摘要:
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.
摘要:
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.
摘要:
The permanent magnet is mounted within the coil in engagement with the magnetic frame so when the coil is energized by a pulse of DC voltage of polarity giving a coil flux aiding the magnet the plunger is actuated against the bias of the spring to move the plunger close enough to the magnet to be retained. A pluse of opposite polarity gives a coil flux opposing the magnet flux so the holding force is less than the spring force and the plunger is moved to its inactive position.
摘要:
“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.
摘要:
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.
摘要翻译:公开了一种线性无刷直流电动机,其通过堆叠形式提供减小的制动力,其具有形成为楔形的端齿,并且其运动方向上的长度近似等于(N P SUB> +½)x极间距,其中N P p等于无刷直流电动机的电枢覆盖的极数,极距等于两个相邻磁体的中心之间的距离 在线性无刷直流电动机的现场组装中具有相反的极性。
摘要:
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.
摘要:
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.
摘要:
“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.
摘要:
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.
摘要:
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. The field blanks include flux path sections which provide a flux path perpendicular to the direction of motion for each pair of magnets of opposite polarity that are separated by the gap, and which thereby results in the height of the actuator of the present invention being largely independent of the lengths of the magnets employed.