Precise bearing support ditherer with piezoelectric drive means
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsGerald L. Assard, Arthur L. Moorcroft
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Abstract
A relatively solid mounting surface, which may be part of a leveling gimb supports a piezoelectric bearing mount which has the properties of an acoustic transducer. The transducer has electrodes thereon which are powered from multi-phase electrical sources causing the bearing mount, and a bearing jewel which is rigid therewith, to move so as to dither the jewel in a rotary or other preselected fashion, thereby reducing bearing friction. Bandwidth, level and phasing sequence of the power sources are adjustable permitting optimized average dynamic motion and corresponding increased readout accuracy.
Claims4
An apparatus for dithering a jewel bearing supporting a precision instrument readout indicator, comprising:
- a rigid, non-magnetic support base having a vertical axis and horizontal x and y axes;
- piezoceramic dithering means, extending vertically upward from said support base, the bottom end thereof being fixedly attached to said support base while the top end thereof is free to move, for controllably moving said dithering means top end in preselected x and y directions;
- a first function generating means, connected to said dithering means, for selectively providing a first variable electrical potential to said dithering means thereby controllably producing said x direction motion;
- a second function generating means, connected to said dithering means, for selectively providing a second variable electrical potential to said dithering means thereby controllably producing said y direction motion, said x motion in conjunction with said y motion thereby producing combined x-y planar motion;
- first electrode means, connected to said first function generating means and fixedly attached to first preselected areas of said dithering means such that said first electrical potential, in conjunction with preselected dithering means piezoceramic polarization, produces said x direction motion of said dithering means top end;
- second electrode means, connected to said second function generating means and fixedly attached to second preselected areas of said dithering means such that said second electrical potential, in conjunction with preselected dithering means piezoceramic polarization, produces said y direction motion of said dithering means top end;
- and
- a bearing support, attached to said dithering means, for supporting said jewel bearing, whereby said jewel bearing moves in direct proportion to said combined x-y motion of said dithering means thereby producing dynamic friction between said jewel bearing and said indicator such that, by averaging readouts therefrom, greater accuracy is achieved.
Dependencies are inferred from the claim text.