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US 2001/0054850 A1Published application
Linear voice coil actuator with compensating coils
AssigneeBEI Technologies, Inc.
InventorMikhail Godkin
Life of this patent
Estimating the term…
Abstract
An actuator is provided in which one or more separate compensating coils are employed to alter the distribution of the magnetic flux density in the air gap to produce a substantially constant force throughout the stroke; and in which current in the separate compensating coils can be adjusted with the stroke using separate power supplies and position feedback.
Claims26
A voice coil actuator comprising
- a core having an axis;
- a permanent magnet having a longitudinal axis, and positioned so that the longitudinal axis of the permanent magnet is substantially parallel to the axis of the core;
- a moving coil positioned to interact with the permanent magnet along the axis of the core;
- and
- a compensating coil positioned to interact with the moving coil, wherein a magneto-motive force in the compensating coil is controlled as a function of a position of the moving coil.
2 more elements
An actuator comprising
- a core;
- a permanent magnet having a longitudinal axis, and positioned so that the longitudinal axis of the permanent magnet is substantially parallel to an axis of the core;
- a moving coil positioned to interact with the permanent magnet along the axis of the core;
- and
- a compensating coil positioned to interact with the moving coil and having a magneto-motive force which is controlled as a function of a position of the moving coil.
2 more elements
An actuator comprising:
- a field blank which forms a housing;
- a core;
- a permanent magnet having a longitudinal axis, positioned in the housing and so that the longitudinal axis of the permanent magnet is substantially parallel to an axis of the core;
- a moving coil positioned to interact with the permanent magnet along the axis of the core;
- and
- a plurality of compensating coils positioned to interact with the moving coil and controlled as a function of a position of the moving coil, including
- a core compensating coil positioned about the core;
- a first compensating coil positioned in a cavity formed between an end of the permanent magnet and the housing.
5 more elements
A voice coil actuator comprising:
- a field blank which forms a housing;
- a core;
- a permanent magnet having a longitudinal axis, and positioned so that the longitudinal axis of the permanent magnet is substantially parallel to an axis of the core;
- a coil positioned about the core to be moveable along and to interact with the permanent magnet along the axis of the core, wherein magnetic flux is produced in an air gap between the moveable coil and the permanent magnet;
- a compensating coil positioned to interact with the moveable coil;
- and
- a power supply coupled to the compensating coil so that magneto-motive force is produced in the compensating coil of a magnitude which is a function of positions of the moveable coil along the core to alter the magnetic flux in the air gap.
4 more elements
Dependencies are inferred from the claim text.