2694 results about "Magnetic bearing" patented technology

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.

An improved magnetic bearing that uses permanent magnets to provide the bias flux. The magnetic circuits generating the control flux and bias fluxes are substantially non-coincident but share the same path over some portions that include radial and axial airgaps allowing for a low reluctance and an efficient path for the electromagnetic flux. The flux paths of the permanent magnets are completely defined with minimized airgaps for achieving higher forces and efficiency and very low control currents that produce extremely large forces. A single coil and amplifier for the axial force control and two coils with one associated amplifier for each radial axis of control provides simplicity and cost effectiveness. A single thrust disk is provided that is reacted against for both radial and the axial displacement. The permanent magnets used in the present invention are first fabricated and axially magnetized as segments or as continuous rings prior to being mounted on the sides of the rotor pole, providing an effective and inexpensive technique of manufacturing magnetic bearings.

The present invention provides a rotational magnetic gimbal with an integral magnetic bearing. Brushless DC motor technology provides electromagnetic suspension, using a single electromagnetic actuator to perform both the radial bearing and rotary torque (motoring) functions. An integrated motor and magnetic bearing consistent with the invention comprises a rotor comprising a plurality of permanent magnets and a stator comprising a plurality of independently controlled coil segments magnetically coupled to the permanent magnets. Embodiments may further comprise first and second radial position sensors, the first radial position sensor disposed in or adjacent to a clearance gap between the rotor and the stator for sensing the position of the rotor with respect to the stator along a first axis, and a second radial position sensor disposed in or adjacent to the clearance gap between the rotor and the stator for sensing the position of the rotor with respect to the stator along a second axis. In method form, a method for providing integral electromagnetic motor and bearing functions comprises sensing a first radial position of a rotor, the rotor comprising a plurality of permanent magnets, with respect to a stator along a first axis, the stator comprising a plurality of independently controlled coil segments magnetically coupled to the permanent magnets; and sensing a second radial position of the rotor with respect to the stator along a second axis; and delivering current to at least one coil segment, the amount of current based on at least one sensed position.

A blood pump has an impeller rotatably disposed and magnetically suspended within a cavity of a stator by a plurality of magnetic bearings including an axial bearing to support the impeller axially in the cavity. The axial bearing includes adjacent impeller magnets and adjacent stator magnets with axially aligned polarities and reverse polarities with respect to adjacent magnets. A motor includes impeller magnets on the impeller and coils and poles associated with the stator. Radial permanent magnet and electromagnetic bearings are also included. The magnetic bearings and the motor have stator magnets or coils and poles disposed radially across the fluid passage from corresponding impeller magnets to define an annular gap positioned radially between the impeller and the stator, and positioned radially between all of the plurality of magnetic bearings, creating a straight through blood path without secondary flow paths.

A convective seating and sleeping system with a plenum for use as a mattress, cushion or as part of seat or other structure to deliver air flow to a user or users. The convective cushion includes a modular plenum made of removable pockets and a thermocouple to provide control data to selectively control the temperature and / or quantity of the air delivered to the cushion. The cushion includes the use of tubular spacer material. The cushion has deep styling lateral and longitudinal pleats and air flow structures around the pleats to provide a controlled air flow to the cushion. The invention includes an improved Stirling cycle heat pump with magnetic bearing structures and relative humidity controls and an improved thermoelectric heat pump that selectively controls the relative humidity of the air delivered to the cushion. The cushion can be activated and operated by remote operation from a telecommunications device.

Mechanisms and methods for clamping force generation are disclosed. In one embodiment, a clamping force generator system includes a permanent magnet bearing coupled to a traction ring and to a torque coupling. The traction ring can be provided with an electromagnetic bearing rotor and the torque coupling can be provided with an electromagnetic bearing stator. In some embodiments, a mechanical load cam, a permanent magnet bearing, and an electromagnetic bearing cooperate to generate a clamping force between the traction rings, the power rollers, and the idler. In other embodiments, a series of permanent magnet bearings and a mechanical bearing configured to produce a clamping force. In one embodiment an electromagnetic bearing is coupled to a control system and produces a specified clamping force that is associated with a torque transmitted in the transmission during operation. In some embodiments, a mechanical load cam produces a clamping force proportional to torque, while a permanent magnet bearing provides a minimum clamping force.

A compact and efficient compressor is provided, based on using magnetic bearing technology, which can operate at high speed and comprises a reliable control system. The compressor of the present invention makes use of two separate compressors mounted on a single common motor, thus sharing a single drive. The balancing of the thrust at high RPM is improved by using a pair of electromagnetic bearings.

