摘要:
A magnetic bearing for the mounting of a shaft, in particular for a spinning rotor of an open-end spinning device, features several pole shanks of a stator for the active radial magnetic mounting of the shaft in two degrees of freedom, which in each case are surrounded by a coil and are radially arranged to each other, in such a manner that they define an opening for the shaft. In the area of the opening, the pole shanks are connected to each other. For the passive axial mounting of the shaft, at least one permanent magnet is arranged between the coils and the opening. The invention also includes a shaft for mounting with at least one corresponding magnetic bearing. The shaft is a composite component, which at least partially consists of non-ferromagnetic material. In the area of the radial and axial mounting, a component made of a ferromagnetic material is arranged. A shaft mounting is also provided and features, for the passive axial mounting of one degree of freedom of the shaft and for the active radial mounting of two degrees of freedom of the shaft, at least one, preferably two, corresponding magnetic bearings.
摘要:
A magnetic bearing assembly is disclosed which provides for correction of shaft deflection, or "bowing", during rotation of the shaft. The assembly comprises two stator rings in spaced relation to each other, and each stator ring comprises a plurality of stator sections which are independently activated. When the shaft "bows", sensors detect the deflection and independently activate the various stator sections producing a force couple which acts on the rotor to produce a bending moment in the shaft which tends to counteract the "bowing".
摘要:
A brushless DC motor is disclosed wherein armature forces can be produced and controlled as both radial forces and as torque couples. A structure is described in which the normal radial destabilizing forces due to the high levels of magnetic flux linking the stator and rotor are reduced and the force gradient is moderated. This is accomplished by locating the rotor between two concentric stator coil assemblies either of which may be used for bearing or torquing to join the rotor magnets via magnetically "soft" iron, thereby reducing the rotor mass and inertia with the consequent improvement in dynamic performance. Since the forces on the rotor are the sum of the forces produced by each individual stator coil, it is possible to combine groups of stator coils in various ways and independently control them to achieve the dual purpose. Radial position sensors and commutation sensors are included, the former to control currents in diagonally opposite pairs of stator coils in response to eccentricity as measured by the position sensors and the latter to make the resultant radial force independent of the rotor magnets angular position and polarity. The same commutation sensors also provide rotor angular information for smooth torque production in the normal manner.
摘要:
A magnetic bearing system (120) includes a first active magnetic bearing (AMB) (202) including a first group of electromagnetic actuators (306, 310, 314, 318) to support a shaft and a second AMB (204) including a second group of electromagnetic actuators (308, 312, 316, 320) to support the shaft. A controller for the two AMB's includes a multi-phase topology (400) with a plurality of active current switches for controlling the electromagnetic actuators (306-320) of each of the first AMB (202) and the second AMB (204). Each electromagnetic actuator (306, 310, 314, 318) of the first AMB (202) is electrically coupled to an electromagnetic actuator (308, 312, 316, 320) of the second AMB (204). Each pair of coupled electromagnetic actuators (306, 316) is respectively connected to three phase legs (418, 420, 422) of the topology (400) of the controller, whereby one end (X2+, X3−) of each of the electromagnetic actuators of a pair (306, 316) is connected to one phase leg (420) of the topology (400) and the other ends (X1+, X4−) are respectively connected to two further phase legs (418, 422) of the topology (400). The controller is operable to receive information indicative of a position of the rotor shaft and supply an adjustment signal to the magnetic bearing system (120) to adjust the position of the shaft.
摘要:
A command procedure for an active magnetic bearing, the magnetic bearing comprising a series of electromagnetic actuators forming a stator, each actuator being suitable for exerting radial force on the rotor, a ferromagnetic body forming a rotor, kept free of contact between the electromagnetic actuators and suitable for being set in rotation around an axis of rotation, the rotor being suitable to undergo precession movements in particular. Sensors suitable for detecting radial displacements of the rotor and issuing position signals representative of the radial position of the rotor in relation to the actuators. Calculation of at least one actuator command signal the calculation of the command signal consisting of the application of at least one transfer function to the position signals, the transfer function containing a number of correction coefficients.
摘要:
A magnetic bearing system (120) includes a first active magnetic bearing (AMB) (202) including a first group of electromagnetic actuators (306, 310, 314, 318) to support a shaft and a second AMB (204) including a second group of electromagnetic actuators (308, 312, 316, 320) to support the shaft. A controller for the two AMB's includes a multi-phase topology (400) with a plurality of active current switches for controlling the electromagnetic actuators (306-320) of each of the first AMB (202) and the second AMB (204). Each electromagnetic actuator (306, 310, 314, 318) of the first AMB (202) is electrically coupled to an electromagnetic actuator (308, 312, 316, 320) of the second AMB (204). Each pair of coupled electromagnetic actuators (306, 316) is respectively connected to three phase legs (418, 420, 422) of the topology (400) of the controller, whereby one end (X2+, X3−) of each of the electromagnetic actuators of a pair (306, 316) is connected to one phase leg (420) of the topology (400) and the other ends (X1+, X4−) are respectively connected to two further phase legs (418, 422) of the topology (400). The controller is operable to receive information indicative of a position of the rotor shaft and supply an adjustment signal to the magnetic bearing system (120) to adjust the position of the shaft.
摘要:
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.
摘要:
A magnetic bearing device has a rotational member mounted for undergoing rotation about a rotary axis, a permanent magnet disposed on the rotational member, and a motor for rotating the rotational member. The motor has a core, projecting portions extending from the core, and motor coils each wound around a respective one of the projecting portions. The motor is disposed opposite to and spaced-apart from the permanent magnet for rotating the rotational member and contactlessly controlling an axial position of the rotational member along the rotary axis only by a magnetic forces generated between the permanent magnet, the core and the motor coils. A magnetic radial bearing contactlessly controls a radial position of the rotational member.
摘要:
A radial, active magnetic bearing apparatus (6) comprising at least three electromagnets (2u, 2v, 2w) which are distributedly arranged is excited by a three-phase rotary current controller (10).
摘要:
A magnetic bearing structure is provided for supporting a rotatable member in a suspended position relative to a stationary member utilizing a constant flux axially polarized magnetic field and a variable flux radially polarized electromagnetic field. In one preferred form of the invention the bearing structure includes axially spaced apart rings associated with the stationary member, which hold a plurality of electromagnetic coils circumferentially about and radially spaced from a rotatable shaft. Electrical current is supplied to the coils generate a radially polarized electromagnetic field surrounding the shaft. At least one cylindrically shaped permanent magnet surrounds a portion of the shaft and is positioned generally between the pair of arcuate rings. The permanent magnet is axially polarized and is linked magnetically to the arcuate rings. Substantially all of the magnetic flux generated by the electromagnetic coils and the permanent magnet is direct radially through only a pair of air gaps between the shaft and the rings. Position sensors, along with a servo control circuit, detect and compensate for any radial displacement of the shaft to maintain it in a metastable position relative to the stationary member. In alternative embodiments the rotatable member may encircle the stationary member, and the permanent magnet may be replaced by a constant flux electromagnet.