forces in the air-gaps.

The device for magnetically suspending a rotor relative to a structure comprises at least one axial active magnetic bearing with a main electromagnet coil disposed in a stator and having load-bearing surfaces placed facing an armature extending essentially perpendicularly to the axis of the rotor. A device for detecting the axial position of the rotor is associated with circuits for servo-controlling the current carried by the main electromagnet coil. A compensation coil is disposed close to the main electromagnet coil, but in a position that is situated away from the load-bearing surfaces of the stator that co-operate with the rotor armature. The compensation coil is connected in series with the main electromagnet coil, but carries current in the opposite direction to that carried by said main electromagnet coil. The device constitutes an axial abutment of optimized capacity without magnetic leakage.

A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

The flux densities formed by plural electromagnet poles M1 to M12 which are arranged at a predetermined interval in a circumferential direction of a rotary body 1 at the same position in an axial direction of the rotary body 1 are gradually changed in the circumferential direction of the rotary body. Even if there is a difference between the maximum value of the flux density and the minimum value, the change of the flux densities between the adjacent electromagnet poles is small and smooth. Accordingly satisfactory detective sensitivity and detection results can be obtained.

In a hybrid magnetic bearing, the electromagnet has a core wound with a control coil and has a main pole and a commutating pole with a commutating pole permanent magnet provided approximately parallel to each other at predetermined intervals in a protruding condition radially or axially to the rotor. In the magnetic bearing provided radially, two electromagnets are placed oppositely to each other across the rotor in an approximately horizontal position, and the rotor is arranged so as to have a predetermined gap with the main pole and the commutating pole, and the permanent magnet is provided between the adjacent electromagnets. In the magnetic bearing provided axially, two electromagnets are placed in parallel in an approximately horizontal position, and the rotor is arranged so as to have a predetermined gap with the main pole and the commutating pole, and the permanent magnet is provided between the adjacent electromagnets.

A magnetic bearing for centering a first body, which is mobile in tilting, relative to a second body includes:a hollow outer part at least part of which is made from a ferromagnetic material and which is attached to the first body and which has an inside surface whose shape is a portion of a sphere,an inner part which is attached to the second body and which includes two separate members which are separated by a space and which each include a plurality of (at least three) ferromagnetic areas which are offset angularly about the reference axis, which each define in conjunction with the inside surface of the hollow outer part two air-gaps offset relative to the reference axis and which are each provided with a specific winding adapted to generate magnetic flux lines closing across the two air-gaps, andan excitation circuit for selectively applying excitation currents to the windings.

Apparatus and method for determining the clearance and wear of mechanical back-up bearings of turbomachinery utilizing electromagnetic bearings. In order to reduce the prospects of catastrophic failure during a shut-down or loss of electrical power, a rotating apparatus utilizes the electromagnetic bearings to manipulate the shaft to measure the clearance of the mechanical back-up bearings. When power is restored, a programmable controller provides power to the electromagnetic bearings to automatically move the shaft in accordance with a predetermined sequence to contact the mechanical back-up bearings to determine the clearance of the mechanical back-up bearings. These values are stored in the controller memory. The measured clearance is compared to prior clearance measurements of the mechanical back-up bearings to determine the wear of the back-up bearings. The actual wear is compared to the allowable wear for the bearings. If actual wear exceeds a predetermined value, a warning is generated. If the actual wear equals or exceeds the allowable wear, the controller automatically locks the turbomachinery from further operation until repair or replacement is accomplished. Otherwise, the controller centers the shaft to permit normal operation of the turbomachinery.

The active magnetic bearing (1) comprises a stator (2) fitted with electromagnet windings (21) and a first stack of ferromagnetic laminations (22), a rotor (3) fitted with a second stack of ferromagnetic laminations (9), servo-control circuits (10), and position detectors (4, 5, 6). The first stack of ferromagnetic laminations (22) comprises in succession in the axial direction: at least a first sub-set (2a) of laminations (22a) presenting first notches housing electromagnet windings (21); a second sub-set (2b) of laminations (22b) presenting both first notches housing electromagnet windings (21) and second notches housing a radial detector (6); and a third sub-set (2a) of laminations (22a) presenting first notches housing electromagnet windings (21). The first stack of ferromagnetic laminations (22) further comprises fourth and fifth sub-sets (2c) of laminations (22c) at its ends, presenting the same notches as each other and housing respective first and second axial detectors (4, 5).

The invention relates to 'repulsive magnetic component, full permanent magnetic and full suspending bearing and compound wind power photovoltaic power system', in particular to a magnetic bearing and a wind power system, wherein, the repulsive magnetic component is arranged on a vertical main shaft. The invention is characterized in that the wind power system comprises an upper repulsive body and a lower repulsive body which are formed by homopolar ring permanent magnets; the upper repulsive body is formed by a piece of hollow ring permanent magnet while the lower repulsive body is formed by a piece of inner ring permanent magnet and a piece of outer ring permanent magnet arranged in a certain radial distance from the inner ring permanent magnet; the hollow ring permanent magnet is positioned in the effective magnetic range of the magnetic force of the two pieces of permanent magnets forming the lower repulsive body. By adopting the full permanent and full suspending bearing of the repulsive magnetic component, and arranging a pull-push magnet component at the upper end of a spiral body of a vertical shaft wind turbine and the repulsive magnetic component at the lower end of the spiral body, the full magnetic and full suspending support of the main shaft or a vertical shaft impeller can be realized, thus eliminating all friction of the spiral body of the wind turbine.

In a hybrid magnetic bearing, the electromagnet has a core wound with a control coil and has a main pole and a commutating pole with a commutating pole permanent magnet provided approximately parallel to each other at predetermined intervals in a protruding condition radially or axially to the rotor. In the magnetic bearing provided radially, two electromagnets are placed oppositely to each other across the rotor in an approximately horizontal position, and the rotor is arranged so as to have a predetermined gap with the main pole and the commutating pole, and the permanent magnet is provided between the adjacent electromagnets. In the magnetic bearing provided axially, two electromagnets are placed in parallel in an approximately horizontal position, and the rotor is arranged so as to have a predetermined gap with the main pole and the commutating pole, and the permanent magnet is provided between the adjacent electromagnets.

A simple permanent-magnet-excited maglev geometry provides levitation forces and is stable against vertical displacements from equilibrium but is unstable against horizontal displacements. An Inductrack system is then used in conjunction with this system to effect stabilization against horizontal displacements and to provide centering forces to overcome centrifugal forces when the vehicle is traversing curved sections of a track or when any other transient horizontal force is present. In some proposed embodiments, the Inductrack track elements are also employed as the stator of a linear induction-motor drive and braking system.