A heart pump including first and second cavities, each cavity including a respective inlet and outlet, a connecting tube extending between the first and second cavities, an impeller including: a first set of vanes mounted on a first rotor in the first cavity portion; a second set of vanes mounted on a second rotor in the second cavity portion; and, a shaft connecting the first and second rotors, the shaft extending through the connecting tube, a drive for rotating the impeller and a magnetic bearing including at least one bearing coil for controlling an axial position of the impeller, at least one of the drive and magnetic bearing being mounted outwardly of the connecting tube, at least partially between the first and second cavity portions.

An improved magnetic bearing that uses permanent magnets to provide the bias flux. The magnetic circuits generating the control flux and bias fluxes are substantially non-coincident but share the same path over some portions that include radial and axial airgaps allowing for a low reluctance and an efficient path for the electromagnetic flux. The flux paths of the permanent magnets are completely defined with minimized airgaps for achieving higher forces and efficiency and very low control currents that produce extremely large forces. A single coil and amplifier for the axial force control and two coils with one associated amplifier for each radial axis of control provides simplicity and cost effectiveness. A single thrust disk is provided that is reacted against for both radial and the axial displacement. The permanent magnets used in the present invention are first fabricated and axially magnetized as segments or as continuous rings prior to being mounted on the sides of the rotor pole, providing an effective and inexpensive technique of manufacturing magnetic bearings.

A compact and efficient compressor is provided, based on using magnetic bearing technology, which can operate at high speed and comprises a reliable control system. The compressor of the present invention makes use of two separate compressors mounted on a single common motor, thus sharing a single drive. The balancing of the thrust at high RPM is improved by using a pair of electromagnetic bearings.

A spindle device equipped with a combined externally pressurized gas-magnetic bearing assembly, and a machining apparatus utilizing the spindle device. The spindle device is capable of accomplishing a high speed rotation with high rotational precision and includes a main shaft (4) rotatably supported by the combined bearing assembly (6 to 9), an electric current detecting device (15 to 18) disposed in a spindle controller (3) for detecting a current supplied to electromagnets of the combined bearing assembly (6 to 9). Also provided is a machining status determining device (19) for determining the machining status in reference to the current detected by the current detecting device (15 to 18). The machining status may be an indication of the extent to which a machining tool is impaired.

Various “contactless” bearing mechanisms including hydrodynamic, hydrostatic, and magnetic bearings are provided for a rotary pump as alternatives to mechanical contact bearings. These design features may be combined. In one embodiment, a pump housing has a spindle extending from a wall of the pump housing into a pumping chamber defined by the pump housing. The spindle has a stepped portion adjacent the wall. In one embodiment, the stepped portion is defined by a change in spindle diameter. The lack of mechanical contact bearings enables longer life pump operation and less damage to working fluids such as blood.

The invention relates to a magnetic suspension controlled moment gyro with double frames, essentially consisting of a flywheel, an inner frame system and an outer frame system. The flywheel is arranged in the middle of the magnetic suspension controlled moment gyro with the double frames and essentially comprises a rotary shaft, a radial mixed magnetic bearing, an axial magnetic bearing, a radial displacement sensor, an axial displacement sensor, a high-speed motor and a gyro room; the inner frame system and the outer frame system essentially comprise the frames, a mechanical bearing, a moment motor, a reducer, an angle position sensor, a conductive slip ring a control system; the inner frame system is connected with a shaft hole on one end of the gyro room through the reducer and at the same time the conductive slip ring and the angle position sensor are connected with the shaft hole on the other end of the gyro room; the outer frame system is connected with a shaft hole on one end of the inner frame through the reducer and at the same time the conductive slip ring and the angle position sensor are connected with the shaft hole on the other end of the inner frame. The invention reduces noise, size and weight of the system through the mixed magnetic bearing, and eliminates bearing friction, and thus prolongs life span and promotes control accuracy of the controlled moment gyro.

An environmental protection system features a clear spinning curved volumetric enclosure to shed and throw off environmental contaminants such as rain, fog and dust that would affect a sensor image. The described design is especially suitable for cameras with extremely wide fields of view, such as panoramic or immersive cameras. Alternate forms of volumetric enclosures are described for different lens arrangements in compound camera systems. In all of these embodiments it is possible to keep the cover and the mechanism spinning it invisible to the cameras. An additional modification of the shape of the volumetric enclosure is described that prevents any accumulation of liquid drops within the fields of view of the sensors within the spinning volumetric enclosure. Alternate forms of construction with air and magnetic bearings are described for smoother and quieter operation of the spinning enclosure.