An axial electromagnetic bearing for supporting the end of a shaft rotating a high speed of the type comprising an armature in the form of a disc attached to the shaft and a fixed annular armature disposed facing the disc armature a short distance from the former so as to define a small axial air gap therebetween, the said fixed armature comprising excitation windings and a ferromagnetic core, the bearing being characterized in that radial grooves are provided in the peripheral portion of the disc and situated facing the annular fixed armature. The arrangement causes a reduction in the effect of Eddy currents without detracting from the mechanicl strength of the bearing.
A magnetic bearing assembly includes at least one electromagnet with a coil at least partially enclosed by a ferrogmagnetic core. Because of this arrangement, heat, inevitably generated within the coil in a conventional bearing, may cause the temperatures of the coil and adjacent parts of the electromagnet to rise to unacceptable values. These temperatures are reduced by placing a heat conducting member, say of copper, contiguous with the coil, and possibly inserted into the coil. Heat is conducted at a high rate to an exposed portion of the member, and is extracted efficiently therefrom by windage, or air flow, created within the apparatus having the magnetic bearing. Advantageously, the exposed portion of the heat conducting member has an extensive surface.
An electromagnetic axial thrust bearing comprises a rotating member, at least one stationary member and a winding for generating a m.m.f. associated with the stationary member. The stationary member is comprised of a solid ferromagnetic material having at least one arc-shaped groove substantially concentric with the turning axis of the rotating member. The groove is lined with laminates of a ferromagnetic material. The winding is laid into the lined groove of the stationary member. The rotating member has a groove facing the groove in the stationary member. Laminates of ferromagnetic material are stacked thereon.
An electromagnetic actuator for producing axial forces between a stator element and a rotor element. The stator and rotor elements comprise structural bases with a laminated magnetic flux carrying assemblies secured therein. The laminated assemblies comprise a plurality of ferromagnetic sheets, each sheet extending substantially radially from and parallel to the axis of rotation. The rotor and stator elements are axially spaced with respective laminated assemblies in facing relationship.
Laminated stator (15, 16) and rotor components (11) of a magnetic thrust bearing comprise a plurality of generally radially disposed laminations (2) fixed at their inner end to a cylindrical hub (3), the laminations all being curved in the same direction so that their outer tips lie in a common cylindrical plane (6) which is concentric with said hub (3).
Laminated stator and rotor components for a magnetic thrust bearing each include a plurality of generally radially directed laminations (10) whose roots lie along the axis of rotation of a shaft located by the bearing and whose distal portions are progressively twisted relative to the axis such that the width of any lamination (t, t') at any given radial distance from the root corresponds to at least the circumferential separation between adjacent laminations at that distance.
