Patent ID: 6307292
Filing Date: 2001-10-23
Classification: F16C,G01R,Y10S,Y10T

Abstract:
A galvanometer comprising:(a) a rotor comprising:1. a permanent magnet armature; and2. first and second shafts extending from the armature;(b) a load element affixed to one of the shafts;(c) a stator having a housing concentric with the rotor, the stator interacting with the flux of the permanent magnet armature;(d) a first bearing assembly axially restrained with respect to both the housing and the first shaft, for rotationally supporting the first shaft, in which the first bearing assembly is internally preloaded, with a relatively high spring constant, such that it substantially prevents axial movement of the first shaft during operation; and(e) a second bearing assembly, with a relatively low spring constant, connected to the housing for rotationally supporting the second shaft,whereby substantially all axial thermal expansion of the armature is accommodated by movement of the second shaft.