Partial arc curvilinear direct drive servomotor
AssigneeThe Keyw Corporation
InventorXiuhong Sun
Life of this patent
Estimating the term…
Abstract
A partial arc servomotor assembly having a curvilinear U-channel with two parallel rare earth permanent magnet plates facing each other and a pivoted ironless three phase coil armature winding moves between the plates. An encoder read head is fixed to a mounting plate above the coil armature winding and a curvilinear encoder scale is curved to be co-axis with the curvilinear U-channel permanent magnet track formed by the permanent magnet plates. Driven by a set of miniaturized power electronics devices closely looped with a positioning feedback encoder, the angular position and velocity of the pivoted payload is programmable and precisely controlled.
Claims25
A partial arc curvilinear direct drive servomotor (PACDDS) assembly comprising:
- a pair of parallel plates having a partial arc separated by a spacer;
- a first plurality of permanent magnets attached to a first of said parallel plates on an inside surface, the permanent magnets being arranged adjacent to each other in an alternating north-south pole pattern forming a first magnetic plate;
- a second plurality of permanent magnets attached to a second of said parallel plates on an inside surface, the permanent magnets being arranged adjacent to each other in an alternating south-north pole pattern symmetrically across from the north-south pole pattern of said first of said parallel plates forming a second magnetic plate;
- a moveable armature winding positioned between said first and second magnetic plates;
- and
- an encoder system having a read head mounted to said armature winding and above a curvilinear encoder scale mounted on top of said first magnetic plate.
In combination:
- a partial arc curvilinear direct drive servomotor (PACDDS) assembly;
- A digital controller coupled to said PACDDS assembly to provide a drive signal to said PACDDS assembly in response to a motion command and a positioning feedback signal;
- and
- a position sensor optical encoder attached to said PACDDS assembly for monitoring reference position of a coil armature or forcer of said PACDDS assembly to the fixed encoder scale and providing said positioning feedback signal to said digital controller to enable closed-loop servomotor operation of said PACDDS assembly.
A method for providing a curvilinear partial arc direct drive servo motor assembly comprising the steps of:
- providing a pair of parallel plates having partial arcs separated by a spacer;
- attaching a first plurality of permanent magnets to a first of said parallel plates on an inside surface;
- arranging said first plurality of permanent magnets adjacent to each other in an alternating north-south pole pattern to form a first magnetic track;
- attaching a second plurality of permanent magnets to a second of said parallel plates on an inside surface;
- arranging said second plurality of permanent magnets adjacent to each other in an alternating south-north pole pattern symmetrically across from the north-south pole pattern of said first of said parallel plates to form a second magnetic track;
- positioning a moveable armature winding between said first and second magnetic tracks;
- and
- mounting an encoder system having a read head to said armature winding and above a curvilinear encoder scale mounted on top of said first magnetic track.
Dependencies are inferred from the claim text.