Hybrid wafer gyroscope
AssigneeThe Charles Stark Draper Laboratory, Inc.
InventorsLyle J. Jenkins, Ralph E. Hopkins, Kaplesh Kumar, Paul Greiff, Edmund R. Foster, Richard M. Walker, Richard H. Coco, Anthony M. Moscaritolo
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Abstract
A hybrid wafer gyroscope includes a combination of micro-machined components and traditional electromechanical components to form a miniature gyroscope having a high degree of stability. The gyroscope includes a rotor, gimbal, flexures, and stop cutouts micro-machined out of one or more layers of silicon, forming a unitary, planar, and disk-shaped rotor subassembly, which spins about a drive shaft.
Claims31
A hybrid wafer gyroscope comprising:
- A. a closed housing disposed about a substantially cylindrical shaped inner region, said inner region extending along a spin axis,
- B. a drive shaft supported by said housing along said spin axis,
- C. a micro-machined unitary planar sheet rotor subassembly disposed within said inner region, said rotor subassembly being generally disk shaped and coaxial with said spin axis, and having:
- (i) a central hub portion coupled to said drive shaft and extending about said spin axis;
- (ii) an annular gimbal portion at a periphery of the hub portion;
- and
- (iii) an annular rotor portion at a periphery of the gimabl portion, wherein said gimbal portion is coupled to said hub portion by flexures permitting relative angular motion of said gimbal portion and said hub portion about a first reference axis perpendicular to and intersecting said spin axis, and
- wherein said gimbal portion is coupled to said rotor portion by flexures permitting relative angular motion between said gimbal portion and said rotor portion about a second reference axis perpendicular to and intersecting said spin axis, said second reference axis being perpendicular to said first reference axis,
- D. a drive assembly including means for driving said rotor subassembly to rotate about said spin axis, wherein said drive shaft is fixed relative to said housing and said drive assembly includes at least one bearing that allows said rotor subassembly to rotate with respect to said drive shaft and
- E. a sensor assembly including means for generating signals representative of displacements of said rotor portion of said rotor subassembly relative to a reference plane perpendicular to said spin axis.
A hybrid wafer gyroscope comprising:
- A. a closed housing disposed about a substantially cylindrical shaped inner region, said inner region extending along a spin axis,
- B. a drive shaft supported by said housing along said spin axis,
- C. a micro-machined unitary planar sheet rotor subassembly disposed within said inner region, said rotor subassembly being generally disk shaped and coaxial with said spin axis, and having:
- (i) a central hub portion coupled to said drive shaft and extending about said spin axis,
- (ii) an annular gimbal portion at a periphery of hub portion;
- and
- (iii) an annular rotor portion at a periphery of the gimbal portion,
- wherein said gimbal portion is coupled to said hub portion by flexures permitting relative angular motion of said gimbal portion and said hub portion about a first reference axis perpendicular to and intersecting said spin axis, and
- wherein said gimbal portion is coupled to said rotor portion by flexures permitting relative angular motion between said gimbal portion and said rotor portion about a second reference axis perpendicular to and intersecting said spin axis, said second reference axis being perpendicular to said first reference axis,
- D. a drive assembly including means for driving said rotor subassembly to rotate about said spin axis, wherein said means for driving said rotor subassembly includes an induction motor and at least one magnet coupled to said rotor subassembly and
- E. a sensor assembly including means for generating signals representative of displacements of said rotor portion of said rotor subassembly relative to a reference plane perpendicular to said spin axis.
A micro-machined unitary planar sheet rotor subassembly, for use in a gyroscope having a closed housing disposed about a substantially cylindrical shaped inner region, said inner region disposed along a spin axis, a drive shaft supported by said housing along said spin axis, and a drive assembly including means for driving said rotor subassembly about said drive shaft, said rotor subassembly comprising:
- (i) a central hub portion coupled to said drive shaft and extending about said spin axis, wherein said drive assembly means includes an induction motor and said rotor subassembly central hub portion includes a plurality of magnet seats disposed substantially symmetrically about said spin axis, to accommodate the housing of a magnet in each magnet seat;
- (ii) an annular rotor portion at a periphery thereof, and
- (iii) an annular gimbal portion between said hub portion and said rotor portion,
- wherein said gimbal portion is coupled to said hub portion by flexures permitting relative angular motion of said gimbal portion and said hub portion about a first reference axis perpendicular to and intersecting said spin axis, and
- wherein said gimbal portion is coupled to said rotor portion by flexures permitting relative angular motion between said gimbal portion and said rotor portion about a second reference axis perpendicular to and intersecting said spin axis, said second reference axis being perpendicular to said first reference axis.
Dependencies are inferred from the claim text.