Abstract: A moving magnet voice coil actuator includes a bobbin that defines a non-straight opening for receiving a magnetic piece. The bobbin may be additively manufactured to a desired shape. The moving magnetic piece may be a curved piece that has a shape that corresponds to the shape of the opening. The magnetic piece may include a stack of magnets, which may be tapered, to allow limited tilting movement of the magnetic piece within the opening. The actuator may be part of a pair of actuators for tilting an object, for example a mirror, about a pivot point. The pair of actuators may be part of a system that includes an additional pair of actuators configured to tilt the object in a second direction that is different from the first direction.

Abstract: Disclosed is a linear actuator which includes a core, a coil, a magnet assembly, and a housing. The coil that is shaped to be positioned about the core for movement along a longitudinal axis of the core. The housing is supported by core flanges and positioned about the coil and the core. The magnet assembly includes magnets of the same polarity facing the coil and shaped to be positioned inside or outside of the coil, and supported by the core or by the housing, respectively. The core includes first and second portions, each having an end face, and the first and second portions are positioned along the longitudinal axis so that the end faces oppose each other and are separated by a gap. A cavity is formed in each of the end faces along the longitudinal axis.

Abstract: “Electromagnetic spring” characteristics can be obtained in a voice coil actuator by deliberately selecting some or all of geometry, location of the housing, field assembly and coils, and/or magnitude and direction of the current applied to the coils; for example, predetermined bidirectional spring characteristics can be provided by appropriate deliberate selection of the relative dimensions of the housing and field assembly, and the spring characteristics can be further altered though the addition of structures, such as a radially magnetized magnet, or a soft magnetic extension, positioned at an end of the housing, and/or by applying current of a selected magnitude and direction to the coil assembly.

Abstract: A linear brushless DC motor is disclosed which provides reduced detent force by way of a stack that features end teeth that are formed to be wedge shaped, and which has a length in the direction of motion which is approximately equal to (Np+½) × pole pitch, where Np equals the number of poles covered by the armature of the brushless DC motor, and the pole pitch equals a distance between centers of two adjacent magnets of opposite polarity in a field assembly of the linear brushless DC motor.

Abstract: Disclosed are a magnetic field assembly and method of configuring the same for use in position sensors of the type, which include a magnetic field sensor. First and second magnets in the field assembly are positioned on a surface of a magnetic plate (return path) and separated from one another by a separation distance. The first magnet has a magnetic axis substantially transverse to the surface of the magnetic plate, and the first magnet has a polarity opposite a polarity of the second magnet. The thicknesses of the first and second magnets are selectively varied along a stroke direction, and the separation distance is selected along with a gap length distance between the magnetic sensor and the field assembly, so that a predetermined flux density versus stroke characteristic can be provided for the position sensor.

Abstract: “Electromagnetic spring” characteristics can be obtained in a voice coil actuator by deliberately selecting some or all of geometry, location of the housing, field assembly and coils, and/or magnitude and direction of the current applied to the coils; for example, predetermined bidirectional spring characteristics can be provided by appropriate deliberate selection of the relative dimensions of the housing and field assembly, and the spring characteristics can be further altered though the addition of structures, such as a radially magnetized magnet, or a soft magnetic extension, positioned at an end of the housing, and/or by applying current of a selected magnitude and direction to the coil assembly.

Abstract: Disclosed are a magnetic field assembly and method of configuring the same for use in position sensors of the type, which include a magnetic field sensor. First and second magnets in the field assembly are positioned on a surface of a magnetic plate (return path) and separated from one another by a separation distance. The first magnet has a magnetic axis substantially transverse to the surface of the magnetic plate, and the first magnet has a polarity opposite a polarity of the second magnet. The thicknesses of the first and second magnets are selectively varied along a stroke direction, and the separation distance is selected along with a gap length distance between the magnetic sensor and the field assembly, so that a predetermined flux density versus stroke characteristic can be provided for the position sensor.

Abstract: A magnetic field assembly and method of configuring the same for use in position sensors of the type which include a magnetic field sensor. First and second magnets in the field assembly are positioned on a surface of a magnetic plate (return path) and separated from one another by a separation distance. The first magnet has a magnetic axis substantially transverse to the surface of the magnetic plate, and the first magnet has a polarity opposite a polarity of the second magnet. The thicknesses of the first and second magnets are selectively varied along a stroke direction, and the separation distance is selected along with a gap length distance between the magnetic sensor and the field assembly, so that a predetermined flux density versus stroke characteristic can be provided for the position sensor.

