Magnetic bearing apparatus and method for varying shaft thrust load support in induction motors and other rotating machinery

摘要

A permanent magnet bearing supports part of thrust loads of a vertical shaft induction motor, or the thrust loads of other types of rotation machinery regardless of shaft rotational axis orientation, in parallel with a lubricated mechanical bearing. The permanent magnet has a stationary magnet portion coupled to a bearing bracket and a rotating portion adapted for coupling to a rotor shaft. The permanent magnet bearing exerts a directional magnetic force that generates a preload support force on the rotor shaft that is selectively varied by varying air gap between the stationary and rotating magnet portions. Air gap between the magnet portions is varied with an air gap adjustment mechanism. The gap adjustment mechanism may be coupled to a control system that in some embodiments causes the permanent magnet bearing to vary the air gap based on external load applied on the motor.

主权项

1. A bearing apparatus for a rotating machine, comprising:
a bearing bracket; at least one lubricated shaft support mechanical bearing coupled to the bearing bracket; a permanent magnet bearing having a stationary permanent magnet portion coupled to a permanent magnet support which is incorporated into the bearing bracket, and a rotating permanent magnet portion coupled to a rotating magnet support, the permanent magnet bearing exerting a directional magnetic force that generates an axial thrust preload support force on a rotating shaft that is selectively varied by varying air gap between the stationary and rotating permanent magnet portions; and an air gap adjustment mechanism for selectively varying the air gap between the stationary and rotating permanent magnet portions, for varying the magnetic force, the air gap adjustment mechanism having a control system coupled thereto for dynamically varying the air gap based on external load applied on the rotating machine, wherein the control system comprises a controller that varies the air gap in response to changing loads imparted on the rotating machine, and wherein the controller is coupled by communication pathway to a load sensor in a feedback loop.