Abstract: A stack assembly is disclosed of the type used in linear brushless DC motors, the stack assembly having a base portion, a plurality of teeth extending from the base portion and about which the windings can be positioned, and in which the plurality of teeth are spaced apart from each other so as to define slot openings at ends of and between adjacent teeth, and magnetic material shaped and positionable to enclose one or more of the slot openings between adjacent teeth. Also disclosed is a mounting bracket positionable along the back iron of the stack assembly and shaped so that the ends of the mounting bracket engage with the ends of the stack assembly.

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.

Abstract: A voice coil actuator is disclosed which provides a proportional solenoid type characteristic and in which first and second magnets are positioned at different ends of a first soft magnetic pole piece and magnetized in opposite directions, the first soft magnetic pole piece having a length greater than the length of the first magnet and the length of the second magnet. A coil having a length less than the lengths of the first soft magnetic pole piece is positioned for travel along an axis common to the first soft magnetic pole piece and first and second magnets, and a structure provides a magnetic path between free ends of the first and second magnets.

Abstract: Disclosed is a linear actuator, controllable as a spring, having a field assembly and a coil assembly positioned for interaction with and movement relative to the field assembly. The field assembly has a soft magnetic housing having an axis, axially magnetized cylindrical magnets and soft magnetic pole pieces which form a stack of alternating cylindrical magnets and pole pieces positioned along the axis. The coil assembly includes a coil base having coil cavities, coils supported in the coil cavity, and an axially magnetized permanent magnet positioned on the coil base so that the axially magnetized permanent magnet is positioned to travel along the axis of the soft magnetic housing. A repulsion force is generated between the coil assembly and the field assembly when the coil assembly is de-energized, and the repulsion force is modified when the coil assembly is energized.

Abstract: Disclosed are a magnetic field assembly and method of configuring the same for use in position sensors of the type, which include a magnetic field sensor. First and second magnets in the field assembly are positioned on a surface of a magnetic plate (return path) and separated from one another by a separation distance. The first magnet has a magnetic axis substantially transverse to the surface of the magnetic plate, and the first magnet has a polarity opposite a polarity of the second magnet. The thicknesses of the first and second magnets are selectively varied along a stroke direction, and the separation distance is selected along with a gap length distance between the magnetic sensor and the field assembly, so that a predetermined flux density versus stroke characteristic can be provided for the position sensor.

Abstract: Disclosed is a linear voice coil actuator having a latching feature, the actuator having a coil assembly, a field assembly, a magnetic structure positioned in the coil assembly, and a stop which limits the position of the magnetic structure with respect to the field assembly when the coil is not energized. The coil assembly has a coil base and a coil located in a cavity in the coil base. The field assembly preferably has an axially magnetized cylindrical magnet, a soft pole piece, and a soft magnetic housing. Preferably the magnetic structure is a magnetic plate positioned coaxially with the axis of magnetization of the magnet and having a diameter or a thickness which is selected to set a latching force between the plate and the magnet when the coil is not energized.

Abstract: A linear brushless DC motor is disclosed which provides reduced detent force by way of a stack that features end teeth that are formed to be wedge shaped, and which has a length in the direction of motion which is approximately equal to (Np+½)×pole pitch, where Np equals the number of poles covered by the armature of the brushless DC motor, and the pole pitch equals a distance between centers of two adjacent magnets of opposite polarity in a field assembly of the linear brushless DC motor.

Abstract: A linear motion device is disclosed which includes an armature assembly, and a field assembly which includes a plurality of permanent magnets each having a length, and a plurality of pole pieces each having a length. The ratio between the length of the plurality of permanent magnets and the length of the plurality of pole pieces is tailored to achieve a constant force versus stroke characteristic, when sinusoidal commutation is used.

Abstract: A linear voice coil actuator is disclosed which includes field subassemblies each including a field blank, and in which at least a one of the field subassemblies includes magnets of alternating polarity positioned on the field blank to form interleaved-magnetic circuits in a direction of motion of the linear voice coil actuator. The field subassemblies are positioned with respect to one another to form a gap between the field subassembly having the magnets, and another of the field subassemblies. Also included is a coil assembly that includes coils positioned in a plane within the gap, wherein the plane is substantially parallel to the direction of motion of the linear voice coil actuator.

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.

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.

Abstract: Disclosed is a linear actuator, controllable as a spring, having a field assembly and a coil assembly positioned for interaction with and movement relative to the field assembly. The field assembly has a soft magnetic housing having an axis, axially magnetized cylindrical magnets and soft magnetic pole pieces which form a stack of alternating cylindrical magnets and pole pieces positioned along the axis. The coil assembly includes a coil base having coil cavities, coils supported in the coil cavity, and an axially magnetized permanent magnet positioned on the coil base so that the axially magnetized permanent magnet is positioned to travel along the axis of the soft magnetic housing. A repulsion force is generated between the coil assembly and the field assembly when the coil assembly is de-energized, and the repulsion force is modified when the coil assembly is energized.